Posted on 05/13/2008 6:18:03 AM PDT by Red Badger
International scientists have used flowing water to simulate a black hole, testing Stephen Hawking's theory that black holes are not black after all.
The researchers, led by Professor Ulf Leonhardt at the University of St Andrews and Dr Germain Rousseaux at the University of Nice, used a water channel to create analogues of black holes, simulating event horizons.
An event horizon is the place in the channel where the water begins to flow faster than the waves. The scientists sent waves against the current, varied the water speed and the wavelength, and filmed the waves with video cameras. Over several months the team painstakingly searched the videos for clues. They wanted to see whether the waves show signs of Stephen Hawking's famous prediction that the event horizon creates particles and anti-particles.
Professor Ulf Leonhardt, from the School of Physics and Astronomy, explained, "It is probably impossible to observe the Hawking radiation of black holes in space, but something like the radiation of black holes can be seen on Earth, even in something as simple as flowing water."
Black holes resemble cosmic drains where space disappears like water going down a plughole. Space seems to flow, and the closer one gets to the black hole, the faster it flows. At the event horizon space appears to reach the speed of light, so nothing, not even light, can escape beyond this point of no return.
The experiments were carried out at the Genimar laboratory near Nice which houses a 30-metre-long water channel with a powerful pump on one end and a wave machine on the other. The normal business of Genimar is testing the environmental impact of currents and waves on coasts or the hulls of French submarines, but the scientists turned the machinery to testing black holes.
The team demonstrated that something as simple and familiar as flowing water might contain clues of the mysterious and exotic physics of black holes. In a forthcoming paper in New Journal of Physics, the scientists report observed traces of "anti-waves" in their videos.
Professor Leonhardt continued, "Flowing water does not create anti-particles, but it may create anti-waves. Normal waves heave up and down in the direction they move, whereas anti-waves do the opposite.
"We definitely have observed these negative-frequency waves. These waves were tiny, but they were still significantly stronger than expected. However, our experiment does not completely agree with theory and so much work remains to be done to understand exactly what happens at the event horizon for water waves."
Half white, half black?
I did that experiment too when I pulled the plug on my bathwater. Think I could get a grant to tell them what color the water was at the event horizon with the soap bubbles being sucked down?
That certainly clarifies things.
Now, if we could only get the water to flow at a speed approaching that of light, we’d REALLY be in business.
How does this demonstrate that “black holes are not black after all.”?
Jessie Jackson & Al Sharpton will PROTEST this finding!!
Radiation from the event horizon represents “color” that can be detected, I suppose.............
Right.
Do “anti-waves” heave down and up in the direction they move (as opposed to up and down)?
Or do they heave up and down in the direction they are NOT moving?
Or do they heave side to side in an anti-clockwise direction but only in the northern hemisphere?
Or maye they sit perfectly still, but they do it in the direction they are NOT moving?
I’m SO confused.
Yeah, next thing you know they’ll be calling Black Holes “Uncle Holes” or “House Holes”, or some such.
It's and interesting physics demonstration, but they are extrapolating from a common physical example to try to understand one of the strangest items in the universe.
It’s hard to imagine how a very classical, Newtonian world of water waves could have anything to do with the very quantum, relativistic world in the vicinity of a black hole’s event horizon. To point out one glaring difference, the speed of sound in water is about 1 km/sec, much faster than the flow.
Mauve Holes?
The VSWR of a black hole must be pretty big.........
Aye tipe fizix gud!
That sounds FABULOUS!.......................
Al (Not so)Sharpton is going to be p!ssed.
LOL!!!
Holes of color, thank you very much...
Just so they don't call them Nappy-Headed Holes. Then there would be real trouble.
Allow me to introduce my new act.....and here is my dummy.
Sure but first you need to be in indoctorated (PHD) by a liberal sckowl.
Buy some mauve balls.
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)
Now, there are 2 black holes.
That's a very strange idea... The idea of space itself flowing down a black hole faster than the speed of light. I've run into it before here (PDF file) but more or less interpreted it as just an analogy, a mathematically equivalently way to look at the problem.
But if space actually is flowing like water, that is just so bizarre.... And with billions, or even trillions, of black holes out there in the universe sucking space down faster than the speed of light, in effect destroying it, or removing it from the universe, it's mind-boggling that there is yet some other mechanism out there (called dark energy) that totally dominates the whole space equation thing, adding space, expanding the universe, much, much faster than all those trillions of black holes can gobble it up and destroy it.
Some illustrious “scientists” suggest it still comes out of a “white hole”, thus there is no discrimination, and all is balanced.
Gray Holes ...
Meet the Indian who took on Stephen Hawking
Rediff.com | August 03, 2004 10:06 IST | Rediff.com
Posted on 08/02/2004 10:16:56 PM PDT by CarrotAndStick
http://www.freerepublic.com/focus/f-news/1183887/posts
I’m really compelled to say that space doesn’t “flow” into a black hole. Gravity is a space-time curvature. I don’t like ridiculous concepts.
bump
What are we suppossed to call them now?
Holes of Color?
In the interest of affirmative action we will no long be able to employ only iceholes when fishing on Lake Michigan. We will also be required to hire black holes (holes of color). This means we will have extra iceholes lying around.
Ethnic holes?.......Multicultural holes?..........
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