Rex wrote:
Can you describe time in
such a way that it can make time travel makes sense (theoretically
speaking)?

Sure. One can "go back in time" via MEMORY. This explicitly displays the
limitations: you can only go back to times and events YOU have
experienced, the going back is imperfect (sometimes wildly so!), and you
are powerless to change anything. Of course memory aids like books and
movies can make the experience far more vivid, and can permit you to "go
back in time" to events other people have experienced.

Now contrast this to dreams. And to fiction....


Tom Roberts

On Aug 24, 8:19 pm, Rex wrote:
They say time is what the clock measures and time is something
that has already happened. But i've been continued puzzled about
what time really is. How come physicists explore the possibility of
time travel. How can you go back to the past when it has already
happened. In newtonian argument, it may be as plain as this. But
in light of SR and GR. Time seems to be something more and
has an almost magical quality to it. Can you describe time in
such a way that it can make time travel makes sense (theoretically
speaking)?

There is nothing magical about it at all. Time is the
extra fuel the looser of a drag race rolls over the
finish line with.

invariance with respect to time translation
gives the well known law of conservation of energy
http://en.wikipedia.org/wiki/Noether's_theorem

Sue...



Rex

"Dr. Planckenstein" escreveu na mensagem
...


Time is dimension and nothing more than that, it is just that simple.

Agree.

Time is the 4th dimension and in my opinion it is probabilistic, as is
length.

Time is probabilistic? That's new.
Since time plays a major role in Physics, if time is probabilistic, as you
say, notice that momentum should be probabilistic, force should be
probabilistic, energy probabilistic, power probabilistic and everything must
be probabilistic.
I don't agree due to the obvious reasons.

Furthermore, in my opinion, there is no need for the concept of energy if
one can manipulate dimension properly to model waves etc, mathematically.

Yes, energy is just a tool, not physical.

And I personally dont think that anything whatsoever exists at all aside
from dimension and waveforms which propagate in it.

This one is very deep.
What we see, in a given moment, is what had existed some time ago, not
what really exists now. It happens because light takes time to reach us.

Androcles wrote:
[snip]
Nothing.

Androclitty in physics is a blind man trying to navigate with a
sextant in a rainstorm. Hey Androclitty, who turned the ocean
upside-down?

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

Androcles wrote:
[snip]
Nothing.

Androclitty in physics is a blind man trying to navigate with a
sextant in a rainstorm. Hey Androclitty, who turned the ocean
upside-down?

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

"Uncle Al" wrote in message
...

Hey cretin!

--
'we establish by definition that the "time" required by
light to travel from A to B equals the "time" it requires
to travel from B to A' because I SAY SO and you have to
agree because I'm the great genius, STOOOPID Jew, don't you
dare question it. -- Rabbi Albert Einstein,
who in 1895 failed an examination that would have allowed
him to study for a diploma as an electrical engineer at
the Eidgenössische Technische Hochschule in Zurich
(couldn't even pass the SATs).

"Counterfactual assumptions yield nonsense.
If such a thing were actually observed, reliably and reproducibly, then
relativity would immediately need a major overhaul if not a complete
replacement." -- Tom Roberts.

"Uncle Al" wrote in message
...

Hey imbecile!

--
'we establish by definition that the "time" required by
light to travel from A to B equals the "time" it requires
to travel from B to A' because I SAY SO and you have to
agree because I'm the great genius, STOOOPID Jew, don't you
dare question it. -- Rabbi Albert Einstein,
who in 1895 failed an examination that would have allowed
him to study for a diploma as an electrical engineer at
the Eidgenössische Technische Hochschule in Zurich
(couldn't even pass the SATs).

"Counterfactual assumptions yield nonsense.
If such a thing were actually observed, reliably and reproducibly, then
relativity would immediately need a major overhaul if not a complete
replacement." -- Tom Roberts.

"JM Albuquerque" wrote in message
...

"Dr. Planckenstein" escreveu na mensagem
...


Time is dimension and nothing more than that, it is just that simple.

Agree.

Time is the 4th dimension and in my opinion it is probabilistic, as is
length.

Time is probabilistic? That's new.
Since time plays a major role in Physics, if time is probabilistic, as you
say, notice that momentum should be probabilistic, force should be
probabilistic, energy probabilistic, power probabilistic and everything
must
be probabilistic.
I don't agree due to the obvious reasons.


Correct. And that it how I would justify the Heisenberg Uncertainty
Principle.

I think that momentum, force, power and energy are all probabilistic on the
quantum scale. Assuming that they still have meaning.

The argument is very simple. Consider a segment divided up into individual
Plancklengths. There is no reason why one configuration would make more
sense than another, so let it be indeterminate, a blur.

So, while it might make sense to mark off graduations like a ruler which are
each 1 Plancklength long, it makes just as much sense to blur the whole
thing and let length be probabilistic. From there things get more
interesting.

But length, being equivalent to time according to SR, means that time is
also probabilistic. And this view seems to explain Paulus' femtosecond
interference experiments. Unless you wish to believe that there are "slits
in time" ? Or that the past can interfere with the future ?

http://faculty.physics.tamu.edu/ggp/





Furthermore, in my opinion, there is no need for the concept of energy
if
one can manipulate dimension properly to model waves etc,
mathematically.

Yes, energy is just a tool, not physical.

And I personally dont think that anything whatsoever exists at all aside
from dimension and waveforms which propagate in it.

This one is very deep.
What we see, in a given moment, is what had existed some time ago, not
what really exists now. It happens because light takes time to reach us.

"Dr. Planckenstein" escreveu na mensagem
. ..

"JM Albuquerque" wrote in message
...


Time is probabilistic? That's new.
Since time plays a major role in Physics, if time is probabilistic, as
you
say, notice that momentum should be probabilistic, force should be
probabilistic, energy probabilistic, power probabilistic and everything
must
be probabilistic.
I don't agree due to the obvious reasons.


Correct. And that it how I would justify the Heisenberg Uncertainty
Principle.

I think that momentum, force, power and energy are all probabilistic on
the
quantum scale. Assuming that they still have meaning.

The argument is very simple. Consider a segment divided up into individual
Plancklengths. There is no reason why one configuration would make more
sense than another, so let it be indeterminate, a blur.

So, while it might make sense to mark off graduations like a ruler which
are
each 1 Plancklength long, it makes just as much sense to blur the whole
thing and let length be probabilistic. From there things get more
interesting.

But length, being equivalent to time according to SR, means that time is
also probabilistic. And this view seems to explain Paulus' femtosecond
interference experiments. Unless you wish to believe that there are "slits
in time" ? Or that the past can interfere with the future ?

I thing you have a strong point here.
You have just explained why SR and QM are incompatible.

Taking this subject a little bit further, one can say that gravity should
also
be probabilistic, since gravity is an accelerations it depends on time
squared.
How do you figure that probability squared?

I'm not an expert in QM, nor SR. My field is classic mechanics
(speciality on the gyroscope and harmonic oscillators, in all of which SR
fails because it doesn't work on accelerated frames of reference).

Looking at Paulus' femtosecond interference experiments:
http://faculty.physics.tamu.edu/ggp/
I say that it looks like resonance.
The laser is an harmonic oscillator and then it is phase-dependent, so
it looks like much as a resonance phenomenon.
But photons don't have mass, so they can't have inertia and so cannot
have or induce resonance (without inertia no-resonance).

On Aug 24, 5:19 pm, Rex wrote:
They say time is what the clock measures and time is something
that has already happened. But i've been continued puzzled about
what time really is.

Viewpoints differ on that.

How come physicists explore the possibility of
time travel.

Because it's "theoretical" physics, hypotheses, thought
experiments. Something new might be learned, even if
it may not actually have to do anything with actual
time travel.

How can you go back to the past when it has already
happened.

Time travel is in no way considered a proven fact.

In newtonian argument, it may be as plain as this. But
in light of SR and GR. Time seems to be something more and
has an almost magical quality to it. Can you describe time in
such a way that it can make time travel makes sense (theoretically
speaking)?

Rex