(adsbygoogle = window.adsbygoogle || []).push({}); While this may not actually seem like a debate, I consider it one, and this is the closest section you can get for this discussion so it's going here.

So as some of you may remember a few weeks ago a group of scientists in Switzerland carried out an experiment in which neutrinos were sent from Switzerland to Italy - and arrived in Rome 60 nanoseconds faster than the speed of light. A couple weeks later the experiment was repeated and the same result was found. There's a lot of room for error when dealing with such small numbers and with the complex calculations, but what with the same result in the repeated experiment it is definitely raising eyebrows.

While this may not sound like a lot, if this were to be true this is an incredible revelation as the very basis of Physics relies upon Einstein's theory that it is impossible to break the speed of light. I'm not going to go into the science too much but as demonstrated by his famous equation E=mc^2, as something gets faster its energy increases and therefore its mass (as energy is equivalent to mass). As the object has become heavier, it requires even more energy to accelerate. Mass is an infinite number and such as velocity increases it would require infinite amounts of energy to go faster than the speed of light.

According to The Theory of Relativity, time which is moving in a moving time frame moves slower than time in a stationary time frame the faster you go. The moving time frame would be whatever you're travelling in, and the stationary time frame would be the Earth. I'm not going to go too much more into the science but as you get closer and closer to the Speed of Light time slows down; so if you were able to break the speed of light, when you returned from the past time would have moved forward far more than you were gone.

Neutrinos wouldn't be the best form of particle to send back in time (say for sending signals to a former self) due to their odd nature; they dont interact with normal matter. However, if this were to be true (and they can travel faster than the speed of light) do you think it opens the possibility of sending signals to the past?

Do you think we will ever be able to time travel?

I didn't read the whole thing but, I believe it will never happen. If it did it would be only for the higher class and people in rank. Since, if anyone was able to get hold of it they would alter the whole world. An imagination simulator would be more like it.

Edit: Finished reading it and I think it would let you travel forward in time maybe but not backwards.

So you think a simulator allowing you materialise imaginations would be more realistic? Can I ask why?

Interesting points you made about it only be available for the upper class, and you would probably be right in that sense, but do you not think if time travel were ever possible we would have heard from the future? Or have we heard from the future and not been told by our respective governments?

This is a very complicated subject, but it is possible. A phenomenon called time dilation is the key here. Time passes more slowly the closer you approach the speed of light; an unbreakable cosmic speed limit. As such, the hands of a clock in a speeding train would move more slowly than those in a stationary clock. The difference would not be humanly noticeable, but when the train pulled back into the station, the two clocks would be off by billionths of a second. If such a train could attain 99.999 percent light speed, only 1 year would pass onboard for every 223 years back at the train station.

But speed isn't the only factor that affects time. On a much smaller scale, mass also influences time. Time slows down the closer you are to the center of a massive object.

"Time runs a little bit faster in space than it does down on Earth," Davies says. "It runs a little faster on the roof than it does in the basement, and that's a measurable effect."

A clock aboard an orbiting satellite experiences time dilation due to both the speed of its orbit and its greater distance from the center of Earth's gravity.

If they have invented time traveling we most likely would have not heard from the future in the sense that it is meant to be kept a secret. I wouldn't doubt that it has been accomplished. I would like to hear from the future it would be nice to see where our economy is going.

The question's that often come up about the future are 'what would this and that be like'; In honesty, you don't know. The present makes both your past and future so you can't really warp into the future unless its a paradox of alternative scenarios. It's always a difficult question, something you really can't put your finger on.

time does not exist. it is something we existed and therefore does not change..

and just a theory, but if you believe in time travel you also believe in alternate universes?

and this argument just goes round and round. its like the argument "does any moment in the world technically exist" (it takes our minds and eyes mili seconds to recognise and register anything, meaning that technically, what you just did, didn't happen then, it happened a nanosecond ago.. which quite alot of the time makes people go made and lose their minds..)

The mind puzzles of time travel.
If I could go back in time 20 minutes and delete this thread, would it be here when I got back, or my post in it?
It is a far cry from driving neutrinos through a tube and propeling a man.

The fastest man made space object was some probe they launched around the sun.
It reached speeds of 150k per hour. That is still nearly 5000 times slower than the speed of light.

Of course a human has density and matter, both of which would be effected as he approached higher speeds.

It is the main problem with interstellar travel.

But I prefer HG Wells time machine, the ultimate stationary bicycle

It's almost universally recognized by the physics community that the CERN experiment was in error. It has basically become a game of "find the error in the haystack." The experiment contradicts all other data, and notably the following:

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Basically, it is saying that if CERN's findings are accurate then neutrinos emitted from supernovae would arrive YEARS earlier than light. This has never been observed.



Not quite. It would be more accurate to say that it is impossible to break the universal speed limit: c. Light need not travel at c. It is conceivable that light might actually travel at a fractionally slower speed. For historical reasons, c retains the name "the speed of light."

(Note that all data does confirm that light travels at c to within a very small margin of error.)



Relativistic mass is a very outdated concept. It is an essentially useless quantity that leads to confusion and misconceptions. An example of this would be the commonly asked question, "If an object travels fast enough will it turn into a black hole?" The answer is obviously no. The invariant, or "rest," mass is what could be considered the "real" mass. This is the mass that effects gravitation; it does not change depending on your frame of reference, and it does NOT increase with increasing velocity. The only people nowadays who still use relativistic mass are pop-sci authors and TV documentary guests because they think it makes relativity more intuitive. In my opinion it does just the opposite.



This is not correct. Plugging in a speed such that v>c into the time dilation equation does NOT lead to negative time - it leads to imaginary (square root of a negative) time. This is clearly nonsensical. You can do the calculation yourself:

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Where:
You must login or register to view this content. is the time experienced by a stationary observer
You must login or register to view this content. is the time experienced by the moving object (called the proper time)
You must login or register to view this content. is the speed of the object relative to the stationary observer
and You must login or register to view this content. is the speed of light




Sure they do, just not very frequently. How do you think we detect them?



If you could send a signal faster than c, then in theory you could send a signal to the past. Wikipedia has a nice proof of this: You must login or register to view this content.



Uh... what?



I don't see the connection.



What argument?



I'm not really sure how this relates to time travel.



Actually, from the perspective of an astronaut moving in uniform linear motion very close to c in the reference frame of Earth, it is he who is at rest and the Earth which is moving at close to c. From his perspective everything is perfectly normal and it is the Earth which undergoes time dilation and length contraction.



Now for my opinion on the subject: time travel into the past is impossible. It leads to slews of paradoxes that cannot be resolved without rash, unfounded assumptions.

For example, consider the famous Grandfather Paradox: A time traveler goes back to a time when his father had not yet been born and kills his grandfather. This means that his father will never be born, and by proxy neither will he. But if he was never born then how could he have gone back in time and killed his grandfather in the first place? He couldn't have, which means his grandfather can't be dead, which means the time traveler was indeed born, which means that he COULD have gone back to kill his grandfather. But if he kills his grandfather then he was never born, and if he was never born then... etc.

Unlike time travel into the past, time travel into the future could be achieved in theory with drastic time dilation, though this is far beyond our current technology.

Another point to remember is special relativity.

I'm doing this entirely from memory, as I basically can't be arsed to Google everything as it's 3am. I'll approach this topic again when I've had a chance to review a few journals that are relevant. If I remember correctly though, gravity has a strong effect on the dilation of time as well, which is something we have to take into account on things like geosynchronous satellites, which if left to calculate time while orbiting earth, even though they're travelling though space at effectively the same speed at the earth, will experience time slower.

What this would mean is as things increase in mass and as such exert gravity on themselves, they would effectively put themselves into stasis and time would slow down around the item to such an extent that from the perspective of the thing travelling years are passing in seconds, where as from our perspective, the thing appears to be frozen in space.

It's this that counteracts the speed issue, where something travelling extremely fast would become extremely massive and therefore cannot break the speed of light barrier. For something extremely small like a particle, gravity is effectively zero, but when travelling at immense speeds it becomes so massive that it would begin to effect itself, and be effected by the gravity of other items.

When it comes down to it, this isn't time travel as we imagine it, it's speeding up and slowing down time. You're not travelling back and forward in time, even if it's theoretically possible. You're either experiencing time slower or faster than you should. For example, if you take a flight in an aeroplane, because of gravity time dilation, you're actually in the air longer than you appear to be on the ground. A 9 hour trans-atlantic flight, from the perspective of the person in the plain, lasts approximately 17 nano-seconds longer than it does for the people on the ground, and the people in the plane do actually age during this time too. If this was space travel, it would be possible for someone to experience a couple more days over the space of many years, compared to someone on the planet. I believe the numbers would be somewhere in the region of every 50 years or so on earth is 50 years and 1 day in space... doesn't sound like much but it's an interesting quirk of nature.

Like I say, I'm not sure if this experiment in the Swiss Alps will lead to anything or what this really means for the theory of relativity (both general relativity and special relativity), but I find it very exciting that it might be theoretically possible for faster than light travel.... time travel however, that's impossible in the sense of moving though time relative to one another. We're always travelling through time, going forward at 1 second per second, and perhaps certain experiments or experiences may allow us to experience time at a slightly different rate such as 1.0001 second per second, but practical time travel as far as I understand is impossible.

Faster than light travel though, that would be interesting. Although it's actually more likely that string theory research will develop methods for us to perceive trans-dimensionally, at which point trans-dimensional travel may be more of a reality. Who knows though? That's the glory of science, we keep experimenting and see where it takes us, and it's one hell of a ride.