What is a black hole?And I mean the kind that occurs in outer space.

you mean what causes it?

i dont know a whole lot, but i have researched them because they are fascinating. its the strongest force in the entire universe. gravity is so powerful that light cannot exist inside.

they don't know what causes them. only theories. one being that it is the result of an imploded planet.

yeah there is alot of evidence that its a collapsed star. after it becomes a supernova, the structure collapses in on itself and creates a massive gravitatonal force. they say that there is a gigantic one at the center of our galaxy. they really are amazing, its unfathomable that light cannot exist inside.

i love anything to do with space and the crazy forces beyond our solar system.

i work in biochemistry but haven't the faintest clue about astrophysics. there are plenty of random pop-science books that you can get anywhere on this topic though.

http://cosmology.berkeley.edu/Education/BHfaq.html#q3

planets don't have enough gravity to cause a black hole.

this is all about gravity. what happens is if you think of space as a wet papertowel, hold it flat and you and then roll a grape on it. you will see a dimple in the paper towel around the grape. the heavier (actually dense) the object the greater the dimple. not imagine if you got something insanely heavey. it would stretch out the paper towel and rip through it. that is a blackhole.

Morbid_Mike said:

Its not so much a collapsed star, it needs to be something with a greater mass (even more than the sun). Some say that after a star supernovas, it forms a neutron star (a star with the size of a large planet, but the mass of a full star). Then, because of the mass, it collapses in on its self and forms a black hole. Also, the gravity of a black hole is not what keeps light in it. Honestly, scientists don't know why light is not released from a black hole, but they do know its not because of gravity. Like, if the sun was to turn into a black hole, we would not be sucked into it. It still has the same gravity as before.

yeti, "light" as we see it doesn't escape but energy does. black holes actualyl radiate energy all the time. the band that they radiate just aren't visible to us, such as X-Rays.

Also, most stars do not have the ability to turn in to black holes because they don't have enough mass. I'm fairly certain that our sun would never turn into a black hole cause you need more mass than our sun has to make a black hole. if our sun tried to turn into a black hole, the outward forces and balancing forces of the atoms themselves would over power the gravitational collapse that would be necessary.

next, light. light is made of photons which are massless, but light has momentum and can be precived when it hits something.
http://www.newscientist.com/article/mg16622424.300.html
there is a simple school experiment that proves this

since light has momentum, simply put, the event horizon of a black hole is a curvature in space-time and the gravitational forces behind that can change the momentum of the photos thus pulling them back into the black hole (or at least keeping them at the event horizon)

actually Man of the Century, you are both wrong and right. Einstein's theory of general relativity explains why... but it's just a theory, right?

people have been trying to disprove this applied part of it for a long time and have failed. how can they prove it wrong? find the mass in a photon. to this day, they have been unable to find the mass of a photon. therefore, einstein's theory is still correct and we do know why light doesn't escape a black hole.

thank you rev, that was extremely enlightening.

I studied a lot of science all through out school. in the end, I followed the money and went with computer science. still, in college, I took 2 advanced chemistry classes, 2 physics classes, advanced biology, advanced microbiology, and a few others. almost all of my science courses in college were 5 credit courses. (normal classes are 4 credits at my college). I also watch the science channel like it's a religion.

i was going to post a picture of a black chicks asshole but i'd probably throw up before i could even post it.

I think the best analogy for thinking of light not escaping the event horizon is thinking of the event horizon as a donut. space-time is warped back in on its self so when light travels away from the black hole the path it has to take (due to gravity's effect on space-time) is a loop along the donut back to the center. and it does this forever. the think that blows people's minds is that it does this at 670M miles per hour.

that is awesome. i would love to see what the inside of a black hole looks like. where does it lead? does it even lead anywhere?

Stephen Hawking, A Brief History of Time

well.. I'm guessing if you were looking forward you wouldn't really see anything different from the outside.
if you were turned around looking out, I'm guessing that you would see all the light around you bend in towards you. it would look like a fisheye and all the light would shift up towards blue (frequency increase) and beyond that... you would start to see infrared, then radio waves as visible light. and then sound.. and then um.. the frequency of your clothing oscillating as you hit the singularity, all the frequencies collapse into an infinite frequency wavelength.


I'm assuming that this would start with a subtle shift of the star light to blue and you would start to see your view fisheye, seeing stars that are behind you. as these stars shiffted off the blue end of your vision, other things would come in that arent visible (other stars/galaxies/etc) and then those would run off the end of the spectrum.
then the entire sky would slowly start glowing and just get brighter and brighter and brighter until you hit the singularity.

remember, there's a reason we can't see radio wave.. or the oscilations of our figures on the keyboard.

Einstein's theory is accepted as fact (I do as well). I just recognize that alot of the theory is built aroung light. And in all actuality, less is known about light than most people think.

I did mess up on how I worded that though. I'm sure that most people have seen the picture of a black hole with one column of light in the middle of it:



The light isn't being sucked in to the black hole because of gravity. Its actually the only place in the Black hole where light can get out. Thats because of the doughnut thing you described, rev.

Also, protons do have a mass. Its just so small that it isn't a factor in anything, not even on the quantum level.

they still haven't found the mass of a photon yet. there for it is still mass less and if they find out that it does have a mass then einstein's theory breaks down.

I searched and as of 2003, if a photon has mass, it needs to be less then 10^-51 grams. and electron is something like 1.7^-29 or something like that.

also, I thought that the "light" that was coming from the blackhole was soley higher energy (gamma/x-rays).

Einstein's theory doesn't work on atoms. Once you get that small, you have to use quantum physics. Rev, have you ever heard of the string theory? I watched a Nova special on it last month, it did a good job at explaning the diffrences and problems with relitvity and quantum physics.

The "light" (I always thought) was a mix of the diffrent higher lever waves. There was some light, but not enough for us to see all the way over here (on earth). Let me go look and double check.

yes, I know conceptually about string theory. it was suppose to be another unifying theory, but it looks like just as neutonia, relativity, and quantum, it doesn't actually unify.. just another theory to use with the others. there is another theory above string theory that they are exploring now. I forget what it's called though and I know nothing about it.

I'm not sure if I saw that nova special. I think it did. it was the one that explained Dbranes? 3 dimension cheerio loops that pepper every point in our 4 dimensional universe, right?

ps: photons still have no mass.

from wikipedia
http://en.wikipedia.org/wiki/Photon

Photon mass and photons in a box

Although a single photon has zero mass, multi-particle objects including photons may collectively have mass. For example, a mirrored box containing a gas of photons, or even a single photon, with total energy E will have greater mass (by Δm = E/c²) than if the box did not contain photon(s). [In the case of a single photon, the weight must be taken in the inertial frame in which the mass of the photon and box sum to zero, see mass of systems in mass in special relativity. However this will generally be close to the rest frame of the empty box.]

ipsofacto photons aint not got no mass.

Rev, an excellent job of explaining all this. I totally agree with the donut analogy and your description of how light would appear to bend in to someone on the inside. (It kind of reminds me of what the cone did to the barrier between the second and third dimension in Treehouse of Horror. "Crap, crap, crap, crap, crap, crap...")

String theory is the shit. I think when people understand what goes on at that lowest common denominator (assuming the universe really has one), we will have a new insight into the mysteries of the brain, the nature of emotion and thought, the intangible powers of music and art, and humanity's perceptions of deity.

the_reverend said:

Thats the one.

the_reverend said:

This whole time, I was reading Proton. But seeing how I'm retarded and you were saying "photon", yeah, you are right. But a photon does have a mass as long as its in motion...

In theory...

hahaha oh man. that was pretty fucking funny.

well that was very informative. chris i'm sure we'll be yammering about this later on on the porch.

we'll have to make it a bluntastic good time.

I don't remember what the theory was called is basically explaining things smaller than Strings (more than 7 dimensions)... it had some name that was based off the String-name... something like stiches or thread theory. Anyhow, I have a feeling that it's going to be really tough to come up with a grand unification theory that folds everything into something we can quantify. the reason is cause when you change your perspective, other things come in to play.

basically:
when looking at the night's sky, nutonia principles work

when looking at matter and energy, einstein's the bomb.

when looking what makes up matter and energy, quantom mechanics.

when looking up what makes up the things that make up the things that we study in quanta, String Theory.

each has their place.

Launch proton torpedoes!

ion cannon....


fire...

proton's have ton's of mass (relatively speaking).

photons don't have any mass when they are moving either (that we've found yet). they do have momentum though! and can be used to push a space craft through space.

I got an A+ in Astronomy but I've already forgotten most of it.

You spelled 'Getting dinner on the table when I get fucking home' wrong.

So Rev, I'm assuming the reason photons can push a spacecraft despite having no mass would be that photons exist as energy and not as matter?

I'm sorry, did you say something about wombats?

Something about cyanide capsules make the meal.

they can push a space craft because they have momentum.

I actually already posted the picture of a radiometer above. here is the "why" of it
http://science.howstuffworks.com/question239.htm

the_reverend said:

I got that part, but that wasn't my question... I'm asking whether photons exist as energy but not as matter.

(I'm thinking: 1. If something has no mass, how can it be matter? 2. That "momentum" has to exist in some form; if not matter, then energy, right?)

Am I totally on the wrong track here?

you knew it was only a matter of time...

you are walking into the basic principle of light here. the answer is 1 and 2. a photon acts as both a particle (matter) and a wave (energy).

you can take a picture, there by regristering all the particles hitting the film (or ccd) inside your camera. you are in essence "sampling" them.

now, take a piece of paper cut a small hole through it and shine a flashlight on the backside. let the light hit a wall. as you get closer and further, you will see the pattern spread out more or less, ie a wave!

So a particle of matter can have no mass... interesting. I don't understand how that would work though... and doesn't a mass of 0 mean that the measurements of each side also have to be 0? How does the thing even exist as matter if it has no measurements to speak of?

I guess you have to qualify that it acts "like a particle" and "like a wave". the effect that you observe from this particle on the other side is in terms of energy, not mass.
E=mcsquare dooder

the_reverend said:

OK, so then my original assumption that only energy cannot have mass was correct (as long as I keep in mind the principle suggested by great minds from Einstein to Data that would seem to contradict it: that matter and energy are ultimately interchangable)

Hopefully I have it right now...

My mom says there are alot of black holes in Africa.

the_reverend said:

are you thinking of F-theory?

Also, for the formation of a black hole, don't the gravitational forces of the compressed atoms in the pre-supernova stage (i.e. in a white dwarf, or neutron star) need to exceed the Chandrasekhar limit? Where the repellant charge forces inherently in the atom are too weak to overcome the gravitational forces exhibited upon it by it's high density, resulting in a collapse and the excess energy getting blown off via nuclear reactions? It's been so long, I'm probably crossing wires here.

Very intelligent question from flying poop destroyer.

(Never thought I'd ever type that sentence)

A little info that may help people (like me) that got a little confused through this:

Photons, themselves, are just a theory. They are needed to make a lot of theories work, and these theories are proven in other ways, but no one can figure out the photon itself.

Did a little looking around over the weekend... I have no life.

yep, you sort of got it going on there.
smart things.