Starship Asterisk*

So I decided to post here in the memory of good old days, right. Not sure if you guys are up to discussing this kind of stuff these days, or if you cooked some stupid rule that forbids it, but anyway - join me in this thought experiment.

Imagine that instant teleportation is possible. Take the simplest scenario, some guy is at rest in our frame until he suddenly disappears and reappears X miles away at the same time. Let us forget for a moment about how everyone will see him at two places at the same time, and focus on how he will experience the jump. So far I have done the easy part of this:



This picture is about when he thinks events happen around him. This is done in old good way - shooting light beams at things at t1, receiving them back at t2, and concluding that things reflected the beam at (t1 + t2) / 2. This is what our guy would do on any other day when he is at rest and, if he was not informed about being subject to secret government experiment, this is what he surely will do now.

Let's skip over the boring parts: green is when everything is normal, red and blue are time shifts (where observer at rest would see events before or after our poor guy), and the yellow zone is where everything happens twice - things are barely unexpected for now. But if we look at what happens at grey areas - it is far more interesting.

I named dark grey area Vegas, because what happens in Vegas stays in Vegas. This area is "black hole" -like, whatever signal you send there, or someone sends from there, cannot reach our guy. These events basically do not exist as far as he is concerned.

Finally, the light grey area is the most interesting. Events that happen there do affect our guy. For example, if he did teleport in order to avoid nuclear explosion that was scheduled in his area, he would see it happened. BUT - he has no way of telling when did it happen. This part is blowing my mind the most.

I mean, he could, in a good faith, attempt to extrapolate iso-time lines from other regions there, but there would be no physical reason to chose either green or blue are to do so, nor to conclude that these events happened twice at the different times - the notion of time for events in that area seems to be completely undefined. As such I feel that I am missing something here.

Help? Just don't call the doctor yet.

I posted briefly on a similar subject regarding teleportation. Your version of teleportation doesn't seem instant, however, if your test subject is seeing things twice. Either way, at some point I concluded that during teleportation your old consciousness is destroyed and a new one is created. So if your not-so-instant teleportation guy sees things during teleportation, I suppose his memory of former location during teleportation would be partial?

PS - I'm moving this to Open Space because afaik it's not astronomy related unless you go by dancing guy APOD rules, which we don't for the forum.

here is another observation about this Neverland: while our guy cannot send the beam there, he can reflect it from previously placed distant mirror o_O if this reflection happens on the edge of left blue area, the kight would cross the Neverland and enter the green area at the same time as it left this could be interpreted as if all the events on the way happen at the same time to our guy, and then it does no longer look that paradoxal.

geckzilla wrote:Your version of teleportation doesn't seem instant, however, if your test subject is seeing things twice.

he does so because he moves faster than light - so in effect he sort of "time travels" and experience same events again.

ps - if we would instead move the guy exactly at c, he would see no events twice and feel like it happened instantly - for him. but we would see him taking long time to get there (as much as it takes the light).

Interesting subject; but it is something I don't want to try;---so I'll keep the skin I'm in! Geckzilla; if you would get a new consciousness; all your body parts would be new too! Basically; you would be a different person!

makc wrote:so in effect he sort of "time travels" and experience same events again

btw this situation gives pretty good insight into what would "actually" happen to time travellers, versus popular culture depictions what we see here is that although events happen twice according to our guy, they are in fact the same event. though there are different types of "experiences" here. for some events our guy can "change" (or "cause") such an event, but only to later see his earlier self doing it again. for other events, on the other hand, the guy can apply some action twice - for example he could shoot everything in the upper right yellow zone twice with projectile hitting it at the same time (edit: same our time, but different times for him (edit2: this part is a bit crazy btw - if he shots twice, he is seing 4 bullets, two pairs hitting the target at two different times )) - however, his earlier self has no chance of knowing that his later self will be doing it again, so there is no paradox (edit: to have paradox you probably need to allow him to reappear in the bottom green area - but that is no longer teleportation but full-scale "let me have the cake and eat it too" time travelling).

orin stepanek wrote:...if you would get a new consciousness; all your body parts would be new too! Basically; you would be a different person!

Lol how do you know that did not happen last night in your sleep? Some alien could come and move you to their planet, quickly scan your body and then return you back to your bed.

makc wrote:

orin stepanek wrote:...if you would get a new consciousness; all your body parts would be new too! Basically; you would be a different person!

Lol how do you know that did not happen last night in your sleep? Some alien could come and move you to their planet, quickly scan your body and then return you back to your bed.

Now that's a scary thought! What would they want with me anyway?

orin stepanek wrote:Interesting subject; but it is something I don't want to try;---so I'll keep the skin I'm in! Geckzilla; if you would get a new consciousness; all your body parts would be new too! Basically; you would be a different person!

Nah. A person is his or her memories which comprise the personality. That would be the same. And of course all aging would still be the same since the cellular wear and tear would also be copied. New consciousness only. Now, if it were an imperfect copy, yeah, you'd probably end up being a different person. Or a completely nonfunctional one, depending on how imperfect the copy ended up being.

geckzilla wrote: Nah. A person is his or her memories which comprise the personality. That would be the same. And of course all aging would still be the same since the cellular wear and tear would also be copied. New consciousness only. Now, if it were an imperfect copy, yeah, you'd probably end up being a different person. Or a completely nonfunctional one, depending on how imperfect the copy ended up being.

IMO It depends on who's fantasy it is! True you may have the same memories if that could be transported! The body may have the same senses and feelings and maladies; but it would not really be you! All the atoms and molecules would be copies and the old you would be dead! Naturally the new you would think it is you!

makc wrote:Imagine that instant teleportation is possible.

An amusing thought experiment, to which you've contributed a good deal of quality analysis. For me, however, it falls apart with your first assumption. I know of nothing about the Universe that precludes teleportation, but the Universe seems quite adamant about its restriction on conveying information faster than light. So this thought experiment becomes just another variation on "what if we could travel faster than light", replete with the same paradoxes and causality variations. Amusing, but with no basis in reality.

Teleportation is an interesting topic, and introduces all sorts of fun physics that is much more real. For instance, how do we handle conservation of momentum and energy during teleportation? If you teleport from the Earth to the Moon, do you come flying out of the teleportation chamber at a few kilometers per second? Do you burst into flames as your high gravitational potential energy on Earth is converted to kinetic energy on the Moon? Does the teleportation technology take care of these energy and momentum mismatches? If so, where does the energy and momentum go, or come from? (I seem to recall a science fiction story that dealt with some of this- probably Niven- where there were huge tubs of water floating in the Great Lakes that were used like mass and energy capacitors, to store and release momentum as people teleported between different latitudes.)

Chris Peterson wrote:...with no basis in reality.

Good deal of content produced by humanity has no basis in reality ) In one word: imagination. Or do any of these papers have any more real basis? Yet, people keep thinking about it.

No login on reply :( wrote:

Chris Peterson wrote:...with no basis in reality.

Good deal of content produced by humanity has no basis in reality ) In one word: imagination. Or do any of these papers have any more real basis? Yet, people keep thinking about it.

Yes, those papers do have a real basis, because they explore the consequences of interpreting known physical laws, and they hold themselves to those laws, not requiring that well understood and accepted laws be violated.

Imagination is a fine tool for expanding our understanding of the Universe, but if you have to disregard known laws, it's just so much bad science fiction. Because once you require throwing out something we have good reason to believe is true, you are permanently divorced from reality. I would suggest that absolutely no scientific knowledge lacks a basis in reality (which is quite different from saying it is all correct).

Chris Peterson wrote:..introduces all sorts of fun physics that is much more real.

This remind me about that guy who wrote a paper about physics of Magneto in XXX movies, and how he was supposed to shine moving heavy things around. Imho this is taking these experiments one step too far but, neverless, still amusing.

Aha, but this

Chris Peterson wrote:you require throwing out something we have good reason to believe is true

is just a matter of interpretation. "Throwing out" is one way to look at it, another is just "extending the equation" in a way that it normally holds and is broken only under some weird condition that noone has yet to achieve. Why the 2nd is suddenly "good physics", I don't know.

makc wrote:Aha, but this

Chris Peterson wrote:you require throwing out something we have good reason to believe is true

is just a matter of interpretation. "Throwing out" is one way to look at it, another is just "extending the equation" in a way that it normally holds and is broken only under some weird condition that noone has yet to achieve. Why the 2nd is suddenly "good physics", I don't know.

Normally, the second isn't "good physics".

woah, the board putting ="makc" in quote, correctly identifying me. how come it does not require me to lg in then?

makc wrote:Magneto in XXX movies, and how he was supposed to shine moving heavy things around

btw, similar reasoning could be applied to http://what-if.xkcd.com/3/