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10,000 times faster than light | 661 comments | Create New Account
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10,000 times faster than light
Authored by: ailuromancy on Sunday, March 31 2013 @ 04:15 AM EDT
10,000x light speed is about warp factor 9.9

Star trek uses technobable - not jargon. Their definition of warp factor depends on what episode you are watching, so warp factor 9.9 does not mean anything.

what do photons weigh at those g-forces?

It is hard work trying to identify a meaningful question in there. Star trek is reasonably consistent about warp factor being a velocity. 10,000x light speed is also a velocity. g-forces are caused by acceleration - the rate of change of velocity. If something were travelling at 10,000x the velocity of light, its velocity would be constant, so the rate of change of velocity would be 0. 0 acceleration means the g-forge is 0. Weight is the force of Earth's gravity acting on a mass. At the Earth's surface, weight is about 9.8 Newtons / kilogram. The mass of a photon depends on its colour. The formula you need is:

m = h / lc

h is Planck's constant (6.6x10^-34 Js).

c is the speed of light (3.0x10^8 m/s).

l is the wave length. The wave length of green light is around 5.5x10^-7 m.

Put those together, and a photon of green light has a mass of 4x10^-36 kg. The weight of that photon is about 3.9x10^-35 Newtons at the surface of the Earth.

would the photons create their own cavitation black holes?

That really is confused. Photons travel at the speed of light. The do not travel at 10,000x the speed of light. In Juan Yin's experiment, there are two entangle photons 16 km apart. Describing the polarisation of the photons in English is not easy. Before you open the box, Schrödinger's cat is neither alive, nor dead but in a superposition of both states. Likewise before you measure the polarisation of one of the photons, it is neither up nor down, but in a superposition of both states. When you open the box, you either find a live cat or a dead cat. Likewise when you measure the polarisation of a photon, it is either up or down.

The fun part of Juan Yin's experiment is that there are two entangled photons. After you measure the polarisation of one photon, the other photon is no longer in a superposition of polarisation states. Its polarisation is the opposite of the first photon. Somehow the results of measuring the first photon change the state of another photon 16km away. Pretend this information is carried for one photon to the other by magic ghost tribbles. Juan Yin's experiment shows that if magic ghost tribbles exist, their speed is at least 10,000x the speed of light.

I think a part of your question refers to relativistic mass increase of matter. The mass of a physical object depends on its velocity. If you plug a velocity faster than light into the appropriate formula, the mass is an imaginary number. If you try to do an experiment to find out what that means, you find you need an infinite amount of energy to accelerate a physical object up to the speed of light. As most people cannot afford an infinite electricity bill, they have to give up before their test object even gets to the speed of light.

If you try to apply that formula to a photon, you do not get anything useful. Photons only have one speed: the speed of light. You know the mass of a photon when it is going at the speed of light - remember green photons have a mass of about 4x10^-36 kg. If you use the formula backwards you can get the mass of a photon if its velocity were 0. The result is 0 kg, for any colour of photon.

"Aha", you say. "I may not be able to afford enough electricity to accelerate a brick up to the speed of light, but what if I start with something that is already going at the speed of light? I can test what an imaginary mass means! If I drop a brick down a well, it gains energy - goes faster. I am going to drop a green photon down a well." The bad news is that does not work as you had hoped. The green photon does gain energy, but it cannot gain velocity as it can only travel at the speed of light. Instead, it changes colour and gets bluer - and its mass increases.

What about magic ghost tribbles? If they actually exist, there is no reason to assume that they use the same formula for mass as a brick - after all, photons don't. Also, you would need to invent a machine that measures the mass of a magic ghost tribble. Good luck with that.

Next up: Cavitation. When you spin a boat's propeller really fast, the propeller leaves the water behind and creates bubbles. The bubbles later collapse with a bang and cause a shock wave that damages the propeller. I am not sure what cavitation is doing in the same sentence as photons and black holes.

There are some ways to squeeze your question into something that has an answer. Photons have mass. Put enough mass in a small enough space and you get a black hole. 'Small' photons have a bigger mass than 'big' ones. Photons do not really have a size. If you know the exact mass of a photon, then the photon is an infinitely long wave. If you restrict a photon to a practical length, you cannot measure its mass with complete accuracy. The smaller the space where a photon can be, the greater the uncertainty in the mass. There is half an excuse for pretending a photon is one wave length long. Now that we have a size and a mass, we can use the formula for the Schwartzschild radius of a black hole:

r = 2 G m / c^2

r is the Schwartzschild radius (the name is black shield, not child).

G is the gravitational constant (6.7e-11Nm^2/kg^2).

c is the speed of light again.

Put enough mass inside the radius, and you get a black hole. If we set l (wave length of a photon) to 2r, the least massive photon that would be a black hole would have a mass of 2.7x10^-8 kg, and a wave length of 8.1x10^35 m. That mass may look a bit small, but express it as an energy, 2.4x10^9J, and you can see the problem. A really big ultra-high energy cosmic ray is about 50J (40,000,000 times the energy of a particle at LHC). Pretending that a photon is about one wave length long is a small step compared to using equations at energies 10^15 times bigger than the experiments that have been used to test them.

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