A Question Concerning Blackholes

student101 · Dec 6, 2005

I actually have 2 questions for y'all. Question 1: Do blackholes consume mere light and darkmatter, or can they also consume physical matter like comets, asteroids, planets, etc? Question 2: Is there any matter too big for a blackhole to consume? I'm guessing that the answer is no. Even an object as large as a planet might not be swallowed whole, but picked apart on a molecular level.

Saiph · Dec 6, 2005

comets asteroids and the such are "light and dark matter". Light matter is matter that emits light, dark matter is matter that does not. Now, there can be some odd properties to dark matter (i.e. we can't find enough asteroids, dust, planets, etc to make up all the dark matter, so there may be another set of stuff out there) but that doesn't exclude comets and the like. So black holes can absorb light (photons) and matter. There is no size restriction to what it can consume. There is a rate restriction (you can only chuck stuff in so fast before a countering pressure builds up, akin to how water doesn't instantaneously disappear down a drain). <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

kmarinas86 · Dec 7, 2005

I prefer the Earthling's perspective of the black hole versus the "black hole's perspective of itself". Suppose we live long enough to see a black hole evaporate (Hawking Radiation). Wouldn't it evaporate? Wouldn't the matter never cross the even horizon from our perspective? Before it crosses the event horizon from our perspective, the black hole is gone - !@#!@#!poof!@#!@!##@!. Even quarks "evaporate"....

CalliArcale · Dec 7, 2005

<blockquote>In reply to:<hr />Question 2: Is there any matter too big for a blackhole to consume? <hr /></blockquote> As Saiph said, no. The problem is that people tend to think of black holes as, well, holes. And obviously you can't get anything into a hole which is bigger than the hole, right? It just won't fit. But black holes aren't really holes in the conventional sense. They're superdense objects. So if you throw a really fantastically big object at it, the two objects will collide. Exactly what happens will vary depending on what you're throwing at the BH, how fast, how dense it is, etc, but the most likely outcome is that they will end up merging. The black hole's mass will grow by the mass of the object you threw at it. In fact, that'll even happen if you're chucking a black hole at another black hole. They'll merge into a single black hole. This may take some time; it likely will not be an instantaneous event. <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

vi3tbomba · Dec 7, 2005

We've never seen a BH in action right?

astrophoto · Dec 7, 2005

There is currently no proof that a black hole exists. That's not to say they don't and that certain observations aren't conveniently explained by their existence ... but no, we've never seen one ... think about it, it would be pretty hard to see one since they are theorized to trap light.

harmonicaman · Dec 7, 2005

Onw way we postulate the existence of BHs is by observing how matter acts in their vicinity; specifically, we see stars and other cosmic debris orbiting these objects at fantastic speeds which can only be accounted for by the presence of an extremely heavy mass - this massive object is not illuminated because we believe the gravity is so great that it traps light. There are several other observations that also infer the existence of BHs.

siriusmre · Dec 7, 2005

They can "only be accounted for by the presence of an extremely heavy mass" ONLY in a paradigm in which gravity rules. There are other viable paradigms and there are other ways to account for the observed motions. <div class="Discussion_UserSignature"> </div>

scull · Dec 7, 2005

Because neutron stars exist, it's not much of a big leap for me to believe that black holes also exist. --

siriusmre · Dec 7, 2005

"Neutron stars" have the same fictional ring to them that "black holes" do. Like "black holes," they are a mathematical construct invented to try to fill a gap in a gravity equation. Just because they exist in a math equation does not make them "real." The shear complexity of modern gravity theory makes me doubt that it accurately portrays Nature. Nature loves efficiency. The theory that Truthfully describes the universe will be exceedingly simple and holistic. <div class="Discussion_UserSignature"> </div>

scull · Dec 7, 2005

Neutron stars are real. They were discovered in 1967 by the British astronomers Jocelyn Bell and Antony Hewish, who noticed a periodic pulsing in a radio signal. Due to this signal, the object began to be called "pulsars." pulsars = neutron stars --

neutron_star69 · Dec 7, 2005

so if neutron stars are real does that mean black holes have to be real?

scull · Dec 7, 2005

Right. Like I said (above), it's not a big leap to think so. <img src="/images/icons/smile.gif" /> --

student101 · Dec 7, 2005

I studied some more on Black Holes, and they seem to be Red Giants that have imploded due to the nuclear fusion core of the star, not being able to withstand the intense gravitational force caused by the mass of the star itself. The star implodes, all molecules of it being packed into a much smaller size.This super-dense mass has the same amount of gravitational force that it had as a star, being able to pull in and absorb many and all objects.

siriusmre · Dec 7, 2005

Correction: A PHENOMENON was discovered in 1967. Astronomers merely took their gravity tool out of their toolbox--cause that's the only one they got!--noted that some of those pulses were extraordinarily fast and POSTULATED the gravity-only concept of "neutron stars:" stars made up of nothing but neutrons. <img src="/images/icons/rolleyes.gif" /> Those are as imaginary as the Tooth Fairy. They exist ONLY in the imaginations of astronomical mathematicians. Just like "black holes." <div class="Discussion_UserSignature"> </div>

scull · Dec 7, 2005

The DISCOVERY of a neutron star was announced to the world with a paper published in Nature on Feb. 28, 1968. Since then other pulsars/neutron stars have been discovered, including the neutron star in the middle of the Crab Nebula, known as the Crab pulsar. Zwicky was right -- these objects do exist. --

nojocujo · Dec 7, 2005

In fact, that'll even happen if you're chucking a black hole at another black hole. They'll merge into a single black hole. This may take some time; it likely will not be an instantaneous event. If there was a merger of bh's why would it not be at near light speed. That would be almost instantaneous to me.

Saiph · Dec 8, 2005

Now, for a flurry of posts: Astrophoto: There is abundante evidence for the existance of black holes. Lots of observations and phenomena indicate objects with the properties of black holes (very massive, very dense, not emitting light). However, there is no "direct" observation of a black hole. But that isn't necessarily required to have a high confidence in their existence. Afterall, direct observations of atoms and atomic structure came quite some time after everybody was confident of that property of matter. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

Saiph · Dec 8, 2005

<blockquote>In reply to:<hr />They can "only be accounted for by the presence of an extremely heavy mass" ONLY in a paradigm in which gravity rules. There are other viable paradigms and there are other ways to account for the observed motions. <hr /></blockquote> Well, not "only" in such a paradigm, but that is the paradigm used, and for good reason. Observations of the strength of every other force fail to provide sufficient means to create the phenomena we see in most cases. Electrical, magnetic, weak and strong forces aren't strong enough. This isn't just a mathematical extension either, but a measurable quantity. The presence of electrical or magnetic fields creates tell-tale signs in the surroundings. These signs do not indicate fields strong enough to shape most phenomena. Now, that said, I believe these have a larger affect than is currently believed (still less than gravity though). For instance, gravity will be the main driving mechanism in the collapse of interstellar gases to form a star. However, ambient magnetic fields likely steer (to a lesser extent) regions. Changing the magnetic field could alter the rate a particular clump collapses (but not as much as gravity does) or could be the deciding factor between the formation of one, two, or three stars from a single clump. Neutron stars started out as a solution to a mathematical model, actually a quantum mechanical system, asking what could provide a countering pressure to gravity for a star without an active energy source. However, now there is plenty of evidence (even direct evidence) of their existence. <blockquote>In reply to:<hr />The shear complexity of modern gravity theory makes me doubt that it accurately portrays Nature. Nature loves efficiency. The theory that Truthfully describes the universe will be exceedingly simple and holistic.<hr /></blockquote> Don' <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

harmonicaman · Dec 8, 2005

Student - "This super-dense mass has the same amount of gravitational force that it had as a star, being able to pull in and absorb many and all objects." The gravity is still the same, it's just that it is now occupying a very small area! BH's do not act like universal vaccuum cleaners sucking in everything around them! The orbittal mechanics do not change around a black hole. BH's have stable Solar Systems just like stars; the only thing that has changed is that the mass of the object has now collapsed into a very small area; otherwise things stay the same.

CalliArcale · Dec 8, 2005

<blockquote>In reply to:<hr />If there was a merger of bh's why would it not be at near light speed. That would be almost instantaneous to me.<hr /></blockquote> It would depend on their relative velocity vectors; basic celestial mechanics. Once they ran into each other, they would be a single black hole. But it might take some time for them to actually touch, depending on how they encountered one another, just like it took Comet Shoemaker-Levy 9 some time to smack into Jupiter. <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

CalliArcale · Dec 8, 2005

<blockquote>In reply to:<hr />I studied some more on Black Holes, and they seem to be Red Giants that have imploded due to the nuclear fusion core of the star, not being able to withstand the intense gravitational force caused by the mass of the star itself. The star implodes, all molecules of it being packed into a much smaller size.This super-dense mass has the same amount of gravitational force that it had as a star, being able to pull in and absorb many and all objects.<hr /></blockquote> That is correct -- the star isn't suddenly more massive now that it's a black hole. You can have microscopic black holes with a mass of only a few grams; density (not mass) is what makes a black hole a black hole. But perhaps not all black holes are formed through the collapse of giant stars. For instance, there is a class of black holes called supermassive black holes. These are far too big to have formed in that way; they could never have ignited as a star, because they were too massive to have resisted their own gravity even that way. They are believed to reside at the cores of galaxies. One has now been detected at the center of our own. There is a radio source called Sagitarrius A* that had long been suspected to be a black hole, but of course the problem with black holes is that you can't see them. You can only see their effect. (Even the radio waves aren't actually emitted by the hole itself; they come from matter being torn apart in its near vicinity.) But recently, astronomers observed a star orbiting very close to Sagitarrius A* to determine whether or not it was in fact orbiting the radio source. Scientists have known for centuries that you can determine the mass of an object by observing the movements of its satellites, so if this star orbited Sagitarrius A* and they could determine its orbital elements, they'd have the mass of the object. Turns out, it is indeed orbiting the object. The star is mo <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

astrophoto · Dec 8, 2005

Because there is observed evidence of a supermassive object or tightly packed objects we cannot directly see does not make it a BH with all the inherent properties that name implies including the singularity.

siriusmre · Dec 8, 2005

Exactly, astrophoto. I am not saying that the observations are wrong; I am questioning the assumptions that drive the interpretations of the observations. So, no, my rejection of the standard assumptions does not negate the observations, nor is that my aim. I am merely advocating a different set of assumptions, a different way of interpreting the same phenomena. <div class="Discussion_UserSignature"> </div>

siriusmre · Dec 8, 2005

<blockquote>In reply to:<hr />"Observations of the strength of every other force fail to provide sufficient means to create the phenomena we see in most cases. Electrical...forces aren't strong enough."<hr /></blockquote> You're kidding, right? Electrical forces are 10^39 times stronger than gravity. <blockquote>In reply to:<hr />"The presence of electrical or magnetic fields creates tell-tale signs in the surroundings. These signs do not indicate fields strong enough to shape most phenomena."<hr /></blockquote> Tell me, what is the most efficient way to create magnetic fields? How do we do it here on Earth? With an electric current, right? <blockquote>In reply to:<hr />"For instance, gravity will be the main driving mechanism in the collapse of interstellar gases to form a star."<hr /></blockquote> Are you sure about that? What if the assumptions underpinning this model are wrong? All this assumes that galaxies, stars, and planets are all isolated bodies in space that have no connection to each other. I just don't think that that is right. Too many "anomolous" observations have been made--especially in the broader EM spectrum--and too many "fixes" have been made to the theory for me to swallow it whole any more. I am not saying that Newton was wrong; I am not saying that Einstein was wrong. I am suggesting that perhaps their models were incomplete. Once people became "convinced" that there can be no charge separation in space, a whole avenue of fruitful research was closed. But WHAT IF there IS charge separation? Then many of the standard assumptions are wrong. And, while pulsars (in the strictest sense of stars that pulse) are real, "neutron stars" may not be. Maybe they pulse for a COMPLETELY different reason that is equally scientifically sound. <blockquote>In reply to:<hr />"However, now there i</blockquote> <div class="Discussion_UserSignature"> </div>

A Question Concerning Blackholes

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