# Does light slow down?

In class I have learned about light and how it is luminous and non-luminous.

I was wondering if you can make it so 1 beam of white light can be hit against another white light will the light bounce back but because of the 2 speed will it cancel each other out? and by beam I mean really small. and does light have different speed depending on energy so is my idea wrong?

Grade 10 science sorry for being stupid.

Relevance

Yes, light does slow down, but not in the way you are thinking.

The speed of light in a vacuum in a constant. It does not slow down no matter what. In fact, if you were in space and turned on a flashlight and tried to race the beam of light--if you were moving at 99% the speed of light, it would still appear to be moving at it's normal speed (compare this to chasing a car at 100mph. If you're moving at 99mph, the car only looks like it's traveling 1mph to you).

When two beams of light run into each other, they don't collide in the way that you're thinking. When waves (whether they're electromagnetic waves, ocean waves, sound waves, etc) collide, they exhibit a phenomenon known as 'interference'. They don't slow down or anything like that--instead, they combine at the point where they collide and their amplitudes sum together. The amplitude has nothing to do with the speed of the wave.

The frequency of the light determines the energy of the photons in the light. Higher frequency, greater energy. Again, nothing to do with the speed of light (except in certain cases I mention below).

The speed of light is a constant depending on what type of medium it's traveling in. Light has one speed in a vacuum, regardless of what frequency/energy it has. Light has a different speeds in different materials such as glass, water, and even air (though when light is travelling in something other than a vacuum, it has a different speed at different frequencies--that's why when light is shined through a prism, you see the rainbow. It's because the different speeds of the different colors of light are bent differently and become separated. Though in general, the higher the frequency, the slower the light propagates, even though it has more energy. Confusing, huh?).

You might think that since light can't escape a blackhole, it must slow down by the gravity and become trapped. Just like you throw a baseball into the sky and it slows down and comes back. Not so. The heavy gravity actually curves spacetime so the light thinks it's traveling in a straight line out of the blackhole but really it just goes around in circles. As an example, think of a plane flying through the sky. The plane thinks it's flying straight--but if it kept going it would just orbit the earth in a circular path. When light is caught by a blackhole, essentially the same thing happens.

And hey, don't *ever* be sorry for asking a question. I think it's great that you're interested in this!

Light is a very small portion of wave spectrum. Each kind of wave travels at the speed of light.

Now, think of optical fiber where light is used to transmit information. Light passes through the core of fiber and is reflected as it travels. Is the speed of light changed or inhibited? The answer is 'NO'.

However, speed of light does NOT change.

• Anonymous
4 years ago

Sorry, you're off. Time quite strikes on a similar value, fairly. What I advise is that in case you have been with the clock that grew to become into shifting close to mild speed(if it quite moved at mild speed it would convert to uncooked capability and be misplaced.. as a clock) it would seem as though purely 10 seconds had handed ( you will possibly purely age 10 seconds ), yet on earth your twin might age plenty extra. that's honestly difficult to entice close the "why" of this, yet while the neatest talkin monkey that ever lived believed it(Einstein) we small brainers are merely gonna might desire to settle for it. the unusual section is that in case you went for a experience at close to mild speed for say a 365 days, the human race might probable injury itself on your absence( it would be like a pair thousand years later or so....).each physique you recognize could have perished of previous age, whether we controlled to stay alive as a race.

• Anonymous