So what did the article say? Well, it started out with a reasonable enough point. One of the basic assumptions of classical physics is that time flows in one direction and that when describing a physical system one needs to know the equations of motion and the initial conditions in order to predict the future behavior of a classical system.This sounds like those convenient devices in time travel novels that keep a piece of mud on your shoe from subtly disrupting the future and causing it to cease to exist. Also, I don't know enough physics to guess whether this is a hoax. But it's amusing, anyway.
However, quantum mechanics changes this a bit. Classical mechanics can be formulated in such a way that one sets up an "action" integral. The solution to the physical system can be expressed as the path that minimizes the action integral. It turns out that in quantum mechanics one needs to not simply take one path--but take the sum over all possible paths. For example, if you want to work out how a photon gets from a lightbulb to your eye, you need to take into account not just its straight-line trajectory, but contributions of all possible paths it could have taken, including paths where the photon bounces round the room. It's a bit strange, but it seems to work and 60 years+ of detailed experiments have confirmed this description over and over again to remarkable quantitative precision.
The authors of this paper claim to show that other terms can be added to the quantum mechanical action that are consistent with current theory and experiment. However, some of these possible terms include conditions in the future that need to be taken into account and summed over. That is to say, what happens in the future could (according to this paper) affect what happens in the present.
Why the LHC? The authors argue that these sorts of time-violating interactions could be associated with whatever new particles we create at the LHC. For example, the production of a large number of Higgs particles in the future could have a backwards-in-time causal effect on the machine that produced them, stopping the machine from ever running. As possible "evidence" for such a backwards-in-time effect, the authors cite the now-canceled Superconducting Super Collider (SSC)--a particle accelerator that was meant to hunt the Higgs and was partially constructed in Texas before Congress pulled the plug on the project. As the authors write in their paper: "Such a cancellation after a huge investment is already in itself an unusual event that should not happen too often. We might take this event as experimental evidence for our model in which an accelerator with the luminosity and beam energy of the SSC will not be built."
It's as though the Higgs plays the role of the time traveler who goes back to the past and murders his grandfather, thus preventing his own birth.
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Worried that the Large Hadron Collider is going to cause the universe to collapse? Well, a very weird paper suggests that it may shut itself down through the magic of time travel:
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I don't know what this has to do with anything, but it was fun to read nonetheless.
I'd just rather watch Primer.
Ker-RRAZY!
Can I use this for an excuse to give to my clients, as to why their project isn't complete? I'm going to start saying it this morning; "Those confounded Higgs particles won't allow your work to be completed! Whatayya' gonna' do?"
Although, if you're worried about the LHC already, this is of little comfort because there's no reason to assume the shutdown itself would be painless. Could it not manifest as the planet blinking out of existence before the Higgs bosons appear? Or the galaxy? Or several of the 11 M-theory dimensions?
Personally, I'm going to avoid shaving, just to be sure.
Not a hoax really, but a joke.
This is undoubtedly what happened to the Super Monkey Collider as well.
(http://www.theonion.com/content/node/30420)
I'm still worrying about dihydrogen monoxide
Yeah, every time I think about that dihydrogen monoxide, I break out into a sweat.
My favorite QM-related jokey idea:
Assume the many worlds hypothesis (every possible random outcome of a quantum mechanical state actually does happen, each in a new universe).
Find a way to destroy the universe.
Now you have the perfect computing machine: Use any old computer to make a random guess at the answer to some incredibly difficult question. If the guess is wrong, destroy the universe. (but make sure that there is a right answer.)
Yeah, every time I think about that dihydrogen monoxide, I break out into a sweat.
Cold sweat, or hot sweat? Knowing which will lead to a more accurate diagnosis and recovery.
After deciding to waste several minutes of my life reading this paper, I'm struggling to come up with the best way to explain why it's wrong. This is not because there's any hope for it to be right, but rather that it's wrong in so many different ways, one's rather spoiled for choice.
In the interest of fairness and clarity, I'm going to pick the simplest one, whilst blindly accepting as many of the author's assumptions as possible. To wit, let me begin with a quick summary (parenthetical comments/objections are unchecked, but give an indication of some deeper problems):
1- The authors change the fundamental mathematical tool we use to do theoretical physics, performing some sleight-of-hand to ensure classical physics still works. (Their motivation seems to be aesthetics, which is not entirely unreasonable, but it is a bit forced.)
2- The authors claim that experimentally-verified quantum physics (including particle physics) is unaffected. (Okay, this is almost certainly wrong, but I was feeling a little too lazy to figure out a good example, I'll post again if something comes to mind. Also, hard to avoid drifting into math.)
3- The authors claim that their new (and, again I stress, fundamental alteration of the natural order of things) would cause weird shit to happen (massive baryon-number non-conservation, i.e. bye-bye protons) in certain circumstances. However, rather than this actually happens, the initial conditions of the universe are tuned to prevent sad circumstances arising. (Okay, this is the really odd part: the theory makes really strange things happen, which we never see, because actually the theory constrains the initial conditions so the strange things can never happen. This is not, as they say, falsifiable. Of course, I may be missing something here, some subtlety lost in the verbiage of the paper, so let's plough on.)
4- A particular process that makes weird shit happen is Higgs production. Hence Higgs production cannot occur, so the initial conditions of the universe will be such as to prevent it. I.e. no LHC. (I suppose, one could also conclude that if the LHC did fire up, this research would mean that it would find the Higgs.)
Right, that's the summary (if anyone is still reading). Here's the problem: the Higgs has already been produced in vast quantities. Not by us, to be sure, but there was a point in the universe's early history when something called the electro-weak phase transition occurred and a lot of Higgs bosons were produced. How sure are we of this? Well, theres some indirect experimental evidence, but more importantly it's a natural consequence of the Standard Model of Particle Physics, even of the crackpot version proposed in this paper. Now, since the universe didn't have initial conditions to prevent this vast production of Higgses from happening (if it didn't happen everything we see wouldn't be here - at least not in the same way) it seems that there's a flaw in the argument, i.e. it's wrong.
There are many, many more reasons we this paper is a bit silly, but, as I said above, I've tried to pick the one that I thought was both most accepting of the paper's assumptions and simplest to explain in none technical language. Though, given how long this post has become, I may have failed in my goal of clarity. Apologies for that, if I think of some neater way to express myself, I will comment again.
Time travel isn't possible because matter cannot exist in 2 places at the same time.
If I were to send a proton into the future, or the past, that same proton would also exist in the future or past. Cannot happen.
Time travel isn't possible because matter cannot exist in 2 places at the same time.
We don't know that for certain. But even if it is true, there's no limit on information being in two places at the same time. If we can send information to the past, we can in theory "travel in time" by remotely manipulating the past. Rather than sending a person into the past we could instruct a machine in the past on how to build a copy of the person in question.
See John Cramer's Einstein's Bridge, in which the Superconducting Super Collider leads to invasion by an extrauniversal hive insect species, and the reversal of the SSC's construction by other extrauniversal time-traveling aliens.
Half Canadian: If I were to send a proton into the future, or the past, that same proton would also exist in the future or past. Cannot happen.
You've seen one proton, you've seen 'em all.
Hold it friends!
There is nothing particularly novel about the concept that the future can affect the past. More than 60 years ago as a schoolboy I noted that as one of the possible implications of Einstein's concepts of relativity. It does not follow from Einstein but is not absolutely barred by his logic.
More recently, experimenters seem to have had some success in teleporting photons instantaneously. If they have really done that, the notion of causation in time as necessarily unidirectional begins to look pretty shaky.
What is wierd is the idea that the Large Hadron Collider should trigger a special effect from future to present. Why the LHC? Our astronomers seem to be detecting very, very much higher energy events elsewhere in this universe which are not debarred by event conditioning from the future.
As possible "evidence" for such a backwards-in-time effect, the authors cite the now-canceled Superconducting Super Collider (SSC)--a particle accelerator that was meant to hunt the Higgs and was partially constructed in Texas before Congress pulled the plug on the project.
[sarcasm]Yeah, because Congress never pulls the plug on government projects.[/sarcasm]
The author is an idiot. The SCC was scrapped because the site became infested with fire ants that ate the insulation off the wiring. There is no effective way to control or eliminate the ants so the project was scrapped. Of course that wouldn't have been a problem if Congress had decided to build the SCC at Fermilab in Chicago, and the project would have cost less there as well...
As to quantum time travel, that is certainly allowed for in the equations but the probability fields collapse so that the only possible path backwards in time is the same one that was followed when going forward. That means it is like hitting rewind on your VCR and does not allow for changing the past.
I'm sorry, sir, but the Higgs particles ate my homework.