Physics question

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Spacewolf

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My understanding of gravity is that something has to have a mass to be attracted by gravity, and photons have no mass which allows them to travel at the speed of light as they are light (i think). So my question is how do black holes suck in light?
 

Cpt_Oblivious

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To the best of my understanding Black Holes are made of anti-matter which which completely annhilates all matter, thus being a region of nothing, not even light.

And everything has mass unless it's a wave, not a particle such as a photon (in wave form it's simply light energy). It's just so incredibly small it's generally ignored.



Of course I may be wrong. I sucked at physics. I still find it interesting though. So pick one of those two, either they're particles and thus have mass to be affected by gravity or black holes are made of anti-matter.

Edit: I am WRONG! Stop correcting me damnit.
 

JWW

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Light acts as both a particle and a wave. Otherwise, I can't help you.
 

Aunel

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wow, that's a great point you got there actually...

you must be like, smart...
[small]just let me play bass, I am not smart enough to tackle this kind of stuff[/small]
 

HardRockSamurai

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1. We're still not sure if they can.
2. A black hole's gravitational pull is believed to be so strong, it can pretty much suck in anything, except for time (although it's theorized that it can bend time.)
3. Please use Google next time.
 

Captain Pancake

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I'm guessing protons must have some mass if that is the case, however minute. Thus, the only thing with a force strong enough to affect light would be a black hole.
 

effilctar

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E=1/2m*v^2. since the maximum speed of a particle is 300,000,000ms^-1, if a photon has more energy than required, it goes to it's wass, so yeah. Photons can temporarily have mass, it's all quantum mechanics.

(The above statement is more than possible to be bullshit.)
 

Cpt_Oblivious

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HardRockSamurai said:
A black hole's gravitational pull is believed to be so strong, it can pretty much suck in anything, except for time
But isn't time mostly based on individual perception?
 

Hurr Durr Derp

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Cpt_Oblivious said:
To the best of my understanding Black Holes are made of anti-matter which which completely annhilates all matter, thus being a region of nothing, not even light.
Black holes are made of superdense matter, not anti-matter.

On topic, IIRC photons are supposed to have exactly zero mass so they're not attracted by a black hole, it's just that once they get past the event horizon they get absorbed and can never get out anymore. I'm no expert though.
 

effilctar

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HardRockSamurai said:
1. We're still not sure if they can.
2. A black hole's gravitational pull is believed to be so strong, it can pretty much suck in anything, except for time (although it's theorized that it can bend time.)
3. Please use Google next time.
Time's a dimension, not a phsyical entity so it can't be absorbed, though time slows down so much near the epicentre that it appears to stop.
 

ResonanceSD

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Cpt_Oblivious said:
To the best of my understanding Black Holes are made of anti-matter which which completely annhilates all matter, thus being a region of nothing, not even light.

And everything has mass unless it's a wave, not a particle such as a photon (in wave form it's simply light energy). It's just so incredibly small it's generally ignored.


Of course I may be wrong. I sucked at physics. I still find it interesting though.

A black hole is a collapsed star. This means that it has an extremely strong gravitational pull. As a result, the event horizon of a black hole is what we can detect, primarily because the resulting mass of the star is now so dense that it's pull warps space around it. It certainly isn't antimatter.

Also, google will provide much better answers!
 

Axioma

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Cpt_Oblivious said:
To the best of my understanding Black Holes are made of anti-matter which which completely annhilates all matter, thus being a region of nothing, not even light.
I'm afraid you're completely and utterly wrong.

As for light, it always travels in a straight line, assuming local spacetime is flat. However, around mass, spacetime is distorted, causing the straight line to become a curve, which is why light bends around heavy objects, such as stars.

The reason why black holes are black is different, however. Any object with a certain mass has an escape velocity. An object's escape velocity is how quickly you need to move off the object's surface to escape its gravity. For planet earth, for an example, the escape velocity is around 11 km/s.

Black holes have an escape velocity greater than the speed of light.
 

ResonanceSD

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Cpt_Oblivious said:
HardRockSamurai said:
A black hole's gravitational pull is believed to be so strong, it can pretty much suck in anything, except for time
But isn't time mostly based on individual perception?
Time does exist, however, it's all relative.

Physics joke aside, measurement of a temporal aspect of the universe is possible. But a year is different from each point of space it's measured from when considering that a human "year" is an orbit of the Earth around the Sun. Time in a Black Hole is (theoretically) very slow.
 

10BIT

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Cpt_Oblivious said:
To the best of my understanding Black Holes are made of anti-matter
Wrong. Black hole are actually points of incredibly high density, hence the large gravity. (or at least that's the current theory)

The reason why light gets sucked in is due to anything possessing energy having a mass gain directly proportional to the energy, so while light is massless at rest, it has mass when it's moving as it possesses kinetic energy.
 

j0z

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Light is both a particle and a wave, and all particles have mass.
And no, Black Holes are not anti-matter, they are a singularity where the gravity is so strong that light can't even escape. Even our sun bends light around, although it is imperceptible to the naked eye.
 

moose49408

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That's kind of a fuzzy area; you're actually hitting on a bit of Einstein's relativity there. To put it short, all gravitational objects affect light, not just black holes. (In fact general relativity was proven by observing that the location of stars shifted from where they should have been when the sun passed in front of them, meaning that the sun's gravity altered the trajectory of the light from those stars) The explanation is a little to complicated to go into here, but here's a link that might help:

http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/961102.html
 

HardRockSamurai

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Cpt_Oblivious said:
HardRockSamurai said:
A black hole's gravitational pull is believed to be so strong, it can pretty much suck in anything, except for time...
But isn't time mostly based on individual perception?
On earth it is. However, there's theorized mathematical model called Spacetime, which suggests that time acts as a fourth dimension, only distorted by gravity, such as a planet's gravitational pull. This might help explain it: [small](the white graph represents time)[/small]
So on earth, yes, time is purely the time we see, but in an environment with less gravity, like space, time would be different. In other words, the time in which we perceive space on earth isn't necessarily the time it's operating at.
 

Canid117

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Light is actually electromagnetic radiation and has several properties similar to matter.

And J0z is right Black Holes are (so far as physicists know) balls of regular matter that have become dense enough to trap light.
 

HardRockSamurai

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effilctar said:
HardRockSamurai said:
1. We're still not sure if they can.
2. A black hole's gravitational pull is believed to be so strong, it can pretty much suck in anything, except for time (although it's theorized that it can bend time.)
3. Please use Google next time.
Time's a dimension, not a physical entity so it can't be absorbed...
I never said it was.