Light??

[Tenshi]

Re: Light??

When an object travels faster, the more massive it becomes, and it needs an equal amount of energy to push it along. But, at about three-quarters the speed of light, an object has infinite mass, so it needs infinite energy to travel, and it is impossible to have infinite energy, because energy can never be created or destroyed. All the energy in the universe would nowhere be enough to make an object travel at the speed of light.

So the fact that light and other electromagnetic waves, such as microwaves, DO travel at the speed of light means that they have no mass, as so need no energy to move them.

 

[Harte]

Re: Light??

<div class='quotetop'>QUOTE(\"Tenshi\")</div>

When an object travels faster, the more massive it becomes, and it needs an equal amount of energy to push it along. But, at about three-quarters the speed of light, an object has infinite mass, so it needs infinite energy to travel, and it is impossible to have infinite energy, because energy can never be created or destroyed. All the energy in the universe would nowhere be enough to make an object travel at the speed of light.

So the fact that light and other electromagnetic waves, such as microwaves, DO travel at the speed of light means that they have no mass, as so need no energy to move them.[/b]

Tenshi,

Mass becomes infinite only at the speed of light. Below are the equations for mass increase with velocity and constriction of length, taken from:
http://www.johnstonsarchive.net/relativity...specialrel.html

Here, L and m are the length and mass, respectively, of an object at rest; L' and m' are the values for the moving reference frame.

A photon has relativistic mass that enables it to be affected by a gravitational field. Were this not true, light could escape from black holes and solar sails would not work. Additionally, the measurements made during eclipses I mentioned above would all be incorrect.

A photon's rest mass = 0. Tell me the next time you see a photon at rest.

http://math.ucr.edu/home/baez/physics/Part...hoton_mass.html

Harte

 

[thenumbersix]

Re: Light??

<div class='quotetop'>QUOTE(\"Harte\")</div>

A photon's rest mass = 0. ?Tell me the next time you see a photon at rest.

http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/photon_mass.html[/b]

heheh, would be interesting to see what happens to it.