Time travellers outsmart the NSA If there are time travellers around, they're being careful not to leave their fingerprints on the Internet. That's the conclusion in a paper published at Arxiv, put together by Michigan Technical University physics professor Robert Nemiroff and PhD candidate Teresa Wilson. They searched the Internet for “prescient” signatures …
If I was a time traveler from the future, I certainly know that I would have no better things to do than tweet about the pope and comet ison.
Also I can't help but notice that time travel, comet ISON, Pope Francis (and the Mayan calendar) are all ingredients in a particularly silly conspiracy theory.
"Getting desperate, the researchers have also asked time travellers, if they exist, to post to the hashtag “#IcanChangeThePast2” or “#IcannotChangeThePast2”, on or before August 2013."
If a time traveller posted “#IcannotChangeThePast2” at any point in their own past, then they would have changed their own past (by revealing the possibility of time travel in the future), thus contradicting their own post.
Then there's the question of what would actually happen if they did tweet with the hashtag in question, and the Everett many worlds interpretation is the correct one. Would the researchers ever see the results of their request? Their timeline and the one in which the tweet was made might presumably be mutually exclusive.
"...the Everett many worlds interpretation is the correct one..."
You are making a distinction without a difference. The Everett many worlds interpretation is "the correct one", as it is entirely equivalent in all ways to the conventional collapsing wavefunction "correct" interpretation. Any competent Physicist could tell you that.
They're being asked to do it; i.e, they haven't, yet. Not in their own personal timeline, that is. If they do it(*) tomorrow, or next month or in twenty years, then that's still in the future to them. So they'll only be changing their own future, not their past, and that's allowed: We all do, all the time.
(*): Where "do it" means "go back to whenever it was and post whatever it was on Twitter."
AC: "Look at lottery tickets instead."
Ah, a hit! Canadian lottery ticket retailers and their extended family members win Canadian lotteries at a rate that is startling. An obvious sign of Time Traveling.
Or perhaps they cheat trusting old folks out of their winnings.
It's either one or the other.
Oh come on, everyone knows the real reason that we are not knee-deep in invading aliens is due to this one man.
Hmm.
Given that language changes over time, I'd've thought that 'I'd've' might change to 'iduv' as a specific conditional perfect construction in the English language.
So we could use a search for 'iduv' as another method of finding out if there are any persons from the future living amongst us, and who may not be completely fluent in 20th Century English.
Unfortunately, IDUV appears to be a currently existing type of film. So bang goes that idea....
Every time I get to thinking that humanity has a chance of survival something comes along to make it once again dubious. This, however, whould be proof. The reason they won't be detected with the twitter methodology is that they would have probably only jumped about 3 seconds into the future with their device. I'm not sure tweeter twits have attention spans much longer than that.
Crewman Daniels
The Starfleet Temporal Commision
The Xindi
Captain Janeway
Crewman Braxton (if he ever gets out and re-promotes himself)
And a slew of others, just from Trek alone, hahaha....
Hahaha
Besides, IF you can timetravel, you owe it to the continuity of time to not assist any frackkin humans of this strain with any quantum or time-related fact.
Further besides, humans are not yet ready for even solar travel.
And, if you help any alphabet soup agencies, you'll screw up the "Earth: Galactic Comedy Central Pitstop" status I "presciently" accorded to this planet weeks ago and intermittently.
You must have your sense of humor switch stuck in the off position.
But seriously the paper cost nothing. A few hours of fun discussion, Internet search and then writing it up. Even publishing on axiv if free. They also do not list any research projects in the acknowledgement section so they did not use the paper on their time sheets .
No, they have not done this on your money. With the possible exception of the professor salary. You never did silly web searches while in work? So throw the first stone. But they at least did their time to produce something funny.
Maybe the timetravellers funded the research as an ironic joke. As a side effect they also managed to send a message to their home time saying help we are stuck here without any scientists realising what was happening and therefore preserving the time line unless someone posts a message such as this.
We are here you know. All of us from everywhen. Screw up badly enough to get a life sentence and they track you down and shunt you into this shitty timeline. The only one -yeah, I guess there had to be one - so far beyond the decimal point that neither space nor time travel exist here. Suicide rock they call it. No way off and no way out. Won't claim me though. Too old. I'll be gone by then. Feel a pang for the juvies tho'. Shit's gonna get real for them.
PHYS771 Lecture 19: Time Travel
Let's talk about the more interesting kind of time travel: the backwards kind. Can closed timelike curves (CTCs) exist in Nature? This question has a very long history of being studied by physicists on weekends. It was discovered early on, by Gödel and others, that classical general relativity admits CTC solutions. All of the known solutions, however, have some element that can be objected to as being "unphysical." For example, some solutions involve wormholes, but that requires "exotic matter" having negative mass to keep the wormhole open. They all, so far, involve either non-standard cosmologies or else types of matter or energy that have yet to be experimentally observed. But that's just classical general relativity. Once you put quantum mechanics in the picture, it becomes an even harder question. General relativity is not just a theory of some fields in spacetime, but of spacetime itself, and so once you quantize it, you'd expect there to be fluctuations in the causal structure of spacetime. The question is, why shouldn't that produce CTCs?
Incidentally, there's an interesting metaquestion here: why have physicists found it so hard to create a quantum theory of gravity? The technical answer usually given is that, unlike (say) Maxwell's equations, general relativity is not renormalizable. But I think there's also a simpler answer, one that's much more understandable to a doofus layperson like me. The real heart of the matter is that general relativity is a theory of spacetime itself, and so a quantum theory of gravity is going to have to be talking about superpositions over spacetime and fluctuations of spacetime. One of the things you'd expect such a theory to answer is whether closed timelike curves can exist. So quantum gravity seems "CTC-hard", in the sense that it's at least as hard as determining if CTCs are possible! And even I can see that this can't possibly be a trivial question to settle. Even if CTCs are impossible, presumably they're not going to be proven impossible without some far-reaching new insight. Of course, this is just one instantiation of a general problem: that no one really has a clear idea of what it means to treat spacetime itself quantum-mechanically.
In the field I come from, it's never our place to ask if some physical object exists or not, it's to assume it exists and see what computations we can do with it. Thus, from now on, we'll assume CTCs exist. What would the consequences be for computational complexity? Perhaps surprisingly, I'll be able to give a clear and specific answer to that.
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