Discussion:
Most important scientific advancements in SF
(too old to reply)
a***@gmail.com
2019-05-30 09:09:58 UTC
Permalink
I guess that the most important scientific advancements in SF are:

FTL travel
AGI machines

Also important are:

Telepathy
Radical life extension
Artificial Gravity
Time travel


I am not a scientist, and the future of science is difficult to predict. But I believe we will continue to radically extend life, as we have already done so over the last century.

What scientific advancement would be the hardest, is time travel to the past. I am not sure that will be ever possible.

FTL travel is important for exploring and colonising the universe. AGI is important for creating intelligent machines that serve us.

Abhinav Lal
Writer & Investor

"I will fear no evil"
D B Davis
2019-05-30 14:44:16 UTC
Permalink
Post by a***@gmail.com
FTL travel
AGI machines
Telepathy
Radical life extension
Artificial Gravity
Time travel
I am not a scientist, and the future of science is difficult to predict.
But I believe we will continue to radically extend life, as we have already
done so over the last century.
What scientific advancement would be the hardest, is time travel to the
past. I am not sure that will be ever possible.
FTL travel is important for exploring and colonising the universe. AGI
is important for creating intelligent machines that serve us.
Time travel to the past is already here. Everyone can use their mind to
time travel to the past. They often do it without the aid of a machine.
Sometimes they use audio-video devices as time machines to enable them
to experience the past, from their oculi to their mind's eye.



Thank you,
--
Don
a***@gmail.com
2019-05-30 16:32:57 UTC
Permalink
Post by D B Davis
Post by a***@gmail.com
FTL travel
AGI machines
Telepathy
Radical life extension
Artificial Gravity
Time travel
I am not a scientist, and the future of science is difficult to predict.
But I believe we will continue to radically extend life, as we have already
done so over the last century.
What scientific advancement would be the hardest, is time travel to the
past. I am not sure that will be ever possible.
FTL travel is important for exploring and colonising the universe. AGI
is important for creating intelligent machines that serve us.
Time travel to the past is already here. Everyone can use their mind to
time travel to the past. They often do it without the aid of a machine.
Sometimes they use audio-video devices as time machines to enable them
to experience the past, from their oculi to their mind's eye.
Watching and listening to audiovisual recordings of the past, is not the same as having a physical presence in the past. The memories contained in the mind are imperfect and can be misleading, thus are not the same thing as a physical presence in the past.

Abhinav Lal
Writer & Investor

"The past is lost forever"


"
Post by D B Davis

Thank you,
--
Don
D B Davis
2019-05-30 17:17:47 UTC
Permalink
Post by a***@gmail.com
Post by D B Davis
Post by a***@gmail.com
FTL travel
AGI machines
Telepathy
Radical life extension
Artificial Gravity
Time travel
I am not a scientist, and the future of science is difficult to predict.
But I believe we will continue to radically extend life, as we have already
done so over the last century.
What scientific advancement would be the hardest, is time travel to the
past. I am not sure that will be ever possible.
FTL travel is important for exploring and colonising the universe. AGI
is important for creating intelligent machines that serve us.
Time travel to the past is already here. Everyone can use their mind to
time travel to the past. They often do it without the aid of a machine.
Sometimes they use audio-video devices as time machines to enable them
to experience the past, from their oculi to their mind's eye.
Watching and listening to audiovisual recordings of the past, is not the
same as having a physical presence in the past. The memories contained
in the mind are imperfect and can be misleading, thus are not the same
thing as a physical presence in the past.
Your line of thought quickly leads to the question, "Whose past?" The
past is a highly subjective experience, which enables it to be exploited
on a daily basis by politicians.
Psychosomatic events alter people's physical presence. Perhaps
similar phenomena occurs when people use their minds to travel to their
past.



Thank you,
--
Don
Dimensional Traveler
2019-05-30 17:50:35 UTC
Permalink
Post by D B Davis
Post by a***@gmail.com
Post by D B Davis
Post by a***@gmail.com
FTL travel
AGI machines
Telepathy
Radical life extension
Artificial Gravity
Time travel
I am not a scientist, and the future of science is difficult to predict.
But I believe we will continue to radically extend life, as we have already
done so over the last century.
What scientific advancement would be the hardest, is time travel to the
past. I am not sure that will be ever possible.
FTL travel is important for exploring and colonising the universe. AGI
is important for creating intelligent machines that serve us.
Time travel to the past is already here. Everyone can use their mind to
time travel to the past. They often do it without the aid of a machine.
Sometimes they use audio-video devices as time machines to enable them
to experience the past, from their oculi to their mind's eye.
Watching and listening to audiovisual recordings of the past, is not the
same as having a physical presence in the past. The memories contained
in the mind are imperfect and can be misleading, thus are not the same
thing as a physical presence in the past.
Your line of thought quickly leads to the question, "Whose past?" The
past is a highly subjective experience, which enables it to be exploited
on a daily basis by politicians.
Psychosomatic events alter people's physical presence. Perhaps
similar phenomena occurs when people use their minds to travel to their
past.
Hell, the _present_ is a highly subjective experience which is being
constantly exploited by politicians and salesmen.
--
Inquiring minds want to know while minds with a self-preservation
instinct are running screaming.
Quadibloc
2019-05-31 03:37:18 UTC
Permalink
Post by D B Davis
Time travel to the past is already here. Everyone can use their mind to
time travel to the past. They often do it without the aid of a machine.
Sometimes they use audio-video devices as time machines to enable them
to experience the past, from their oculi to their mind's eye.
That isn't time travel to the past. Travel somewhere is actually being there, just
as I would actually be in Bangkok, and able to buy things in the stores there, if
I had purchased a suitable airplane ticket.

John Savard
D B Davis
2019-05-31 13:51:24 UTC
Permalink
Post by Quadibloc
Post by D B Davis
Time travel to the past is already here. Everyone can use their mind to
time travel to the past. They often do it without the aid of a machine.
Sometimes they use audio-video devices as time machines to enable them
to experience the past, from their oculi to their mind's eye.
That isn't time travel to the past. Travel somewhere is actually being
there, just as I would actually be in Bangkok, and able to buy things in the stores there, if
I had purchased a suitable airplane ticket.
_Time Machines_ (Nahin) at least recognizes the validity of mental/
emotional time travel. Nahin then tries to use physics handwavium and a
machine to exclude mental/emotional time travel from further discussion.
The trouble with Nahin's mechanistic litmus test is that a machine
called a PC can be used to stimulate mental/emotional time travel.
You also seek to exclude phenomena such as memory as time travel
from further discussion. You may be on to something with temporal
locality of place. If a traveler walks into World Trade Center 1 and
puts a lobby pamphlet into his pocket he's in the past as you see it.
The trouble with "the past" is that it's highly subjective. For
instance, there's at least two versions of "the past" in regards to
Trump. In one version of "the past," Trump is Putin's puppet. In an
alternate version of "the past," Trump is never-Trump's victim. Ergo,
"the past" depends upon who you talk to.



Thank you,
--
Don
Quadibloc
2019-05-31 20:28:55 UTC
Permalink
Post by D B Davis
The trouble with "the past" is that it's highly subjective.
Reality isn't subjective. If there are two different versions of what happened in
the past, at least one of them is wrong.

Of course, though, how we _interpret_ reality is subjective. So there's room for
differences of opinion on what the things that happened meant.

John Savard
David DeLaney
2019-06-03 10:10:07 UTC
Permalink
Post by Quadibloc
Post by D B Davis
The trouble with "the past" is that it's highly subjective.
Reality isn't subjective.
If there are two different versions of what happened in
the past, at least one of them is wrong.
Not so.

You know how SF treats the future as a garden of forking paths, or a diverging
cloud of probabilities, or any of a number of other metaphors that inform one
of the chance events that can't be predicted before they happen, so that the
singular present moment has many possible futures?

Almost nobody ever thinks about how this ALSO applies to the past.

"But", I hear you cry, "the Past is fixed! Immutable! As though it were
preserved in mega-amber! WILL NO-BODY THINK OF THE AKASHIC RECORDS??2?"

Sure, okay. But WHICH past?

If there's processes or happenings that go unrecorded, all of which lead to
the same singular present state, guress what? You can't tell NOW what heppened
THEN,fs or when. (Of course, it's harder to do this in reverse, much like
retrograde chess puzzles, so that it all DOES add up to "exactly now". But
not impossible. And this isn't even considering special relativity's lesson to
us that if it was outside your past light cone, you don't know WHAT it was, and
it doesn't actually make sense to ask "when?" for anything in Elsewhere
either. Stuff outside your twin light cones can't causally influence or be
influenced by you, so in a very real sense Doesn't Matter. Until it crosses
into your past light cone, of course.)

Dave
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.
David Johnston
2019-06-01 01:56:39 UTC
Permalink
Post by D B Davis
Post by Quadibloc
Post by D B Davis
Time travel to the past is already here. Everyone can use their mind to
time travel to the past. They often do it without the aid of a machine.
Sometimes they use audio-video devices as time machines to enable them
to experience the past, from their oculi to their mind's eye.
That isn't time travel to the past. Travel somewhere is actually being
there, just as I would actually be in Bangkok, and able to buy things in the stores there, if
I had purchased a suitable airplane ticket.
_Time Machines_ (Nahin) at least recognizes the validity of mental/
emotional time travel.
It's always a neat trick to recognized the validity of something that
has none.
D B Davis
2019-06-01 02:39:55 UTC
Permalink
Post by D B Davis
Post by Quadibloc
Post by D B Davis
Time travel to the past is already here. Everyone can use their mind to
time travel to the past. They often do it without the aid of a machine.
Sometimes they use audio-video devices as time machines to enable them
to experience the past, from their oculi to their mind's eye.
That isn't time travel to the past. Travel somewhere is actually being
there, just as I would actually be in Bangkok, and able to buy things in the stores there, if
I had purchased a suitable airplane ticket.
_Time Machines_ (Nahin) at least recognizes the validity of mental/
emotional time travel.
It's always a neat trick to recognized the validity of something that has none.
Mental time travel (Chronesthesia) in relation to episodic
memory is the ability to travel mentally to the past. ...
https://sites.psu.edu/psych256fa17001/2017/10/15/mental-time-travel/

... Another issue concerns the role of autonoesis in forms of
mental time travel other than episodic memory. Episodic memory
is increasingly understood as a form of past-oriented mental
time travel on a par with future-oriented mental time travel,
or episodic future thought t (Suddendorf & Corballis 2007). ...
https://plato.stanford.edu/entries/memory/

New insight on how brain performs 'mental time travel'
https://news.vanderbilt.edu/2015/02/17/new-insight-on-how-brain-performs/

Mental time travel (Chronesthesia) in relation to episodic memory
is the ability to travel mentally to the past. ...
https://sites.psu.edu/psych256fa17001/2017/10/15/mental-time-travel/



Thank you,
--
Don
Quadibloc
2019-06-01 02:52:08 UTC
Permalink
Post by D B Davis
Mental time travel (Chronesthesia) in relation to episodic memory
is the ability to travel mentally to the past. ...
The English language isn't as precise as mathematical notation.

If you remember the past vividly - and not just in the sense of recall, but
actually experience what you are remembering, like the events in a dream - of
course one way to speak of that is "mentally travelling to the past".

But that is still a process that is happening *inside your brain* and it's not
happening in the past, it's happening in the present time. It doesn't actually
involve relocating your body, your brain, or your mind or soul _to_ the past.

Nobody ever was able to kill Hitler with a vivid memory of the past.

John Savard
J. Clarke
2019-06-01 03:02:38 UTC
Permalink
On Fri, 31 May 2019 19:52:08 -0700 (PDT), Quadibloc
Post by Quadibloc
Post by D B Davis
Mental time travel (Chronesthesia) in relation to episodic memory
is the ability to travel mentally to the past. ...
The English language isn't as precise as mathematical notation.
If you remember the past vividly - and not just in the sense of recall, but
actually experience what you are remembering, like the events in a dream - of
course one way to speak of that is "mentally travelling to the past".
But that is still a process that is happening *inside your brain* and it's not
happening in the past, it's happening in the present time. It doesn't actually
involve relocating your body, your brain, or your mind or soul _to_ the past.
Nobody ever was able to kill Hitler with a vivid memory of the past.
Suppose "reality" is really somebody's virtual reality video game.
Then you can do anything that the designers want to do.

It will be amusing if relativity and quantum theory turn out to be
irreconcilable because the game designers figured that nobody would
ever try to get down to that level of detail in the game.
Juho Julkunen
2019-06-01 14:31:40 UTC
Permalink
In article <***@4ax.com>, jclarke.873638
@gmail.com says...
Post by J. Clarke
On Fri, 31 May 2019 19:52:08 -0700 (PDT), Quadibloc
Post by Quadibloc
Post by D B Davis
Mental time travel (Chronesthesia) in relation to episodic memory
is the ability to travel mentally to the past. ...
The English language isn't as precise as mathematical notation.
If you remember the past vividly - and not just in the sense of recall, but
actually experience what you are remembering, like the events in a dream - of
course one way to speak of that is "mentally travelling to the past".
But that is still a process that is happening *inside your brain* and it's not
happening in the past, it's happening in the present time. It doesn't actually
involve relocating your body, your brain, or your mind or soul _to_ the past.
Nobody ever was able to kill Hitler with a vivid memory of the past.
Suppose "reality" is really somebody's virtual reality video game.
Then you can do anything that the designers want to do.
It will be amusing if relativity and quantum theory turn out to be
irreconcilable because the game designers figured that nobody would
ever try to get down to that level of detail in the game.
The devs have to keep making the models more detailed as we build more
powerful particle accelerators. ("Higgs boson": implement or not?)

Quantum uncertainty obviously comes from them being too lazy to
properly model things at that level, and just using an RNG.
--
Juho Julkunen
David DeLaney
2019-06-03 10:12:34 UTC
Permalink
Post by Quadibloc
Nobody ever was able to kill Hitler with a vivid memory of the past.
Well, duh. The Brains floating at the end of time have MUCH more vivid
memories of everything than you ever can.

Dave, yes, even of all the stuff you were thinking about vat-girls. TREMBLE
PU-NY FIRST-LEVEL INTELLIGENCE
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.
D B Davis
2019-06-01 04:00:26 UTC
Permalink
Post by Quadibloc
Post by D B Davis
Mental time travel (Chronesthesia) in relation to episodic memory
is the ability to travel mentally to the past. ...
The English language isn't as precise as mathematical notation.
If you remember the past vividly - and not just in the sense of recall, but
actually experience what you are remembering, like the events in a dream - of
course one way to speak of that is "mentally travelling to the past".
But that is still a process that is happening *inside your brain* and it's not
happening in the past, it's happening in the present time. It doesn't actually
involve relocating your body, your brain, or your mind or soul _to_ the past.
Nobody ever was able to kill Hitler with a vivid memory of the past.
The last of these three _Man and Time_ (Priestly) excerpts (St
Augustine's thoughts are enclosed in double quote marks) illustrate
how the notion of time itself happens *inside your brain*.

We abstract a concept from our experience of succession, call
it Time, then turn it into an immeasurably vast container, in
which everything goes; and then we wonder why we cannot make
head or tail of it.

"What then is time? If no one asks me, I know; if I want to
explain it to a questioner, I do not know." - St Augustine

"All the while, man's attentive mind, which is present, is
is relegating the future to the past. That past increases
in proportion as the future diminishes, until the future is
entirely absorbed and the whole becomes past." But of course
the future does not yet exist and the past no longer exists.
The mind, however, has three functions; "expectation - for
the future, attention - for the present, memory - for the
past."



Thank you,
--
Don
Quadibloc
2019-06-01 06:24:06 UTC
Permalink
Post by D B Davis
Post by Quadibloc
Post by D B Davis
Mental time travel (Chronesthesia) in relation to episodic memory
is the ability to travel mentally to the past. ...
The English language isn't as precise as mathematical notation.
If you remember the past vividly - and not just in the sense of recall, but
actually experience what you are remembering, like the events in a dream - of
course one way to speak of that is "mentally travelling to the past".
But that is still a process that is happening *inside your brain* and it's not
happening in the past, it's happening in the present time. It doesn't actually
involve relocating your body, your brain, or your mind or soul _to_ the past.
Nobody ever was able to kill Hitler with a vivid memory of the past.
The last of these three _Man and Time_ (Priestly) excerpts (St
Augustine's thoughts are enclosed in double quote marks) illustrate
how the notion of time itself happens *inside your brain*.
We abstract a concept from our experience of succession, call
it Time, then turn it into an immeasurably vast container, in
which everything goes; and then we wonder why we cannot make
head or tail of it.
"What then is time? If no one asks me, I know; if I want to
explain it to a questioner, I do not know." - St Augustine
"All the while, man's attentive mind, which is present, is
is relegating the future to the past. That past increases
in proportion as the future diminishes, until the future is
entirely absorbed and the whole becomes past." But of course
the future does not yet exist and the past no longer exists.
The mind, however, has three functions; "expectation - for
the future, attention - for the present, memory - for the
past."
We speak of a thing called "time". But it is true that when pressed for a
definition of time, many people will have difficulty. Some people have said that
"time" should be a verb, not a noun. I think that the grammatical category of a
noun is the right one; it's broad enough to include abstractions.

I think that there _is_ a real and objective phenomenon of the external world
that corresponds to what we call time.

We put a candle, an ice cube, and a clock beside one another in the same room.
When the ice cube is half melted, the hands on the clock have moved a certain
distance, and the candle has become a certain distance shorter.

Then we repeat this, but we put each of the three objects in different rooms. In
one of the rooms, perhaps there is a person reading an interesting book, in
another there is a person sleeping, and the third room has no one in it.

It does not happen, though, that this time we find that while the ice cube has
half melted, more time has passed by the clock, but the candle has scarcely
shortened at all. Instead, change and the succession of events not only had the
same direction in those places, it passed by at the same rate.

It's because time is real and objective that things which happen in different
places are tied together like that.

Unlike some, I don't think the subjective is of no value.

Thus, for example, while I think that a person could be "uploaded" if his new
computer brain were kept attached to his original one for a while, so he could
gradually start to use it like an additional brain hemisphere, then his
consciousness could migrate to it. But if you just scan his brain, and then in
another room make a copy - that copy might be his identical duplicate, but it
could be activated while he still lived, and he would not know what it
experienced, so if it was activated after his death, there would be no reason to
believe that his own consciousness would continue within it.

But I do believe that the subjective is one thing, the objective is another
thing, each one has its role, and it's quite important not to confuse the two.
Doing so has led to all manner of superstitious belief in the past.

John Savard
Thomas Koenig
2019-06-01 08:42:24 UTC
Permalink
Post by Quadibloc
We put a candle, an ice cube, and a clock beside one another in the same room.
When the ice cube is half melted, the hands on the clock have moved a certain
distance, and the candle has become a certain distance shorter.
Then we repeat this, but we put each of the three objects in different rooms. In
one of the rooms, perhaps there is a person reading an interesting book, in
another there is a person sleeping, and the third room has no one in it.
It is likely that the candle will influence the rate that the ice cube
melts.
Quadibloc
2019-06-01 13:59:38 UTC
Permalink
Post by Thomas Koenig
It is likely that the candle will influence the rate that the ice cube
melts.
Well, I was assuming temperature was kept equal and the ice cube wasn't too close
to the candle when they were in the same room...

Putting the ice cube in a refrigerator certainly is simpler than putting it on a
rocket travelling at an appreciable fraction of the speed of light.

John Savard
D B Davis
2019-06-01 14:31:49 UTC
Permalink
Post by Quadibloc
Post by D B Davis
Post by Quadibloc
Post by D B Davis
Mental time travel (Chronesthesia) in relation to episodic memory
is the ability to travel mentally to the past. ...
The English language isn't as precise as mathematical notation.
If you remember the past vividly - and not just in the sense of recall, but
actually experience what you are remembering, like the events in a dream - of
course one way to speak of that is "mentally travelling to the past".
But that is still a process that is happening *inside your brain* and it's not
happening in the past, it's happening in the present time. It doesn't actually
involve relocating your body, your brain, or your mind or soul _to_ the past.
Nobody ever was able to kill Hitler with a vivid memory of the past.
The last of these three _Man and Time_ (Priestly) excerpts (St
Augustine's thoughts are enclosed in double quote marks) illustrates
how the notion of time itself happens *inside your brain*.
We abstract a concept from our experience of succession, call
it Time, then turn it into an immeasurably vast container, in
which everything goes; and then we wonder why we cannot make
head or tail of it.
"What then is time? If no one asks me, I know; if I want to
explain it to a questioner, I do not know." - St Augustine
"All the while, man's attentive mind, which is present, is
is relegating the future to the past. That past increases
in proportion as the future diminishes, until the future is
entirely absorbed and the whole becomes past." But of course
the future does not yet exist and the past no longer exists.
The mind, however, has three functions; "expectation - for
the future, attention - for the present, memory - for the
past."
We speak of a thing called "time". But it is true that when pressed for
a definition of time, many people will have difficulty. Some people have
said that "time" should be a verb, not a noun. I think that the grammatical
category of a noun is the right one; it's broad enough to include abstractions.
I think that there _is_ a real and objective phenomenon of the external
world that corresponds to what we call time.
We put a candle, an ice cube, and a clock beside one another in the same room.
When the ice cube is half melted, the hands on the clock have moved a certain
distance, and the candle has become a certain distance shorter.
Then we repeat this, but we put each of the three objects in different rooms. In
one of the rooms, perhaps there is a person reading an interesting book, in
another there is a person sleeping, and the third room has no one in it.
It does not happen, though, that this time we find that while the ice cube has
half melted, more time has passed by the clock, but the candle has scarcely
shortened at all. Instead, change and the succession of events not only had the
same direction in those places, it passed by at the same rate.
It's because time is real and objective that things which happen in different
places are tied together like that.
Unlike some, I don't think the subjective is of no value.
Thus, for example, while I think that a person could be "uploaded" if his new
computer brain were kept attached to his original one for a while, so he could
gradually start to use it like an additional brain hemisphere, then his
consciousness could migrate to it. But if you just scan his brain, and then in
another room make a copy - that copy might be his identical duplicate, but it
could be activated while he still lived, and he would not know what it
experienced, so if it was activated after his death, there would be no reason to
believe that his own consciousness would continue within it.
But I do believe that the subjective is one thing, the objective is another
thing, each one has its role, and it's quite important not to confuse the two.
Doing so has led to all manner of superstitious belief in the past.
OK. It makes sense to me now. Subjective time is internal psychological
time. Objective time is external celestial/sidereal/solar time.
Nahin uses machines as a litmus test for objective time travel only,
whereas a PC machine can only induce subjective time travel. So, it's
comparing apples to oranges when the two are combined. Here's the three
possibilities:

1. objective time travel by machine
2. objective time travel by mental/emotional process
3. subjective time travel by mental/emotional process possibly
induced by machine

Nahin doesn't consider the third possibility, and that's what threw
me off. Nahin scopes his book to fit possibility 1 and discards
possibility 2, which seems to mirror the commentators in this thread.
Thanks for playing along. You helped me remove a splinter in my
mind, as ?Lucas? says.



Thank you,
--
Don
Quadibloc
2019-06-01 15:05:11 UTC
Permalink
Post by D B Davis
OK. It makes sense to me now. Subjective time is internal psychological
time. Objective time is external celestial/sidereal/solar time.
Nahin uses machines as a litmus test for objective time travel only,
whereas a PC machine can only induce subjective time travel. So, it's
comparing apples to oranges when the two are combined. Here's the three
1. objective time travel by machine
2. objective time travel by mental/emotional process
3. subjective time travel by mental/emotional process possibly
induced by machine
Nahin doesn't consider the third possibility, and that's what threw
me off. Nahin scopes his book to fit possibility 1 and discards
possibility 2, which seems to mirror the commentators in this thread.
Thanks for playing along. You helped me remove a splinter in my
mind, as ?Lucas? says.
Ah, yes. "Splinter in the Mind's Eye" was an early Star Wars novel.

I do remember #2 from some old Batman comics - the professor who hypnotized
Bruce Wayne and Dick Grayson to send them back in time later reappeared as the
mentor of a pair of superhero twins much more recently.

John Savard
Kevrob
2019-06-01 23:41:31 UTC
Permalink
Post by Quadibloc
Post by D B Davis
OK. It makes sense to me now. Subjective time is internal psychological
time. Objective time is external celestial/sidereal/solar time.
Nahin uses machines as a litmus test for objective time travel only,
whereas a PC machine can only induce subjective time travel. So, it's
comparing apples to oranges when the two are combined. Here's the three
1. objective time travel by machine
2. objective time travel by mental/emotional process
3. subjective time travel by mental/emotional process possibly
induced by machine
Nahin doesn't consider the third possibility, and that's what threw
me off. Nahin scopes his book to fit possibility 1 and discards
possibility 2, which seems to mirror the commentators in this thread.
Thanks for playing along. You helped me remove a splinter in my
mind, as ?Lucas? says.
Ah, yes. "Splinter in the Mind's Eye" was an early Star Wars novel.
I do remember #2 from some old Batman comics - the professor who hypnotized
Bruce Wayne and Dick Grayson to send them back in time later reappeared as the
mentor of a pair of superhero twins much more recently.
{ Racdcu powers activate! }

Carter Nichols.

https://en.wikipedia.org/wiki/Professor_Carter_Nichols

The teen heroes were Jan and Zayna, the alien Wonder Twins
added to the "Super Friends" TV show, when Wendy and Marvin
were....sent off to college.

https://en.wikipedia.org/wiki/Wonder_Twins

{racdcu powers de-activate! }

Who am I kidding? Those are always running in the background.

Kevin R
Ted Nolan <tednolan>
2019-06-02 00:03:48 UTC
Permalink
Post by Quadibloc
Post by Quadibloc
Post by D B Davis
OK. It makes sense to me now. Subjective time is internal psychological
time. Objective time is external celestial/sidereal/solar time.
Nahin uses machines as a litmus test for objective time travel only,
whereas a PC machine can only induce subjective time travel. So, it's
comparing apples to oranges when the two are combined. Here's the three
1. objective time travel by machine
2. objective time travel by mental/emotional process
3. subjective time travel by mental/emotional process possibly
induced by machine
Nahin doesn't consider the third possibility, and that's what threw
me off. Nahin scopes his book to fit possibility 1 and discards
possibility 2, which seems to mirror the commentators in this thread.
Thanks for playing along. You helped me remove a splinter in my
mind, as ?Lucas? says.
Ah, yes. "Splinter in the Mind's Eye" was an early Star Wars novel.
I do remember #2 from some old Batman comics - the professor who hypnotized
Bruce Wayne and Dick Grayson to send them back in time later
reappeared as the
Post by Quadibloc
mentor of a pair of superhero twins much more recently.
{ Racdcu powers activate! }
Carter Nichols.
https://en.wikipedia.org/wiki/Professor_Carter_Nichols
The teen heroes were Jan and Zayna, the alien Wonder Twins
added to the "Super Friends" TV show, when Wendy and Marvin
were....sent off to college.
https://en.wikipedia.org/wiki/Wonder_Twins
{racdcu powers de-activate! }
Who am I kidding? Those are always running in the background.
Marvin & Wonderdog had some of the worst character designs on Saturday
morning. The fact that the Wonder Twins were a step up indicates that
the basement was the starting floor..
--
------
columbiaclosings.com
What's not in Columbia anymore..
Kevrob
2019-06-02 01:07:49 UTC
Permalink
Post by Ted Nolan <tednolan>
Marvin & Wonderdog had some of the worst character designs on Saturday
morning. The fact that the Wonder Twins were a step up indicates that
the basement was the starting floor..
Wendy was kinda cute, though. SF was running in the background at the
comics shop I cashiered at on Saturday mornings, in the mid-70s. I
turned 18 in my freshman year. My "back home girlfriend" wouldn't
graduate high school until I reached sophomore status. And, you know
those actresses playing teens on TV are almost always "playing younger."

I am also reminded of this wicked "Blip v Gleek" image:

http://www.unitarduniverse.com/comic-fight-club-unitard-universe/

From WIZARD #151, May 2004, illus by Frank Cho

"Winner takes on Mojo Jojo? And Mojo Jojo takes on the winner?
But he will not be winner for long, for he who takes on Mojo
Jojo finds Mojo Jojo is the winner! So say I, Mojo Jojo!"

{Kevrob dials Prof. Utonium....}


Kevin R
Ted Nolan <tednolan>
2019-06-02 01:45:19 UTC
Permalink
Post by Kevrob
Post by Ted Nolan <tednolan>
Marvin & Wonderdog had some of the worst character designs on Saturday
morning. The fact that the Wonder Twins were a step up indicates that
the basement was the starting floor..
Wendy was kinda cute, though. SF was running in the background at the
comics shop I cashiered at on Saturday mornings, in the mid-70s. I
turned 18 in my freshman year. My "back home girlfriend" wouldn't
graduate high school until I reached sophomore status. And, you know
those actresses playing teens on TV are almost always "playing younger."
http://www.unitarduniverse.com/comic-fight-club-unitard-universe/
From WIZARD #151, May 2004, illus by Frank Cho
"Winner takes on Mojo Jojo? And Mojo Jojo takes on the winner?
But he will not be winner for long, for he who takes on Mojo
Jojo finds Mojo Jojo is the winner! So say I, Mojo Jojo!"
Heh. Winner takes on Debbie The Bloop...
--
------
columbiaclosings.com
What's not in Columbia anymore..
Kevrob
2019-06-02 02:06:11 UTC
Permalink
Post by Ted Nolan <tednolan>
Post by Kevrob
Post by Ted Nolan <tednolan>
Marvin & Wonderdog had some of the worst character designs on Saturday
morning. The fact that the Wonder Twins were a step up indicates that
the basement was the starting floor..
Wendy was kinda cute, though. SF was running in the background at the
comics shop I cashiered at on Saturday mornings, in the mid-70s. I
turned 18 in my freshman year. My "back home girlfriend" wouldn't
graduate high school until I reached sophomore status. And, you know
those actresses playing teens on TV are almost always "playing younger."
http://www.unitarduniverse.com/comic-fight-club-unitard-universe/
From WIZARD #151, May 2004, illus by Frank Cho
"Winner takes on Mojo Jojo? And Mojo Jojo takes on the winner?
But he will not be winner for long, for he who takes on Mojo
Jojo finds Mojo Jojo is the winner! So say I, Mojo Jojo!"
Heh. Winner takes on Debbie The Bloop...
[quote]

Debbie was played by Judy the Chimp; probably best
remembered for her role on the TV series "Daktari."

[/quote]

https://lostinspace.fandom.com/wiki/Debbie_the_Bloop

Maybe Debbie's the prize? Alpha gets the "movie star?"

:)

Kevin R
David DeLaney
2019-06-03 10:21:35 UTC
Permalink
Post by Quadibloc
Post by D B Davis
Thanks for playing along. You helped me remove a splinter in my
mind, as ?Lucas? says.
Ah, yes. "Splinter in the Mind's Eye" was an early Star Wars novel.
The very first, in fact. From before some details planned for the initial
trilogy got revealed.

Dave, oopsie, but it'll still play in Alabama
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.
David DeLaney
2019-06-03 10:19:54 UTC
Permalink
Post by D B Davis
Post by Quadibloc
I think that there _is_ a real and objective phenomenon of the external
world that corresponds to what we call time.
pssst: the "external world" is, in a VERY real sense, an illusion assembled
inside our brains. The closest good approximation we've got right now involves
factorizable portions inside a gigantic wavefunction expression. "things" and
"qualities" are emergent phenomena.

(Also see "timeless physics", which is A Thing.)
Post by D B Davis
OK. It makes sense to me now. Subjective time is internal psychological
time. Objective time is external celestial/sidereal/solar time.
"Subjective time is measured by the number of learning events experienced."

Dave, name the Doc Smith novel
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.
Mike Van Pelt
2019-05-30 21:37:51 UTC
Permalink
Post by a***@gmail.com
What scientific advancement would be the hardest, is time travel
to the past. I am not sure that will be ever possible.
FTL travel is important for exploring and colonising the universe.
FTL travel is, alas, the same thing as time travel into the
past. Assuming relativity is correct, of course. If you can
make any effect happen at point B at a distance from the cause
at point A more quickly than light could travel from point A
to point B, you can use that ability to make the effect happen
earlier in time than the cause, whether that's a message, or
the arrival of a spacecraft. It's just the nature of how
relativity works.

As I said, assuming relativity is correct. But that is an
exceptionally well tested theory, to the point that even if
it is overturned at some point in the future, it's almost
certain that the replacement theory will have the same very
annoying speed limit.

Almost... But you need to understand why relativity has
this characteristic in order to properly break it for a
story. Traditionally, it's just been handwaved.
--
Mike Van Pelt | "I don't advise it unless you're nuts."
mvp at calweb.com | -- Ray Wilkinson, after riding out Hurricane
KE6BVH | Ike on Surfside Beach in Galveston
Jibini Kula Tumbili Kujisalimisha
2019-05-30 21:54:18 UTC
Permalink
Post by Mike Van Pelt
As I said, assuming relativity is correct. But that is an
exceptionally well tested theory, to the point that even if
it is overturned at some point in the future, it's almost
certain that the replacement theory will have the same very
annoying speed limit.
One of the less handwavium excuses is that while it's correct, it's
not complete. After all, it is incompatable with some aspects of
quantum physics, and we know both to be correct.
--
Terry Austin

Proof that Alan Baker is a liar and a fool, and even stupider than
Lynn:
https://www.cbp.gov/newsroom/stats/sw-border-migration

Vacation photos from Iceland:
https://plus.google.com/u/0/collection/QaXQkB

"Terry Austin: like the polio vaccine, only with more asshole."
Mike Van Pelt
2019-05-30 22:32:57 UTC
Permalink
Post by Jibini Kula Tumbili Kujisalimisha
Post by Mike Van Pelt
As I said, assuming relativity is correct. But that is an
exceptionally well tested theory, to the point that even if
it is overturned at some point in the future, it's almost
certain that the replacement theory will have the same very
annoying speed limit.
One of the less handwavium excuses is that while it's correct, it's
not complete. After all, it is incompatable with some aspects of
quantum physics, and we know both to be correct.
Well, as they say, the map is not the territory. The theories
are maps, sets of equations that work (and work exceptionally
well to a lot of decimal places) in all the places they can
be tested by experiment. About which there's not a lot of
overlap where the two theories can be directly bashed together.

For my stories, I'm tentatively going with all frames are not
equivalent, for FTL purposes. All FTL jumps have to happen
in one "special" reference frame, so you can't change reference
frames between FTL jumps to go back in time. Yeah, this means
you might have to expend substantial delta-V at both ends
of a jump to land where you're trying to get to. Unless you're
happy with a flat hyperbolic fly-by. Or lithobraking of your
payload from c-fractional.
--
Mike Van Pelt | "I don't advise it unless you're nuts."
mvp at calweb.com | -- Ray Wilkinson, after riding out Hurricane
KE6BVH | Ike on Surfside Beach in Galveston
Alan Baker
2019-05-31 05:38:18 UTC
Permalink
Post by Jibini Kula Tumbili Kujisalimisha
Post by Mike Van Pelt
As I said, assuming relativity is correct. But that is an
exceptionally well tested theory, to the point that even if
it is overturned at some point in the future, it's almost
certain that the replacement theory will have the same very
annoying speed limit.
One of the less handwavium excuses is that while it's correct, it's
not complete. After all, it is incompatable with some aspects of
quantum physics, and we know both to be correct.
With what aspects of quantum physics is relativity incompatible?

:-)
Quadibloc
2019-05-31 06:28:48 UTC
Permalink
Post by Alan Baker
With what aspects of quantum physics is relativity incompatible?
Well, as noted, there is the fact that the Einstein-Podolsky-Rosen "paradox" is
proved experimentally to really happen. Quantum entanglement is explained by
some as simply meaning that reality is "nonlocal", but that isn't clearly
defined.

Quantum entanglement, as understood from a pedestrian point of view at least,
despite the fact that *we* can't use it to tranmit information faster than
light, Nature is transmitting information faster than light behind the scenes in
order for the consistent behavior we see to be possible.

John Savard
Jibini Kula Tumbili Kujisalimisha
2019-06-01 00:10:47 UTC
Permalink
On Thursday, May 30, 2019 at 11:38:07 PM UTC-6, Alan Baker
Post by Alan Baker
With what aspects of quantum physics is relativity
incompatible?
Well, as noted, there is the fact that the
Einstein-Podolsky-Rosen "paradox" is proved experimentally to
really happen. Quantum entanglement is explained by some as
simply meaning that reality is "nonlocal", but that isn't
clearly defined.
Quantum entanglement, as understood from a pedestrian point of
view at least, despite the fact that *we* can't use it to
tranmit information faster than light, Nature is transmitting
information faster than light behind the scenes in order for the
consistent behavior we see to be possible.
Congratulations, Alan. You made Quaddie look like the smart one.

A 0.47 second search on Google for "quantum physics relativity
conflicts" produces a little shy of two million hits.

Dumbass.

I asked you first.

Why are you so afraid to answer the questions, Alan?

So exactly what part of the CBP numbers on how many illegals are
crossing the border per month right now (90,000 in March) do you
dispute, and why?
Be specific. Name names. Who is the head of the criminal conspiracy
to inflate the numbers?

Or are you running away, tail between your legs, again?
--
Terry Austin

Proof that Alan Baker is a liar and a fool, and even stupider than
Lynn:
https://www.cbp.gov/newsroom/stats/sw-border-migration

Vacation photos from Iceland:
https://plus.google.com/u/0/collection/QaXQkB

"Terry Austin: like the polio vaccine, only with more asshole."
David DeLaney
2019-06-03 10:29:57 UTC
Permalink
Post by Alan Baker
Post by Jibini Kula Tumbili Kujisalimisha
One of the less handwavium excuses is that while it's correct, it's
not complete. After all, it is incompatable with some aspects of
quantum physics, and we know both to be correct.
With what aspects of quantum physics is relativity incompatible?
Sorry, Alan, Terry is QUITE correct this time. It's one of the central problems
in theoretical physics, since Einstein first came up with general relativity.

We've unified electricity, magnetism, amd the weak force, and have some hope
of getting the strong force melded in. Gravity does not work right to fit,
mathematically.

Rather than continue on my own, Google has presented me with the succinct

"In general relativity, events are continuous and deterministic, meaning that
every cause matches up to a specific, local effect. In quantum mechanics,
events produced by the interaction of subatomic particles happen in jumps
(yes, quantum leaps), with probabilistic rather than definite outcomes."

Dave
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.
Quadibloc
2019-06-03 15:34:18 UTC
Permalink
Post by David DeLaney
We've unified electricity, magnetism, amd the weak force, and have some hope
of getting the strong force melded in. Gravity does not work right to fit,
mathematically.
Aren't you behind the times? Electromagnetism got unified with the weak force by
means of the electroweak theory, but then the strong force got unified with
quantum chromodynamics. And while trying to fit gravity directly to
electromagnetism didn't fit - Kaluza-Klein wasn't renormalizable - once we had
quantum chromodynamics, gravity got unified with that for the first time in
supergravity, and now we also have innumerable string theories to choose from.

John Savard
Quadibloc
2019-06-03 15:51:56 UTC
Permalink
Post by Quadibloc
Post by David DeLaney
We've unified electricity, magnetism, amd the weak force, and have some hope
of getting the strong force melded in. Gravity does not work right to fit,
mathematically.
Aren't you behind the times? Electromagnetism got unified with the weak force by
means of the electroweak theory,
in 1959
Post by Quadibloc
but then the strong force got unified with
quantum chromodynamics.
Quantum chromodynamics dates from 1974, but the unification of the strong force with the electroweak theory apparently didn't take place until 1975; it was supersymmetry that was the theory that did that instead, so I was apparently mistaken here.
Post by Quadibloc
And while trying to fit gravity directly to
electromagnetism didn't fit - Kaluza-Klein wasn't renormalizable - once we had
quantum chromodynamics, gravity got unified with that for the first time in
supergravity,
And supergravity is from 1976.
Post by Quadibloc
and now we also have innumerable string theories to choose from.
John Savard
David DeLaney
2019-06-06 15:28:57 UTC
Permalink
Post by Quadibloc
Quantum chromodynamics dates from 1974, but the unification of the strong
force with the electroweak theory apparently didn't take place until 1975; it
was supersymmetry that was the theory that did that instead, so I was
apparently mistaken here.

Sure, supersymmetry does that ... but we have ZERO experimental evidence for
ANYTHING supersymmetric at all. Even the stuff that we should have started
seeing by now, if parametes of the SUSY theory were semi-reasonable. So SUSY
at present, yes even now in 2019, is filed with string theory and supergravity
and loop quantum gravity and a whole host of other stuff as "okay, there's
{some/a whole lot of} {good/interesting} math here, but either this isn't
making any predictins at all, or the predictions it's making aren't where we
can test them, and nothing here is contradicting the Standard Model as such,
so this isn't actually PHYSICS, it's MATH".

Dave, who was attending SUSY seminars in the late '80s thank you very much
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.
J. Clarke
2019-06-04 00:20:06 UTC
Permalink
Post by Quadibloc
Post by David DeLaney
We've unified electricity, magnetism, amd the weak force, and have some hope
of getting the strong force melded in. Gravity does not work right to fit,
mathematically.
Aren't you behind the times? Electromagnetism got unified with the weak force by
means of the electroweak theory, but then the strong force got unified with
quantum chromodynamics. And while trying to fit gravity directly to
electromagnetism didn't fit - Kaluza-Klein wasn't renormalizable - once we had
quantum chromodynamics, gravity got unified with that for the first time in
supergravity, and now we also have innumerable string theories to choose from.i
Whoa. If gravity actually got unified with supergravity there
wouldn't be any need for string theory. All the quantum gravity
models are hypothesis and none of them so far have proven to be
testable in any meaningful way (i.e. they don't make a prediction that
is different from what is predicted by quantum theory or relativity).
David DeLaney
2019-06-06 15:21:07 UTC
Permalink
Post by Quadibloc
Post by David DeLaney
We've unified electricity, magnetism, amd the weak force, and have some hope
of getting the strong force melded in. Gravity does not work right to fit,
mathematically.
Aren't you behind the times? Electromagnetism got unified with the weak force
by means of the electroweak theory, but then the strong force got unified with
quantum chromodynamics.
Sorry. QCD is NOT a unification. It's a calculation method and framework. It
does not by itself unify gluons with any other carrier bosons. The main
problem with QCD is that the strong force is STRONG, relative to EM and the weak
force ... so the pertubation methods that work nicely to give Feynman diagrams
for them that can be added up order by order to get extremely precise answers?
Diverge, for QCD. Ooopsie.

(Asymptotic freedom means that at high energies, the quarks DON'T interact
very strongly at all, so perturbation theory works for that regime. But not
for low energies, where confinement occurs. ... Particle physicists are having
a good deal of fun, in some sense of that word, finding other ways to get low-
energy QCD calculations done.)

We're pretty sure that QCD _does_ unify with electroweak at some higher energy,
but it is currently beyond the reach of any experiments we can do AND hasn't
dangled any traces down into the Standard Model's region of applicability. So
there's new physics up there somewhere, but we don't know what or quite where
yet.
Post by Quadibloc
And while trying to fit gravity directly to
electromagnetism didn't fit - Kaluza-Klein wasn't renormalizable - once we had
quantum chromodynamics, gravity got unified with that for the first time in
supergravity, and now we also have innumerable string theories to choose from.
For a version of "unified" that translates to "there's no experimental
evidence that supports ANY of these attempted unifications, or attempts to get
gravity to behave, or attempts to model point particles as tiny strings in some
number of curled-up dimensions". Basically ALL of that is castles in the
rarefied air of pure mathematics, flights of mathematical fancy that may even
be self-consistent. And may be useful someday. But which don't have even any
good way to simplify down to the Standard Model at lower energies, which is
never a good sign.

Dave, been there, done the seminars, got the Santa Cruz banana slug-particle
energy t-shirt
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.
Quadibloc
2019-06-06 15:35:20 UTC
Permalink
Post by David DeLaney
For a version of "unified" that translates to "there's no experimental
evidence that supports ANY of these attempted unifications, or attempts to get
gravity to behave, or attempts to model point particles as tiny strings in some
number of curled-up dimensions". Basically ALL of that is castles in the
rarefied air of pure mathematics, flights of mathematical fancy that may even
be self-consistent. And may be useful someday. But which don't have even any
good way to simplify down to the Standard Model at lower energies, which is
never a good sign.
Funny you should say that; I was just reading this article the other day:

https://www.livescience.com/65628-theory-of-everything-millennia-away.html

which derived the "millenia" from the time it might take to build a particle
accelerator big enough to do experimental testing of that sort of theory.

But it should take a lot less time than millenia to get the math worked out, and
if it all adds up, I doubt that for the remaining time until experimental
verification rolls in that we will suffer from any great degree of anxiety. So
I'm not sure if I can see this as a source of job security in physics
departments.

John Savard
J. Clarke
2019-06-06 18:27:03 UTC
Permalink
Post by Quadibloc
Post by David DeLaney
For a version of "unified" that translates to "there's no experimental
evidence that supports ANY of these attempted unifications, or attempts to get
gravity to behave, or attempts to model point particles as tiny strings in some
number of curled-up dimensions". Basically ALL of that is castles in the
rarefied air of pure mathematics, flights of mathematical fancy that may even
be self-consistent. And may be useful someday. But which don't have even any
good way to simplify down to the Standard Model at lower energies, which is
never a good sign.
https://www.livescience.com/65628-theory-of-everything-millennia-away.html
which derived the "millenia" from the time it might take to build a particle
accelerator big enough to do experimental testing of that sort of theory.
But it should take a lot less time than millenia to get the math worked out, and
if it all adds up, I doubt that for the remaining time until experimental
verification rolls in that we will suffer from any great degree of anxiety. So
I'm not sure if I can see this as a source of job security in physics
departments.
Personally I'm of the opinion that String Theory is going to prove
analogous to epicycles. Keep adding dimensions until you get
something that matches. Never mind that it doesn't actually give you
any physical insight.
Dimensional Traveler
2019-06-06 22:20:19 UTC
Permalink
Post by J. Clarke
Post by Quadibloc
Post by David DeLaney
For a version of "unified" that translates to "there's no experimental
evidence that supports ANY of these attempted unifications, or attempts to get
gravity to behave, or attempts to model point particles as tiny strings in some
number of curled-up dimensions". Basically ALL of that is castles in the
rarefied air of pure mathematics, flights of mathematical fancy that may even
be self-consistent. And may be useful someday. But which don't have even any
good way to simplify down to the Standard Model at lower energies, which is
never a good sign.
https://www.livescience.com/65628-theory-of-everything-millennia-away.html
which derived the "millenia" from the time it might take to build a particle
accelerator big enough to do experimental testing of that sort of theory.
But it should take a lot less time than millenia to get the math worked out, and
if it all adds up, I doubt that for the remaining time until experimental
verification rolls in that we will suffer from any great degree of anxiety. So
I'm not sure if I can see this as a source of job security in physics
departments.
Personally I'm of the opinion that String Theory is going to prove
analogous to epicycles. Keep adding dimensions until you get
something that matches. Never mind that it doesn't actually give you
any physical insight.
But its just such a COOL theory! :P
--
Inquiring minds want to know while minds with a self-preservation
instinct are running screaming.
Robert Carnegie
2019-06-06 22:48:26 UTC
Permalink
Post by Quadibloc
Post by David DeLaney
For a version of "unified" that translates to "there's no experimental
evidence that supports ANY of these attempted unifications, or attempts to get
gravity to behave, or attempts to model point particles as tiny strings in some
number of curled-up dimensions". Basically ALL of that is castles in the
rarefied air of pure mathematics, flights of mathematical fancy that may even
be self-consistent. And may be useful someday. But which don't have even any
good way to simplify down to the Standard Model at lower energies, which is
never a good sign.
https://www.livescience.com/65628-theory-of-everything-millennia-away.html
which derived the "millenia" from the time it might take to build a particle
accelerator big enough to do experimental testing of that sort of theory.
But it should take a lot less time than millenia to get the math worked out, and
if it all adds up, I doubt that for the remaining time until experimental
verification rolls in that we will suffer from any great degree of anxiety. So
I'm not sure if I can see this as a source of job security in physics
departments.
It worked for philosophers in _The Hitchhiker's Guide
to the Galaxy_...

In which, "Deep Thought" is a computer designed to tell
the Answer to the Ultimate Question of Life, The Universe,
and Everything.

Philosophers picket the machine, complaining that that
will put them out of a job. (Later, psychiatrists also
have issues with this project.)

The philosophers are reconciled to the plan when the
computer tells them that it will take some time to
produce the Answer and in the meantime there will be
publicity beyond the wildest dreams of their discipline.

That, in fact, it will take seven and a half million years.

So, if you want to know the Answer, read the book. :-)
Quadibloc
2019-06-07 03:44:03 UTC
Permalink
Post by Robert Carnegie
So, if you want to know the Answer, read the book. :-)
But the answer is a disappointment, unless you know what the real wording of the
question to go with it should be.

John Savard

Sjouke Burry
2019-05-30 22:39:12 UTC
Permalink
Post by Mike Van Pelt
Post by a***@gmail.com
What scientific advancement would be the hardest, is time travel
to the past. I am not sure that will be ever possible.
FTL travel is important for exploring and colonising the universe.
FTL travel is, alas, the same thing as time travel into the
past. Assuming relativity is correct, of course. If you can
make any effect happen at point B at a distance from the cause
at point A more quickly than light could travel from point A
to point B, you can use that ability to make the effect happen
earlier in time than the cause, whether that's a message, or
the arrival of a spacecraft. It's just the nature of how
relativity works.
As I said, assuming relativity is correct. But that is an
exceptionally well tested theory, to the point that even if
it is overturned at some point in the future, it's almost
certain that the replacement theory will have the same very
annoying speed limit.
Almost... But you need to understand why relativity has
this characteristic in order to properly break it for a
story. Traditionally, it's just been handwaved.
Relativity theory does forbid travel AT light speed.
But it tells nothing about higher speeds.
Quantum entanglement suggests at least info travels (almost?)
instantaneously.
So passing/jumping the light speed barrier is a possibility according to
theory.
Years ago some particle seemed to always be at higher speed,
but turned out to be wrong.
Although I have no idea about how to do it.........
Suggestions please(with drawings) ?
Dimensional Traveler
2019-05-30 23:58:23 UTC
Permalink
Post by Sjouke Burry
Post by Mike Van Pelt
Post by a***@gmail.com
What scientific advancement would be the hardest, is time travel
to the past. I am not sure that will be ever possible.
FTL travel is important for exploring and colonising the universe.
FTL travel is, alas, the same thing as time travel into the
past. Assuming relativity is correct, of course. If you can
make any effect happen at point B at a distance from the cause
at point A more quickly than light could travel from point A
to point B, you can use that ability to make the effect happen
earlier in time than the cause, whether that's a message, or
the arrival of a spacecraft. It's just the nature of how
relativity works.
As I said, assuming relativity is correct. But that is an
exceptionally well tested theory, to the point that even if
it is overturned at some point in the future, it's almost
certain that the replacement theory will have the same very
annoying speed limit.
Almost... But you need to understand why relativity has
this characteristic in order to properly break it for a
story. Traditionally, it's just been handwaved.
Relativity theory does forbid travel AT light speed.
But it tells nothing about higher speeds.
Quantum entanglement suggests at least info travels (almost?)
instantaneously.
So passing/jumping the light speed barrier is a possibility according to
theory.
Years ago some particle seemed to always be at higher speed,
but turned out to be wrong.
Although I have no idea about how to do it.........
Suggestions please(with drawings) ?
There is also nothing in Relativity that says spacetime can't move
faster than light.
--
Inquiring minds want to know while minds with a self-preservation
instinct are running screaming.
Quadibloc
2019-05-31 03:52:24 UTC
Permalink
Post by Dimensional Traveler
There is also nothing in Relativity that says spacetime can't move
faster than light.
That is the principle behind the Alcubierre warp drive - and if it becomes a
reality, it could involve travel into the past. Like in Star Trek. So the
_indirect_ argument from Special Relativity still applies with full force, even
if General Relatively doesn't _directly_ make that kind of FTL travel
impossible.

Now, maybe an Alcubierre ship could only travel into something that _appears_ to
be the past - alternate time lines and so on - meaning that it will lead to new
discoveries extending our understanding of what's going on.

John Savard
Mike Van Pelt
2019-05-31 19:56:43 UTC
Permalink
Post by Quadibloc
Post by Dimensional Traveler
There is also nothing in Relativity that says spacetime can't move
faster than light.
That is the principle behind the Alcubierre warp drive -
Yeah... inflates space behind the starship, and deflates
space in front of it. Nice trick if you can do it.

Of course, assuming you can... What are the implications for
unfortunate beings who happen to be somewhere along the line
between where you are and where you're going? It sounds
likely to be rather cataclysmic.

As I recall, you need negative mass in stellar quantities
to make the Alcubierre warp work, so I don't suppose it's
likely to be a near-term problem.

Unless a Vogon Constructor Fleet shows up.
--
Mike Van Pelt | "I don't advise it unless you're nuts."
mvp at calweb.com | -- Ray Wilkinson, after riding out Hurricane
KE6BVH | Ike on Surfside Beach in Galveston
Quadibloc
2019-05-31 20:30:56 UTC
Permalink
Post by Mike Van Pelt
As I recall, you need negative mass in stellar quantities
to make the Alcubierre warp work, so I don't suppose it's
likely to be a near-term problem.
There was a recent discovery that reduced the amoount of negative energy needed by
an order of magnitude. Which, of course, doesn't really help because we have no
idea how to obtain *any* of that stuff.

John Savard
J. Clarke
2019-05-31 22:42:30 UTC
Permalink
Post by Mike Van Pelt
Post by Quadibloc
Post by Dimensional Traveler
There is also nothing in Relativity that says spacetime can't move
faster than light.
That is the principle behind the Alcubierre warp drive -
Yeah... inflates space behind the starship, and deflates
space in front of it. Nice trick if you can do it.
Of course, assuming you can... What are the implications for
unfortunate beings who happen to be somewhere along the line
between where you are and where you're going? It sounds
likely to be rather cataclysmic.
As I recall, you need negative mass in stellar quantities
to make the Alcubierre warp work, so I don't suppose it's
likely to be a near-term problem.
That was an early calculation. I believe that now you need it in
Volkswagen quantities.
Post by Mike Van Pelt
Unless a Vogon Constructor Fleet shows up.
J. Clarke
2019-05-31 22:41:32 UTC
Permalink
On Thu, 30 May 2019 20:52:24 -0700 (PDT), Quadibloc
Post by Quadibloc
Post by Dimensional Traveler
There is also nothing in Relativity that says spacetime can't move
faster than light.
That is the principle behind the Alcubierre warp drive - and if it becomes a
reality, it could involve travel into the past. Like in Star Trek. So the
_indirect_ argument from Special Relativity still applies with full force, even
if General Relatively doesn't _directly_ make that kind of FTL travel
impossible.
Now, maybe an Alcubierre ship could only travel into something that _appears_ to
be the past - alternate time lines and so on - meaning that it will lead to new
discoveries extending our understanding of what's going on.
John, there is no "indirect argument from special relativity" that
supersedes General Relativity. Special relativity is General
Relativity with simplifying assumptions. I think Einstein made a
mistake by calling it "Special" because people think that that makes
it somehow better than "General". "Simplified Relativity" is a more
accurate description than "Special Relativity".
Quadibloc
2019-06-01 02:38:41 UTC
Permalink
Post by J. Clarke
I think Einstein made a
mistake by calling it "Special" because people think that that makes
it somehow better than "General".
We can be thankful, then, that Einstein didn't call it "Exceptional Relativity".

However, my understanding is not that Special Relativity is to General
Relativity as classical physics is to relativity. Rather, Special Relativity
only explains the case where there is no gravity or acceleration properly;
subject to that condition, it is not in any way inconsistent with General
Relativity.

As a valid piece of General Relativity, GR didn't make SR stop being true. SR
does still imply that if you go faster than light while obeying relativity -
which GR seems to say you can actually do - then you *will* be able to go
backwards in time. Which is absurd because causality.

However, just as Quantum Mechanics didn't reconcile itself with relativity in
ways that made Einstein happy, it's too early to say if our preconceived notions
of causality will survive when Alcubierre ships start being flown. If, indeed,
they can be.

John Savard
J. Clarke
2019-06-01 02:53:47 UTC
Permalink
On Fri, 31 May 2019 19:38:41 -0700 (PDT), Quadibloc
Post by Quadibloc
Post by J. Clarke
I think Einstein made a
mistake by calling it "Special" because people think that that makes
it somehow better than "General".
We can be thankful, then, that Einstein didn't call it "Exceptional Relativity".
However, my understanding is not that Special Relativity is to General
Relativity as classical physics is to relativity. Rather, Special Relativity
only explains the case where there is no gravity or acceleration properly;
subject to that condition, it is not in any way inconsistent with General
Relativity.
"Classical physics" is also not in any way inconsistent with General
Relativity. It's just General Relativity with even more simplifying
assumptions than Special Relativity.
Post by Quadibloc
As a valid piece of General Relativity, GR didn't make SR stop being true. SR
does still imply that if you go faster than light while obeying relativity -
which GR seems to say you can actually do - then you *will* be able to go
backwards in time. Which is absurd because causality.
Show me a calculation in Special Relativity that shows time travel in
a single frame. Every "proof" that I've seen has jumped from
reference frame to reference frame to reference frame and then said
"See!". And don't cite wiki, they show that demonstration.
Post by Quadibloc
However, just as Quantum Mechanics didn't reconcile itself with relativity in
ways that made Einstein happy, it's too early to say if our preconceived notions
of causality will survive when Alcubierre ships start being flown. If, indeed,
they can be.
If you've got enough computer power you can run the numbers you know
and work out the trajectory.
David DeLaney
2019-06-03 10:36:40 UTC
Permalink
Post by J. Clarke
Show me a calculation in Special Relativity that shows time travel in
a single frame. Every "proof" that I've seen has jumped from
reference frame to reference frame to reference frame and then said
"See!". And don't cite wiki, they show that demonstration.
You need more than one frame to do it, AND this shows you don't quite
understand what a "frame of reference" IS.

"jumping from frame to frame", for inertial reference frames, means the same
thing as "changing velocities". Which equates to "accelerating". It's not a
magic trick, nor does it invalidate the proof in any way.

You can show what's happening in a single reference frame, say that of someone
sitting on Earth watching the spaceship go back and forth into Elsewhere. But
to show HOW the spaceship can end up in its own past light cone, you have to
let it do something other than cruise at constant FTL velocity forever.

Dave, and a spaceship that can't stop isn't very useful even f it IS an FTL one
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.
Quadibloc
2019-05-31 03:48:38 UTC
Permalink
Post by Sjouke Burry
Relativity theory does forbid travel AT light speed.
But it tells nothing about higher speeds.
No, that's not true.

It's true that traveling exactly at light speed requires infinite energy, and is
forbidden for that reason.

But travelling faster than light speed... means your journey could also take you
into the past from some equally-valid points of view. As long as the FTL drive
has to be fully bound by relativity, working the same in any inertial reference
frame, that lets you set up a journey so that...

using approximately the same principle that lets a boat tack against the wind...

you could leave Earth today and come back to Earth a hundred years ago. Really.
Which leads to logical paradoxes.

Also, multiplying your mass by the square root of minus one may be just as hard
as making it infinite, but communications at FTL speeds are just as paradoxical
as travel, so that's a _minor_ objection. So if tachyons exist, it must be
impossible to manipulate and/or detect them.

John Savard
J. Clarke
2019-05-31 22:48:58 UTC
Permalink
On Thu, 30 May 2019 20:48:38 -0700 (PDT), Quadibloc
Post by Quadibloc
Post by Sjouke Burry
Relativity theory does forbid travel AT light speed.
But it tells nothing about higher speeds.
No, that's not true.
It's true that traveling exactly at light speed requires infinite energy, and is
forbidden for that reason.
But travelling faster than light speed... means your journey could also take you
into the past from some equally-valid points of view. As long as the FTL drive
has to be fully bound by relativity, working the same in any inertial reference
frame, that lets you set up a journey so that...
Most of those calculations seem to be using Special Relativity and
jumping from reference frame to reference frame with mad abandon.
While there is no preferred frame, when you do calculations you have
to pick a frame and stick to it. If you want to know what things look
like from another frame, you have to do them in that frame and _only_
that frame.

The thing that is fairly clear about FTL other than the kind described
by Alcubierre or the kind of pseudo FTL that results from traveling
STL to a black hole and then using the black hole to travel into the
past is that either (a) the physics in that domain is so bizarre that
it is highly unlikely that humans or human technology could survive it
or (b) it is outside the domain of applicability of General
Relativity.
Post by Quadibloc
using approximately the same principle that lets a boat tack against the wind...
you could leave Earth today and come back to Earth a hundred years ago. Really.
Which leads to logical paradoxes.
Also, multiplying your mass by the square root of minus one may be just as hard
as making it infinite, but communications at FTL speeds are just as paradoxical
as travel, so that's a _minor_ objection. So if tachyons exist, it must be
impossible to manipulate and/or detect them.
John Savard
David DeLaney
2019-06-03 10:42:39 UTC
Permalink
Post by J. Clarke
Most of those calculations seem to be using Special Relativity and
jumping from reference frame to reference frame with mad abandon.
While there is no preferred frame, when you do calculations you have
to pick a frame and stick to it. If you want to know what things look
like from another frame, you have to do them in that frame and _only_
that frame.
And, again, nope. The entire idea behind relativity is that it doesn't
MATTER which frame you do the calculations in. And there are things called
"invariants" you can calculate which don't change, which in turn can help you
in whatever frame you're in.

Another part of relativity is that it tells you HOW to translate from one frame
to another, inertial or not, with precision and exactness. Your claim, or
feeling, or whatever it is, that changing from one frame to another must
necessarily screw up any and all calculations going on is simply not the case.

At all.
Post by J. Clarke
or (b) it is outside the domain of applicability of General
Relativity.
... and just how do you think one might GET outside that domain? Hmmm? Let
us know, do.

Dave, it's quite possible you simply don't understand the math and concepts
well enough. nothing wrong with that. but please be aware that in this state,
trying to "correct" people who DO leaves you looking foolish.
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.
Quadibloc
2019-05-31 03:43:05 UTC
Permalink
Post by Mike Van Pelt
FTL travel is, alas, the same thing as time travel into the
past. Assuming relativity is correct, of course.
Yes, but relativity can also be correct "most of the time".

"In order to travel at speeds faster than light, a spaceship has to drop into subspace. There, different laws of physics apply. But they're logically consistent with our Universe, just the same. Any faster-than-light journey that is possible in subspace is, from the viewpoint of our Universe, a journey forwards in time from the unique inertial reference frame the importance and special nature of which is revealed by the subspace drive."

"In our Universe, the laws of Special Relativity still apply, and all possible journeys must be forwards in time from the view of all reference frames, which means they must be slower than light speed, because nothing in our Universe - except its connection to subspace, which the FTL drive uses - differentiates between inertial reference frames."

...how it could be explained in a science-fiction story.

John Savard
Mike Van Pelt
2019-05-31 20:00:09 UTC
Permalink
Post by Quadibloc
Post by Mike Van Pelt
FTL travel is, alas, the same thing as time travel into the
past. Assuming relativity is correct, of course.
Yes, but relativity can also be correct "most of the time".
That's the dodge I use for my stories.

FTL jumps must be done from and to the same preferred
reference frame. This means that doing a FTL jump
may require you to do substantial delta-v at both ends.
Destinations might be easy to get to based on their
how close they are to the special reference frame,
irrespective of their distance.
--
Mike Van Pelt | "I don't advise it unless you're nuts."
mvp at calweb.com | -- Ray Wilkinson, after riding out Hurricane
KE6BVH | Ike on Surfside Beach in Galveston
David DeLaney
2019-06-03 10:46:41 UTC
Permalink
Post by Mike Van Pelt
FTL jumps must be done from and to the same preferred
reference frame.
Note that it's VERY tempting to make this the rest frame of the combined mass
of the observable universe, Mach's background inertial frame for his Principle.
Post by Mike Van Pelt
Destinations might be easy to get to based on their
how close they are to the special reference frame,
irrespective of their distance.
ObSF: Niven's hyperdrives in the Ringworld universe.

Dave, and the Slavers never figuring out why their watches ran slow
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.
Gene Wirchenko
2019-06-01 06:02:33 UTC
Permalink
On Thu, 30 May 2019 20:43:05 -0700 (PDT), Quadibloc
Post by Quadibloc
Post by Mike Van Pelt
FTL travel is, alas, the same thing as time travel into the
past. Assuming relativity is correct, of course.
Yes, but relativity can also be correct "most of the time".
"In order to travel at speeds faster than light, a spaceship has to drop into subspace. There, different laws of physics apply. But they're logically consistent with our Universe, just the same. Any faster-than-light journey that is possible in subspace is, from the viewpoint of our Universe, a journey forwards in time from the unique inertial reference frame the importance and special nature of which is revealed by the subspace drive."
"In our Universe, the laws of Special Relativity still apply, and all possible journeys must be forwards in time from the view of all reference frames, which means they must be slower than light speed, because nothing in our Universe - except its connection to subspace, which the FTL drive uses - differentiates between inertial reference frames."
...how it could be explained in a science-fiction story.
ObSF: I recall one story (but not the author or title) where
details on hyperspace were kept all hush-hush. At the end, the reveal
was the the speed of light was

S
P
O
I
L
E
R

S
P
A
C
E

*slower* in hyperspace.

Sincerely,

Gene Wirchenko

---
This email has been checked for viruses by AVG.
https://www.avg.com
Dimensional Traveler
2019-06-01 06:48:26 UTC
Permalink
Post by Gene Wirchenko
On Thu, 30 May 2019 20:43:05 -0700 (PDT), Quadibloc
Post by Quadibloc
Post by Mike Van Pelt
FTL travel is, alas, the same thing as time travel into the
past. Assuming relativity is correct, of course.
Yes, but relativity can also be correct "most of the time".
"In order to travel at speeds faster than light, a spaceship has to drop into subspace. There, different laws of physics apply. But they're logically consistent with our Universe, just the same. Any faster-than-light journey that is possible in subspace is, from the viewpoint of our Universe, a journey forwards in time from the unique inertial reference frame the importance and special nature of which is revealed by the subspace drive."
"In our Universe, the laws of Special Relativity still apply, and all possible journeys must be forwards in time from the view of all reference frames, which means they must be slower than light speed, because nothing in our Universe - except its connection to subspace, which the FTL drive uses - differentiates between inertial reference frames."
...how it could be explained in a science-fiction story.
ObSF: I recall one story (but not the author or title) where
details on hyperspace were kept all hush-hush. At the end, the reveal
was the the speed of light was
S
P
O
I
L
E
R
S
P
A
C
E
*slower* in hyperspace.
That's an _OLD_ story, '40s or '50s I believe. A researcher/scientist
was complaining to his superior that his hyperspace project wasn't being
funded or supported. Finally he was told that several others had
already succeeded and found out your spoiler.
--
Inquiring minds want to know while minds with a self-preservation
instinct are running screaming.
Jerry Brown
2019-06-01 16:13:16 UTC
Permalink
On Fri, 31 May 2019 23:48:26 -0700, Dimensional Traveler
Post by Dimensional Traveler
Post by Gene Wirchenko
On Thu, 30 May 2019 20:43:05 -0700 (PDT), Quadibloc
Post by Quadibloc
Post by Mike Van Pelt
FTL travel is, alas, the same thing as time travel into the
past. Assuming relativity is correct, of course.
Yes, but relativity can also be correct "most of the time".
"In order to travel at speeds faster than light, a spaceship has to drop into subspace. There, different laws of physics apply. But they're logically consistent with our Universe, just the same. Any faster-than-light journey that is possible in subspace is, from the viewpoint of our Universe, a journey forwards in time from the unique inertial reference frame the importance and special nature of which is revealed by the subspace drive."
"In our Universe, the laws of Special Relativity still apply, and all possible journeys must be forwards in time from the view of all reference frames, which means they must be slower than light speed, because nothing in our Universe - except its connection to subspace, which the FTL drive uses - differentiates between inertial reference frames."
...how it could be explained in a science-fiction story.
ObSF: I recall one story (but not the author or title) where
details on hyperspace were kept all hush-hush. At the end, the reveal
was the the speed of light was
S
P
O
I
L
E
R
S
P
A
C
E
*slower* in hyperspace.
That's an _OLD_ story, '40s or '50s I believe. A researcher/scientist
was complaining to his superior that his hyperspace project wasn't being
funded or supported. Finally he was told that several others had
already succeeded and found out your spoiler.
"FTA" (1974) by George R R Martin.
--
Jerry Brown

A cat may look at a king
(but probably won't bother)
Dimensional Traveler
2019-06-01 17:46:00 UTC
Permalink
Post by Jerry Brown
On Fri, 31 May 2019 23:48:26 -0700, Dimensional Traveler
Post by Dimensional Traveler
Post by Gene Wirchenko
On Thu, 30 May 2019 20:43:05 -0700 (PDT), Quadibloc
Post by Quadibloc
Post by Mike Van Pelt
FTL travel is, alas, the same thing as time travel into the
past. Assuming relativity is correct, of course.
Yes, but relativity can also be correct "most of the time".
"In order to travel at speeds faster than light, a spaceship has to drop into subspace. There, different laws of physics apply. But they're logically consistent with our Universe, just the same. Any faster-than-light journey that is possible in subspace is, from the viewpoint of our Universe, a journey forwards in time from the unique inertial reference frame the importance and special nature of which is revealed by the subspace drive."
"In our Universe, the laws of Special Relativity still apply, and all possible journeys must be forwards in time from the view of all reference frames, which means they must be slower than light speed, because nothing in our Universe - except its connection to subspace, which the FTL drive uses - differentiates between inertial reference frames."
...how it could be explained in a science-fiction story.
ObSF: I recall one story (but not the author or title) where
details on hyperspace were kept all hush-hush. At the end, the reveal
was the the speed of light was
S
P
O
I
L
E
R
S
P
A
C
E
*slower* in hyperspace.
That's an _OLD_ story, '40s or '50s I believe. A researcher/scientist
was complaining to his superior that his hyperspace project wasn't being
funded or supported. Finally he was told that several others had
already succeeded and found out your spoiler.
"FTA" (1974) by George R R Martin.
*scratches head* Okay, not as old as I thought. Thank you.
--
Inquiring minds want to know while minds with a self-preservation
instinct are running screaming.
a***@gmail.com
2019-06-01 13:52:06 UTC
Permalink
Post by Mike Van Pelt
Post by a***@gmail.com
What scientific advancement would be the hardest, is time travel
to the past. I am not sure that will be ever possible.
FTL travel is important for exploring and colonising the universe.
FTL travel is, alas, the same thing as time travel into the
past. Assuming relativity is correct, of course. If you can
make any effect happen at point B at a distance from the cause
at point A more quickly than light could travel from point A
to point B, you can use that ability to make the effect happen
earlier in time than the cause, whether that's a message, or
the arrival of a spacecraft. It's just the nature of how
relativity works.
As I said, assuming relativity is correct. But that is an
exceptionally well tested theory, to the point that even if
it is overturned at some point in the future, it's almost
certain that the replacement theory will have the same very
annoying speed limit.
Almost... But you need to understand why relativity has
this characteristic in order to properly break it for a
story. Traditionally, it's just been handwaved.
All scientific theories are provisional. Theories of physics build models of reality. It is likely that SR will eventually be replaced by a better theory.

Some people have a strong belief in space time, that all of the past and future always exist. But that may lead to determinism, and turn us into automatons without free will.

I believe that the distant past is lost forever, and the distant future does not exist. I am not sure how to define the present. But according to my viewpoint time travel to the past is impossible.

As far as FTL travel, we can use wormholes or hyperspace, or some as yet unknown physics.

All this is guesswork, and we cannot be certain what will be possible or impossible in the future.

Abhinav Lal
Writer & Investor

"Imagination is more important than knowledge"
Post by Mike Van Pelt
--
Mike Van Pelt | "I don't advise it unless you're nuts."
mvp at calweb.com | -- Ray Wilkinson, after riding out Hurricane
KE6BVH | Ike on Surfside Beach in Galveston
Dan Tilque
2019-05-31 22:05:25 UTC
Permalink
Post by a***@gmail.com
I am not a scientist, and the future of science is difficult to predict. But I believe we will continue to radically extend life, as we have already done so over the last century.
We've *never* radically extended lifespan. Or for that matter, extended
lifespan at all.

What has been extended is life expectancy, which is something a little
different. And all improvements in life expectancy have been
incremental, and so far, mainly done by reducing the various ways people
die young by accident or disease. If you add all these increments up,
the average life expectancy has improved dramatically over the last
couple hundred years, so that might seem to be radical. But that still
leaves lifespan about the same it was 200 years ago, or for that matter,
2000 years ago.
--
Dan Tilque
J. Clarke
2019-05-31 22:55:35 UTC
Permalink
Post by Dan Tilque
Post by a***@gmail.com
I am not a scientist, and the future of science is difficult to predict. But I believe we will continue to radically extend life, as we have already done so over the last century.
We've *never* radically extended lifespan. Or for that matter, extended
lifespan at all.
What has been extended is life expectancy, which is something a little
different. And all improvements in life expectancy have been
incremental, and so far, mainly done by reducing the various ways people
die young by accident or disease. If you add all these increments up,
the average life expectancy has improved dramatically over the last
couple hundred years, so that might seem to be radical. But that still
leaves lifespan about the same it was 200 years ago, or for that matter,
2000 years ago.
The 1947 CSO tables go out to age 100. The 2017 CSO tables go out to
age 120. There's enough people living to 120 to be a concern for
life insurance companies. And the biotech revolution hasn't really
gotten rolling yet.
Scott Lurndal
2019-05-31 22:59:28 UTC
Permalink
Post by J. Clarke
Post by Dan Tilque
Post by a***@gmail.com
I am not a scientist, and the future of science is difficult to predict. But I believe we will continue to radically extend life, as we have already done so over the last century.
We've *never* radically extended lifespan. Or for that matter, extended
lifespan at all.
What has been extended is life expectancy, which is something a little
different. And all improvements in life expectancy have been
incremental, and so far, mainly done by reducing the various ways people
die young by accident or disease. If you add all these increments up,
the average life expectancy has improved dramatically over the last
couple hundred years, so that might seem to be radical. But that still
leaves lifespan about the same it was 200 years ago, or for that matter,
2000 years ago.
The 1947 CSO tables go out to age 100. The 2017 CSO tables go out to
age 120. There's enough people living to 120 to be a concern for
life insurance companies.
But are the new CSO tables a function of a longer life expectancy (which
has IIRC decreased lately in the US of A) or a function of a larger population
base (almost 4-fold since 1947) in the actuary data?
Dan Tilque
2019-05-31 23:43:34 UTC
Permalink
Post by Scott Lurndal
Post by J. Clarke
Post by Dan Tilque
Post by a***@gmail.com
I am not a scientist, and the future of science is difficult to predict. But I believe we will continue to radically extend life, as we have already done so over the last century.
We've *never* radically extended lifespan. Or for that matter, extended
lifespan at all.
What has been extended is life expectancy, which is something a little
different. And all improvements in life expectancy have been
incremental, and so far, mainly done by reducing the various ways people
die young by accident or disease. If you add all these increments up,
the average life expectancy has improved dramatically over the last
couple hundred years, so that might seem to be radical. But that still
leaves lifespan about the same it was 200 years ago, or for that matter,
2000 years ago.
The 1947 CSO tables go out to age 100. The 2017 CSO tables go out to
age 120. There's enough people living to 120 to be a concern for
life insurance companies.
There's only one person who's lived to 120, and she was an extreme
statistical outlier. Anyone living over the age of 100 is an outlier;
it's just that with increased total population, there are more outliers.

When we have a radical increase in lifespan (not expectancy), the
average person will expect to live to 120 (or some other age above 100)
as long as they avoid accidents. This will take a technological advance
beyond improving the human environment (e.g. better water supplies,
sewers, better food supply, etc.) and typical health care (e.g. treating
diseases and injuries) which lead to the increased life expectancy up to
this point.
Post by Scott Lurndal
But are the new CSO tables a function of a longer life expectancy (which
has IIRC decreased lately in the US of A) or a function of a larger population
base (almost 4-fold since 1947) in the actuary data?
The decrease in expectancy is mainly attributable to the opioid
epidemic. That can be fixed with the right political environment (which
we mostly don't have right now). But some may be due to other factors:
pollution, decreased quality of the food supply, and changed lifestyle
(increased sedentarism and poor choice of diet). These will become more
significant in the future.

--
Dan Tilque
J. Clarke
2019-06-01 01:44:58 UTC
Permalink
Post by Dan Tilque
Post by Scott Lurndal
Post by J. Clarke
Post by Dan Tilque
Post by a***@gmail.com
I am not a scientist, and the future of science is difficult to predict. But I believe we will continue to radically extend life, as we have already done so over the last century.
We've *never* radically extended lifespan. Or for that matter, extended
lifespan at all.
What has been extended is life expectancy, which is something a little
different. And all improvements in life expectancy have been
incremental, and so far, mainly done by reducing the various ways people
die young by accident or disease. If you add all these increments up,
the average life expectancy has improved dramatically over the last
couple hundred years, so that might seem to be radical. But that still
leaves lifespan about the same it was 200 years ago, or for that matter,
2000 years ago.
The 1947 CSO tables go out to age 100. The 2017 CSO tables go out to
age 120. There's enough people living to 120 to be a concern for
life insurance companies.
There's only one person who's lived to 120, and she was an extreme
statistical outlier. Anyone living over the age of 100 is an outlier;
it's just that with increased total population, there are more outliers.
I didn't create the CSO tables. If you don't like them take the
matter up with the Society of Actuaries. Yes, living to be 100 is an
outlier but it is not nearly as much of an outlier as it used to be.
Post by Dan Tilque
When we have a radical increase in lifespan (not expectancy), the
average person will expect to live to 120 (or some other age above 100)
as long as they avoid accidents. This will take a technological advance
beyond improving the human environment (e.g. better water supplies,
sewers, better food supply, etc.) and typical health care (e.g. treating
diseases and injuries) which lead to the increased life expectancy up to
this point.
Or not as the case may be.
Post by Dan Tilque
Post by Scott Lurndal
But are the new CSO tables a function of a longer life expectancy (which
has IIRC decreased lately in the US of A) or a function of a larger population
base (almost 4-fold since 1947) in the actuary data?
The CSO tables tend to be conservative.
Post by Dan Tilque
The decrease in expectancy is mainly attributable to the opioid
epidemic. That can be fixed with the right political environment (which
pollution, decreased quality of the food supply, and changed lifestyle
(increased sedentarism and poor choice of diet). These will become more
significant in the future.
The "opioid epidemic" is another made-up crisis. If you're ever
suffering from chronic pain you'll find out how made-up it is.
David DeLaney
2019-06-03 10:52:25 UTC
Permalink
Post by J. Clarke
The "opioid epidemic" is another made-up crisis. If you're ever
suffering from chronic pain you'll find out how made-up it is.
Um, really most SINCERELY no.

The chronic pain sufferers who are using opiods just to get back to where they
can function without pain are NOT the "opioid epidemic" pill-mill customers and
extreme overusers. Do not conflate the two. ESPECIALLY do not conflate the two
with the aim of saying "there's no crisis at all, because SOME people actually
need opioids and use them as prescribed and responsibly".

Sheesh.

Dave, next you'll be telling us allergies aren't a real thing
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.
m***@sky.com
2019-06-01 08:45:58 UTC
Permalink
Post by Dan Tilque
Post by Scott Lurndal
Post by J. Clarke
Post by Dan Tilque
Post by a***@gmail.com
I am not a scientist, and the future of science is difficult to predict. But I believe we will continue to radically extend life, as we have already done so over the last century.
We've *never* radically extended lifespan. Or for that matter, extended
lifespan at all.
What has been extended is life expectancy, which is something a little
different. And all improvements in life expectancy have been
incremental, and so far, mainly done by reducing the various ways people
die young by accident or disease. If you add all these increments up,
the average life expectancy has improved dramatically over the last
couple hundred years, so that might seem to be radical. But that still
leaves lifespan about the same it was 200 years ago, or for that matter,
2000 years ago.
The 1947 CSO tables go out to age 100. The 2017 CSO tables go out to
age 120. There's enough people living to 120 to be a concern for
life insurance companies.
There's only one person who's lived to 120, and she was an extreme
statistical outlier. Anyone living over the age of 100 is an outlier;
it's just that with increased total population, there are more outliers.
When we have a radical increase in lifespan (not expectancy), the
average person will expect to live to 120 (or some other age above 100)
as long as they avoid accidents. This will take a technological advance
beyond improving the human environment (e.g. better water supplies,
sewers, better food supply, etc.) and typical health care (e.g. treating
diseases and injuries) which lead to the increased life expectancy up to
this point.
Post by Scott Lurndal
But are the new CSO tables a function of a longer life expectancy (which
has IIRC decreased lately in the US of A) or a function of a larger population
base (almost 4-fold since 1947) in the actuary data?
The decrease in expectancy is mainly attributable to the opioid
epidemic. That can be fixed with the right political environment (which
pollution, decreased quality of the food supply, and changed lifestyle
(increased sedentarism and poor choice of diet). These will become more
significant in the future.
--
Dan Tilque
My grandparents didn't last much past 70, and my Father's Father died of a heart attack, so my Father counted every year past 70 as a bonus. He died in his nineties, after the NHS had brought him through two heart attacks and two cancers (third cancer killed him). His elder brother will be 99 on New Year's eve, thanks partly to heart treatment, I think with a stent, plus a now standard cocktail of blood pressure and other heart medication. I think there are incremental increases in lifespan. For those that adhere to the resulting guidelines, I think the newly gained knowledge on the benefits of diet and exercise are also very valuable. Hygiene has also improved - my Father could remember meat being brought into the village on an open cart, and people dying young of TB - in fact his Mother died of TB when he was something like three or four. The woman I was brought up to think of as my Father's Mother was in fact a second wife.
Quadibloc
2019-06-01 02:46:12 UTC
Permalink
Post by Dan Tilque
We've *never* radically extended lifespan. Or for that matter, extended
lifespan at all.
What has been extended is life expectancy, which is something a little
different.
That's true enough, but it's not the same as saying we *never will*. Learning
about telomeres, having CRISPR, maybe even connecting some kind of neural net to
the brain so we can upload gradually into a "third hemisphere" so as to survive
biological death... possibilities are starting to emerge.

The thing is, spending 400 years on a voyage to Alpha Centauri without Internet
access is boring enough, but if you're an uploaded being that thinks, and
therefore lives, at a speed 1,000 times faster than a normal biological human
being, it's even worse. (Of course, suspended animation may be as easy as just
temporarily slowing your clock.)

So maybe a spaceship to Alpha Centauri... would carry people who don't need life
support, because they're uploaded into electronics the size of a matchbox... but
the ship is still large, because it has to carry a community of a million of
them, the size of a small country, in order to prevent them from going crazy
from boredom on the way there.

John Savard
J. Clarke
2019-06-01 02:57:06 UTC
Permalink
On Fri, 31 May 2019 19:46:12 -0700 (PDT), Quadibloc
Post by Quadibloc
Post by Dan Tilque
We've *never* radically extended lifespan. Or for that matter, extended
lifespan at all.
What has been extended is life expectancy, which is something a little
different.
That's true enough, but it's not the same as saying we *never will*. Learning
about telomeres, having CRISPR, maybe even connecting some kind of neural net to
the brain so we can upload gradually into a "third hemisphere" so as to survive
biological death... possibilities are starting to emerge.
The thing is, spending 400 years on a voyage to Alpha Centauri without Internet
access is boring enough, but if you're an uploaded being that thinks, and
therefore lives, at a speed 1,000 times faster than a normal biological human
being, it's even worse. (Of course, suspended animation may be as easy as just
temporarily slowing your clock.)
Whether AIs will actually think that quickly is an unknown. Just
having a high clock speed doesn't guarantee rapid response--ask any
Windows user. And we don't really know how an AI will work anyway. It
might not even be doable with digital technology.

In any case, that problem can be addressed by just turning down the
clock speed, or just stopping the clock altogether.
Post by Quadibloc
So maybe a spaceship to Alpha Centauri... would carry people who don't need life
support, because they're uploaded into electronics the size of a matchbox... but
the ship is still large, because it has to carry a community of a million of
them, the size of a small country, in order to prevent them from going crazy
from boredom on the way there.
a***@gmail.com
2019-06-01 03:18:53 UTC
Permalink
Post by Dan Tilque
Post by a***@gmail.com
I am not a scientist, and the future of science is difficult to predict. But I believe we will continue to radically extend life, as we have already done so over the last century.
We've *never* radically extended lifespan. Or for that matter, extended
lifespan at all.
Yes we have extended lifespan, which is "the average length of life of a kind of organism", according to one dictionary.

Abhinav Lal
Writer & Investor

"Imagination is more important than knowledge"
Post by Dan Tilque
What has been extended is life expectancy, which is something a little
different. And all improvements in life expectancy have been
incremental, and so far, mainly done by reducing the various ways people
die young by accident or disease. If you add all these increments up,
the average life expectancy has improved dramatically over the last
couple hundred years, so that might seem to be radical. But that still
leaves lifespan about the same it was 200 years ago, or for that matter,
2000 years ago.
--
Dan Tilque
David DeLaney
2019-06-03 10:48:47 UTC
Permalink
Post by Dan Tilque
We've *never* radically extended lifespan. Or for that matter, extended
lifespan at all.
"You got what everyone gets. You got a lifetime." -- Death, to an infant

Dave, endless Sunday afternoons
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.
Juho Julkunen
2019-06-03 15:46:56 UTC
Permalink
Post by David DeLaney
Post by Dan Tilque
We've *never* radically extended lifespan. Or for that matter, extended
lifespan at all.
"You got what everyone gets. You got a lifetime." -- Death, to an infant
I'm afraid I have to contradict you there. That sounds like Death's
answer to Bernie Capax in chapter three of _Brief Lives_:

"But I did okay, didn't I? I mean I got, what, fifteen thousand years.
That's pretty good. Isn't it? I lived a pretty long time."

"You lived what anyone gets, Bernie. You got a lifetime."

The only exchange with an infant I can recall off the top of my head is
in "The Sound of Her Wings":

"But... is that all there was? Is that all I get?"

"Yes, I'm afraid so."
--
Juho Julkunen
the equivalence is implied
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