Gravitational Lensing General

you can try it at home, just take a photo of your mom

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>>8721101
INCLUDE ME IN LE REDDIT SCREENCAP GUIS

>>8721101
OP BTFO

>>8721096
Is gravitational mirroring a thing also?

>>8721146
idk

>>8721101
wow

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>>8721101
>>8721133
>>8721139
>>8721196
This thread is cancer

>>8721206
>So I'll bump it

Nice going, faggot. You're the real cancer.

>>8721210
bump

>>8721096
mass and energy bend spacetime (if you're interested read about einstein's GR)
when there is a large concentration of mass/energy (like a galaxy or a black hole) spacetime is bent to such an extent that it makes light move in an extremely curved path, just like a lens.
that's about it.

>>8721213
So basically wouldn't light be affected by gravity?

>>8721220
gravity = the curvature of spacetime.
we're basically talking about the same thing.

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>>8721096
Fun fact : If you're seeing gravitational lensing, you are looking directly at a blackhole.

>>8721228
>>8721228
But shouldn't light have mass to be affected by gravity?

>>8721231
No.

>>8721231
you don't have to have mass, you just need to have momentum, which light has.

>>8721240
So basically light acts like it has mass?

>>8721242
i wouldn't exactly put it like that, but yeah, that is the general result.

>>8721245
Ok, thanks anon.

WHO THE FUCK INVITED /POL/

>>8721255
some wagecuck brainlets

>>8721255
Dude, there's nothing wrong with people wanting to learn.

>>8721240
how can you have momentum with no mass?
p=mv
m=p/v
either p and v need to be 0
or m > 0

>>8721270
Light sort of acts like it has mass, but doesn't.

>>8721270
[math] p = \hbar / \lambda [/math]

>>8721270
E=mc^2 + p^2 c^4 actually
it's enough if you have energy
or
p = hv/c if you like where p is momentum

>>8721280
oops i fucked that up
it should have been
E^2 = (pc)^2 + (mc^2)^2

>>8721280
Isn't it E^2=(mc^2)^2+(pc)^2?

>>8721280
sorry anon i posted >>8721288 before the post >>8721287 appeared and then it appeared when i posted it.

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>>8721101

>>8721293
cuck

>>8721101
>>8721133
>>8721196
>>8721206
>>8721210
>>8721211
>>8721255
>>8721257
>>8721293
>>8721294
this

>>8721146
no.

>>8721276
what is this formula called?
Is this a different type of momentum than the type people commonly talk about, which is defined as p=mv? or does mv=ℏ/λ?

>>8721446
That's the de Brogile hypothesis.

>>8721446
momentum is classically taught as a 3 dimensional vector with 3 spacial components:
[math] p=m(v_x \hat{x} +v_y \hat{y} +v_z \hat{z} ) [/math]
But momentum is actually a 4-dimensional vector in space-time. The 3 spacial components, along with a time component which is equal to E/c (the energy of the particle divided by the speed of light). For photons, the mass is 0 so there is only a time component. The energy of a photon corresponds to the wavelength, that is where that formula comes from. So for photons, [math] p=E/c= \hbar / \lambda [/math] . For particles with no energy, [math] mv= \hbar / \lambda [/math] . But I'm not sure if particles without energy actually exist, so more generally you can say [math] (mv)^2 - (E/c)^2 = ( \hbar / \lambda )^2 [/math] (this is just pythagoreans theorem but the temporal component gets subtracted instead of added for some reason that nobody has really explained to me)