Why does light travel at 670 million miles per hour?

Impactor returns 2.0 · Post by **Impactor returns 2.0** » Thu Aug 18, 2005 9:00 pm

Why does light travel at this speed? why not 700 m'mph ?

Kup_1 · Post by **Kup_1** » Thu Aug 18, 2005 9:06 pm

Speed bumps.

Señior's Covenant · Post by **Señior's Covenant** » Thu Aug 18, 2005 9:11 pm

Why not 800 million mph then? 900? How about 1000? It's a nice round number.

Jetfire · Post by **Jetfire** » Thu Aug 18, 2005 9:25 pm

I believe it's due to the units we have chosen rather than light itself.

Brendocon · Post by **Brendocon** » Thu Aug 18, 2005 9:28 pm

Shockwave's fault.

I measure distance in units called smugs. 1 smug is equal to roughly 67 miles.

Light travels at 10 million smugs per hour.

Sorted, innit?

Impactor returns 2.0 · Post by **Impactor returns 2.0** » Thu Aug 18, 2005 9:32 pm

ok why does it travel at 1 smug?

why not a bit faster, what governs the speed of light, is it friction with elctro-magnetism or somthing? answers I demand the...

rebis!

*opens kennel*

Legion · Post by **Legion** » Thu Aug 18, 2005 9:56 pm

speed cameras i reckon are to blame

Señior's Covenant · Post by **Señior's Covenant** » Thu Aug 18, 2005 9:57 pm

Well, that's it then. The answer to Impy's question is that cameras are addicted to speed.

Metal Vendetta · Post by **Metal Vendetta** » Thu Aug 18, 2005 10:12 pm

http://science.howstuffworks.com/light3.htm
Gives some explanation, though I suspect they are talking down to us.

Impactor returns 2.0 · Post by **Impactor returns 2.0** » Thu Aug 18, 2005 11:44 pm

thats sort of ok, but can ppl see what im asking here?

Im asking 'why' does light move at the speed it does, what governs its speed, what difference does it make if it was slower, or perhaps faster. what in the universe made it move this fast in the first place.

"hello im a light wave, and today I shall be moving at X speed!" - why?

After watching a C4 drama/docu on the ppl behind E=MC2, and how E,M,C2 were concived I was left asking a question, why does light travel at speed X ?

certain factors must effect light and im sure for some high level physics people its probaly relevent.

asking questions is all important?

Metal Vendetta · Post by **Metal Vendetta** » Fri Aug 19, 2005 12:07 am

Isn't it to do with its place within the electromagnetic spectrum? Visible light (the kind we can measure) has a certain frequency and wavelength and therefore energy, and travels at a certain speed (presumably with a slight variance due to whether it's towards the red end or the violet end) and infra-red, microwaves and radio waves have a different speed, right? Does that make sense or am I talking bollocks?

Impactor returns 2.0 · Post by **Impactor returns 2.0** » Fri Aug 19, 2005 12:15 am

it makes some sense, but light being the enitre spectrum itself, red,green,blue etc... doesnt the lot travel at the same speed?

Post by **snarl** » Fri Aug 19, 2005 1:19 am

Freddie Mercury travels at 669 and spreads the old AIDS wherever he goes - bad AIDS I migt add. Light does what it's got to.

Kup_1 · Post by **Kup_1** » Fri Aug 19, 2005 1:24 am

snarl wrote:Freddie Mercury travels at 669 and spreads the old AIDS wherever he goes - bad AIDS I migt add. Light does what it's got to.

what in the....?????

Impactor returns 2.0 · Post by **Impactor returns 2.0** » Fri Aug 19, 2005 1:45 am

Kup_1 wrote:
snarl wrote:Freddie Mercury travels at 669 and spreads the old AIDS wherever he goes - bad AIDS I migt add. Light does what it's got to.
what in the....?????

seriously, because rob said it, it makes sense to me - all is good again.

Jetfire · Post by **Jetfire** » Fri Aug 19, 2005 11:00 am

Legion wrote:speed cameras i reckon are to blame

jboyler · Post by **jboyler** » Sat Aug 20, 2005 7:13 am

Check out these articles:

http://en.wikipedia.org/wiki/Physical_constant
http://en.wikipedia.org/wiki/Permittivity
http://en.wikipedia.org/wiki/Permeabili ... gnetism%29

I have not a clue what the last two are talking about, but I'm fairly sure the answer is in there, somewhere.

-J

Guest · Post by **Guest** » Sat Aug 20, 2005 9:19 pm

Well, I was going to do some explaining, but I see that rob got in first, and his explanation does all the talking anyone needs to.

Well, ok, I'll say something in a slightly-technical way to appease your questioning mind, impy, but it'll be to do with the speed of light, and not other aspects of light, ok?

Light is the propagation of electromagnetic energy within the spacetime continuum. This propagation does not travel at any speed as we understand it, but is the necessary rate at which to traverse a block of spacetime on one of the diagonals. We perceive this to be a speed, however, as the axes of the block, if shown diagrammatically, are of both distance and time, distance/time=speed.

The speed of light is always a constant, even though it's called 'the speed of light in a vaccuum', because even in the most dense of objects, there is still a lot of space between the individual particles. The particles themselves have mass, however, which in turn produces gravitational fields, which distort the spacetime around them. This causes the direction the light takes to change, and therefore when it eventually leaves the object, it has taken a much longer route than if the object hadn't been there, it appears to have travelled more slowly.

An example of this is nuclear activity in the Sun's core. The energy generated from fusion in the Sun's core begins its journey away from the Sun. But, due to the large diameter of the Sun, and therefore the sheer amount of particles in its way, that energy's journey is extended to something around a million years before it even leaves the Sun's surface. If it is not absorbed by any of the Sun's particles before then, that is.

As to differing wavelengths and frequencies, light still has only one speed, but increasing the frequency (decreasing the wavelength) increases the energy, so when under the influence of a refractive object's particles, there is a greater energy change in high energy light, than in lower energy light, and therefore a greater change in direction to compensate for the resultant change of momentum.

I hope that's cleared that up, but I'm sure it hasn't.

TransFans.co.uk

Why does light travel at 670 million miles per hour?

Re: Why does light travel at 670 million miles per hour?