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Can Time Flow Backwards?
PD writes "Exoscience has a story about the possibility that in some regions of space, time can actually flow backwards. Eggs would unbreak, supernovae would unexplode into stars, and living things would grow younger. I wonder if it makes hair grow back."
Correct, but it is still a problem as to how we perceive the reverse-time.
If we view time as moving away from boundry conditions, and the other state views them as moving away from their boundry conditions, but towards those defined for our spacetime, then we each perceive time as as moving forward for each other, but backwards with respect to the other.
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No, not once you accept that effect does not necessarily follow cause.
The "motion" of electrons is one example. It is difficult to predict where they are at any one moment, sometimes they can be considered to be in several places at once.
If you need an easier example, just run a videotape backwards. You can see things "unhappening" in front of you. We won't see any of these things happen in our universe, but if they did, that's what it would look like.
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Before your head explodes, read the following explanation why the universe has 4 dimensions, not 7 or some other number.
--LP
Before your head explodes, read the following explanation why the universe has 4 dimensions, not 7 or some other number:
;-)
http://www.hep.upenn.edu/~max/dimensions.html
--LP
Maybe time is already flowing backwards at the macro level and we just aren't aware of it. The apparent bizareness of quantum physics could be caused by the fact that quantum events and macro events are occuring with different temporal arrows.
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This is something that I just haven't been able to make sense of. How can time go "backwards"? Isn't the whole concept of "backwards" relative to time?
That is, you'd need some concept of "time" outside of our time by which the flow of our time could be viewed as "backwards". Or would you?
Am I making any sense here?
Well until now there is no problem, since you're forcing the particles to go back in time (in the thermo dynamic sense). But the amazing thing is that regions where future condition could co-exist with regions with past conditions and exchange information without damaging the time arrows.
Well matter going from chaos to order is reverse time in the thermo dynamic sense, but as said there are other ways to define time. For instance you can define past everything that you can remember. The passage of time can be defined by memory and you percieve time passing by comparing what you see with your memory of a few seconds ago.
Even time units are defined by "memory", since they are defined by events that repeat, like for instance the tic-tac of a clock. You can only define this because you have some kind of memory that this event has happen before.
Now my question for the author of this article would be, if someone would step into erverse time regions, would this unfurtunate person begin to forget past events, as it grows younger? That would be in my definition of time a reversed time arrow. If this is true in both directions, than would this be enougth to prove that the two time arrows are in fact one?
Please notice that my definition of memory is more abrangent than simply biological, it could mean computer memory or any other way to store information.
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So if time went "backwards" we wouldn't notice it. And it may be going backards, we just percieve it as "forwards". Or perhapse there is no time Just an "IS" but are Minds can not handle that concept, so we percieve time as a "flow".
I would like to see some other terms used instead of Forward and backward when we talk about time. Those terms belong to other dimensions, not to time. Of course, I can't think of any, but I'm not a world class physics geek.
HOW to travel through time:
jump to the left,
and Step to the right
put your hands on your hips,
tuck your knees in tight
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paradox would preclude you ever entering. The border'd be like the lint trap of the universe.
:-) Since your entry would be reversed once you leave, you'd be trapped again.
Here's an example:
You fly towards the zone of reverse time. Upon crossing the border, you go "back" in time, and reverse your newtonian motion back over the line. Once in "forward" zone, you get normal newtonian mechanics pushing you back in, ad nausieum.
If you wanted to leave in the reverse zone, you'd have to be in it already (good luck!), and you'd have to be reversing along to your entry point. Otherwise, the flow of time would be in defience of itself
So before you go boldy reversing where no one has reversed before, you have to understand that you're either in it or not, relatively speaking, as your frame of reference would preclude you ever jumping to an alternate time stream/zone. If you were born there, we seem reversed. Vice versa. And there's no way to pass messages or objects, so there'd technically be no way for things to escape. Perhaps black holes are partially pockets of antitime?
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However, in my limited experience, I can definiately say 2 things:
My hot load of jizz can't flow backwards
First Post
There is a theory which states that if anyone ever discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable.
I wasn't entirely clear how he got around that whole "Second Law of Thermodynamics" problem. From my understanding, entropy increases because all possible microstates of a system are equally likely, and the greatest number of microstates correspond to the most disordered macrostate (basically, that there exist more ways for a collection of air molecules to be scattered around a room than for them to be in a small box...this isn't even physics, it's math/statistics). So how does this become no longer true? Anyone who knows a little more about this theory care to enlighten me?
Sure I get the part that Object A will travel distance X, while Object B will travel distance Y.
If I throw an object it ends up somewhere else.
But I don't understand the part that you can suddenly get them to move "back". Does the "before" actually exist anymore? Seems rather strange if it does.
What if the multiverse thing holds true? In one multiverse someone goes backwards in time, but not in the other? Can that work?
What am I missing? Any pointers to proof that there is a "Before"?
Link.
I see his point that future boundary conditions imply regions of space where the arrow of time appears reversed. But, he's wrong in suggesting that the fact that a future crunch with all of the matter in the universe condensed means a highly ordered state. Hawking states that it is a highly disordered state and differs from the initial conditions of the Universe whice were in a highly ordered state. It's all condense becuase the Universe is smaller. It's not all condensed in a corner of a largely empty Universe just as the initial state wasn't condensed in the corner of an empty universe.
Also the odds for a future crunch don't look too good with all the observed deviations from a flat univers falling on the side of an open universe.
In short, Dude needs to drink more. We did better as undergrads in philosophy after a bender.
Anomalous: inconsistent with or deviating from what is usual, normal, or expected
Anomalous: deviating from what is usual, normal, or expected
Canard: a false or unfounded repor
Very easy:
First, find out what time is.
Second, make it go backwards.
We can measure time, but thats all we know about time. If you suscribe to the idea that there are 7 dimensions to the universe,and because of there inherant instability, they collaspe into a set of 3 dimension, and a set of 4 dimensions. This means there is an universe without time(the 3 dimensional universe)and a 4 dimensional universe(ours)with HWD and T.Now this means there is an universe WITHOUT time.
Now get your brain around this: Not only does that universe not have time, It doesn't have Height, Width, or, Depth either.
Must go now head exploding
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Future constraints is a "given" which I don't easily accept. Atomic cowboys are going to coral the atoms into a 1m cube in five minutes? Sounds like work to me! Or maybe it's like the pool-table trick where all the balls return to the triangle. Who sets up the shot? The devil is a pool shark!
When people talk about "time flowing backward" or "moving through time" what they are really meaning is "I want to step outside this point of reference (time) as if it no longer effects me and then step back in at another point". This doesn't work with any other dimension so why should it work with time? In fact it contradicts the meaning of "dimension". If you move to the left you end up to the left and you also have to pass all the points in between in that journey to the left. If you ended up to the right or didn't pass the points in between that wouldn't make sense. Time, as a dimension should be the same. If you go forward you experience it forward. If you go backward YOU CAN'T TELL because you would experience it backwards (unexperience it). Going backwards and thinking you could experience it forward doesn't make sense. Time may flow backward but we won't notice it because we would be going backwards with it.
The examples stated in the news story (i.e. eggs uncracking, organisms becoming younger) do not make sense. If this area of space has time that is constantly flowing backwards, how could the egg have ever cracked? How could the organisms become older? For this to happen, time must be swaying back and forth in a pendulum-esque motion, rather than just going in one direction.
First of all, the talk about the big crunch has nothing to do with reverse time. Throw a ball up in the air....the earth ball system gained entropy....and on the way back it loses the entropy it gained (order and disorder)....but overall the entropy is constant (adiabatic too since no heat transfer). The same logic can be applied to the universe expanding and contracting. The initial conditions of the big bang could either hurl the particles fast enough to leave the gravitational field, or with not enough energy so everything returns to the same point. That is the debate in astronomy....since there is no concrete value of dark matter in the universe, no one is sure if the gravitational field is strong enough to contract everything. I think it will contract...but there is still no reverse time arrow. The experiment he ran on the computer doesn't prove anything. You can set up any model you damn well please to get any results you want. Throw sin(anything) in the equation and it will continue to return to the same values. His model does not represent natural laws. When models are made in fluid mechanics, the energy equation, conservation of mass (continuity equation), and momentum equations are used. That is based on observable physics. His model is just numbers he picked that fit the results he "was surprised" to find. Anyway....neat reading...but nothing there....
In a universe whose interactions respond to future conditions rather than past conditions, wouldn't the "future" conditions be experienced as the past?
The "cause" of gas diffusion in our time-forward universe is that at time 0 it was in some unlikely state (past boundary condition), and it migrated to a more likely state by time 1. In a time-reverse universe, the "cause" of gas un-diffusion would be that at time 1 it must be in some unlikely state (future boundary condition), so it will migrate there from some likely state at time 0.
But, being a time-reverse universe, the "cause" of the future condition will be an even-more-future condition, and so on, and so on. In such a universe, the "record" of time would be a record of future conditions. Since we define "past" time as time that we have experienced, i.e. that we have a record of, it seems to me that the time perception in a time-reversed universe would be precisely the same as our time-forward perception.
So, a universe where future conditions will "cause" natural phenomena IS a world where past conditions did "cause" natural phenomena.
Correct or crazy?
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