If light can travel forever through space,what type of locomotion makes it move?

Question

According to Einstein,light has mass,that is the reason light gets trapped in a black hole to never be seen again,but if light travels at such speed what makes it go

Answer 1

Everyone answering that "light has no mass" are all wrong. Light does in fact have mass, though very very tiny. For any object to be affected by gravity, it must have mass. For light without mass, gravity would be a none-issue. Black-holes would have no effect on light. Light has no REST MASS (because it can never be at rest!), it does have an effective mass which (it turns out) has all the properties one expects from MASS - in particular, it has weight in a gravitational field [photons can "fall''] and exerts a gravitational attraction of its own on other masses. The classic Gedankenexperiment on this topic is one in which the net mass of a closed box with mirrored sides increases if it is filled with light bouncing back and forth off the mirrors! And as most us know, black-holes swallow up light with a vengeance. Therefore, light has a mass.

Is that weird, or what?

Light follows the laws of thermo-dynamics of the conservation of energy and Einstein's law of energy mass equivalence but only to a point. The newtonian laws have proved valid for all mechanical problems not involving speeds comparable with the speed of light and not involving atomic or subatomic particles. Therefore to answer your question, what makes light move is its natural momentum as a particle with mass that has stored energy by its conversion from some other form of stored energy to maintain its state or behaviour unless acted upon by an external force. What messes everything up is that when light passes through glass it slows down, and regains its speed upon emerging from the other side. This is where light's duality as both a particle and energy come to play. It behaves as a particle in one instance and as an energy in the next. What makes it even messier is that light itself hasn't slowed down, but instead our perception of time has changed. Time itself is plastic and changeable. Pandora's box is wide open. Should I keep going?

Answer 2

The speed of light is an aspect of it's existence.
If a photon stops it goes out of existence.
The universe is a finite entity so nothing can travel forever.
With a black hole,if it could exist,the surface gravity is such that the escape velocity is greater than the speed of light so the entity would not be visible.

Answer 3

Ok, I have to chime in here.

First, Osku is 100% dead wrong. Light has no mass. It exerts a pressure, but light is pure energy. Yes, like everyone has already said, energy and mass are equivalent - meaning one can be converted into the other by the factor c^2, or the speed of light squared. To say light possesses "effective mass" is like saying a donut possesses "effective light". It's stupid. Light and energy are equivalent through Einstein's special relativity, but EM radiation, including light, has no mass. Period.

Second, as others have said, light is affected by gravity due to the warpage of space - it has nothing to do with light having mass. The more massive an object, the more it warps space. The greater the warping, the greater the ENERGY required to escape the warp. That's why it's easier to escape the moon's gravity than the Earth's - Earth is more massive, so it requires more energy to reach escape velocity. Eventually you reach a mass where space is so warped even pure energy (EM radiation, including light) cannot escape. That is the definition of a black hole. Under these conditions, generality relativity says no known force can stop the warping of space. Time, mass, and space are warped into a singularity, where known physic breaks down.

What Osku is referring to is relatavistic mass, and that is not used in physics (see link). A little knowledge is a bad thing. Questioning whether light has mass is one thing - stating definitively it does not makes you look like an idiot.

Answer 4

No, light does not have mass. What Einstein said is that energy and mass are the same; like looking at different sides of the same coin. Light is pure energy, an electromagnetic wave.

Now, since the time of Newton, scientists thought that since light was a wave, it needed a medium to move in, like sound needs air or water waves need water. They even invented a name - Ether. Then they determined all the physical properties Ether must have - but no one ever found a shred of evidence that Ether existed. By the very early 20th ca, it was clear that Ether either did not exist, or would be undetectable.

When Einstein created special relativity, and looked at Maxwell's EM laws, he found they were invariant. Essentially, the magnetic component propels the electrical component, which propels the magnetic component, etc, to infinity. That's not really correct in a strict sense, but you get the idea.

So light does not have mass - it is pure EM energy, which is self-propelling.

Answer 5

Light does *not* have mass. It can't escape a black hole because the gravity of the black hole causes space to collapse in on itself so that there is no way out.

Light travels through space as an expanding wave because space conducts it, as first described by James Clerk Maxwell.

Answer 6

Light is electromagnetic radiated mass. Where the molecules are in friction at such a speed that heat is eminated, light and it's speedis created. But even radiation expires with time and the light dims even though it travels billions of light years and will eventually blot out.

Answer 7

Think of light as a vector.

The reason light might get trapped is NOT because it has mass, but because gravity bends space. Light travels a straight line through space, but since the space through which light travels is bent by gravity, the path it takes appears bent.

Light is particularly fascinating. It does not age--no time passes for a particle of light. As far as light is concerned, it is not travelling at all. From the perspective of a particle of light, the universe lacks dimensions of time and space. A particle of light might stretch across the breadth of the universe in, from its perspective, no time whatsoever.

But light is far, far stranger than that. In the two slit experiment, if you set up a detector to switch on AFTER light passes through one of the slits, you destroy the interference pattern. How does the light "know" you're going to make an effort to detect which slit it passed through AFTER it does so?

Personally I think it has to do with the fact that here and there are foreign concepts to light, but, who knows?

Answer 8

These are physical theories based on speculation which is continually proven false. The next world is not physical. Also, the Bible tells us no one can die and come back. In fact the only person to have done this was Paul the Apostle. He said it was not lawful for him to describe what it was like, and that it would be impossible anyhow. These near death experiences are false. I remember on TBN there is a book by a young boy who claims he say a female angel on the other side. Excuse me but angels do not have offspring except in the case of fallen angels. The Bible never describes female angels, they are all male.

Answer 9

If you throw a ball in space it will keep going forever.
If you emit a photon in space it will keep going forever.

if a ball is thrown into water, it will slow down and eventually stop.

if light "hits" a medium like the earth's atmosphere, the average speed of the photons will slow down due to scattering.

Answer 10

all light particles travel in a wavelength pattern .