Understanding Light Physics: Tips and Tricks for Beginners

[springbottom]

-Im kinda bad with physics and just thought any help with understanding this is great

So I just read on the internet a little bit about light, and as far as I have learnt, light is made of photons, and photons demonstrate qualities of both particles and waves. Whilst apparently they have no mass, because they are particles does this mean that technically if we could somehow group them that we could make "solid light"? Also, after reading about constructive interference (just a little bit), I was just wondering if we shined, say 1000 torches, arranged in a semisphere, at one single point, does that mean that at that point all the light waves converge and make that area brighter than the surrounding area? And since photons demonstrate qualities of a particle, does that mean that in this area there is a "denser" form of light?

 

[tiny-tim]

hi springbottom! welcome to pf!

Whilst apparently they have no mass, because they are particles does this mean that technically if we could somehow group them that we could make "solid light"?

neutrinos do have mass, but we can't still make anything "solid" out of them, since they don't interact enough with each other, or with anything else

light interacts more strongly than neutrinos (because, unlike neutrinos, light "feels" the electromagnetic interaction), so we can clump light together into laser pulses …

that's about as good as it gets​

… if we shined, say 1000 torches, arranged in a semisphere, at one single point, does that mean that at that point all the light waves converge and make that area brighter than the surrounding area?

yes

(but they're not stationary there, they're just passing through)

And since photons demonstrate qualities of a particle, does that mean that in this area there is a "denser" form of light?

i suppose so …

but what good does it do?

 

[springbottom]

i guess there is no way to make like say a car from really dense light huh

or am I just being really dense

hohonahh I am just like have very little knowledge with this kind of stuff and I was just thinking that if like THEORETICALLY if you made a car from light and you rode it, then if you moved ANY PART OF YOUR BODY like a fraction then wouldn't it mean that you are going faster than the speed of light? After trying to explain this to some of my friends they end up laughing at me(which i can understand) something about "speed of light is relative to you?" and "if you are going at the speed of light, nothing works any more?" Just wondering, what WOULD happen if you had like MANY MANY MANY MANY energy and you went at the speed of light? Because only light can go at the speed of light (lel) that means, would you... BECOME LIGHT? I asked around, but apparently you would become a body of infinite mass or something (black hole)

help pls

 

[tiny-tim]

hi springbottom!

… if like THEORETICALLY if you made a car from light and you rode it, then if you moved ANY PART OF YOUR BODY like a fraction then wouldn't it mean that you are going faster than the speed of light? After trying to explain this to some of my friends they end up laughing at me(which i can understand) something about "speed of light is relative to you?" and "if you are going at the speed of light, nothing works any more?"

your friends are correct, if the object "made of light" is moving at the speed of light, then you can't keep up with it

if you can persuade the light to move in a circle … for example, a laser pulse in a circular tube … then of course you can ride with it, but really you'll just be riding on the tube!

Just wondering, what WOULD happen if you had like MANY MANY MANY MANY energy and you went at the speed of light?

you can't

no matter how much energy you add, you can never quite get to the speed of light

 

[sardar]

Hello there! It's great that you are interested in learning more about light physics. Light is indeed made up of particles called photons, which also exhibit wave-like behavior. And while photons have no mass, they do have energy and momentum. As for your question about "solid light," it's not possible to group photons together to form a solid because they are constantly moving and interacting with their surroundings.

Regarding constructive interference, yes, if you have a large number of light sources all shining at the same point, the light waves will indeed converge and create a brighter spot at that point. This is because the waves are all in phase (meaning their peaks and troughs line up) and thus amplify each other. And while the photons in this area may seem to be "denser," it's important to remember that they are still individual particles and not a solid mass.

I would also like to mention that the behavior of light can be quite complex and is still being studied by scientists. There are many interesting phenomena and theories surrounding light, so don't worry if you feel like you are just scratching the surface. Keep exploring and learning, and don't be afraid to ask questions or seek out resources to help you better understand this fascinating subject. Best of luck on your journey to understanding light physics!