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Black Hole Search Begins In Australian Outback
Sandeater writes: "BBC news is reporting that an new telescope has just been completed to search out black holes from the Australian outback. The astronomers using the telescope will be looking for huge black holes at the centres of galaxies, as well as seeing how they evolve.
The Cangaroo II will be offically opened tomorrow.
The BBC link can be found here."
Ah, but do the disclaimers apply to the disclaimers? If not, then if a disclaimer should break down, you could be sued! :)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Somehow I get the feeling that Astronomers are working against the grain of normal science right now. I.e. they theorize that something exists because it would have to in order for some other theory to be true. Then they go off and do whatever it takes to prove it's existence.
When they fail to achieve this they just try again.
Eventually. some theories will have to be abandoned and others that were previously called laughable are found to be true. This whole "dark matter" thing is an example. I.e. there is a vast amount of matter in the universe that doesn't show up on any of the scans. In fact, vastly more than dose show up or can be accounted for in interstellar gas and black holes etc...
Why dose this dark matter exist ? Because without it the Big Bang is called into question. Of course the BB can't be wrong. We have built whole curriculums around this. It MUST be true.
Other scientists are quicker to throw away used theories. Maybe I am being too harsh. After all it's hard to sit in one far corner of the universe and see what the whole looks like.
--= Isn't it surprising how badly I spell ?
Those guys are still working! Yahoo's website is www.yahoo.com, and Paul Hogan was working on a show called Hogan's Heroes.
If tits were wings it'd be flying around.
The theory of what the dark matter actually is that I seem to like the most is that its dead white dwarf stars that have cooled beyond the limit which is visible by today's telescopes. This would mean that the vast majority of stars are therefore small whitedwarf stars, and that there's a whole hell of a lot of them.
WIMPs, MACHOs, etc. they're just patch work. Neat ideas with absolutely no backup evidence.
White Dwarves on the other hand have more potential. I wish I had a link to some info... I'll need to find one.
Having something up in space will mean it is not going be hearing all the crap from ground based transmitters - or a lot less of it anyway. Of course, being in the part of OZ they are in, I really don't think there is going to be much of a problem with that. It is pretty desolate there.
An example of this is the boundary around the telescope at Green Bank. I know Part 97 of the FCC rules states that you have to have permission to set up amateur radio beacons if you are near it (check the ARRL Website and do a search on 'Green Bank'). I am not sure about some of the other radio services. The reason is because of the interference generated by transmitters.
Radio receivers can cause lots of noise also if they are not properly designed, btw.
Black holes come from the Australian Outback? Well, at least they're exporting something these days. Too bad the market for black holes, well, really sucks.
Be careful in Perth. Its near the Schwartzchild radius.
What? What's that you say? Oh. I see. Maybe I should wake up more thuroughly before posting.
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CAIMLAS
~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
How are they going to find a black hole now that all their Athlons have been tampered with? Sounds like sabotage to me...
-JD
Why all the rush to study remote galaxies as such, why not turn our eyes towards the center of our own galaxy? Is it such that our galaxy doesn't fit their parameters that have been postulated to contain a black hole?
I say point those bad boys to the center of the milky way and see what beats in the heart of all that matter. Even if there is no black holes to be found I would surely help determine which galaxies would and wouldn't contain a black hole. Thus raising the chance of finding a black hole in a remote galaxy.
--
9) My first girlfriend's [CENSORED.] I mean, it seemed to suck everything in...
8) California. Don't all the ... holes come from there?
7) The press coverage surrounding Elian will soon achieve critial mass and implode.
6) What the hell is that space between Letterman's teeth, anyway?
5) The fox sunday night line up. Between Futurama and the Simpsons and between the Simpsons and the X files.
4) Hey Terence! How'd you like to look for black holes [FART]! Ooo! You farted on my head! Ha ha ha ha ha!
3) The space between a first poster's ears.
2) Any song in the top 40.
And the number 1 place to look for black holes:
1) The Microsoft E-mail backups.
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
I mean - i understand that every techie/geek here /.?
has to be brought up on Star Treck and all, so
let it be here. But how did it get to be the
only science field getting any coverage on
It has little to do with computers, as for
"stuff that matters" - i am sure , say automotive
news or medical science, matter a lot to great
many here. And the list can go on.
So i'd say either discuss them *all* or get the
damn astronomy out of here. Personal tastes of
site founders should not be a guiding line in
what is posted for a site that is used and trusted
by as many people as this one.
While I applaud the ingenuity of checking in Australia for black holes, I think they may wish to start with outer space, instead. Still, all those weird-ass animals have to be coming from somewhere.
"This is your world. These are your people. You can live for yourself today, or help build tomorrow for everyone."
Couldn't they just rent that Disney Sci-Fi flick instead of going to Austrailia to find a copy? Sheesh...
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"The only difference between me and a madman is that I'm not mad." - Salvador Dali (1904-1989)
According to the article, the telescope scans for gamma waves. These aren't suject to atmospheric effects the way light is. This means they can build a much bigger telescope, which is considerably easier to maintain, for a lot less money.
Once you get past the event horizon, it *does* look suspiciously like Australia. I got there through L-space once, purely by accident. There I was, in the back of a Barnes & Noble, browsing the Terry Pratchett section, and before I knew it, BLAM! There I was in a rather demented futuristic Australian Outback. I know it was a black hole because they worshipped people from the movie. Needless to say, I found the nearest local bookseller, and got back home before dinner got cold.
It's probably the space time flux caused by that wandering entity who likes to add on bits to worlds that look like Australia retroactively that causes the black holes in the first place. Just another case of Science imitating Science Fiction...
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pb Reply or e-mail; don't vaguely moderate.
pb Reply or e-mail; don't vaguely moderate.
IMHO, Australia is a brilliant place for such observations. The sky is crystal-clear (relative to anywhere in the northern hemisphere) and there is a lot of empty space to build a telescope without burger bars, shopping malls and strip joints surrounding it within a week.
I've often wondered if Australia might be a good place for SETI, for the same reason. Sod the 1Km array! It would be practical to build a 5 mile array Down Under. (A 5 mile array would give you an image 18 pixels x 18 pixels of an Earth-sized planet, 1 Astronomical Unit from a Sol-like star, up to 100 light-years away. That would be enough resolution to check the atmosphere, determine the climate and look for radio leakage rather than deliberate signals.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Good reply, you obviously know what you're talking about. However the main reason you use a ground based telescope is that you require a detector the size of a football pitch to see enough gamma rays of this energy to say anything useful. Thus it's impractical to launch one into space. Instead you use the atmosphere as your detector. Space based telescopes exist already which see lower energy gamma radiation from blazars, such as CGRO . I should also mention the experiment which discovered very high energy gamma rays from blazars, using the Cerenkov technique: The Whipple experiment (a blatant plug for my own PhD experiment!).
The purpose of orbiting telescopes is to avoid atmospheric absorption/distortion of the signal. Earth's atmosphere is opaque to many bands of IR and UV lights corresponding to atomic and molecular transition lines. Of course, atmospheric turbulence can wreak havoc with visible light. However, at the high X-ray energies they are looking at, the atmosphere is practiaclly transparent.
Also, the cost of an orbiting satellite is significantly higher than that of a ground based instrument, and with the booming Australian and Japanese space programs, they would have had to shell out more bucks to NASA or ESA to launch the thing.
Eric
The interesting thing I found about this is that unlike the reasoning behind Hubble (the atmosphere distorts light so get outside it) the Cangaroo II telescopes will use that very distortion to view the black holes.
I'd assume that the Southern Skies are a lot less mapped than their Northern cousins given the dearth of countries south of the equator.
But if they'd really wanted to go to a place where the atmosphere distorts the view then a Cafe Bar in Amsterdam would be their best bet
An Eye for an Eye will make the whole world blind - Gandhi
It should be noted that this telescope will actually search for Active Galactic Nuclei (AGN), of which supermassive black holes play a small, but important role. There is alot of other really interesting physics here though! For a cool picture of an AGN, click here. For more info, click here.
Do you think they'll find the black hole that sucked away all the talent of Australian soap stars?
Why dose this dark matter exist ? Because without it the Big Bang is called into question. Of course the BB can't be wrong. We have built whole curriculums around this. It MUST be true.
You forget a possibly more important reason for dark matter to exist - in order to explain why galaxies are stable. In order for a stable, rotating galaxy to exist it must satisfy the Virial Theorem which is 2V+T=0 (I think), where V is the gravitational potential energy and T the rotational kinetic energy.
Given what we know from observations of both our own and other galaxies we can make reasonable estimates of both of these figures, using average stellar masses, the no. of stars/galaxy, the radius of a galaxy and its rotational period. What we get from these numbers is that there is only 10% of the necessary mass in the galaxies we see for them to be stable.
If there was no dark matter then the stars within galaxies wouldn't be gravitationally bound and would be flung out by the galaxy's rotation. But since we can look out to the Universe and see stable galaxies of many different ages we have to conclude that there is extra mass present in galaxies that we simply can't see. Each galaxy is embedded in a huge disc of dark matter, and without it there would be no galaxy.
Well, for one, the cost of a ground based installation is much less than a satellite, but that's the obvious answer :)
What they're doing is looking for the Cerenkov radiation produced when a high energy gamma ray from the "blazar" produced by a black hole hits the upper atmosphere. Cerenkov radiation is the product of electron/positron pair creation and bremmstrahlung and consists of relativistic particles which travel at velocities faster than the local speed of light. This results in the production of Cerenkov radiation in the blue part of the visible spectrum, which is what the telescopes actually detect.
However there is a far greater amount of Cerenkov radiation from normal cosmic ray incidents than there is from gamma rays produced in blazars. Since the cosmic ray particles are charged (they are usually protons) whereas the gamma rays aren't, they can be distinguished by whether they curve in the galactic magnetic field.
Anyway, since this is a proven technique, there's really no need for a space-based detector as of yet.