|
|
Joined: Apr 2000
Posts: 3,065
Carpal Tunnel
|
Carpal Tunnel
Joined: Apr 2000
Posts: 3,065 |
If I remember correctly, what happened was that somebody called Chandrasekhar (spelling?) worked out that given a big enough star and Einstein's theories, a black hole is what would result when the star ran out of "fuel" and collapsed in on itself. Other people, such as Penrose and Hawkings, then took that idea and worked out mathematically some of the implications. Then astronomers actually started looking for black holes.
So basically the theoreticians said that black holes with certain properties should exist, and then the practical astronomers dutifully found them.
Bingley
Bingley
|
|
|
|
|
Joined: Mar 2000
Posts: 11,613
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2000
Posts: 11,613 |
So basically the theoreticians said that black holes with certain properties should exist, and then the practical astronomers dutifully found them.Yes, and that's the way many of the higher-number elements were found, too. doc--Thank you, sir!  'Preciate your time.
|
|
|
|
|
Joined: Sep 2000
Posts: 4,757
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2000
Posts: 4,757 |
and that's the way many of the higher-number elements were found, tooand quite a few other scientific "discoveries", which started out as abstracted postulates. Indeed®, as with the recently announced Nobel Prize for Physics: The researchers were cited for creating a Bose-Einstein condensation (BEC) and for their investigation of its fundamental properties.
The BEC was predicted in 1924 but was first created in 1995. It occurs when atoms are cooled to almost absolute zero. http://news.bbc.co.uk/hi/english/in_depth/sci_tech/newsid_1588000/1588594.stmas for “as cold as…”, try this for a cross-thread link! http://www.colorado.edu/physics/2000/bec/temperature.html
|
|
|
|
|
Joined: Aug 2001
Posts: 2,605
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Aug 2001
Posts: 2,605 |
My guess would be that in modern times most discoveries and breakthroughs in pure science (as opposed to technology) occur precisely this way: when observational data is sought to confirm an existing theory. The data found may indeed confirm the theory -- or may be contrary to the theory, spurring a hunt to discover what is wrong with the theory.
Examples would be the discovery of the planets Neptune and Pluto, the non-discovery of the planet Vulcan (and no, I am not talking about Star Trek), and the Michaelson-Morley experiment.
|
|
|
|
|
Joined: Dec 2000
Posts: 13,803
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Dec 2000
Posts: 13,803 |
When nothing becomes matter and anti-matter, energy is produced as well. Hence when matter and anti-matter combine, the process requires energy.
I thought it was the other way around. Did I have my head on backwards that day in physics class?
|
|
|
|
|
Joined: Mar 2000
Posts: 11,613
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2000
Posts: 11,613 |
maverick! Oh! Oh, thank you!! How utterly cool (pun intended)! I never heard of the Bose Einstein condensate before, and ooh, I want to know more! I also never heard of the Joint Institute for Laboratory Astrophysics before--I really ought to get around to reading all those Discover magazines that are piling up... Here's a link from your site that tells more detail about how they did it: http://jilawww.colorado.edu/www/press/bose-ein.html
|
|
|
|
|
Joined: Jun 2001
Posts: 2,636
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Jun 2001
Posts: 2,636 |
Mav, I had so much fun! Like, wow, man. I learned something and got to play with cold balls and ping pong machines and psychedelic lights. LOL and giggles too,especially if you think of the other thread while reading the intro.
|
|
|
|
|
Joined: Jan 2001
Posts: 1,819
Pooh-Bah
|
|
Pooh-Bah
Joined: Jan 2001
Posts: 1,819 |
Just my two cents worth...
Matter being sucked into a black hole is accelerated faster and faster by the gravitational pull of the black hole. As the matter reaches very high speeds but before it crosses the event horizon, it releases X-rays and other forms of energy. (I'm sketchy on the details here.) It is these x-rays and particles that a black hole is emitting, albeit from outside the event horizon.
Anyone interested in fractals should read James Gleick's wonderful book "Chaos." It helped make a math major out of me.
I am not sure why anyone ever talks about entering a black hole. The poor little atoms that make up your body might all enter the black hole, but their organization that constituted a person would be history. i.e. You'd be ripped apart by the gravitational energy of the black hole and then you'd be squashed down into the singularity. The only consolation would be that it would happen so fast that you wouldn't feel much.
When two antiparticles collide, they annihilate each other and produce energy. It takes input of energy to create antiparticles. One process by which this is known to occur is called "pair production."
In pair production, an incoming amount of electromagnetic radiation (i.e. a photon) with an energy of at least 1.02 MeV (mega electron volts) interacts with the elctromagnetic field of the atomic nucleus of a target atom. The energy of the photon is absorbed in the process of creating a pair of antiparticles -- an electron and a positron. A positron is essentially an electron that has a positive electric charge instead of a negative electric charge.
|
|
|
|
|
Joined: Dec 2000
Posts: 13,803
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Dec 2000
Posts: 13,803 |
When two antiparticles collide, they annihilate each other and produce energy. It takes input of energy to create antiparticles. One process by which this is known to occur is called "pair production."
That's what I thought. Electron and positron meet in a dark alley and, poof! nothin but energy at the rate E=mc˛.
|
|
|
|
|
Joined: Sep 2000
Posts: 2,891
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2000
Posts: 2,891 |
Seriously, I feel as dumb as a box of hammers reading all your posts. I see all the words and the sentences all follow one another but dang if I understand a quarter of what you are saying. Does anybody want to talk about what makes a fine chocolate, or how shampoo and foam bath is made or the grades of garbage bags or french fries or profiteroles with real Chantilly cream? Or how to explain all that to a buyer and make him give you the business. Now that I know.  The black hole stuff -- colour me clueless even though I do try. My hat is off to you if you do.
|
|
|
|
Forums16
Topics13,913
Posts229,330
Members9,182
| |
Most Online3,341
Dec 9th, 2011
|
|
|
0 members (),
917
guests, and
0
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
|
