How does light travel at light speed?

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it fast...Show more

You information was incorrect about all energy having mass. Radiation, or light waves contain no mass. Some people argue that it has an 'effective mass' given by some of the E=hf (engery=plank's constant times the frequency), but that's still debated. Reguardless, light has no mass, and that's why it can travel @ the speed of light c. You are correct about accelerating a partlice towards the speed of light would require infinite amount of energy. If you're really intrested look @ Lorentz transformations, and you can see the fairly easy why anything with mass can not reach the speed of light....Show more

No one as actually answered the question. The question basically was 'why can't particles with mass reach the speed of light?'

The answer is that mass is resistance to acceleration. You need to do work and put energy into a particle to accelerate it to any speed. As you approach the speed of light, relativity tells us its mass must also increase. A particle which has mass can never reach the speed of light because any energy put into it at high velocities will only serve to increase its mass, not further increase its velocity. Therefore you need and infinite amount of energy for it to reach the speed of light.

Light has no mass, it is a wave. It is a changing electric and magnetic field. The reason it travels at the speed of light is that that is the only speed it may propagate that allows a changing magnetic field create an electric field and visa versa....Show more

The speed or velocity of light is approximately 186,000 miles per second or 300,000 kilometers per second in a vacuum. All electromagnetic waves--which include visible light--travel at that speed. With such an enormous speed, it has been difficult to devise experiments to measure it. The speed of the electromagnetic waves slows down when they pass through matter. According to the Theory of Relativity, the speed of light is the fastest at which anything can travel.

Since the speed of light is so great, it is very difficult to measure.

Note that the terms speed of light and velocity of light are used. Either one is acceptable, but you must remember that speed means how fast something is going, while velocity means how fast it is going in a given direction.

t was thought that the velocity of light could be measured that same way as for the velocity of sound. A common method to measure the velocity of sound is to calculate the time it takes for an echo to return and then divide that by the distance the sound travels there and back. Since distance equals velocity times time:

c = d / t

where

* c = speed of light (light's speed is always denoted as c)
* d = distance traveled
* t = time it takes to go that distance

But the velocity of light is so large at 186,000 miles/sec (300,000 km/sec), that in 1/1000 of a second, the light would travel from Milwaukee to Chicago and back (or from Los Angeles to San Diego and back). That is over 90 miles (150 km) one way.

If you used a timer or shutter that could measure in 1/100,000 of a second, it might be be more practical....Show more

Light is Unique combination.
We are still learning about the properties of light.

Sometime light acts as Electro magnetic Wave which has no mass and can travel at speed of light, but other times it acts as a small particles moving very fast (called Photons)

You will learn this if you take College Level electro magnetic course

EM Fields-1 & 2

thanks
SANDIP...Show more