Quantum Time Machine and viewing the past?

[iZPhysics]

I read this interesting article about time travel, quantum mechanics, and the infamous grandfather paradox:

Quantum Time Machine Lets You Travel to the Past Without Fear of Grandfather Paradox

This got me thinking: I know that I can't use it to visit the past, but maybe to "view" the past. But I do have one question that is left unanswered. If I build such a device, could I use it to view the past before the device's existence?

The reason I ask this is because I know that all time machine models proposed in General Relativity forbid time travel before the creation of the time machine due to the laws of causality. And in this Quantum Mechanics version of "Retrocausality" proposed by John Cramer, it only uses retarded time created by fiber optics and quantum entanglement to enable instantaneous communication between the particles. Therefore, the photon's nature (wave or particle) will be seen before the photon reaches the detector.

http://www.seattlepi..._timeguy15.html

Back to my main question: can I use it to view the past before its existence? Thanks!!

[swansont]

The second article is from 2006, before Cramer did the experiment. Anything on how it turned out?

[steevey]

All time is, is a measurement of something periodic. There was something in the universe that took 1 second to complete before it relapsed, so we adopted that. I could at any point in my life replace the word time with something like "A ran 5 miles per 1000 swings of that pendulum". It's just that we all use the same pendulum, and over time without changing, we take it as a given, and confuse it for some mystical force that's always there.

 

If you really wanted to time travel, you'd have to re-arrange all the atoms in the universe to a specific state that it previously was or once was, which would also eliminate the paradoxes of other time travel.

Edited November 27, 2010 by steevey

[Anura]

I believe time traveling is a silly concept.

[Moontanman]

I read a novel about time travel but they could only view the past. At first it was outrageously expensive technology requiring many gigawatts of power and the great moments of the past were viewed and recored for posterity but eventually the technology became cheap and required almost no power and the time viewer became nothing more than a way to be a peeping tom in the past and it was used to invade peoples privacy since any point in the past could be viewed everyones most intimate moments were easily viewed and time viewing just became another type of pornography.

 

So next time you take a shower remember the future could be watching.....

[Spyman]

To see something requires photons to enter our eyes or equipment for observation and as such photons from the past would either have had to been delayed, like what they normally are when coming from a distance or get trapped in the past in a container and then released today, which in both cases doesn't need a timemachine or other timedevices.

 

If we build a device that could view visions from the past, then that device must interact with the photons in the past to either duplicate them or simply catch them. This interaction would make it subjected to the same problems as with other timemachines since these interactions should interfere with the past.

[Sharapovaphan]

I believe time traveling is a silly concept.

 

Accelerating infinite mass does seem a silly concept. Considering that it would take an infinate amount of energy to accelerate it...

[steevey]

To see something requires photons to enter our eyes or equipment for observation and as such photons from the past would either have had to been delayed, like what they normally are when coming from a distance or get trapped in the past in a container and then released today, which in both cases doesn't need a timemachine or other timedevices.

 

If we build a device that could view visions from the past, then that device must interact with the photons in the past to either duplicate them or simply catch them. This interaction would make it subjected to the same problems as with other timemachines since these interactions should interfere with the past.

 

Or the information for every event is still there and thus the only way to travel back would be to re-arrange all matter and energy in the universe to an exact previous state it once was.

[Sharapovaphan]

Or the information for every event is still there and thus the only way to travel back would be to re-arrange all matter and energy in the universe to an exact previous state it once was.

 

There are no negative temperatures and faster than LS isn't obtainable... to date.

[IM Egdall]

I believe time traveling is a silly concept.

 

We actually time travel all the time! Into the future and into the past. And no time machine is necessary. It all comes from gravitional time dilation of general relativity. See my blog: It's Relative.

Edited February 20, 2011 by I ME

[36grit]

If we are to expect to get out of a time machine and explore the past, then must also have expeceted our time machine to alter the outside while preserving us in our previous time state.

 

If you (and the things inside the time machine) went back in time there might not be anything there. Unless we expect that: the interduction of present time mass force matrix might cause an instantanious chain reaction, that could reproof the momentums of time past. You will have created a new past radiating from your presence. Within minutes the new past should start seeing small changes from to old past. And the longer you are there the more different it will be. You could go and kill yourself and still exist because you are not the same person or mass that you were in the past. Your presence in the past will have created a new present moment in the past.

Edited February 23, 2011 by 36grit