/sci/ - Science & Math

it has almost no mass

>>2990505
This

Also, light is an electromagnetic wave that is self propagating.
http://simple.wikipedia.org/wiki/Light
http://en.wikipedia.org/wiki/Light

>>2990505
Hm, but what I want to know is, what propels it?
I know there's almost no friction, but what's making it move from a nonmoving object to such insanely high speeds?

>>2990505
> Implying light does have a mass

>>2990505
Well, not entirely accurate. Light has no mass but it has inertia and momentum due to relativity. Also known as relativistic mass.

>>2990505
It has zero mass. Theory demands it, experimental upper boundary is around <span class="math">10^{-18}\frac{\mathrm{eV}}{c^2}[/spoiler].

>>2990513
it's self propagating you fuck

>>2990505
Light doesn't "amost have no mass"

It has no mass literally.

How come light cant travel at 300,000,000m/s? If you were light wouldn't you be really pissed that you could hit that milestone

>>2990518
Why? What makes light like this? Is sound the same way?

>>2990513
The fact that it is a self propagating wave of energy is why it moves so fast.

>>2990526
no sound bounces off things. stuff doesnt make sound, but stuff in contact with other stuff makes sound. light doesnt need contact between stuff to be light

you cant ask why

>>2990526
sound is a disturbance in a medium, such as air. Sound does not self propagate as it is a single energy wave. Light has an electric wave creating a magnetic wave and they keep creating eachother. This is why it is known as an electromagnetic wave.

>>2990526
about time we pull out Feynman's response to why questions

>>2990526
The next step down is quantum field theory, where light is an operator on a many particle fock space, with its properties defined by gauge invariance. I don't think that's the answer you were looking for. The easy to answer questions have to end somewhere, don't they

Not philosopherfag or a theologianfag but gonna try and answer a why question from the only perspective I know how: pop science.


light is the way that it is because that was a condition of the energy from the quantum fluctuation that spawned everything.


How did I do?

>>2990545
No, that's what I'm looking for, bro. I want to know exactly how, as deep down as I can. Feynman's "why" speech thing is what I want. I want to ask why, why and why again and go down to the furthest property of light. Doesn't matter if I don't understand completely, I'll just store the info in my head until I find more info that allows me to complete a full understanding.
So gimme some sources where I can read about this quantum field theory!

Light bulbs are not actually "light bulbs" but dark absorbers. When you turn them on, they suck the dark out of the room. You can prove this by holding your hand under a "light bulb". The dark will stack up under your hand where its path to the absorber is blocked by your hand. When they quit working and turn a dark color, it's not because they burnt out, it's because they're full.

>>2990588
Really? o,o

>>2990588

>No kick
The kick is electrons passing through the filament(or gas in halogen bulbs), Causing other electrons to constantly jump between energy states, as they jump down they release a photon.

>>2990571
You can read the introduction of the Wikipedia article to get a general idea about how things come together in QFT, but don't expect to understand it. (In fact, the better you understand what's written there, the bigger the question mark will be.)
The absolutely shortest answer that isn't completely wrong is saying "massless particles fly at the speed of light", but that's not very satisfying if you ask me, because that immediately boils down to "why are photons massless", which isn't explained very easily.

>>2990588
I love these post on /sci/ today. After the time source, this, what's next ?

How can you believe in electromagnetic radiation if it's just a theory (a gauss)?

It's called a physics textbook.
Have at it. Start at page one and read through page 1392. See how long your "why"s last....

Pic related

captcha: rtarcent fish

>>2990639
haha fail