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Einstein may have been wrong about not surpassing the speed of light? (pg. 5)
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| infinity HiGH |
| quote: | Originally posted by DJ_Science
As an active physics researcher all I have to say is please wait until another group confirms the result. A single experiment means nothing until it is confirmed independently. |
From what I've found out through discussions with some friends, a lab or school in Chicago reached the same conclusions as CERN, but way earlier, and their margin of error was a lot higher. CERN's LHC is the second go around at trying to [successfully] break the speed of light |
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| pozz |
| that he was wrong might not even be the point. we still built an atom bomb on that principle. physics is something that works without having to be true. |
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| DJ_Science |
| quote: | Originally posted by infinity HiGH
From what I've found out through discussions with some friends, a lab or school in Chicago reached the same conclusions as CERN, but way earlier, and their margin of error was a lot higher. CERN's LHC is the second go around at trying to [successfully] break the speed of light |
I'd like to see a paper from the Chicago group. I've not seen anything other than the CERN announcement. Do you happen to know the group leader's name? |
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| DJ_Science |
| quote: | Originally posted by cammaxwell
if you were on that train walked from the back to the front you would essentially be traveling faster than the train (or faster than the speed of light). |
This isn't correct. If you walk on a train traveling near the speed of light you can't just add the velocities together as you do for every day speeds. You have to add them in a way which is Lorentz invariant. Once you do, you find that the sum of the velocities is not faster than the speed of light. |
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| Prometheus Xex |
| quote: | Originally posted by DJ_Science
This isn't correct. If you walk on a train traveling near the speed of light you can't just add the velocities together as you do for every day speeds. You have to add them in a way which is Lorentz invariant. Once you do, you find that the sum of the velocities is not faster than the speed of light. |
Not knowing the actual terms for what you've explained, I do remember something to the effect that your talking about. One example that's a variant of the train example was a person traveling near the speed of light and shining a flashlight with the beam pointing forward. That fast as light beam is still not travelling faster than the speed of light due to the laws of relativity. This is why the train scenario put a bad taste in my mouth but I couldn't quite place as to why till you mentioned adding velocities. |
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| neuromancer |
| quote: | Originally posted by pozz
physics is something that works without having to be true. |
what does that even means ! |
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| DJ_Science |
| quote: | Originally posted by neuromancer
what does that even means ! |
Yeah, I am with you on that one. |
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| spitty |
| quote: | Originally posted by DJ_Science
This isn't correct. If you walk on a train traveling near the speed of light you can't just add the velocities together as you do for every day speeds. You have to add them in a way which is Lorentz invariant. Once you do, you find that the sum of the velocities is not faster than the speed of light. |
I am beyond confused about most of this, but its so interesting that I want to try to understand. Can you explain (as simply as possible) what you mean by this? the sum of the velocities.
sorry to make you dumb it down! |
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| DJ_Science |
| quote: | Originally posted by spitty
I am beyond confused about most of this, but its so interesting that I want to try to understand. Can you explain (as simply as possible) what you mean by this? the sum of the velocities.
sorry to make you dumb it down! |
No problem and I'll see what I can do...
In classical physics (which applies as speeds well below that of light) velocities can simply be added together to get a total velocity.
For example, suppose you are standing on the side of the road and you see a truck drive by at 80 km/h with someone standing on it. Now suppose this person tosses a ball in the same direction the truck is driving and they throw the ball at a velocity of say 20 km/h. To you, the ball is traveling at 100 km/h which is the velocity of the truck plus the extra bit given to the ball by the thrower. If the person were to throw the ball in the opposite direction, against the motion of the truck, it would appear to you that the ball is traveling 60 km/h. This is what I mean by adding velocity.
To make contact with the train discussion, now suppose this truck is driving at the speed of light "c". Now the person tosses the ball. Classical physics says the total velocity of the ball is c + 20 km/h, which is faster than the speed of light. But this is not correct and relativity gives new rules for adding velocities (the formula is written down here if you're interested http://en.wikipedia.org/wiki/Velocity-addition_formula). |
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| cammaxwell |
Ok, I found a article where Stephen Hawking is discussing the numerous ways we good travel through time. Here is the article:
ARTICLE
But here is the section with the train, as his words are obviously better than mine!
| quote: | But there's one more possibility: traveling super fast.
"This is due to another strange fact about the universe," writes Hawking -- the cosmic speed limit: 186,000 miles per second, or the speed of light.
"Nothing can exceed that speed. It's one of the best established principles in science," writes Hawking, but "believe it or not, traveling at near the speed of light transports you to the future."
"Imagine a track that goes right around Earth, a track for a super-fast train. Onboard are passengers with a one-way ticket to the future. The train begins to accelerate, faster and faster. Soon it's circling the Earth over and over again.
"To approach the speed of light means circling the Earth seven times a second. But no matter how much power the train has, it can never quite reach the speed of light, since the laws of physics forbid it.
"Instead, let's say it gets close," writes Hawking. "Something extraordinary happens: Time starts flowing slowly on board relative to the rest of the world, just like near the black hole, only more so. Everything on the train is in slow motion."
Speed of Light Protection
This happens to protect the cosmic speed limit, Hawking said. Here's why:
Say there's a child running forward up the train. "Her forward speed is added to the speed of the train, so couldn't she break the speed limit simply by accident? The answer is no," writes Hawking. "The laws of nature prevent the possibility by slowing down time onboard. Now she can't run fast enough to break the limit. Time will always slow down just enough to protect the speed limit."
This is the essence of why time travel into the future is possible.
"Imagine that the train left the station on January 1, 2050. It circles Earth over and over again for 100 years before finally coming to a halt on New Year's Day, 2150. The passengers will have only lived one week because time is slowed down that much inside the train. When they got out they'd find a very different world from the one they'd left. In one week they'd have travelled 100 years into the future," Hawking writes.
Right now, the fastest motion on Earth is taking place in the circular tunnels of the world's largest particle accelerator at CERN, in Geneva.
"When the power is turned on (particles) accelerate from zero to 60,000 mph in a fraction of a second. Increase the power and the particles go faster and faster, until they're whizzing around the tunnel 11,000 times a second, which is almost the speed of light. But just like the train, they never quite reach that ultimate speed. They can only get to 99.99 per cent of the limit. When that happens, they too start to travel in time. We know this because of some extremely short-lived particles, called pimesons. Ordinarily, they disintegrate after just 25 billionths of a second. But when they are accelerated to near-light speed they last 30 times longer."
To accelerate humans to that speed, we'll need to be in space, concludes Hawking, noting that so far, the fastest that people have traveled is 25,000 mph aboard Apollo 10.
"To travel in time we'll have to go more than 2,000 times faster (than Apollo 10). And to do that we'd need a much bigger ship, a truly enormous machinebig enough to carry a huge amount of fuel, enough to accelerate it to nearly the speed of light. Getting to just beneath the cosmic speed limit would require six whole years at full power.
"We could, in theory, travel extraordinary distances within one lifetime," Hawking writes. "A trip to the edge of the galaxy would take just 80 years." |
Thought some of you may be interested in actually reading that... |
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| cammaxwell |
| quote: | Originally posted by DJ_Science
This isn't correct. If you walk on a train traveling near the speed of light you can't just add the velocities together as you do for every day speeds. You have to add them in a way which is Lorentz invariant. Once you do, you find that the sum of the velocities is not faster than the speed of light. |
I am just basing my comments on Stephen Hawking's article, so I'm not sure what to say on this. I don't have enough knowledge in physics to state whether this is true or not, although I do get what you're saying.
But...I would have to wonder why Stephen Hawking stated that if it wasn't true? I think he would be VERY well aware of any issues with his theories... |
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| Dinoz2013 |
IF you are on a .9c Train, and you yourself are moving .9c on the train, your speed is .9c. From outside the train your speed will be seen to increase by factor 1/((1-(v^2/c^2)).
SOMETIMES from outside the perspective of the train, it can appear that objects within the Train (you) are moving faster than the speed of light.
With these Neutrinos, I believe either the medium it is travelling through is moving at an increased speed (not sure how, maybe due to small scale, effects increased) or it has something to do with the method which these neutrinos go through "phase" changes. Also due to the small but non-zero mass of a Neutrino, it may help it get past the "infinite density" problem with the speed of light.
Or it could very well be an error. |
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