The repeating day problem

D

Designer

Temporal Navigator
The repeating day problem.

Tell me the solution to this problem if time travel
is possible; to the repeating day problem.

The only way time travel is possible is that every
single day must constantly repeat forever so you can
visit it at any time.

So if the day constantly repeats then there would be
a build up of physical mass in the past; that's a problem.

If the past repeats itself it maybe not an exact
match thus a divergence due to loss of information
for the repeating day. A loss of information could
be as simple as a time traveler pick up 10 dollar
bill in which a poor person should have taking it to
buy a meal from it; thus a loss of information caused
by the time traveller.

The problem with the repeating day is there is no
mechanism for the day to constantly repeat if I am right.

There can be no mass in the past since all the mass
is in the present where it belongs thus no repeating
day is possible.

But note you need a repeating day if you wish time
travel to work or else there is nothing back there
to go to.

Any comments.

Thx.

PS. If time travel is possible then there will be a build
up in mass in the past. Maybe this is why this planet is
gradually expand which shows up in plate movements or is
this the creation of dark matter? LOL. /ttiforum/images/graemlins/confused.gif
 
Designer,

If the past repeats itself it maybe not an exact
match
Click to expand...

If mass built up in the past then every instant would be unique. This assumes that there is no singularity, that is, the mass didn't suddenly appear from all of those "changing" instants at one place simultaneously. If it did all appear simultaneously then a gravitational singularity forms and that location in spacetime literally disappears from our universe (as defined by black hole mechanics) behind an event horizon.

That is probably not what would actually occur because we are thinking in terms of normal physics in a situation where quantum mechanics takes over.
 
The problem with mass with respect to time travel.

The only way it can work for time travel to the past is that mass
will come into being when there is an observer or else nothing
will be there just a place holder that exists.

I believe mass moves along the time line and does not exist
in the past thus time travel is impossible due to the theory
of conservation of mass and thus all past moments in time do
not have mass.

I hope I am clear in stated these points by say time travel
is impossible since there is nothing to go back there because
all mass is in the present and not the past so all mass in
accounted for in the present can't be two places at once.
 
Sorry for the last unclear post.

All I wish to say is mass travel with you into the future and does not exist in the past that all. Thus time travel is impossible.

Thx.
:D
 
I hope I am clear in stated these points by say time travel
is impossible since there is nothing to go back there because
all mass is in the present and not the past so all mass in
accounted for in the present can't be two places at once.
Click to expand...

There is an existing principle that already covers that.......the conservation of mass/energy.
 
Twilight,

As I said above my analysis is "probably" not correct. In fact its stronger than that. It is incorrect. I was making a locical extension of Designer's analysis.

Time travel to the past is probably not possible but we aren't completely sure. It would be wrong to say that it is impossible but there are many, many problems that pop up with the physics, even though General Relativity has time travel solutions, that pose unsurrmountable problems so far as the present state of physics is concerned (not to mention any extension of physics that we can currently imagine).

That all being said we can't really fall back on concervation of mass/energy. In pre-relativistic Classical physics conservation of mass/energy/momentum is universal. Not so, globally, in General Relativity. It is globally conserved in flat spacetime and locally if you're using differential calculus because you treat each step as you differeniate your problem as an unfinitesimally tiny slice of spacetime - so tiny that it is flat. But that's not surprising because flat spacetime is Newtonian spacetime.

If on the other hand you are in a curved spacetime problems with conservation become apparent. Straight differential calculus no longer applies if you want to solve problems in General Relativity. The proper math is analytic geometry - geometry expressed in terms of differential (especially partial differential) calculus and integral calculus. The conservation laws no longer strictly hold. When you try to "parallel transport" your frame (basically move your coordinates straight across, up, down) in curved space the coordinates change. The symmetry that was present in flat spacetime is lost and the new frame is different than the original.

I don't want to attempt to get deeply into the math because it's boring
but a little online research on "conservation of mass in general relativity" will yield dozens of articles.
 
Twilight,

I'd add that when we talk about General Relativity on a site like this we're speaking as rank amateurs - that includes me.

General Relativity is complex - really, really complex. It actually does require a PhD in General Relativity to talk about the subject with any real authority. You've probably seen the Einstein equation for GR at some time. To give you an idea just how complex it is there's a term in the equation "G", the Einstein curvature metric. Obviously "G" is shorthand for something else. Within the full explicit form of "G" there is the Ricci tensor "R". The Ricci tensor had 60 individual expressions in it that include partial differentials. It took decades for Einstein and many others to partially solve the equation. It still hasn't been fully solved else we would fully understand gravity.
 
I think we are all a little to close
to the math. A lot of Einstein work
could have been resolve with thought
experiments.

A simple though experiment will resolve
these problems. If mass flows with
you along time there can be no grandfather
paradox or the ability to see yourself in the
past since you exist as a point on a time
graph and not as line on a graph. Therefor
time travel is impossible.

If mass continually build up over time for example
a non moving rock we would find that gravity
would build up at that point; but in reality
this never happen. But note a simple test could be
conducted and prove this with an accelerometer
to detect a gradual increase in gravity over time.
Please remember gravity transcends space and time and
over all dimensions. We would thus notice a rock
gravity around it would get really strong at that
one place. But note this never happens.

Thx.
 
I understand what you're saying, but I feel your argument is flawed. Blah blah. Conservation of mass/energy says something like:

dm/dt + dE/dt = 0
for all times t

So if at some future time t(f) you transport some mass back to a past moment t(p), you get:

at t(f):
dm/dt < 0 because the mass doesn't exist there anymore
dE/dt = -dm/dt > 0

so energy is expended at the future time. Meanwhile in the past:

at t(p):
dm/dt > 0 because mass has suddenly appeared
dE/dt = -dm/dt < 0

so the mass has very low energy when it arrives in the past (it may be cold, or energy in the past may be converted to the new mass).

Don't worry if it doesn't make sense. I'm hungover. :D
 
I just realized I didn't do the equation right (different units). Ummm... Try this:

(c^2)dm/dt + dE/dt = 0
E = .5 m v^2

dE/dt = P = power
and the first part is mass flow into or out of a moment in time.
 
so the mass has very low energy when it arrives in the past
Click to expand...

Hmm. What happens if I transport my watch back to yesterday ? There are then two watches...made from the same atoms. That's an aspect of time travel to the past that is clearly a paradox. Unless the original watch disappears.

If you replace the original atoms with the ones from the future, you then have a nice little loop. As the future watch would not arrive at the same place as the original.....the effect to someone in the past would be the same as if the watch had been teleported somewhere else, it would just disappear and arrive somewhere else.

That also hints at a possible link between teleporting and time travel.
 
It's not a paradox. It's just not they way we're used to thinking about things. There's no need for the original atoms to disappear, either. It would simply create the illusion of instant, non-localized causality. What I mean by that is you could smash the "original" watch, and instantly the one which was transported to the past would change forms (to be smashed). In reality, when you smash the original watch, it goes forward in time as usual up until the point where it's sent to the past. Then a smashed watch is sent back in time instead of a shiny new one. Or, perhaps, we decide to send back a different watch instead, since the original one is broken. :oops:
 
It's not a paradox.
Click to expand...


Well, paradoxes in travelling to the past are inescapable.

If I time travel to yesyterday, then there are two of me.....including one who was not originally there yesterday. If I had successfully travelled back to yesterday, then why didn't the me alive yesterday originally meet the time traveller from today ?

People think that timelines get round this....but they don't. If I always have to travel back to a different timeline.....it's really not a problem to arrive back at my own, it just involves another step. I simply travel back to yesterday in a different timeline, wait a day until it is 'today'.....then there is nothing to stop me travelling back to 'yesterday' in my original timeline ( which is now effectively a different timeline ).
 
Paradoxes are a philosophical problem, not a scientific one. They stem from the notion that time is immutable and therefore bound to a single static logical flow of cause and effect from an individual perspective bound to linear time. Let's focus on the physics and ignore the philosophical difficulties which arise, as they will work themselves out once time travel is realized in actuality. :D
 
TimeLord

So the mass has very low energy when it arrives in the past.
Click to expand...

If there is lower energy in the past then mass is lower too so what happens is we all shrink in size. I don’t think so if there is lower mass in the past there is "no past” since this would result in a loss of information in relation to mass.

So in conclusion it will be impossible for anything to exist there (Past) due to loss of information.
 
TimeLord

dE/dt = P = power
and the first part is mass flow into or out of a moment in time.
Click to expand...
If mass enters and exits constantly over time
the only way this is possible to make an identical
match(person) is though quantum entanglement.

In other word you don't need to shrink as a person
when mass leave your time. Quantum entanglement
is the only way to preserve mass information entanglement
when new mass enters a person body or else we will all
turn into frogs.

thx.
 
The only way time travel is
possible is if one partical
can be two places at one.
One partical in the past and
the other in present thus the
conservation of mass would stay
true. My question is what does
Quantum Mechanics say about
particals; with one partical in two
places at the same time. If
Quantum Mechanics say this is true;
time travel is then possible, /ttiforum/images/graemlins/confused.gif
 
Had a bad writing day again.

All I am trying to say is if
quantum mechanics say a partial
can be two places at once then
the conservation of mass can stay
true and thus mass can stay in the
past as well as the present at
the same time. In conclusion people
can visit the pass because mass
would be there to visit at any time.
/ttiforum/images/graemlins/smile.gif
 
To my knowledge, quantum mechanics say nothing about the nature of time itself. It simply treats time as an independent variable, much like classical mechanics. You will see, at least in elementary teachings, there is a time-dependent and time-independent schrodinger wave equation. The former treats time as an independent (and therefore assumed to exist) variable, and the latter says nothing about time at all. Unfortunately, unless there is a spectacular QM equation of which I do not know (very likely), then QM won't help with time travel yet. New theories are needed. Isn't that exciting? There's still stuff to discover. /ttiforum/images/graemlins/smile.gif
 
All I am trying to say is if
quantum mechanics say a partial
can be two places at once then
the conservation of mass can stay
true and thus mass can stay in the
past as well as the present at
the same time.
Click to expand...

QM doesn't actually say that a particle can be in two places at one time. What it says that there is a fundamental uncertainty about particles' positions (the Uncertainty Principle). You can measure the position with extreme accuracy but only at the cost of having the momentum of the particle tend to infinity. Conversely, you can measure the momentum to extreme accuracy but at the cost of having the position of the particle spreading out to infinity.

And I believe that both TimeLord and I can both see that you're struggling with the word "time" in describing your position as it involves time travel. Don't feel too bad about that. Real physicists struggle with the concept because it is very define to try to describe how "time" as something that has some sense of motion and itself changes - without using the term "time" in the definition. i.e., physicist So-and-So defines time as something with "momentum" that changes over time. (Not a real definition - just an lame example that I made up on the fly. /ttiforum/images/graemlins/smile.gif) Maybe a better example is the first sentence in this post:

QM doesn't actually say that a particle can be in two places at one time
Click to expand...

You just read a very good post by TimeLord that explains that the concept of time in QM is different than in classical physics - yet you and I are forced by the limits of our language to use the term in describing our intent in our posts about QM. So we're both laboring with the concept of a subatomic particle being in two places simultaneously in a QM setting where the concept of time is somewhat vague in QM.
 
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