The recent experiment appears to show nuetrinos travelling faster than light. If this is true then physics has just smashed its most important physical constant and they have to go right back to the drawing board and start again. If this is true, then the most famous equation in history, E=MC2 , is wrong. But, it is unlikely that physics has been wrong for the last 100 years, they have proved and measured too much with the Einsteinian model to be completely wrong.
What may be happening is that the neutrinos are travelling in more than 4 dimensions, taking short cuts through exotic dimensions which were, until now, only theoretical. By taking these short cuts, the neutrinos arrive earlier than light would in our 4D 'reality'. So they aren't really travelling faster than the speed of light, they are somehow skipping out part of the journey. If this is what is happening, then faster-than-light time travel is still not possible.
And, may I say, I am immensely proud of the scientific community that has, once again, proved it does not cling to treasured theories if the data forces them to reject them. Last week a group of scientists, very very tentatively, published evidence which suggests that Einstein's model is in some way incomplete. And while many scientists are skeptical, no-one tried to supress the data or castigate the people involved, in fact it has been welcomed with shouts of delight.
Science for the win!
This discussion is great. I want to respond to the comment: "it is unlikely that physics has been wrong for the last 100 years, they have proved and measured too much with the Einsteinian model to be completely wrong."
Actually, if the history of science is any indicator, odds seem to me to be very good that indeed physics "has been wrong for the last 100 years." "Wrong" may be too strong. Maybe "not wholly accurate" fits better. Newtonian physics isn't wrong, but it's not wholly accurate, either. Given the track record for pretty much all scientific models, I expect that Einsteinian physics won't remain unchallenged forever. Just think about how long the Ptolemaic and Copernican models of the universe were held to reflect the full truth of how things actually are. We seem to be generating new insights and new theories at a more rapid pace than ever before. A theory that's been around for 100 years seems overdue for some serious challenges.
I believe that time travel is a logical fallacy called argument by analogy. We are comparing time to space, and then pretending that the comparison allows us to imagine that time has all the properties of space, including the property of moving around in it. Time, for living things, is a mental construction; nothing more than the strength of one's memory -- in other words, your childhood, for example, doesn't exist; it just is fading memories, that is, fading synapses and electric impulses traveling through our brains and weakening with age. The historical past is collective memories preserved in physical forms -- books, pictures, etc. Mathematical time is just that -- mathematics, a convenient language to construct useful ideas (like building a building). Someone said (Einstein?) that time is a convenient invention so everything doesn't happen at once. Therefore, just because we can form the phrase "time travel" doesn't guarantee the existence of a signified to go with the signifier.
To date, man has travelled at speeds that are nowhere near the speed of light. She has travelled at thousands of miles per hour in space, but such speed is insignificant compared to the speed of light...186 thousand miles per second!
The idea of exceeding the speed of light and thereby traveling in time is only a theoretical concept. It could prove to be wrong.
Also, as an object approaches the speed of light (such as an atomic particle in a linear accelerator), the energy need to incrementally increase the speed 1 mile per second increases exponentially.
It is my opinion that 1. man will never develop the capability of moving a human at a speed greater than the speed of light, and 2. there is not enough energy producable by man that could accomplish such a task.
Time travel won't happen...ever.
The scientific community is approaching the announcement of the faster-than-light neutrinos with great caution, because the odds are excellent that this is much ado about nothing. The calculations have to be thoroughly rechecked, and it's important to note that neutrinos generally pass through matter without interacting, so it's unlikely that, even if they do go that fast, they could be used in any way to create time travel or anything else.
The other thing that makes time travel unlikely that hasn't been mentioned here yet is why e=mc2 creates the lightspeed barrier that it does. It's possible to calculate the amount of energy required to accelerate a particle of known mass a certain amount. The faster you accelerate it, the more energy needs to be used to do so. To accelerate a particle with any mass of more than zero to any speed above the speed of light will use up all the energy in the universe.If we ever invent time travel (and I doubt we ever will), it won't be done via lightspeed travel, it will have to exploit wormholes or other geometric shortcuts through spacetime.
I think the only way possible to "time travel" is when crossing time zones. While this does not exactly align with what you are asking, when crossing a time zone, either forward or back, we can either relive an hour (according to the clock) or skip an hour completely.
Is there not a difference between what is theoretically possible and what is actually possible? Personally, I think we would be better off if this technology is never developed. Let us remember the disastrous happenings that many short stories show as resulting from time travel. Consider Ray Bradbury's "A Sound of Thunder" or Nathaniel Hawthorne's "Dr. Heidegger's Experiment."
Relative to this discussion is a short story by Rad Bradbury entitled, "A Sound of Thunder" in which a hunter from 2066 travels back to the dinosaur age in order to hunt a Tyrannosaurus Rex. The story is based upon the butterfly effect,
the sensitive dependence on initial conditions; where a small change at one place in a nonlinear system can result in large differences to a later state.
If this be the case, time travel will cause absolute chaos.
I find this topic fascinating. Ironically, a group of us were visiting just tonight and somehow the topic of time travel, the speed of light and Stephen Hawking came up. It seems that there may be something that does travel faster than light, which would disprove Einstein's theory of relativity—as I was told.
If we reflect on what technology has done—good and bad, like the Internet—the idea of time travel is frightening in a way...if our choices no longer mattered and we could fix any mistake, make better choices, invest in the stock market to make money, etc., how would we survive it? It's hard to imagine that under these circumstances people would try as hard as they do or care as much as they do, if they (we) knew that nothing was "final."
I think the idea is that faster than light travel might possibly make some sort of time travel theoretically possible. It's not as if it would be a guaranteed thing. Furthermore, there appears to be some dispute as to whether those neutrinos really did travel faster than the speed of light.
So, there is a lot of theorizing to be done if the neutrinos at CERN are confirmed to have gone faster than light. But there is certainly no guarantee that time travel would become possible. Read this article for more.
Ever since I was a kid and saw Back to the Future I have always been fascinated with time travel. You should watch a program about the "string theory" because it explains the connect between time and space. Really Cool!
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