Faster-than-light communication and earthshattering physics?

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Topic:	Science > Physics
User:	"mike3"
Date:	15 Mar 2007 01:22:05 AM
Object:	Faster-than-light communication and earthshattering physics?

Hi.
Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?
I was also curious about something else. I heard of this theory about
"tachyons", particles that supposedly go faster than light. I've also
heard that it is not possible to send stuff back in time and violate
causality with this. But is it possible to send information "forward"
in time with this, ie. like how normal communication works, except at
a speed
faster than light? If not, why not?
.

User: "greysky"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 08:15:40 AM

"mike3" <mike4ty4@yahoo.com> wrote in message
news:1173939725.454664.159750@o5g2000hsb.googlegroups.com...

Hi.

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

Of course. See: www.allocations.cc for the kind of thinking you need to
have to make a FTL radio.
Greysky

I was also curious about something else. I heard of this theory about
"tachyons", particles that supposedly go faster than light. I've also
heard that it is not possible to send stuff back in time and violate
causality with this. But is it possible to send information "forward"
in time with this, ie. like how normal communication works, except at
a speed
faster than light? If not, why not?

User: "Eric Gisse"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 08:29:33 AM

On Mar 15, 5:15 am, "greysky" <grey...@sbcglobal.net> wrote:

"mike3" <mike4...@yahoo.com> wrote in message

news:1173939725.454664.159750@o5g2000hsb.googlegroups.com...

Hi.

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

Of course. See: www.allocations.cc for the kind of thinking you need to
have to make a FTL radio.

So...how about showing a working model?
You have been spewing about "FTL radios" for years, yet no actual
demonstration exists...

Greysky

User: "mike3"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 05:32:18 PM

On Mar 15, 6:15 am, "greysky" <grey...@sbcglobal.net> wrote:

"mike3" <mike4...@yahoo.com> wrote in message

news:1173939725.454664.159750@o5g2000hsb.googlegroups.com...

Hi.

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

Of course. See: www.allocations.cc for the kind of thinking you need to
have to make a FTL radio.

Greysky

Have you built one? Could you give us a demonstration?
.

User: "BernardZ"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 02:55:06 AM

In article <1173939725.454664.159750@o5g2000hsb.googlegroups.com>,
mike4ty4@yahoo.com says...

Hi.

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

It would mean that you can pick any 2 of the 3 that you like as
something has to go.
Relativity
FTL
causality

Check out the discussion here on causality.
http://en.wikipedia.org/wiki/Tachyon
--
Magnificent and wonderous.
http://www.globalwarmingart.com/images/e/e5/Earth_Lights_from_Space.jpg
Observations of Bernard - No 110

.

User: "mike3"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 03:37:06 AM

On Mar 15, 12:55 am, BernardZ <berna...@Nospam.com> wrote:

In article <1173939725.454664.159...@o5g2000hsb.googlegroups.com>,
mike4...@yahoo.com says...

Hi.

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

It would mean that you can pick any 2 of the 3 that you like as
something has to go.

Relativity
FTL
causality

So then does this mean that if my hypothetical thing worked, that
if a hypothetical machine existed that could send a message faster
than the speed of light *without* time travel, relativity would have
to go. Since relativity is a well-proven theory, it probably won't go.
Relativity therefore _demands_ that such machines violate causality
-- they _must_ go back in time and hence are pretty much worthless
for communication even if we don't care about causality (the goal
of communications is not to talk into the past!). If we choose then to
accept causality along with relativity, the FTL machine must go.
Thus, it would be "earthshattering", as such a non-time-traveling
FTL machine, if built, would falsify current relativity theory in much
the same way that the construction of a perpetual motion machine
would falsify thermodynamics.
Am I spot on with all the above?

Check out the discussion here on causality.

http://en.wikipedia.org/wiki/Tachyon

So is my interpretation right, then, forward-in-time (ie. _non_-
causality
violating) communication with tachyons is impossible?

--
Magnificent and wonderous.

http://www.globalwarmingart.com/images/e/e5/Earth_Lights_from_Space.jpg

Observations of Bernard - No 110

User: "Jim Black"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 12:29:23 PM

On Mar 15, 3:37 am, "mike3" <mike4...@yahoo.com> wrote:

Not quite. Special relativity says that if you had a machine that
could communicate faster than light, you could turn it into a machine
that could communicate with the past by a suitable boost. So if you
built a faster-than-light communications device that could not be
altered to make a communication-with-the-past device, you would have
shown special relativity to be invalid.
--
Jim E. Black
.

User: "Ian Parker"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 06:49:08 AM

On 15 Mar, 06:22, "mike3" <mike4...@yahoo.com> wrote:

Hi.

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

I was also curious about something else. I heard of this theory about
"tachyons", particles that supposedly go faster than light. I've also
heard that it is not possible to send stuff back in time and violate
causality with this. But is it possible to send information "forward"
in time with this, ie. like how normal communication works, except at
a speed
faster than light? If not, why not?

Yes it would be Earth shattering. It would mean one of three things.
1) We would have established an Aether. Now having tried to get rid of
such a concept it has now cropped up.
2) One suggestion of avoiding the causality paradox is to have a many
world hypothesis. Personally - people may crucify me for this I do not
find it at all convincing. People talk about quantum many world.
Personally I simply view the QM computer as simply presenting a
Hamiltonian. That is to say we do not have many worlds, what we have
is an analogue computer that diagonalizes Hermetian matrices. I
challenge other people to argue that one!
3) We have a world in which past and future are bound up in a self
consistent solution. This is something that people seem unwilling to
explore. The orthodox view of tachyons is that they are reemmited as
they are abasorbed and do not convey any information. I wonder.
- Ian Parker
.

User: "Autymn D. C."
Title: Re: Faster-than-light communication and earthshattering physics?	17 Mar 2007 10:43:44 PM

On Mar 14, 11:22 pm, "mike3" <mike4...@yahoo.com> wrote:

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

Glue is fast; rockets are swift; humans are dolts; folks are
nescient. And "go" means "try", not "drift".
Apparently, it depends on semantics: http://google.com/groups?q=Autymn+VSL.

Yes, with VSL.
-Aut
.

User: "The Ghost In The Machine"
Title: Re: Faster-than-light communication and earthshattering physics?	18 Mar 2007 01:39:05 PM

In sci.physics, Autymn D. C.
<lysdexia@sbcglobal.net>
wrote
on 17 Mar 2007 20:43:44 -0700
<1174189424.410438.162790@e1g2000hsg.googlegroups.com>:

On Mar 14, 11:22 pm, "mike3" <mike4...@yahoo.com> wrote:

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

Glue is fast; rockets are swift; humans are dolts; folks are
nescient. And "go" means "try", not "drift".

Apparently, it depends on semantics: http://google.com/groups?q=Autymn+VSL.

Yes, with VSL.

-Aut

OK. Can anyone show variable speed of light in this
context? Thus far, all experiments are consistent with
general relativity, which among other things postulates
a constant c (within measurement error in the case of
Pound-Rebka-Snyder, since the unit of length at the top
of the tower is a very very teeny tiny bit different from
the unit of length at the bottom -- not enough to make
any difference, though; it's much less than gh/c^2).
--
#191,

Useless C++ Programming Idea #104392:
for(int i = 0; i < 1000000; i++) sleep(0);
--
Posted via a free Usenet account from http://www.teranews.com
.

User: "boson boss"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 11:39:19 AM

On Mar 15, 7:22 am, "mike3" <mike4...@yahoo.com> wrote:

Hi.

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

I was also curious about something else. I heard of this theory about
"tachyons", particles that supposedly go faster than light. I've also
heard that it is not possible to send stuff back in time and violate
causality with this. But is it possible to send information "forward"
in time with this, ie. like how normal communication works, except at
a speed
faster than light? If not, why not?

There is infinite room among the universes for all theories. Where do
you want to be?
.

User: "Sam Wormley"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 11:48:06 AM

boson boss wrote:

On Mar 15, 7:22 am, "mike3" <mike4...@yahoo.com> wrote:

Hi.

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

I was also curious about something else. I heard of this theory about
"tachyons", particles that supposedly go faster than light. I've also
heard that it is not possible to send stuff back in time and violate
causality with this. But is it possible to send information "forward"
in time with this, ie. like how normal communication works, except at
a speed
faster than light? If not, why not?

There is infinite room among the universes for all theories. Where do
you want to be?

As far as we are concerned, there is but one... and it has a
speed limit.
.

User: "Ian Parker"
Title: Re: Faster-than-light communication and earthshattering physics?	16 Mar 2007 11:26:56 AM

On 15 Mar, 16:48, Sam Wormley <sworml...@mchsi.com> wrote:

As far as we are concerned, there is but one... and it has a
speed limit.- Hide quoted text -

I'm going to throw another spanner in the works - Inflation. There is
one time when FTL travel did take place! Now the Big Bang expanded
into empty space. Empty space does not on the face of it violate
causality principles. How did the Big Bang "know" it was empty space?
There is a can of worms here!
- Ian Parker
.

User: "Greg Neill"
Title: Re: Faster-than-light communication and earthshattering physics?	16 Mar 2007 11:36:07 AM

"Ian Parker" <ianparker2@gmail.com> wrote in message
news:1174062416.492845.19510@l75g2000hse.googlegroups.com...

On 15 Mar, 16:48, Sam Wormley <sworml...@mchsi.com> wrote:

As far as we are concerned, there is but one... and it has a
speed limit.- Hide quoted text -

Not really. The Big Bang was an expansion of
space itself, not stuff into pre-existing space.
There was no space "there" before the BB (in fact
there was no "there" there either).
General Relativity places no restrictions on the
speed at which (distant) regions of space may have
with respect to one another.
.

User: "Sam Wormley"
Title: Re: Faster-than-light communication and earthshattering physics?	16 Mar 2007 11:41:58 AM

Ian Parker wrote:

Ian--Neither inflation nor the current expansion of the universe
violates the speed of light as no two bodies can be observed to
have velocity greater than (or even equal to) c... now or in the
past.
.

User: "G. L. Bradford"
Title: Re: Faster-than-light communication and earthshattering physics?	17 Mar 2007 06:24:35 AM

"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:qNzKh.20121$y92.11362@attbi_s22...

Ian Parker wrote:

Ian--Neither inflation nor the current expansion of the universe
violates the speed of light as no two bodies can be observed to
have velocity greater than (or even equal to) c... now or in the
past.

It isn't even based upon what you speak of, Samantha. It is based upon
amount of contraction versus amount of expanse (EXPANSE!) in the universe at
whatever the distance observed, which should return c. Also straight-line
distance in light-TIME observed between here and any there, especially the
farthest reaches of the universe [observable in space-TIME!], which should
return c as [the overall average speed factor].
The relative velocity of subjective light-TIME space-TIME objects
[observed] is . . . well . . . relatively subjective rather than ABSOLUTE!
or anything having to do with OBJECTIVITY.
And one more thing. Any object OBSERVED to be going away from the OBSERVER
at 1/2c should in fact be doing c. Any object observed to be traveling away
from the observer faster than 1/2c should in fact be traveling faster than c
relative to the observer.
If an object averages a speed of c to a observed destination observed to
be ten light years from the observer, and reaches it [from] here as point of
origin, the observation made of arrival at destination would be an
observation made twenty years after departure, or ten years after actual
arrival. Whether you know it or not, Samantha, it takes ten years for light
to travel here to the observer from a point ten light years from here. Two
way, AB | BA, the traveler takes ten years to there, the light [at time of
arrival there] takes ten years from there this way to reach here to the
observer telling the observer, observationally, that the traveler just
reached the destination right then according to the observer's time. Though
that traveler would be seen to be ten years younger than if he were standing
beside the observer. And the traveler's perfect time keeping piece would
show a time just about precisely ten years off and before current time
according to the observer's perfect time keeping piece. The observer might
think it and the traveler had LOST ten years in time enroute on a voyage
that [observably] took TWENTY years to make, relative to the observer's
observation of voyage time, that is. An observed [relative] velocity -- for
a ten light year run -- of 1/2c.
But of course science, especially your science, is not based upon anything
like "observers" and their "observations" made using the speed of light as
base for such observations. Particularly it is not based upon anything "two
way," such as traveler that way (AB) and light this way (BA), or traveler
this way (BA) and light this way (BA). Your observer never suffers from time
lag between space-TIME of point of propagation of light and TIME of
observation made.The traveler never travels one silly millimeter on in his
voyage until the exact second in time the observer at any distance from him
will observe his exact relative [position] at any distance thus to be able
to calculate his exact relative [velocity].
But that is not the way it really works. Calculating velocity is based
upon observing in some way position of the thing being observed at velocity.
If the thing being observed is actually positioned twice the distance away,
going away, from the observed position, the actual velocity of the thing
will be around twice the velocity (herein, "1/2c") observed for it.
Oncoming (BA) is such a vastly different story it is almost mindnumbing
trying to figure out the observer's observation of it, if any observation
could even possibly be made concerning it, that is. I've tried several times
and each time I find it, my visualization, corrupted badly in some way.
Split out in some way because in the traveler's own frame, c will be normal
even when a transmission of light is made forward of the traveler doing c or
better -- relative to any observer forward of the traveler, that is. If such
observer can make such observation of such a traveler actually doing c or
better relative to him, then the observer would have to observably position
the traveler, per light being propagated at c from the traveler doing c
relative to..., well forward in space-TIME of the traveler's actual position
in order to give the traveler a relative velocity something less than c. The
observer would have to observe the subjective traveler to be closer in
light-TIME space-TIME to him than the objective traveler really,
[objectively], is. Yet observe him to be much younger than he really is, and
aging much faster than normal for such OBSERVED (subjectively apparent)
slowness oncoming.
Observing a subjective traveler going away into an observable past in
going away from the observer is so easy to picture. It's the one even
competent physicists picture as time slowing down for the traveler. Not the
virtual traveler actually being observed, but the real traveler even though
that object traveler can never be obseved, just the subjective virtual
traveler always this side of the real (objective) traveler can ever be
observed, regardless of what you believe, Samantha. That same subjective
traveler, versus the objectively real traveler, oncoming from out an
observable light-TIME-distant past toward the now of the observer, at c or
better, as the real traveler sustains and measures c as c locally and
presumes it in transmissions out from, is a little harder to picture. To
drop the relative velocity -- to be observed -- down below c, especially
down well below c, then the subjective virtual traveler, always the observed
traveler, has to be to be observed as being much closer in space to the
observer, thus observed to be traveling much slower in velocity, than the
real traveler oncoming at c or better (relative to the observer) would be.
GLB
.

User: "Ian Parker"
Title: Re: Faster-than-light communication and earthshattering physics?	16 Mar 2007 12:28:15 PM

On 16 Mar, 16:41, Sam Wormley <sworml...@mchsi.com> wrote:

Ian Parker wrote:

Ian--Neither inflation nor the current expansion of the universe
violates the speed of light as no two bodies can be observed to
have velocity greater than (or even equal to) c... now or in the
past.

I am aware of the fact that space itself was expanding and that no 2
points were ever seen to be moving apart FTL - True.
Suppose however that a Universe statred within another. I suppose what
would be observed would be the shifting of objects we had been
obersving beyond an event horizon.
- Ian Parker
.

User: "Uncle Al"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 10:52:31 AM

mike3 wrote:

Hi.

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

I was also curious about something else. I heard of this theory about
"tachyons", particles that supposedly go faster than light. I've also
heard that it is not possible to send stuff back in time and violate
causality with this. But is it possible to send information "forward"
in time with this, ie. like how normal communication works, except at
a speed
faster than light? If not, why not?

FTL communication violates causality. The universe does not tolerate
contradiction.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2
.

User: "Dwib"
Title: Re: Faster-than-light communication and earthshattering physics?	16 Mar 2007 03:01:55 PM

On Mar 15, 10:52 am, Uncle Al <Uncle...@hate.spam.net> wrote:

FTL communication violates causality. The universe does not tolerate
contradiction.

Is there is brief explanation as to why FTL communications violates
causality?
Dwib
.

User: "Androcles"
Title: Re: Faster-than-light communication and earthshattering physics?	16 Mar 2007 05:11:39 PM

"Dwib" <dwibdwib@gmail.com> wrote in message =
news:1174075315.159258.47450@l77g2000hsb.googlegroups.com...

On Mar 15, 10:52 am, Uncle Al <Uncle...@hate.spam.net> wrote:

FTL communication violates causality. The universe does not tolerate
contradiction.

=20
Is there is brief explanation as to why FTL communications violates
causality?
=20
Dwib

Yes. Al Schwartz (aka Uncle Fuckwit) is psychotic.
.

User: "mike3"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 05:31:32 PM

On Mar 15, 8:52 am, Uncle Al <Uncle...@hate.spam.net> wrote:

mike3 wrote:

Hi.

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

FTL communication violates causality. The universe does not tolerate
contradiction.

I was asking: What if one discovered a hypothetical machine that could
go faster than light WITHOUT traveling back in time? Would this be an
earthshattering discovery, falsifying relativity? Not that this is
impossible,
as it's still possible that somewhere relativity breaks down, but not
very likely. This is a purely hypothetical exercise.

--
Uncle Alhttp://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)http://www.mazepath.com/uncleal/lajos.htm#a2

User: "Sam Wormley"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 08:11:31 AM

mike3 wrote:

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

No
.

User: "Sam Lloyd"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 08:39:32 AM

mike3 wrote:

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

FTL communications would mean that you saved some time:
You sent something faster than the speed of light
so you saved some time.
If you saved some time you should be able to use that time.
You could use it to do work (expend energy)
but physicists don't see any evidence of such surplus time
being used. If there was surplus time we would also
find surplus energy.
In one situation where the idea of FTL is used,
it has to pay back the gained time before it can be used.
It does this by sending the virtual energy that it represents
back in time. This is only done only in calculations.
It's a fudge.
The only reason a fudge is necessary is because there's a
blind spot where the Heisenberg Uncertainty is working and
physicists can't measure what's going on in that area.
So they trade-off knowledge of time for knowledge of energy.
But outside of the blind spot everything measured shows
that there is no evidence of surplus of time and corresponding
surplus of energy that would be created by FTL.

Everything totals up nicely. If it didn't total up nicely
Einstein's theory would have been tossed out a long time ago.
Causality and Information
http://people.cornell.edu/pages/jag8/causal.html
"The more energy borrowed, the faster it must be paid back.
This virtual component of time may be construed as "wrong-way" time,
that is, time running into the future rather than the past.
Thus virtual energy is borrowed from the future and immediately
paid back (always faster than light speed, ct) in the present.
This is the only physically acceptable way to think of time reversal,
and it is strictly contained within Heisenberg's "Uncertainty Relation",
which is also obeyed by Feynman's "path integrals"
(where it is expressed as the canceling of oppositely directed vectors)."
.

User: "Ben Rudiak-Gould"
Title: Re: Faster-than-light communication and earthshattering physics?	15 Mar 2007 09:33:56 AM

mike3 wrote:

Would a hypothetical faster-than-light communication system that did
_not_ go back in time be a physics-shattering discovery, if it was
possible?

Your question presupposes that relativity predicts that a faster-than-light
signal would go back in time, which isn't true. Any sort of
faster-than-light communication system would be big news.

I was also curious about something else. I heard of this theory about
"tachyons", particles that supposedly go faster than light.

A tachyon isn't a particular kind of faster-than-light particle, it's just a
generic word for faster-than-light particles wherever they come up. So
there's no theory of tachyons, but there are theories that predict
tachyons---which makes them failed theories, since there don't seem to be
any tachyons.
-- Ben
.

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