Time - is it reversible?

[Time And Space]

How I can reverse the time of universe???

Edited January 15, 2013 by imatfaal
Colours removed to ease reading -a nd title made into a question

[lightspeed]

Some have said you would have to excellerate a magnetic field faster than light speed or you would have to go faster than light speed.You should try to research that.

[swansont]

Some have said you would have to excellerate a magnetic field faster than light speed or you would have to go faster than light speed.You should try to research that.

 

When you do you will find out that such an effort is not possible under known physics. In terms of what we know, the answer to the proposal is that it can't be done.

[J.C.MacSwell]

How I can reverse the time of universe???

 

How do we know it's not reversing right now?

[Tres Juicy]

The question does not make sense.

 

For time to reverse everything in the universe would have to revert to a previous state, entropy would need to decrease...

 

These things are not possible.

[juanrga]

How I can reverse the time of universe???

 

You cannot because all your causality is defined with reference to that same time. You are part of the universe.

[michel123456]

I think that commonly people have a wrong view of time as if it was something that had the power to put things going on. As much as i know, Time is not a force. Time is not one of the 4 interactions. Time should be considered more as an effect, not as a cause.

 

IOW the question should be changed by asking "what do I have to change in physics in order to observe time reversal?"

[36grit]

I believe it was Hawkings that suggested going back in time may be impossible because of spacial looping, or something like that. And compaired it to holding an electric guitar to an amplifier.

This made some sence to me.

[juanrga]

I believe it was Hawkings that suggested going back in time may be impossible because of spacial looping, or something like that. And compaired it to holding an electric guitar to an amplifier.

This made some sence to me.

 

Stuckelberg and Feynman showed how antiparticles can be tough of as particles travelling backward in time. This interpretation is at the core of his diagrammatic approach to QED:

 

http://prola.aps.org/abstract/PR/v76/i6/p749_1

[Przemyslaw.Gruchala]

How I can reverse the time of universe???

 

You need to become god in the next incarnation..

[rigney]

Time is not an entity unto itself nor a part of anything else, only a measurement we have found useful to describe natural events. Even using it as Einstein did to describe space time seems wrong to me. (the atomic clock thing), or speeding along at the speed of light and changing course. When you alter the outcome of events, you also change time duration and perception.

 

http://mysearch.avg.com/search?q=why+is+the+combining+of+space+and+time+ok+by+einstein%3F&sap=hp〈=en&mid=fa37236bd2e84428a02040aaab8db9a5-5b7622d8d0b80c4f9baf95d97b35744efe6b39f0&cid=%7B7CC3D9A6-6F0D-4709-8CF8-DC8917A8E4F4%7D&v=14.2.0.1&ds=hk018&d=2%2F16%2F2013+11%3A53%3A24+AM&snd=hp&pid=safeguard&sg=1&sap_acp=0

 

http://www.ws5.com/spacetime/

 

http://pages.towson.edu/zverev/conceptual/5.htm

Edited February 17, 2013 by rigney

[swansont]

Time is not an entity unto itself nor a part of anything else, only a measurement we have found useful to describe natural events. Even using it as Einstein did to describe space time seems wrong to me. (the atomic clock thing), or speeding along at the speed of light and changing course. When you alter the outcome of events, you also change time duration and perception.

Fortunately we judge by whether a theory agrees with nature, and not according to the whim of select individuals. Which atomic clock thing bothers you?

 

Only light or other massless particles speed along at the speed of light. Everything else is constrained to go slower.

 

Nobody is claiming you can alter the outcome of events.

[rafman400]

Some particles move back forth through time often. Maybe this will give you some insight.

 

http://en.m.wikipedia.org/wiki/Minkowski_diagram

Edited February 23, 2013 by rafman400

[swansont]

Some particles move back forth through time often. Maybe this will give you some insight.

 

http://en.m.wikipedia.org/wiki/Minkowski_diagram

 

I don't see how you draw that conclusion from a Minkowski diagram.

[rafman400]

I don't see how you draw that conclusion from a Minkowski diagram.

your right. I meant to post this specific diagram.

 

http://i786.photobucket.com/albums/yy143/DrDil_frms/ufo-blog_com-forum/quantum_quackery_figure_2.jpg

 

an electron moves back and forth in time to absorb photons.

 

may not apply but maybe it does

[ACG52]

I don't see what your diagram is supposed to show. All movement along the time axis is in the forward direction.

[SamBridge]

entropy would need to decrease...

It's possible for entropy to increase in various systems, but otherwise time going forward is based on out definition of the mathematics to describe it. We say time is going forward if the difference between the last time increment and the this time increment is positive. If time goes from 1 to 2, 2-1 = 1, which is positive, so it was an increase, and we are continually measuring time going from one number to a larger number which always makes the difference positive.

Edited February 24, 2013 by SamBridge

[rafman400]

I don't see what your diagram is supposed to show. All movement along the time axis is in the forward direction.

 

HERE: http://i57.photobucket.com/albums/g222/The_bacon_guy/Feymanmultidirectional.jpg

 

I didnt want to go and find the specificone but merley introduce the idea. ^this is the one

[ACG52]

So you took the original diagram and reversed some arrows and added a dotted line.

 

It's meaningless.

[rafman400]

So you took the original diagram and reversed some arrows and added a dotted line.

 

It's meaningless.

I didn't do anything to original diagram. I thought the other one was this one at a glance. An electron is moving forward in time. It then absorbs a photon travels back in time, discharges that photon and moves forward again.

 

Solid line is the electron, dotted is the photon and arrows denote direction. I believe the anti particle of the electron(i think the positron) is created at some point in the diagram, I'm not sure though.

 

There some physicists that don't think it so meaningless

Edited February 23, 2013 by rafman400

[swansont]

Other than the photon direction, it looks like a schematic for pair production and annihilation. There are three particles depicted, not one, in addition to the photons.

[juanrga]

I didn't do anything to original diagram. I thought the other one was this one at a glance. An electron is moving forward in time. It then absorbs a photon travels back in time, discharges that photon and moves forward again.

 

Solid line is the electron, dotted is the photon and arrows denote direction. I believe the anti particle of the electron(i think the positron) is created at some point in the diagram, I'm not sure though.

 

There some physicists that don't think it so meaningless

 

There is no need to reinvent the wheel...

 

http://www.scienceforums.net/topic/72113-time-is-it-reversible/#entry729283

 

In the first place, the dotted lines are technically representing anti-photons, not photons (although the photon is its own antiparticle this distinction is needed for a correct interpretation of the diagram, see below).

 

In the second place, that diagram is a representation of an electron-photon scattering

 

e^- + y = e^- + y

 

Third, the electron travelling backward is not real but a formal representation of the real positron travelling forward. Moreover, this is a virtual particle not a real particle, that is why it is in the middle of the diagram, being immediately absorbed to satisfy conservation laws.

Edited February 24, 2013 by juanrga

[Tamorph]

How do we know it's not reversing right now?

 

Simply because entropy is increasing, as it always does.

[warped space]

Ok so film a moving object and play it in reverse lol I mean literally time as we know it is mearly perspective draw two points and connect them and ask where does it start and end because both points you can assume are starting points and going backwards the only logical thing that happens according to the universe is that physics would applys backwards as it does forward and you would go backwards walking backwards like a rewinding film unless you skipped a portion and that is impossible

 

Hypathetically speaking

 

Hypathetically speaking