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Black Holes 'Do Not Exist,' Contends Physicist
SpaceAdmiral writes "Nature reports that, according to a physicist at the Lawrence Livermore National Laboratory in California, 'It's a near certainty that black holes don't exist.' George Chapline argues that the collapse of massive stars is more likely to lead to dark energy stars. These dark energy stars behave somewhat like a black hole outside of the surface, but the negative gravity inside could cause matter to 'bounce back out again.'"
Here is his actual article (PDF).
Theres always someone who has a diferent theory.
On the other hand though...
Tell someone there are a million stars in the sky and they'll believe you...
Tell them paint is wet and...
http://www.sandstorming.com
I contend that ass holes don't exist!
Oh yeah? Proof by contradiction; you.
I've been fooled by Captain Kirk and Mr. Spock all these years. DOH!
You mean they told you that they loved you, but it turned out they were just using you for sex?
You know MC Hawking isn't going to stand for this shit.
Apparently they look something like this
In other news, donuts almost certainly don't exist. Instead it is much more likely that there exists circular pieces of cooked dough with a hole in the centre.
This idea that "singularities" don't really exist has been around for a few years now. The idea is that a very small bubble forms that is unable to compress into a singularity because of the "dark energy" concept of reverse-gravity. However, the new theories that "dark energy" really doesn't exist, and that the expansion of the universe can be explained by the negative higgs field + spacetime ripples of the early inflation of the universe run contrary to this "no black hole" concept.
Someone you trust is one of us.
Crackpottery would be saying something is true and then saying everything must conform to that. Science doesn't work like that. You have a bunch of data, and you make a theory that best fits the evidence. Or you make a theory that makes some prediction. That theory remains valid until some piece of data is uncovered that does not fit in with the theory, at which point the theory is modified.
Right now, black holes are what seem to fit observations and theory. If we get more data (perhaps what this article is referring to) that does not conform, then the theory will change with it.
Thats not crackpottery, thats the way its supposed to work. There is no such thing as a 'final' theory. Its a process.
What did they do?: http://science.slashdot.org/article.pl?sid=05/03/1 7/1541230&from=rss
>Linux is not user-friendly.
It _is_ user-friendly. It is not ignorant-friendly and idiot-friendly.
No, "dark energy" denotes energy which is in a form which does not interact with most of the universe, or interacts very weakly. Just like "dark matter" (eg neutrinos) interacts very weakly, with zillions of them passing through the earth with little effect.
Daniel
Carpe Diem
If you can read this sig - the bitch fell off.
Over the past few years, observations of the motions of galaxies have shown that some 70% the Universe seems to be composed of a strange 'dark energy' that is driving the Universe's accelerating expansion
Ah, but I at least one theory exists that says dark energy isn't really needed.
Not there's anything wrong with having different theories, we'll let observational data sort it out later. Could a physicist around here explain how these proposed dark energy stars could explain the expansion of the universe if they behave exactly like black holes outside the event horizon?
Warning: Opinions known to be heavily biased.
The researcher is claiming that his theory accounts for both dark matter and dark energy, as well as some observations like x-ray bursts from the cores of active galaxies.
Conventional theory doesn't tie dark matter to dark energy at all. If the popularizations hadn't used the word dark in both cases, the two concepts would easily be completely unrelated.
Several candidates for dark matter are very conventional forms of matter, such as neutrinos or even plain old neutronium, which don't need an exotic explanation. Others involve particles we have produced in accelerators or theorize on the basis of data we have obtained ever since the 1940's.
Dark Energy, o.t.o.h., is something very different. The evidence for it is all very recent, and the theories proposed are all well outside the standard model for Cosmology.
Thinking we even need a single theory to explain both only makes sense if you can first disprove the more conventional explanations for dark matter.
Who is John Cabal?
Preach it brother! And add to that list time dialation, length dialation, non simultaneity, spontaneous quantum particle creation, particle smearing, the particle-wave duality, 2-slit experiments, splitting atoms, bowling balls and feathers falling at the same speeds, and the earth being round. Crackpottery, all.
Geez, just because you don't understand it doesn't make it wrong. Weirder stuff has already been proven.
The ______ Agenda
You going to tell me that Terra isn't flat? That the humours don't control disease? That there are no dragons off the edge of the map? Puh-leeze.
This is why I make it a point to never listen to scientists. They change their minds too often. You'd think women would dominate science, considering their natural talents in that area.
http://xkcd.com/386/
There is an enormous amount of work that makes Quantum Mechanics play well with relativity.
The problem with quantum mechanics and relativity is that the theory of quantum mechanics only works well when gravity is so weak that it can be neglected. Particle theory only works when we pretend gravity doesn't exist. On the other hand, general relativity only works when we pretend that the Universe is purely classical and that quantum mechanics is not needed in our description of nature.
The solution is string theory. This website has a nice list of expirements that have been done in favor of string theory.
No. The event horizon is the distance at which the escape velocity is the speed of light - you can't travel at the speed of light, so it's impossible to escape. (That's something of a simplification, but it will do) I suppose you could have an electric version of a black hole (not magnetic though, it would have to be a magnetic monopole [magnet with only one pole, rather than the usual north and south poles] which are thought not to exist). An object with sufficent charge that no charge object could escape it. Neutral opjects would still be able to leave, of course, and the event horizon would be different depending on the charge of the object trying to leave...
He says that electron-positron anihilation could account for the radiation observed at the center of the galaxy. The radiation produced when an electron collides with a positron is of a very specific wavelength - I think someone would have noticed if the radiation at the centre of the galaxy was at that wavelength, rather than a distribution of wavelengths in the way you would expect from a very hot object (superheated plasma in this case).
What is "true science?". Science is a process, not a result. Things that turned out to be wrong, like phlogiston or ether, aren't necessarily bad science, they are still part of the process.
They were disproved, and lead to better (as in having more accurate predictive power) theories. Black Holes are extrapolations of existing theories that seem good (like General Relativity), so they shouldn't be dismissed unless we can disprove them or come up with a better theory.
That, after all, is science.
Who modded this insightful? Probably someone who's never been to a conference...
Take a look at the header - this was submitted to a conference, *not* a full peer-reviewed journal. Many conferences (I know for sure most IEEE conferences are like this) limit paper submissions to 4 pages. URSI (Union Radio-Scientifique Internationale - they're just like IEEE Antennas and Propigation Society, with mostly the same members and co-host their conference) papers are even limited to 1 page for their conference. *Conference* papers really more discussion points than full blown "proofs". I'd suspect he'd follow this up with an "official" paper in one of their peer-reviewed journals.
That's what they wanted you to think :P
You're making a very dangerous generalized assumption there. Both forces go like 1/r^2. Both forces get multiplied by something to determine its strength. In normal lab conditions, you aren't going to be able to gather enough mass to exceed the magnetic fields we are able to create. However, it's much harder to create a magnetic field that can, say, carry enough force to make the moon orbit the earth. Remember, to form a magnetic field you need a huge number of charges moving roughly in unison. To form a gravitational field you just need a big hunk of matter. With a black hole, you're talking quite a lot of mass, and it would be very difficult for a man-made device to move enough charge to create a field anywhere close to the magnitude of a black hole.
Plus, say you can create a strong enough magnetic field. What are you going to push/pull against? Some star out in the middle of nowhere? It probably doesn't have a strong enough magnetic field of its own? The black hole itself? Now you're getting into all kinds of other problems.
One final thing to note about your idea - gravity affects electromagnetic radiation, and hence it's affecting magnetic fields. Ever heard of gravitational lensing? Ever heard the statement that the event horizon is the point after which "even light can't excape"? It's not as simple as trying to create a bigger force, as the gravity of the black hole itself would be distorting the magnetic field you are trying to create.
They created something that behaves like a black hole. If the theory about dark energy stars is right, it could have been a ball of dark energy instead.
IAAP (I am a physicist), and I'm annoyed that this is modded "Informative".
The RHIC collaboration at Brookhaven has fewer pion jets than their complicated Monte Carlo simulations say should exist. One possible (and highly attention-getting) explanation is analogous to a black hole, in the same way that "slow light" experiments can create something analogous to an event horizon. Neither experiment is actually creating a black hole , in the sense of a quantity of matter compressed to a region smaller than its Schwarzchild radius.
Regarding the original article, it's interesting speculation, but without any evidence to support it yet. For those interested in some of its underlying ideas (e.g. the vacuum as a superfluid), I strongly recommend Bob Laughlin's new popular book (readable by nonphysicists!) on the subject, A Different Universe: Reinventing Physics from the Bottom Down.
No. An object does not have to reach escape velocity to escape a planet's gravitational pull. Escape velocity is the speed with which a ballistic (unpowered) object has to be launched from the surface of the planet in order to escape its gravitational field. You calculate it by setting the initial kinetic energy (given by (mv^2)/2, a half the mass times the square of the veloicty) equal to the gravitational potential energy (given by GM/r^2, where G is the gravitational constant, M the mass of the planet, and r^2 the square of the radius of the planet).
That gives a figure for the escape velocity of
v = sqrt(2GM/m(r*r))
However, for a rocket (or other powered device) to escape a planet's gravitational pull, as the GP said, all it has to do is provide enough vertical thrust to provide a positive acceleration. That acceleration does not have to accelerate it to the escape velocity - in fact, you could adjust it to compensate for the falling gravitational pull and so maintain a constant velocity of whatever you want, and (if you have sufficient power/fuel) you'll still escape.
That doesn't work for a black hole because all of that is based on Newtonian mechanics, which do not apply in the large gravitational fields close to the event horizon. There, you must use General Relativity, which is counter to our everyday common sense view of the world (precisely because on our scales, it's irrelevant). I don't know enough about GR to demonstrate why this is, however.
It's official. Most of you are morons.
Whenever, over the ages, science seems to get too complicated, the usual answer is that it has gone off in a tangent. Most of the best theories have been elegantly simple at explaining our observations. These "discoveries" when proposed were considered revolutionary ideas. Later, when they were developed they usually were over-complicated by trying to explain everything. That's when a revolution in simplification happened and the process began from nearly scratch. Think of what happened to Keplerians' formulas and Newton's idea of gravity. They are still used today, even though they are wrong, and have been supplanted by Einstein's Theory of Gravity, because the models of Newton & Kepler are very accurate. Better yet: look at the models offered by geo-centric solar system projections. Here is one really nice animation: http://catholicoutlook.com/images/movingsolar7.gif
The idea is that once it gets too complicated all of the evolutionary ideas that get developed are probably causing more harm to the original thesis. Although the original work did a great job of explaining a certain observation when new data was added the theory had to expanded to a level of undue complexity to have weight. Then a competing and revolutionary idea was developed, seemed to match the data, and the process began anew.
I guess it's getting time for a powerful new theory. One that will get ruined in the future, since we really know so little.
Four pages is all it should take to briefly introduce a new theory, which is what George is doing.
p.s. George Chapline is very a bright fella with a history of suggesting contrarian theories. At least one of those theories has led to a entire branch of nuclear physics.
They mention being cault up in a black hole in "Tomorrow is Yesterday". Its the first time they use the sling-shot time travel method.
Warping away from the black hole caused the Enterprise to pass beyond Warp 10, which evidently caused it to go back in time (though passing Warp 10 sometimes doesn't). They wind up on earth in the 1960's and have some dealings with the USAF.
I don't think it was the fist time they did the time warp, there was also an early episode where it occured because the had to "hard start" the warp drive.
Cool art gallery, if you're into that sort of thing.
What has that got to do with a black h-- oh. Oh god.
You seem to be a very skeptical person, or perhaps you have not looked very far, In 1971, experiments were carried out using four caesium beam atomic clocks (The Hafele-Keating Experiment). Two of the atomic clocks were put on commercial jets and flown in opposite directions around the world. The predicted time dilation matched up to the difference in the atomic clocks.
I find it rather unlikely that this is a coincidence. What are the chances that two pairs of atomic clocks would fail, and fail by exactly the same amount as theory predicts. Pretty slim.
Of course, this was an experiment done on the macroscopic scale. In particle accelerators, time dilation directly affects the half-life of particles such a muons. Thousands of experiments have confirmed that the half-life of particles is affected by velocity in the exact way that Einstein predicted. Again, this is very hard to chalk down to coincidence.
Furthermore, experiments with the speed of light show that the speed of light is constant. Albert Michelson and Edward Morley tested the speed of light parallel to the Earth's velocity, and perpendicular to it; there was no difference in the results. From this we can conclude that either the experiment, and all the hundreds similar experiments performed after, were fundamentally flawed in precisely the same way (a stretch of the imagination). That the earth does not move around the sun. Or that the speed of light is independant of one's velocity. Indirectly, if these experiements are correct, this proves time dilation.
How? Consider a man on a spaceship travelling at high speeds. Upon the floor of his spaceship is a laser, a light sensor, both connected to a very accurate stopwatch. Upon the ceiling is a mirror. When the man presses a button, the laser beam is fired up at the mirror, and the stopwatch starts timing. The laser beam will bounce off the mirror, hit the light sensor, and the stopwatch will stop. Thus, the man will now know the time it takes for a laser beam to cover the distance between the laser beam, the mirror, and the light sensor.
With me so far? The problem comes when an observer upon the earth watches the spaceship zip past. To the man inside, the laser beam heads straight up and down, taking a purely vertical path. To the observer on earth, the spaceship moves horizontally whilst the experiment takes place, so to the observer, the laser-beam takes a longer, diagonal path. Because light is a constant speed, to the observer, the light beam travels at the same speed for both the observer and the man in the spacecraft. However, for the observer, the light beam travels a further distance than for the man in the spaceship, and therefore takes a longer time. So to the observer, the whole event takes a longer time than it does for the man inside the spaceship. That's time dilation.
An object does not have to reach escape velocity to escape a planet's gravitational pull.
;)
;)
You're partly right. You can NEVER escape a planet's gravitational pull. It just keeps pulling, no matter how far you go.
Escape velocity is the inital speed needed for a ballistic object to ensure that the gravitational pull of the planet will never be able to bring it to a complete stop, relative to the planet. As you move away from the planet, the gravitational force weakens. If you can move away faster than the force can slow you down, then the gravity of the planet can never stop you. That's the escape velocity.
However, for a rocket (or other powered device) to escape a planet's gravitational pull, as the GP said, all it has to do is provide enough vertical thrust to provide a positive acceleration. That acceleration does not have to accelerate it to the escape velocity - in fact, you could adjust it to compensate for the falling gravitational pull and so maintain a constant velocity of whatever you want, and (if you have sufficient power/fuel) you'll still escape.
In theory, you're partly correct here. If you could overcome gravity to provide a 1 foot per second squared upward accelleration, then yeah, you'd get to outer space. Eventually. It'd take one hell of a lot of fuel though, because you're only barely overcoming gravity. It's not actually *possible* because no ship exists that can do that and also have enough fuel to do it.
Any acceleration larger than gravity will get you there eventually if you assume enough fuel. And as gravity drops off due to distance, eventually you'll be travelling faster than escape velocity for the given height you happen to be at. And then you're free.
That doesn't work for a black hole because all of that is based on Newtonian mechanics, which do not apply in the large gravitational fields close to the event horizon. There, you must use General Relativity, which is counter to our everyday common sense view of the world (precisely because on our scales, it's irrelevant). I don't know enough about GR to demonstrate why this is, however.
The main reason is similar to the above: You don't have enough fuel. And not just because the technology doesn't exist, but because inside the event horizon, the acceleration due to gravity is so high that even light itself isn't moving fast enough to go "up". No amount of acceleration will let you make any forward progress at all, because you cannot possibly give it enough speed to exceed the speed of light. So you can't even go up at 1 foot per second, you can only go down.
To put it another way, inside the event horizon, space is bent in such a way that moving away from the singularity is no longer an available option.
Outside the event horizon, the normal, simple, equations still apply, more or less. The gravity is high, but the concept is the same. With a higher gravity comes a higher escape velocity, that's all. Also time dilation, but that's rather irrelevent to this discussion.
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
You mean they told you that they loved you, but it turned out they were just using you for sex?
...
More or less. I guess I should have figured it out for myself
-- Kirk kept shouting, "Oh Janice, oh Janice!"
-- Spock only did it every seven years.
-kgj
-kgj
Actually "Tomorrow is Yesterday" mentions a "black star" not a "black hole". "Tommorow is Yeserday" was first aired in Jan 1967 and AFAIK produced in 1966. As previously mentioned, John Wheeler coined "black hole" in late 1967. So it predates the existance of the term "black hole" by a small but important amount.