How to change the past - a fact of quantum physics

[beavis]

We do not know how to send information back in time, but we know how to change the past without knowing what the past was that we're changing, and we do know we're changing it and what it changes to. Therefore the past can be changed, and we should expect time machines will exist in the future and therefore in the past and present if their operators choose to.

In the double-slit experiment, a laser sends 1 photon or electron or other particle/wave at 2 holes in a wall. The particle/wave goes through the left slit, the right slit, both, or bounces off the wall. Put a detector past the slit wall, which is set up to be close enough to detect or far enough not to detect as controlled  by a choose-to-detect switch that is activated after the particle goes through the slits but before its time that it may or may not be detected. If choose-to-detect is true, then the sum of 2 bell curves will be observed on the farthest back wall. If choose-to-detect is false, then a wave interference pattern will be observed on the farthest back wall. The pattern is a statistical distribution over time that converges exponentially toward certainty, not for individual tests.

By changing choose-to-detect from true to false or from false to true, after the particle/wave has gone through the slit(s) but before where it would be detected, the past can be changed between: (1) went through only 1 slit, resulting in the sum of 2 bell curves on the farthest back wall, or (2) went through both slits, resulting in a wave interference pattern on the back wall.

This is a fact of quantum physics. Its been proven. The past has been changed many times in labs this way, except I don't know if they've added such a switch, but the switch is a trivial change and the behavior of the experiment depends only on if its observed or not. Time travel exists. Its a fact.

Also, information may be sendable to the past by changing the angle and position that detection is done (if choose-to-detect is true it detects) so that a small amount of statistical information can be known about the previous position of the particle/wave before it went through the slit(s) (and if it goes through one slit or both depends on what happens in the future, setting choose-to-detect or not), so by running many of these experiments simultaneously with the same choice of choose-to-detect, information maybe can be exponentially-reliably sent to the past, and by chaining any number of these experiments together, information could maybe be sent as far back in the past as you have machines, where each machine gets you a very small fraction of a second. Maybe a loop made of mirrors would allow re-using the same machines?

[delysia]

This is interseting. I have just read a book by JW DUNNE called 'nothing ever dies" its a strange little book but it appears to predict the advent of quantum physics. JW Dunne was an aeronautical engineer back in the 1920's(?) He also puts people and time into perspective and was has pointed out that people travel through time (Obvious I know) but perhaps its easy for us to be glib about these things in this century. The book influenced my favourite childhood writer CS Lewis and JR Tolkein.

[Xanth]

Tom Campbell illustrated this concept well with the experiments regarding the Hospital Patients length of stay at their hospital and the group of individuals who used their collective Intent to change what the end results were.  Obviously, they couldn't change the history of what actually happened... however they COULD change the data that represented the results.  But changing the data that represents the results isn't changing history, it's just changing the data that was taken but not observed until much later.

In that, I disagree that Time Travel exists.  At least not in the form we expect it to be in.

[blis]

but we know how to change the past without knowing what the past was that we're changing

If you dont know what it was, how can you know if it's changed?

[manwesulimo2004]

So, I don't really know anything about quantum mechanics (or science in general) but I always feel the ramifications of research in this field are blown up out of proportion. Now I'm probably completely misunderstanding a whole number of things but I'll try to explain at least one point about what bothers me here:

If we observe the particle/wave going through the slits we get particle behaviour and lose the wave properties. If we don't observe it the wave behaviour remains uninhibited and the particle potentiality remains (waiting to be observed). It appears we influence the particle/wave by observing it. So if we set up our detection instruments and get a reading on our left device it doesn't necessarily mean a particle went through the left slit, it could mean the particle/wave went through both slits but that observing it made the interference pattern of the wave-aspect collapse or reset, giving us a fresh new particle/wave at the observed position.

The way I see it, it doesn't matter where you place the observing devices. Observing something changes it in that moment, not in retrospect.

Dunno if that makes any sense.

[majour ka]

Well, it sounds interesting, but since the past only exists in the mind and  you would need would need to move consciousnesses as well as light or physical matter. Plus everything happens in the present anyway, so really the past doesn't really exist...only as an abstract idea....

[Kaje The Astral Newbie]

I know bout the double slit theory, and how you explained the looping theory (just named it myself) from past preceded by the future or something.
If what you say is correct, and can be done with other things, what things will it be done too?