Yahoo! Makes Black Holes Hip

Disclaimer:  As a certified nerd in high school, I never really knew what the kids were saying even when I was one of them, so "hip" may not be the right word.  Whatever the appropriate vernacular, Yahoo! is doing it for news about black holes - complete with pop culture analogies.  You can see the video here (curse you Yahoo! and your lack of embedding options).  The specific "discovery" they reference was an observation of a peculiar gamma ray burst by the SWIFT satellite, which is a pretty amazing bit of science and certainly worthy of mention.  Besides, everybody likes black holes due to their position on the top of the cosmic sexiness ladder.

As someone who once hoped to model almost exactly what was observed, I have to say that Yahoo! did a decent job with the science.  Sure, they make it sound like we have close-up video of the event rather than a brief gamma ray point source and they think astrophysicists wear lab-coats and write "science" on glass plates, but those are forgivable mistakes in my book.  My only two questions are how can we get more videos like this and why for the love of everything holy don't they have an embed option?

Black Holes are Racist

I know, it is hard to believe but someone has managed to play the race card and think that black holes are racist. So in Phillips Hall (the physics building at UNC) there is a bathroom (Shocking! I know.) and on one of the walls someone scribbled some graffiti (not too surprising). While the original statement has since been lost due to scribblings and crossings out, it had to do with throwing into a black hole (right now I think it says something about sheep and how they have glory...yeah, um...yeah I won't elaborate). Well it turns out that someone saw the word "black" scribbled on the wall of a bathroom and considered that to be disrespectful and racist so they crossed it out (or they blacked it out;) so as to remove the "offensive" word. So apparently they thought that it was racist to have the word "black" scrawled on the wall of a bathroom even though it was only a reference to "black holes".

On a serious note, this made me think, how can we be expected to "overcome" racism when we constantly have to be watchful to not use such a common word such as "black" for fear that we will be accused of racism and be called offensive, regardless of context? How are we to stop worrying about racism when we keep talking about it? If we constantly have to be watchful of our language to avoid offending someone how can we ever get past our past? Especially the past that I was not a part of.

The LHC is Declared Safe

The LHC Safety Assessment Group (LSAG), (seriously that's what 's called) has released their report that is an update of an earlier report released in 2003. A summary by the European Organization for Nuclear Research can be found here. The report addresses concerns ranging from the creation of mini-black holes that could "gobble up the earth" to the creation of strangelets.

Their basic argument comes down to this: "Over the past billions of years, Nature has already generated on Earth as many collisions as about a million LHC experiments – and the planet still exists. Astronomers observe an enormous number of larger astronomical bodies throughout the Universe, all of which are also struck by cosmic rays. The Universe as a whole conducts more than 10 million million LHC-like experiments per second. The possibility of any dangerous consequences contradicts what astronomers see - stars and galaxies still exist."

In other words: The universe has not ceased to exist, therefore it will continue to exist. Hmmm, novel thought.

The release of this report has given the Department of Energy some ammunition to respond to a lawsuit filed in Hawaii back in March to force the Federal Government to cease operations at CERN. A news article about the lawsuit can be read here. Basically their response is that the federal government does not have jurisdiction in this case and cannot force CERN to not turn on the LHC, and also there has been no credible objection to conducting the experiment as "the claims of potential injury are 'overly speculative and not credible'".

So the LHC can go ahead and do its stuff and we can rest easy knowing that if the earth is destroyed because of the LHC someone somewhere will get some pleasure thinking "I told them so!" milliseconds before they are sucked into a black hole, or converted into a strangelet.

Breaking: Two Supermassive Black Holes in Same Galaxy

From Harvard:

For the first time, scientists have proof two supermassive black holes exist together in the same galaxy, thanks to data from NASA's Chandra X-ray Observatory. These black holes are orbiting each other and will merge several hundred million years from now, to create an even larger black hole resulting in a catastrophic event that will unleash intense radiation and gravitational waves.

The Chandra image reveals that the nucleus of an extraordinarily bright galaxy, known as NGC 6240, contains not one, but two giant black holes, actively accreting material from their surroundings. This discovery shows that massive black holes can grow through mergers in the centers of galaxies, and that these enigmatic events will be detectable with future space-borne gravitational wave observatories.

"The breakthrough came with Chandra's ability to clearly distinguish the two nuclei, and measure the details of the X-radiation from each nucleus," said Guenther Hasinger, of the Max Planck Institute for Extraterrestrial Physics in Germany, a coauthor of an upcoming Astrophysical Journal Letters paper describing the research. "These cosmic fingerprints revealed features characteristic of supermassive black holes -- an excess of high-energy photons from gas swirling around a black hole, and X-rays from fluorescing iron atoms in gas near black holes," he said.

Previous X-ray observatories had shown that the central region produces X-rays, while radio, infrared and optical observations had detected two bright nuclei, but the nature of this region remained a mystery. Astronomers did not know the location of the X-ray source, or the nature of the two bright nuclei.

"With Chandra, we hoped to determine which one, if either, of the nuclei was an active supermassive black hole," said Stefanie Komossa, also of the Max Planck Institute, lead author of the paper on NGC 6240. "Much to our surprise, we found that both were active black holes!"

Relativistic Jets from GRMHD

For some time now it has been known that rotating black holes can produce extremely powerful jets of gamma rays and very high energy particles that shoot out along their axes of rotation. This phenomena is believed to be the power source for active galatic nuclei, pulsars, quasars, a number of other phenomena ending in -sars, and possibly some types of gamma ray bursts. The mechanism for creating these jets, however, remained mysterious. To complicate matters, whatever process is powering these jets appears to be extremely efficient in converting gravitational potential energy from the in-falling material into these high energy streams of photons and particles. So how does a black hole with an accretion disk swirling around it efficiently shoot jets out of its poles?

Nothing like this jumps out of either the linearized magnetohydrodynamics equations or the Einstein equations, so people knew that it had to be some kind of funky non-linear effect, but was it from the MHD equations, the Einstein equations, or some combination of the two? Since the jets were always created by in-falling plasma it seemed safe to say that MHD was involved. And because these jets were only observed around black holes, it seemed pretty reasonable to assume that GR played a role in creating these jets, but the real question was whether it was just the non-linear GR effects that were needed or was this something to do with the event horizon. As Joe mentioned in his post, there is reason to believe that event horizons are trickier than we generally expect, so could these jets be some sort of mechanism for the black hole to deal with matter trying to pass it's event horizon?

Well, the debate now appears to be settled. Researchers at MIT and the University of Wisconsin have published evidence for relativistic jets coming out of a binary star system with an accreting neutron star (pictured on the left). Since neutron stars obviously don't have event horizons the jets must be produced by the non-linearity in the GRMHD (General Relativistic Magnetohydrodynamics) equations alone and not by some trick of the event horizon.

As a side note, they also found that both the overall energy in the jets and the efficiency of the process decreased in the case of the neutron star, perhaps signaling that the effect scales with the gravitational field strength (i.e. curvature). That gives numerical people a good idea of where to look in the non-linear terms for the driving mechanism. GO NUMERICAL METHODS!!!

You can look at the pre-print or read the ScienceDaily summary for more details.

Breaking: Black Holes May Not Even Form!

I recieved an email today from Los Alamos; since I am still on their mailing list. An article was just approved for publication in Physics Review D that states analysis shows that black holes cannot form.

As mass contracts on the way to black hole formation, you begin to have intense pre-hawking radiation which evaporates enough of the mass quickly enough that you never get a black hole. All structuers in the universe that should be black holes are objects trying to become black holes but will never fully get there.

The analysis suggests if black holes exist they had to have been formed immeadiatly at the Big bang. This is a similar to getting to the speed of light. No matter how hard you try, you never quite get there. However if a particle could be created at the speed of light it would be able to traverse that speed.

Here is a link to an article.

Here is a portion of the email.

BLACK HOLES AREN'T: CASE RESEARCHERS MAY HAVE SOLVED
Information loss paradox to find black holes do not form

"Nothing there," is what Case Western Reserve University physicists concluded about black holes after spending a year working on complex formulas to calculate the formation of new black holes. In nearly 13 printed pages with a host of calculations, the research may solve the information loss paradox that has perplexed physicists for the past 40 years.

Case physicists Tanmay Vachaspati, Dejan Stojkovic and Lawrence Krauss report in the article, "Observation of Incipient Black Holes and the Information Loss Problem," that has been accepted for publication by Physical Review D.

"If you define the black hole as some place where you can lose objects, then there is no such thing because the black hole evaporates before anything is seen to fall in," said Vachaspati.

The masses on the edge of the incipient black hole continue to appear into infinity that they are collapsing but never fall over inside what is known as the event horizon, the region from which there is no return, according to the researchers.

By starting out with something that was nonsingular and then collapsing that matter, they were determined to see if an event horizon formed, signaling the creation of a black hole.

The mass shrinks in size, but it never gets to collapse inside an event horizon due to evidence of pre-Hawking radiation, a non-thermal radiation that allows information of the nature of what is collapsing to be recovered far from the collapsing mass.