Massive Black Hole Stumps Researchers
 

As each day goes by we seem to learn a bit more about the solar system and Earth's past but this stuff throws up more questions than answers.

I can't even begin to fathom this,yet it fascinates the fuck outta me.

How insignificant are we? WOW.


Link contains a pop up.
LINK & REST OF STORY


Massive Black Hole Stumps Researchers
By Tariq Malik
Staff Writer
posted: 06:30 am ET
28 June 2004

http://a52.g.akamaitech.net/f/52/827...mystery_01.jpg

A team of astronomers have found a colossal black hole so ancient, they're not sure how it had enough time to grow to its current size, about 10 billion times the mass of the Sun.

Sitting at the heart of a distant galaxy, the black hole appears to be about 12.7 billion years old, which means it formed just one billion years after the universe began and is one of the oldest supermassive black holes ever known.

The black hole, researchers said, is big enough to hold 1,000 of our own Solar Systems and weighs about as much as all the stars in the Milky Way.

"The universe was awfully young at the time this was formed," said astronomer Roger Romani, a Stanford University associate professor whose team found the object. "It's a bit of a challenge to understand how this black hole got enough mass to reach its size."

Romani told SPACE.com that the black hole is unique because it dates back to just after a period researchers call the 'Dark Ages,' a time when the universe cooled down after the initial Big Bang 13.7 billion years ago. That cooling period lasted about one billion years, when the first black holes, stars and galaxies began to appear, he added. The research appeared June 10 on the online version of Astrophysical Journal Letters.

Invisible to the naked eye, black holes can only be detected by the radiation they spew and their gravitational influence on their stellar neighbors. Astronomers generally agree that black holes come in at least two types, stellar and supermassive. Stellar black holes form from collapsed, massive stars a few times the mass of the Sun, while their supermassive counterparts can reach billions of solar masses.

A supermassive black hole a few million times the mass of the Sun is thought to sit at the center of our own Milky Way galaxy, and some of the largest supermassives seen date have reached up to two billion solar masses, researchers said.

holy freaking crap!!! that makes absolutely no sense whatsoever. i mean, that would be like having a 3 month old weigh 300 pounds. well, i guess it's back to the drawing board!

astronomy isn't a very reliable science is it? :D

At least science is willing to admit it when something shows that things need to be revised.

Are they talking about length and width dimensions or in terms of mass? I thought that the phyiscal size of black holes was reletively small.

um, so its really really big, and really really old . . . . hmmm, sounds like my mother-in-law

S

That is cool. I wish people gave a crap about astronomy nowadays. It was one of my favorite courses in college. Just don't take it in the fall semester, as those 1:00 a.m. lab sessions get pretty cold.

interesting stuff, thanks for the link.

Whenever I try to contemplate the vastness of outerspace and its many mysteries, my brain whimpers in pain.

I'll just concentrate on my own massive black hole, Mr. Mouth.

Very cool article.

We truly are just insignificant specks on the everchanging tapestry of the universe...

Reality is far more complex than we are physically capable of contemplating.

Did anybody notice this little oddity?

Spews jets of radiation.... wait a minute... *looks down at watch* ah crap.

I'm an Astronomy nerd. I'm taking it in school starting in the fall.

I just wanted to point out that the black hole would be as massive as 1,000 of our solar systems. They don't mean as large. The black hole is probably smaller than our sun, but way more massive. You were correct, black holes are very small. They collapse on themselves constantly, which makes them very small, and their gravity is more forceful than any other known thing, and can even pull in light, this the reason why it's a black hole.

Anyway, something like this doesn't surprise me at all. We have recently discovered that supermassive black holes reside at the centre of most, if not all galaxies in our universe.

There are many different things you have to put into play when looking at the age of this black hole, which wasn't mentioned in the article, and should have been.

When astronomers looked at a recent discovery of a distant supernovae, it appeared that the redshift (how fast it is moving away from us) didn't match with it's brightness based on the current calculations for what it should be.

In other words, when using two different ways to calculate distance, they didn't match.

What did this in turn tell us?

It showed that it's possible that the universe is a) Expanding at an accelerating rate, rather than a constant one, or b) Time is actually slowing down.

If either of these are true, the universe is much older than previously thought with Hubbles calculations, or time was actually moving faster in the past, which would explain why the blackhole looks so old now.

Also, it's thought that the universe is about 13 billion years old, but the actual numbers that Hubbles law proves is between 13 and 17 billion years old. If it's 17, it's more likely that something like this isn't such a huge deal, and it's more likely for something like this to exist.

It is very interesting, however. Thank you for pointing this out. I'll have to do some more research on the topic.




Also, here's a little bit of a better explanation for the above about the supernovae. I am kind of going out on a tangent here, but this will kind of help you understand the unknowns about related subjects such as this, and the fact that they are huge findings, but always played as something bigger than they actually are, in a way. We don't have rethink all of our theories regarding astronomy, but we might have to think about some theories, and what this supports. That's basically what astronomy does. You find something new, figure out everything you can about it, and find out what theories it supports.

Astronomy is one of the most precise sciences. It becomes hard for people to understand when you start talking about things, such as the black hole, that a lot of people don't really understand. Black holes have just recently been proven to exist, and were just theories before this. We don't know what existed before that black hole, or around it, and we will never know. It's possible that our calculations for finding out the age of this black hole is wrong. We might just have to figure out more about black holes, and what they do exactly. Since we can't see inside them, it's hard to know exactly what is going on.

Anyway, now for my whole tangent part of my post. I just thought this was interesting, and might help to explain the 'mysterious' age of this black hole. It's also just to show you that the age factor isn't that big of a deal, and isn't concrete either. The size of it is insanely huge, which makes this black hole amazing.







Recently astronomers took a look at a far off supernova. This supernova was quite interesting, because it appeared that the redshift (how fast it is moving away from us) didn't match with it's brightness based on the current calculations for what it should be.

What does this tell us?

Well, one of 3 things, now.

At first it was believed that this could have been caused by an accelerating universe, rather than an expanding universe at a constant rate.

If this were true then, back when this supernova emitted the light rays that we are seeing today the universe would have been expanding at a different rate. A slower rate. Which would thus explain why the supernova isn't as bright as it's redshift suggests. The redshifts suggests that the supernova should be closer than it actually is, but since the universe was expanding at a slower rate in the past, if this theory were true, then this would explain things a little better.


At this time another theory was also suggested to explain why this supernova appears to be further than what the redshift suggests.

To understand this, you must first understand that the speed of light and time are directly related. It's called time dilation, which is explained by the general (or special) theory of relativity.

Time dilation basically states as your speed increases, time decreases. Or, the faster you move, the slower time goes.

Now, in physics, and astronomy and anything related, we set time as a constant, c. However, if you were to change that constant, it would also change the value of how fast time goes by compared to how fast you are moving.

So, relating to this situation, if you were to set the speed of light, c, at a lower rate for the past than it is now, you come up with a pretty interesting conclusion.

It's kind of confusing to understand, so i'll try my best to explain it.

If the speed of light were moving at a faster rate in the past, this means that the light coming from the supernova would have taken less time to get to us than what we would expect.

Basically look at it this way. If something was moving very fast 10 minutes ago and you measured how fast it got to you, but it was slowing down, you would get some number, lets say x.

If you then measured something that was moving at the rate that this object you just observed at the time it got to you, you would get another number, lets say y.

y has to be greater than x, because it would have taken less time to get to you, since it was moving faster to begin with.

Same thing here. Our first view would be the second object from the above. This is what we would expect from this supernova. But, if the speed of light were slowing down, the objects light would have taken that much less time to get to us, because the light was travelling at a faster rate to begin with.

This would explain why the object seems to be much further than we thought.

The interesting thing about this is, if the speed of light is in fact slowing down, this means that the speed of time is speeding up. If this theory is true, it also changes many formulas, including E=mc^2, because c can no longer be looked at as a constant.


Now, very recently it has also been suggested that another force might cause this to happen. This theory is also supported by many other strange occurences in the universe, such as gravity. The way some cosmological objects move and act, such as black holes and galaxies and such, compared to what is around them, is sometimes very strange.

The theory that 'dark matter' exists in the universe has been around for many years, but you can also apply it to this specific case too.

Dark matter is basically what a lot of things point to. It's kind of there to explain the unknown things that happen in the universe. It's there to explain why some objects act the way they do, and why there is this missing piece of energy (referred to as dark energy).

If you figure out the makeup of the entire universe, with what we know today, and you find the mass of the entire universe, you will end up getting errors, and you will end up getting numbers that aren't consistant with other theories and fomulas to figure out the same thing.

The reason why this happens is summerized by this mysterious 'dark matter', and 'dark energy'.

Basically what they are is, something that is unobservable. It's there, but you can't see it or detect it. It's the opposite of everything else, but produces effects that counter balance our universe into what our theories show. Dark energy is the opposite of gravity, it pushes rather than pulls.

If there is this 'dark matter' in the universe, it could also explain why this might happen with this supernova. The distance that this object has travelled away from us is in fact where the light shows (neglecting dark matter) and is in fact where the redshift shows (because of dark matter).

Basically, the light has to travel though the dark matter, but it doesn't change the properties of the light, except for the redshift. It's hard to imagine, and i don't know much about it, but it's an interesting thought.

Basically if there is this mysterious dark matter, the light that came from that supernova would have traveled through it, thus giving the redshift and brightness of the supernova different conclusions regarding figuring out how far away this supernova is.





EDIT:

I just read my post over, and, well, i didn't do the best job at explaining some things. I'll come back tomorrow and explain anything that anyone has any questions about, and explain myself and thoughts on it a little better. I'm way too tired right now, which is why some of this might not make a whole lot of sense.

Jesus, that is one long post.
But good stuff never the less.
Always interesting to study things much larger than ourselves.

i've always wondered what would happen if one day the universe just ended. or the sun collapsed. we'd all be fucked and no one would have any idea what happened before all life on Earth is gone. we know nothing about the universe and it makes me just want to go out and live every second of life because it makes me realize what little time we have here and how everything we do is so insignifigant that we need to make them signifigant insignifigant things... if that makes sense..... :p

i've always had an idea in my head since i was a kid that the universe is in a jar in some fungus in a janitors closet in another dimension. just hope the janitor doesn't come in and knock over the jar, lol.

I'm curious how much money we're putting into this sort of thing and exactly what great good it's doing to help us. Homeless, hungry, needy families? Fuck that, we've got a black hole we can't see and has nothing to do with us over 12 billion light years away!

*throws cash around into the wind*

The world is small place after all!

Good question. I think astrology is cool and all, but we really shouldn't be spending much of our time and money on much outside of our own galaxy.

It would surprise if the government spent half as much on science as it does on welfare.

I dunno, I'd rather the cash be spent discovering things out there like. The amount spent on this type of research is a good deal at twice the price .

Thanks for the great post toag.

*runs around and grabs analog's cash*

I'd have to go with splick here. When all of my great great great great great grand children are boarding space craft escaping the earth that is slipping into death, they can all look back at analog's ancestors and wish them luck on their floating rock that is about to be obliterated.

It may not mean shit now, but in 10 - 10000000000000000000000 years it may.

And after all, you never know. There is the very good chance that some rock may be speeding toward our general area. That rock may smack into us killing EVERYTHING, or it may come close, throwing us out of orbit, killing EVERYTHING. I like the fact that we stand some chance of having SOMETHING survive as long as we look out for that one thing that may kill us all.

And again, this science may come to help us in every way possible. A force that moves galaxies and ripples the whole universe itself (gravity) may prove to help us all in imense measures. Geeks, and whatever you all may think of the people looking though little lenses on a hill, may be the cause of the salvation of all known life. A microscopic percentage of my tax dollars is well deserved.

I feel discoveries made by astronomy have been worth the time and effort. Stellar navigation helped us travel around the world. It revolutionized the way we see the world (ie. we travel around the sun, we are not at the centre of the universe). Astronomy resulted in space travel, from which we have satellites, superpens, and many discoveries that were made possible because of the vacuum and zero-gravity of space (well relative zero-gravity at least). More stuff about how great astronomy is here. Some stuff about how space travel has benifited the average citizen. Tie-in back to astronomy. Conclusion.

What about the 80 billiion +++ that went to Iraq, for no reason whatsoever. That's a waste of money. Atleast this is peaceful research that will benefit our understanding of the universe. Would you like to live in a mud hut, and run around in a loin cloth?
No? Well, the reason you're not, is because of technology, and advances in science over the ages.

This post sorta got lost in the discussion. They are talking about mass.

Very interesting and cool indeed. *Goes to read "Black Holes and Time Warps" again* Great book for anyone interested in this stuff. Probably a bit out of date by now though, but interesting nonetheless.

Thanks taog,that is one hell of a post.

The concept of feeding the planet only to have it wiped out by something that could be prevented is a risk worth taking imo.
More dollars need to be spent on this planet first.
But.
Mankinds thirst for knowledge,as others have said,re navigation,technology and indeed what lays ahead provides the key.

The balancing act is the hard part.

You have to admit that astronomy (NOT science) has done absolutely nothing to improve my, or your, way of life at home. It has just taken tax dollars away from me, to prevent me from buying comfy chairs and wide screen tv's.
You dont see a little sticker on your computer saying "This was made based on the technology of NASA"


But science, science has done tons to improve my life.
Just cut out that astronomy deal and im happy.

Thanks for the info taog. I understood your explanation quite clearly.

Just my personal opinion without scientific fact to back it up but what we don't know about black holes (and space in general) could be the answer to many problems on our puny little planet, even homelessness.

What sort of effect would free electricity for all have on the political and economical state of the world as we know it?

*edit*

No problem dudes. I'll come back with some more facts, and some things that Astronomy has done to help your life.

I do agree that we shouldn't be spending so much money on moon and mars missions, however. The reason being, we can get it done with robots a lot cheaper and easier.


Also, this bugged me a little, so I thought I would point it out and correct the poster. No harm intended, but I just wanted to point out the fact that Astrology is way way way different than Astronomy.

When people make this mistake, though I know it's harmless, it's like someones nails on a chalkboard.

thanks cchris...

I figure dark matter explains most of what we don't know about the universe.

anyway, I'm not a researcher but I'm stumped too.

No. Supermassive black holes at the cores of galaxies have masses millions of times larger than our sun. The paper claims this one has a mass of around 10 billion suns! The characteristic radius of the black hole then works out to be about 100 times larger than the earth's orbit around the sun. "Regular" black holes only a few times more massive than the sun will be very small -- a few kilometers or so. (I'm using the term radius very loosely here, as the concept doesn't formally exist in this case, but that's a long story.)

There's a lot to say about these things (I deal with black holes for a living), but I don't like writing as much as taog apparently does :D.

That's because NASA doesn't have to advertise. Although not the main point of astronomy to anyone who does it, there are actually a lot of technological spinoffs. Admittedly, this mostly comes from space travel, which isn't really astronomy in the sense of this thread.

I don't want to get into a rant on the fundamental value of knowledge, but arguments can be made that this sort of fundamental research is useful to the average person in the sense you're discussing. The equipment needed to make astronomical measurements usually requires a lot of new technology that often ends up being adopted by engineers later on.

Also, fundamental physics is often tested using astronomy because we don't have the technology to perform any direct experiments. What was considered completely "useless" physics 70 years ago is now used to develop computer chips among other things. Everything is connected in physics.

Fascinating.

you couldn't be further from the truth. there are many things that have been developed by NASA that benefit peoples every day lives. i used to have a list somewhere around on my computer, i'll look for it now, but one of the technologies in particular are artificial hearts. artificial hearts are based on technologies used on satellites. another technology used on satellites that benefits us are solar panels. while solar panels, and the concept they are based on, did not specifically come from space exploration, the required use of solar panels in space has made it so that NASA has had to develop better and more efficient solar panels, which can be used on earth. i'll add more to this list as i find stuff, but it's sheer ignorance to say that space exploration does not benefit us at all.

We're not talking about astrology. We're talking about astronomy. Keep that clear in your mind.

Astrology has to do with fortune telling.
Astronomy has to do with reality: looking at it, figuring it out.

As far as how much money is going into this, figure "not much". And for those who have a problem with that, why, exactly, do we bother living if we don't have any fun?

More to the point, this is basic research. Someone around here has a sig "If we knew what we were going to get, we wouldn't call it 'research'." Leave it at that for now.

Studying astronomy is hardly worthless. Recently a new "force" was discovered and labled the "dark" force, a very bad name conjuring Star Wars tie ins. The dark force was hinted at by Einstein and they think its the reason are universe is expanding and speeding up. The down side is if unchecked the is new force could eventually accelerate the universe to the point were it would stretch us into atoms. Its being debated now and we know nothing about it nor any possible benefits to us. One thing I would like point out unless we study outside our little world we won't know all the rules and will be stuck with what we can expierence here.

okay, while i did not find the specific information i was looking for, i did find some other useful info on why we need to explore space:

Colonization - in another twenty years it is estimated the population of the earth will reach over 8 billion. We could use a place to live.

International Diplomacy - we went to the moon to beat the Russians, now we're building the International Space Station as a way to work with the Russians. Go figure. In any event, prestige and international relations are among the most powerful reasons we've had for going into space.

Natural Resources - some day we may be able to mine the Moon for green cheese and the asteroids for minerals and ores.

Many applications that can be accomplished only from orbit, for example - telephone & TV communications around the world, weather observation and prediction (notably hurricanes), land surveys, and navigation (notably the Global Positioning System, GPS).

And here are some more technological advancements that benefit peoples lives as a result of space research:

Kidney dialysis, which has kept (and still keeps) countless people alive, came from the Apollo program.

New insulin pumps, which can eliminate the need for injections for diabetics.

And the space program is constantly producing new materials for prosthetic devices.

Also, NASA's development of small solid-state lasers led to the development of CD's and DVD's.

so basically, i don't want to hear people whining about how there is no benefit to exploring space. whoever says that is saying so out of pure ignorance.

I have to do nothing of the kind. And astronomy very much is science. It corrects itself when it finds theories conflicting with observed reality, for instance. Just because you don't recognize the benefits doesn't mean there aren't any.

(edit) spelling correction

Oh, and I just wanna say, "super massive black holes are WAAAAAAY COOL!" Like, super chilled, man. But don't put your beer in them for refridgeration! You'll only get them out again in itty bitty bits, sorta, according to Hawking.

OTOH, little tiny black holes are hot stuff! But not in the "porn" sense.

:hmm:

Astronomy led to the discovery that you could navigate the earth by the stars, which led to global exploration, international trade, and a little country called the United States. Astronomy is a science, and it has provided immense benefits to our civilization.

I wonder what our society would be like if we never supported science like this. How many discoveries have we made simply as an offshoot of pure research? How many times has our society benefited from research that had no plausible application at the time?

A few decades ago some guys thought up a form of theory called quantum mechanics. Back then it was revolutionary, but had little application. Who could possibly have imagined that, less than a century later, we would be using that theory to develop the next generation of superfast computers?

The greatness of a civilization is measured by how it treats its thinkers. Our civilization is pretty amazing, and it's in part because we treat our scientists and researchers so well.

Science is the highest form of a society. Advances do not come without research, and pure research and pure thinking leads to giant leaps in technology, society, and living

Great points there degrawj.

It may not be inevitable,but colonization of other planets after the moon might become a reality down the track.
Discoveries may be made that can accellerate what is now deemed just theory.

I know shit when it comes to the technical side of all this but I do know that 50 yrs ago everything we are witnessing now was a pipe dream.

Bring on the next 100 yrs.

okay, this is like the fourth or fifth time that i have gone through this thread reading peoples posts and i just can't help but get really ticked off. i am pretty disappointed that somebody such as a moderator would make a post such as this. as far as i read, the point of the original thread was essentially "wow, this is really wierd and interesting, what are your thoughts on it?" not, "what are your opinions on space exploration and whether or not we should spend money on it." i have gotten reprimanded several times for leaving posts that were off subject and semi-tasteless. but a respectful moderator can feel free to toss his opinion around when it's not the topic of discussion? i wouldn't be surprised if this post gets edited or deleted but this is a serious issue and i hope that somebody does something about it.

That's interesting about supermassive black holes. I didn't know they had such a large 'radius'. I guess they are a lot bigger than i thought. I really don' tknow much about black holes, but find it very interesting that you study them for a living. What do you do exactly?

Also, most of this type of astronomy isn't funded by the government. A lot of it is worked on by profs and students. The students pay the prof's wages, so the students are paying for the research on said topics to be done.

NASA is a space agency, not an astronomical agency. Though they are directly related, and NASA is astronomy based, the goal of NASA is more for inner solar system research, rather than what's beyond the solar system. Though, now it seems that bush has made NASA's biggest goal manned missions to the moon and mars, which i believe is usless right now.

Anyway, the greatest minds and the best discoveries are founded and funded by universities rather than your taxes.

Other than that, Astronomy is good for the reasons that have been stated in this thread.

One huge thing that people need to realize is the fact that an asteriod or meteor could crash into earth, and either destroy earth on impact, or start a nuclear war or something, if a big enough meteor landed overtop of a country who has nuclear weapons. Imagine that, the blast would look like a nuclear explosion, which would cause a chain reaction of 'who bombed us'. The country where the meteor hit might believe it was their enemy, and turn around and bomb them. This could lead to a nuclear war, and the destruction of earth.

This is fully possible. A lot of people would say, 'we have the sky covered. We can see what is coming towards us and when.' The fact is, we won't know, and we can't see. It's impossible to watch every portion of the sky for asteriods of meteors coming to earth, and picking up ones that are heading our way, before it's too late. Hell, a few years back some astronomers noticed another object orbiting earth. At first, astronomers thought this might have been a second moon to earth that had been missed for hundreds of years. It ended up being part of some spacecraft, a mission to jupiter i think. Astronomers weren't surprised that we could have missed a second moon to earth. This proves that we don't have that close of an eye on the sky.

So, astronomy gives us at least a bit more of a chance, because we are always watching the sky. Becauise of astronomy, we just might have a chance to beat that asteriod that just might be heading for earths path right now.

Hey degrawj,I wouldn't worry about it too much as it is people such as yourself that keep people like me posting about weird and wonderful stuff anyway.
Iv'e been around here long enough to know that persistence is the key to getting a point across and occasionally threads go way off topic due to reading something the wrong way.

An example was this.

I thought this hilarious but he and I are more insignificant than his mother in law.

analog may believe that money spent on this is wasted but others don't.
I personally don't have a problem with that so I hope we can all get back on track here.

"Goes back to building space ship".

I do theoretical work in general relativity. So I don't go looking for black holes etc., but work out their (expected) properties, and things related to that.

Recently, I've been looking into the gravitational self-force/radiation reaction problem. An accelerated object will emit gravitational radiation (like a charge will emit light). This carries away energy, so the object will feel a force due to its own radiation. It turns out to be very difficult to work this out properly, but its understanding it has a lot of interesting implications.

You're right that most of these sorts of things are studied at universities, but a large chunk of their money ultimately comes from the government.

I imagine that the astronomers simply used an already-built satellite (probably Hubble since our atmosphere makes Earth-based telescopes exponentionally less-powerful than satellite-scopes in orbit) to find out this information. Not that much money was used. Either way, astronomy is a very, very important science.

Awesome article -- I took Astronomy 1 and 2 at college the past year and can say that it's *easily* the most interesting classes I've had (and probably ever will have).

-Lasereth

Science is hard...

But cool..

Supermassive black holes... Maybe if when we think about it, the answer is like a toilet? We are on the outskirts, whirling around in circles till one day we finally make it in to the center of the black hole, then down the drain we go?

Hmm....

Wow, that's amazing. Congrats on being one of the few people in the world that actually challanges their mind on a regular basis. What did you take in school to land something like that? Also, if you don't mind, what is the company you work for?


I'll sum up what I believe a black hole is. Though, like i have stated, I'm no expert on black holes. stingc would probably be able to give us a much better explanation of a black hole.

Basically a black hole is something that has such an intense gravitational force that it even traps light.

Now, black holes to reside at the centre of galaxies, but it doesn't mean that we are going to be sucked into that black hole. We are so far from the black hole at the centre of our galaxy that it's gravitational pull doesn't have any effect on us at all.

Our orbit in our galaxy isn't influenced by the black hole at the centre. Rather, it's influenced by the cluster of stars and the overall gravitational force of everything in our galaxy combined.

Again, I don't know a whole lot about the makeup of galaxies, or how they came to be, but I do know that we don't have to worry about being sucked into the black hole at the centre of our galaxy. That gives you an idea of how large our galaxy is, and how large this new black hole finding is, also.

However, it is possible that there is a black hole close to us. This wouldn't be a supermassive black hole. It would be small, but 'could' gobble up our solar system, if we got close enough. Though, it would take a long time for it to finally reach our planet. We would be warned of the black hole way ahead of time.

In other words, we can't really think of it as your toilet scenerio. It's an interesting thought, and kind of works for objects in the range of the black holes gravity, but the matter is just condenced and accelerated to speeds higher than the speed of light, or so people think. This is where many questions about black holes come into play. Relativity suggests that nothing with a mass can go the speed of light. If it does, it's mass will be infinite, since your mass increases as you move faster, it's speed of time would be 0, and the energy it would take to get to that speed would also be infinite. It's very hard to think about.

Black holes are very interesting for many reasons.

If you are interested in astronomy, this is a great site to go for definitions of things.

www.bbc.co.uk/science/space

This is *so* f-ing cool. I love astronomy.

Well, taog, I thank you for the explanation.

I kinda sorta knew what a black hole did, but then you got into the whole infinite mass, speed, and all that stuff, and with the condition I'm in tonight, I'm just gonna restate my past opinion and say that...

Science is hard...

But cool!

Thanks for the clarification!

One last post about how astronomy aids mankind. Anybody remember late last year when the Sun was freaking out and hosing us with solar flares? Because there are a bunch of scientist up on the hill checking out the heavens we were able to know in advance that the Earth was about to get rocked by solar radiation. This gave people enough time to shut down satellites and save their electronics from the effects. This probably saved us millions of dollars and a huge headache. There are things out there that can affect us, and it's probably a good idea that we know about that stuff.

And besides like G.I. Joe says "Knowing is half the battle!"

Nice. That's my second favourite quote. My first one is, 'imagination is more important than knowledge. Knowledge is limited, imagination encircles the world' - Albert Einstein.

In science you need to have a good imagination. If Einstein didn't have a good imagination, i bet he wouldn't have been able to come up with half the stuff he came up with. He had the intelligence to apply it with math, and come up with one of, if not the greatest known theory in the world. General and special theory of relativity gives us so much knowledge about so many different things. Take a look at E=mc^2 for example, the most well known formula in the world. If this didn't exist, we woudln't have half of the weapons we have on earth today. True, in this case, it was used for something bad, but the same thing can come out to result in something good.

Energy is a huge topic in astronomy. Figuring out how to do things differently, using less energy, or using a better way to come about that energy is challanged in all areas of science. These things are then applied to our every day lives. Knowing how we were created, and figuring it out, by looking at nebulae and things like that, gives us a better understanding of how things are formed, and thus, a better understanding about how to conserve these things. Again, a good thing that has come out of it is how to harness the energy in our every day lives.

There has been so much work done with different types of waves in astronomy as well. If astronomy didn't exist, I'm sure that half of these things wouldn't be known about different types of waves. We would know little about them, and little about how to keep ourselves shaded from the harmful waves that are entering our atmosphere on a daily basis.

Knowing if half the battle. Acting upon the knowledge is the other half. You can't know unless you use your imagination and figure the knowledge out. Astronomy helps us in so many aspects, including individual intelligence.

If it weren't for astronomy, there is no way I would have applied myself and there is no way I would be willing to use my brain at it's true potential. Astronomy is my love, and I know it will challange my brain on a daily basis, as it already does. It brings me intelligence, and lets me feel like I'm doing something good for myself. It makes me happy when i read about a theory and fully understand the meaning behind it. It makes me feel good to come on here and post about what I have learned, so I can give other people a bit of my knowledge. If one million people feel the same way, it's also helping society on a person to person basis. It might just keep some people from being a menace to society.

What I have learned is that we shouldn't knock any profession. Each profession has it's own little way of bringing back good to society or humanity. Even if it's owning one of the biggest companies in the world who doesn't like to finish their operating systems before they start a new one.

I used to think that Archaeology was a usless science. I have now learned that there are many good things that come out of Archaeology. I'm an 'Archaeologist' at the moment actually. I am working for an archaeology company, doing field work and things like that. It's quite interesting to find out what you can find out about the past. There are many things that you can apply to our lives today, to better the way we live, or to help with how we do things.

It's true that most sciences also focus on pure subject related knowledge and information, but all sciences will apply to how we live our lives in some way or another, moreso than you would expect most of the time.

On a last note for this 'argument', Astronomy and every area related all relate back to physics someway or another. Our lives depend on physics more than any other science out there. Some type of physics can be applied to basically anything you do in your daily routine. A lot of physics has been foud or proven through astronomy, and thus used in our daily lives, even though you might not be able to tell. Your whole house is controlled by physics. A lot of those devices in your house have been constructed trhough the finding of proofs and theories proven through physics, astronomy, or some other science. It's all about figuring something out, and applying it to somehing on earth. It just makes sense to do that, and scientists do that daily. They use their imagination to apply things to make things easier for us, or more efficient.

Anyway, that's why science is the best thing for us.

Now, back to topic.

That guy who's doing research and stuff on black holes. Would you be able to kind of sum up what a black hole is exactly for everyone to read? I am basing my explanation on readings from old text books, and I don't really know if anything new has been figured out.

Also, if you could, could you maybe explain the event horizon a little too? That's always an interesting black hole subject.

And, why is the radius of a black hole potentially infinite?

I'm a little confused by your "time was faster in the past" statement because, well, how can that possibly be an objective statement?

I've started thinking of time as a measurement of change and that thinking has helped me out a bit. So if what you mean is that more stuff went on in the past...ie. the universe was changing more, matter was less stable and chaotic, then yeah, I understand that.

Plenty of new things have been figured out, but the basics are the same. You mostly have the right idea, although you've confused some details. All that stuff about going faster than light is incorrect for example.

I'll try to describe a black hole intuitively. This is very very minimal btw:

If you think about the gravitational field of a planet, it obviously gets stronger as you get closer to it. There's a limit though. If you dug a hole into the planet's surface, you'd find that the field starts getting small again. It vanishes completely at the center (by symmetry).

So a planet has the most gravitational pull at its surface. This suggests a very simple way of increasing the maximum field: let the planet collapse into itself without losing any mass.

A black hole is something that has collapsed as much as possible. If you get close enough to one, its gravitational field is so strong that not even light could ever fully escape.

It is important to say that black holes are not cosmic vacuum cleaners. The collapse process only increases the maximum gravitational field. It doesn't affect anything far away. If the sun could turn into a black hole right now, the earth would continue moving along in exactly the same orbit. Strange things only happen if you go too close.

These 'strange things' are what really make black holes interesting I think. In general relativity, gravity is a manifestation of geometry. It turns out that geometry doesn't quite work the way you learned in high school. There are very minute differences that give rise to the effects we associate with gravity. It is rather difficult to think of the attraction between the sun and the earth this way, and it isn't really needed (although it can be done). Newton's old theory works fine for that. When you start to talk about black holes, though, the geometrical viewpoint is unavoidable. Regular Euclidean geometry completely breaks down.

The replacement describes both space and time as a single intertwined structure. So both time and space act very differently near a black hole. Expanding on that more precisely would take many pages to explain properly.

Arsenic is right that time is a measure of change, but it can be quantified in various ways. You have to be very careful though because different people might quantify it differently. When someone talks about time "slowing down," or something like that, they mean that time as quantified by one person (in an apparently reasonable way) does not agree with someone else's apparently reasonable version of time. That's probably confusing, but it can be made precise. People should be much more careful about discussing time in relativity because most of the time their statements do end up being completely subjective (I'm including physicists here too). Its possible to do it right though.

denim, just like time, space can be quantified in different ways. There are definitions in which the radius of a black hole is infinite, but it doesn't mean much to say that. Someone looking at the hole will see something that certainly doesn't seem infinite. Its better to measure its surface area (there's more than one reasonable definition of surface too -- just choose one), which is always finite, and would be measured the same by everyone.

My degrees are in physics. I'm at Penn State right now (there's a big gravity group here). Companies don't hire anyone to do this kind of research.

I guess what is important to keep track of in all that, is the name "theory of relativity".

As in, it's all about different perceptions, relative to where the perception was made. So to person X, outside of the range of gravitational pull of a black hole, it might take 4 hours to see another person Y come out of the black hole, while to the person Y it might seem like it only took 4 minutes.

The same way, when the universe was young, and alot more close together, there was more intense gravity between holes, planets and stars on the whole (since gravity becomes weaker at greater distances). So time indeed did pass faster. Gravity was higher, so time-space was warped to a greater degree.

At least, that's how I understand it :)

stingc:

if an accelerated object emits a gravitational radiation, and for a planet to revolve around the sun, it takes a constant accelaration towards the sun, does that mean that the earth produces gravity in 2 kinds? as in: acceleration gravity and mass-based gravity?

or am I thinking too far and not getting it right anyway? :)

I think a more interesting question is, what is the speed of gravity? I've read somewhere that it's many orders of magnitude faster than light.

Perhaps the great publishing companies of Ursa Minor were the ones trying to bind together the rules of Brockian Ultra Cricket.

"None of these facts, however strange or inexplicable, is as
strange or inexplicable as the rules of the game of Brockian Ultra
Cricket, as played in the higher dimensions. A full set of rules is
so massively complicated that the only time they were all bound
together in a single volume they underwent gravitational collapse and
became a black hole."

:lol:

hu??
where did I type this then? :)

If we don't know anything about the world around us, and the universe we live in, how will we expand our scientific knowledge and understanding?

The advancement of knowlege and the scientific pursuits are actually high priorities in my book.

That's right. The 'acceleration gravity' is immeasurably small in the case of the earth though. It takes a much more extreme situation for the effect to become significant.

There are systems with two very small (but massive) stars orbiting each other once every few hours (!) where the acceleration is enough to cause an observable energy loss. Hulse and Taylor were given a Nobel prize a few years ago for showing that this happened in exactly the amount predicted.

denim,
The speed of gravity is yet another thing that is hard to define. You measure how fast something is going by finding how far it goes in a given time. Since gravity is itself changing the nature of space and time as it goes along, its hard to think of what it would mean to define a speed for it.

It only makes sense if we ask what is the speed of a very weak gravitational wave, so geometry remains almost constant as the wave passes. In that case, relativity predicts that the speed of gravity has components travelling at the speed of light and all slower speeds in general. In the solar system, the components moving at less than the speed of light would be negligible, but they're important in more extreme situations.

So define "time" and "gravity".

I can't do it simply.

How do they relate? I can't find my 22 year old physics book, so I'm afraid you'll have to start from g and t.

t and g don't relate in Newtonian physics, so I doubt your old text will talk about it. I'll try to give the first steps towards what's involved. I don't expect people without a technical background to understand this.

The metric in Euclidean geometry is given by the pythagorean theorem, dL^2=dx^2+dy^2+dz^2. {x,y,z} are not intrinsically meaningful. There's nothing preventing you from going to any number of different coordinate systems. L does have meaning though. The distance between any two points is the same for everyone.

Special relativity modified this relation by introducing a fourth coordinate -- time:

dL^2=-(cdt)^2+dx^2+dy^2+dz^2

Just like {x,y,z}, t is not fundamental. You can do coordinate transformations on it. L is again the same to everybody.

This is used to define what it means for something to be moving at the speed of light independent of coordinate choices. If dL=0 along an objects path (in 4D spacetime), then it is moving at light speed. In the above coordinates, this means e.g. dx/dt=c, as expected.

Objects moving at less than the speed of light have dL^2<0 (its ok for dL to be imaginary). One can define what's called the proper time as dT^2=-dL^2. This is uniquely defined, and has many nice properties.

If dL^2>0, then this represents something moving faster than light. Its possible to show with the above equation that an object moving on this type of path will violate causality.

Now as stated before, there are many possible forms for dL depending on the coordinates chosen. If there's no gravity, though, it is always possible to transform back to the metric given above. Gravity modifies the equation for L such that it can no longer be brought into that simple form by any choice of coordinates. Its probably better to say that gravity IS the (invariant) difference in the true metric and the special relativistic version.

Ok so I was ignorant. But Im pretty pissed that money is being spent on things that we dont need to know about. Why the fuck are these people studying black holes while they should be looking out for meteors?

And on the black holes, if light isnt matter, how can it be pulled by gravity?

Redarrow, you're still acting ignorant. Go back and re-read the thread again. If that doesn't work, come back in 10 years once you've got some real life experience. The question will likely resolve itself for you in the meantime.

Black holes pull everything, not just matter. Matter is a dense form of energy, so saying gravity pulls matter is just another way to say it pulls energy too. Light is a form of energy, if I understand correctly, so gravity can bend it.

Okay, there are still a couple of things I'm missing. L is what? If gravity makes the situation less simple, just what kind of math is needed? You got into some level 1 calculus there, I see, but I wonder what I'd need to take to add in gravity.

L is a (4D) distance. Its useful to talk about because knowing distances between points in a space allows you to derive almost anything else you might be interested in (there are important exceptions though).

dL is always a quadratic function in the four coordinates, even with gravity. It is a solution of Einstein's equation, which is a nonlinear partial differential equation.

Most of this falls under differential geometry. Tensor calculus is also very useful.

hey, stingc

I was wondering if you would be interested in helping out on a database type website for astronomy and related topics. I'll get into more detail later, but basically what I plan on doing is creating a huge complex database of different theories and things like that, including different scientists and everything, that is searchable and everything. It will take me a bit to get the basic database design going, and to actually get a small site going, but I'm just wondering if you would be interested in helping out populate the database?


Also, I hope to make it bigger than just astronomy. I hope to merge many different science databases into one kind of thing. It will take a few years to get that far, but I think it will be very rewarding in the future.


Oh yeah, and back on topic.

This black hole doesn't seem so 'surprising' if you read about different ways and theories on how the universe may have started. Some of them would suggest that something like this could have spawned only 1 billion years after the big bang. It's an amazing find, and I'm probably more excited about it than most people on here, but from reading some books this week about the early universe, it doesn't seem taht surprising that something like this existed 12.7 billion years ago.

Ok, maybe. PM me with more details.

I believe there is now a theoretical possibilty that Photons have an extremely small amount of mass, and are thus suseptible to large gravitational fields, I could be wrong in this. But, I guess we could just kill all funding to find out and instead focus on NEO's as you suggest.