Faster than the speed of light?

Question

I was reading an article about the big chill theory which stated, "The Big Chill theory has been around for decades but has been strengthened by the dark energy findings. If dark energy behaves as predicted, the galaxies will recede from each other at an accelerating rate - eventually faster than lightspeed. When that happens, they will literally vanish from view."

I thought nothing could travel faster than the speed of light. Why do scientists believe it can happen in this case?

Answer 1

A surprising array of answers -- all so far have missed the mark.

ambient_d is wrong about relative speeds (they don't add up that way when the speeds are significant fractions of lightspeed); and yello_tofu is incorrect when he says that relativity doesn't apply to lightspeed.

The REAL answer is that the Big Chill refers to the expansion of space itself. It turns out that there are a couple of ways things can recede from each other. One is by means of the two objects moving _through_ space relative to one another; the other is when the space between the two objects actually "stretches." This is a weird concept, but has been accepted since Einstein's time.

Relative velocities _through_ space cannot exceed lightspeed. But there is no such restriction on the rate at which space itself can "stretch" or expand. _Space_ can expand at faster-than-light speeds; and therefore the things that its carrying within it, can recede from each other at faster-than-light speeds.

Expansion of space is not noticible in the local neighborhood. Just as if you were stretching a huge sheet of rubber, any two dots on the sheet that are right next to each other, won't seem to be separating very fast. But two dots that are many feet apart, will be separating at a higher speed. It works the same way with the expansion of space in the universe. That's why you'll see this faster-than-light thing only in galaxies that are far away from us.

BTW, the article you reading is wrong about the the galaxies "vanishing from view" at the moment they exceed lightspeed. There are in fact about 1,000 galaxies currently catalogued, that are ALREADY receding from us at faster than lightspeed. They certainly haven't vanished from view. It _is_ true that the light from them will gradually get stretched to the point where it loses its energy and we can no longer detect it. But this will happen long after they reach speeds faster than lightspeed.

Answer 2

Things get real complicated with the speed of light, nothing has been clocked going faster than light but every so often things on paper don't work unless the ultimate speed limit gets broken. Most physicists say it due to a lack of knowledge and not a break down of Einstein's theory of relativity.

Of course the one big thing that keeps universe in order is causality, if you do A it will lead to B. If you could had someway of traveling faster than light you would have a way of sending information back into the past, which like a time machine would give to a chance to mess-up the present by affecting the past and thus breaking down causality.

If you read up on String Theory, there some who say the theory supports time travel and others there is no law of physics that says it can't be done but the possibility is probably nil. About ten years ago there was some interesting stuff on the possibility of tachyons traveling faster than light. Which as far as I understand they don't.

I know there has been several good articles in Scientific America magazine. Start with a search on tachyons.

Answer 3

Nothing can travel faster than light -- unless it is a quantum particle "tunneling" through a barrier that, according to good old Newtonian physics, it should not be able to penetrate at all. Physicists have puzzled for decades over how long this mysterious tunneling process takes, but they need puzzle now longer, for it has been measured. And, sure enough, it takes place faster than light.

Quantum tunneling is of more than just esoteric interest. The phenomenon is related to quantum uncertainty, and to wave-particle duality. When two quantum particles, such as two protons, come close to one another, but do not actually touch, the uncertainty in their positions allows their quantum waves to overlap to some extent. As a result, they may "tunnel through" the gap between them, and interact. This is exactly what happens inside the Sun and stars -- protons which are kept at a distance from one another by the repulsion of their positive charge can still fuse together because of tunneling. And that nuclear fusion is what keeps the interior of the Sun hot, and makes its surface shine. Without tunneling, we would not be here.

Answer 4

It is no object WITH MASS can accelerate to the speed of light.Strange as it may sound,the theory is not that galaxies are receding from each other THROUGH space,but rather that the space itself is expanding.Much as if you draw two dots on a balloon and blow it up,the dots appear to be receding,but in reality,the dots don't move,the space between them gets larger.Space itself has no mass,and thus is not constrained by the light speed barrier.Strange but true

Answer 5

I think the science is all still in its infancy. How can we know for sure light speed is the fastest? Mathematics yes but there is nothing yet to prove or disprove the theory.
What about the speed of thought. I'm not talking religion but if there is a spirit world as such - wouldn't the speed of thought be the fasted we could travel? Just a thought....

Answer 6

The warp rigidity works by ability of the indisputable fact that even however rely or something with mass can't return and forth swifter than easy, area itself can. meaning that isn't the deliver that strikes, that is area that strikes by ability of the employer collapsing the area in front of the deliver and increasing the area in the back of it. in reality it shortens the area from easy years to 300 million kilometres. As to the G forces, there are no G-forces to to fret approximately. The warp rigidity isn't a great effective antimatter rocket, yet an engine that strikes area. and because that is area that strikes and not the deliver, then there are no G-forces because of the fact the deliver would not enhance up.

Answer 7

people always get confused and think that they understand realativity theory...what most of these people fail to realize is that space and time are connected...you cant have one without the other. therfore nothing can travel faster than the speed of light...things only "appear" to be moving faster than the speed of light. when space gets "streched" its not "moving" i think people are too used to euclidian geometry. i know this stuff can be very confusing. just trust me on this one NOTHING can travel faster than the speed of light. although these people have a little insight into physics, i think that they just havent actually studied the subject in depth. ill give you these easiest way to understand what is and is not visible in the universe. if the universe started out, lets say 14 billion years ago, then we will not be able to see anything thats farther away than 14 billion light years. hope this helped at least a little!!!!

Answer 8

Our current view of science states that it's impossible to exceed the speed of light. That view will most likely persist until clear evidence to the contrary is presented. Although everyone alive today will have been dead for billions of years by the time you're talking about.

Answer 9

They should more correctly say "faster than light speed relative to each other" If one object is heading north at slightly over half light speed and another is heading south at the same or greater speed, the light from one object will never catch up to the other, thus making them appear to slowly vanish.

Answer 10

An object in space cannot move faster than light.
If space, (not an object), is expanding, as we believe,
there are already areas moving away from us faster
than light. We can never see them, but objects within
them still must observe the local speed limit.