Thread: Which is faster?

Oh, nothing is faster than the speed of light.

I agree.
Don't even think to doubt that.
Nothing goes faster than light.

that was one of my points. then i thought, how can you really measure the speed of gravity? can you send gravity from one point to another in order to measure its speed?...

Errr... does this even make SENSE??? First of all, how would you measure the 'speed' of gravity?

how can you really measure the speed of gravity

simple, find something that would generate a measurable amount of gravitational waves (like two black holes colliding) find when the event occurred and then measure how long the waves took to get to the measuring thingy and then do distance/time to find the speed.

I saw the answer on a ducomentary about string theory here. The gravity part is on 2nd and 3rd chapter of Einsteins dream. Basically they make a scenario where the Sun dissapears. In newtons theory all the planets would fly away before the light would eaven reach them. Ofcourse Einstein saw a problem and solved it by finding out that a gravitational wave (on the fabric of space-time) would travel with the speed of light. The lack of gravity would take effect exactly when the light reached the planets.

Also en.wikipedia.org/wiki/Speed_of_gravity .

As far as I know, gravity can be faster, givin the size of the object creating the gravitational pull. This is the reason why an object large enough to create a black hole can keep light from escaping, or, at least, that's what I was able to get out of a recent conversation.

yes light cannot escape the pull of a black hole, surely that means the gravitational force caught the light and dragged it in FASTER then the light could escape.

I heard somewhere you CAN in fact go faster than the speed of light...

The speed of light in vacuum is about 300.000 km/s. It is abbreviated as C.

Now the speed of light may vary in different materials. The speed of light in water, for example is 0,75C.

Now it is proven that you can go faster than the speed of light: Can you imagine a nuclear reactor? It has a large reactor core filled with water. In this water, the electrons are fired which trigger the reaction. Now these electrons actually go faster than the lightspeed in water.

Did you ever see the inside of the core? If you have, even on photographs, then you probably think about one thing: What is that blue fog?

Well: It isn't fog, It is radiation... Cherenkov Radiation to be exact. This radiation comes into existence when objects are travelling faster than the speed of light's constant in a medium.

So: Technically speaking... You would be able to go faster than light...

"Light" is photons, and photons are the carriers of the electromagnetic force (= they travels through space to transmit the repulsion or attraction force between electrically charge particles).
In the same way, gravity is believed to be composed of (transmitted by) gravitons.
Photons and gravitons have no mass, and like any particle with no mass, they must travel at C, the "speed of light".

And as already posted, the wikipedia page says that Speed of gravity is equal to the speed of light according to the latest experiments.

( Nothing can go faster than C, the speed of light in vacuum. It is possible to go faster than "the speed of light in a material", because it's less than the absolute C)

The article about the most recent tests that proved gravity travels at the speed of light was posted here a while back.

Right now it is possible for information and elementary particles to travel faster than the speed of light. However, the method is far from stable and usable.

Originally Posted by Squall

Right now it is possible for information and elementary particles to travel faster than the speed of light. However, the method is far from stable and usable.

Quick reply : No. It is not possible.

Detailed reply: I'm not a physicist, but I follow the research. Mainstream news sometimes report physic experiments with a sensationalistic wording wich completely destroys their real meaning.
If we had found a way to transmit real information (energy, particles) faster than light, it would be huge. It would be the first serious failure of Relativity (and the first sign of interesting new theories to come).

However there are some "effects", predicted by Quantum Theory, which appear to be instantaneous accross huge distance; however, they occur in a way that make them unusable to transmit information or energy.
It basically can be summarized this way: two particles are "linked" in a certain way (called quantum entanglement), and they can each travel at an opposite side of the galaxy. Then, we ask them the equivalent of flipping a coin. The "effect" is that we can now be sure that they both got the same result. There is no useful information transmitted, because it's random (we can't choose the result, and can't use it to communicate).

One of these "action at a distance" is for example Quantum teleportation. These effect cannot be used to transmit informations; however they are useful, for example to generate the same random key at two distant points, which can be used for cryptographic communication at the usual speed of light.

Look up EPR

This proves that some things go faster then the speed of light.

If we had found a way to transmit real information (energy, particles) faster than light, it would be huge. It would be the first serious failure of Relativity (and the first sign of interesting new theories to come).

Worm holes don't contradict relativity.

This proves that some things go faster then the speed of light.

No it doesn't, a wormhole just shortens the distance between two points.

No it doesn't, a wormhole just shortens the distance between two points.

I made two comment one on EPR i.e. This proves that some things go faster then the speed of light which it does, and one about wormholes Worm holes don't contradict relativity. Time is relative so a wormhole would be taken as moving faster then light to another observer.

Gravity is like hitscan shit, man.

It works 'right away', riiight?

Originally Posted by Neruo

Gravity is like hitscan shit, man.

It works 'right away', riiight?

You'd think so but if a massive object were to suddenly appear, there would have to be a finite propagation time from appearance till when the full strength of the "field" takes effect or reaches its full extended distance. If that makes any sense.

(I didn't read the entire thread so pardon me if that's already been mentioned, disputed, whatever.)

I haven't read the replies too carefully but guys, nothing travels faster than the speed of light. Nada. Zip.

The reason why light cannot escape black holes is because of the immense gravitational pull. A black hole basically bends the fabric of the universe. But you cannot conclude from that that the pull of gravity is faster.

By the way Wikipedia has been shown to have false information on many occasions. Which is disconcerting.

If you want to know more about the speed of light and why it's the fastest, go read Stephen Hawkings. If not that then any credible textbook will do.

well , i have the belief that gravity is a force reather than a particle.
Its not that it travels faster , but rather its always here.
Even the furthest particle in our galaxy has a gravity field that it even reach us.
But its such a infinite tiny force that we cannot feel or measure by any means.
There is already an algorythm to find the gravity field of every object.

Imagine space being a blanket.
If you instanteniously put a rock on the blanket , it will instanteniously affect all the blanket no matter the dinstance.

I've read that in quantum physic gravity can be explained better if we imagine this force as particles , called gravitons. But its not that they are measured yet. Gravity still is the most peculiar force for the scientists.

EDIT: oh , and about wormholes.

Speed is said to equals distance/time. In a wormhole the distance between 2 points is 0 , so you can't really measure the speed there. Its just that , there is no distance to measure. How can you measure your speed if you are standing still? O>O

Gravity can cause things to go faster I believe. If there is a black hole, would light speed up as it is getting pulled into the black hole like everything else? If that is true, doesn't that mean that light can go faster than the speed of light? I have no idea whether I am right or not, it is just my theory.

If gravity waves move at the speed of light, and gravity is merely a stretch in the fabric of space/time, then does this mean space/time cannot move faster than light? That is, the you cannot overcome the light barrier by moving space/time rather than yourself? Or was this idea already rubbish anyway?

Originally Posted by RedfishBluefish

If gravity waves move at the speed of light, and gravity is merely a stretch in the fabric of space/time, then does this mean space/time cannot move faster than light? That is, the you cannot overcome the light barrier by moving space/time rather than yourself? Or was this idea already rubbish anyway?

Yes, I think that thoretically they want to create the warp-drive. Which bends space and goes way faster than light. I'm no scientist, but I think it has something to do with the casimir effect, quantum vacum, zero point energy...?

Edit: I searched a bit and I found an article on NASAs website :http://www.nasa.gov/centers/glenn/research/warp/warp.html

Originally Posted by RedfishBluefish

... then does this mean space/time cannot move faster than light?

Who said time moves? We're the ones that move through time. Therefore I deduct time is stationary.:p

Originally Posted by Harrycombs

Gravity can cause things to go faster I believe. If there is a black hole, would light speed up as it is getting pulled into the black hole like everything else? If that is true, doesn't that mean that light can go faster than the speed of light? I have no idea whether I am right or not, it is just my theory.

Light doesn't speed up upon entering a black hole. A black hole bends the fabric of the universe and all light is doing is traveling along that fabric, same speed as always.