Black Hole Found in Globular Cluster!
If any pleasure approaches that of scientific discovery, it can be found in the cockpit. Flying high above the Earth puts many problems in perspective. Cities at night are ablaze with a million lights. From experience we know that the pools of light are just a hint of the mass below. Between those lights are roads, buildings, and people going about their business. The majority of mass lies hidden in the darkness.
When they have nothing better to do, scientists speculate about multiple universes. Another Universe does exist, occupying the same Space/Time but hidden from our eyes. Theory predicts, and observations confirm, that the mass we can see is just 4.507034% of the total. To be aware of the other 95.49% is to be a seeing woman among the blind.
Globular cluster Messier 80 contains hundreds of thousands of stars orbiting our Milky Way. Astronomer Harold Shapley used observations of these objects to locate the galaxy’s centre. A globular cluster contains some of the oldest stars in our galaxy. Astronomers did not know how the globular clusters formed so early, or what holds them together. One way to form them would be from a medium-sized Black Hole captured by the Milky Way. Since this Black Hole formed primordially, it would have been a magnet for early star formation.
The prediction above was written some weeks ago, for a book yet to be published. With a nod to Kea, there is some wonderful news. BBC reports discovery of a medium-sized Black Hole inside a globular cluster! Obervations were made by ESA's XMM-Newton satellite with follow-up observations by the Chandra X-ray Observatory.
Astronomer Tom Maccarone said, "We were preparing for a long, systematic search of thousands of globular clusters with the hope of finding just one black hole. But bingo, we found one as soon as we started the search."
The Beeb continues: "Some models have suggested that large black holes - several hundred times the mass of our Sun - could develop in the densest inner regions of clusters. Other simulations, however, predict that such gravitational interplay would probably eject most or all of the black holes that form in such an environment."
One lesson is: Don't trust computer simulations! They are not nature. My computer says Lara Croft can fight with those boobs. It is now likely that every globular cluster contains a Black Hole.
The Black Hole is predicted to have been there before the globular cluster. It provided an anchor for the cluster to form. It is wonderful, wonderful to make a prediction that turns out to be true.
posted by L. Riofrio at 5:24 PM
9 Comments:
Great news indeed. I can't wait until somebody (you?) adds up all the BH mass from astronomical estimates and compares it to theory.
We're discovering new objects all the time. Somebody used an estimate of about 30% to "prove" that the other 70% is "dark energy," but those estimates may soon be obsolete. We're still winning.
Babe, your boobs talk just made it to my hall of fame... ;)
http://dorigo.wordpress.com/2007/01/06/the-say-of-the-week-22/
Cheers,
T.
Thank you, TD! I enjoyed your "Publishing" entry Jan 5 too. Conferences are a good way to get published.
... especially if they are hard to distinguish from paid vacations in fancy places!
The Corfu 2005 conference was in-between a few summer schools in a nice venue in Corfu. Objectively, it was not a very important international event, and I was able to get a review talk through some negotiations of my boss...
I have learned that it pays off to attend to less fashionable events - big collaborations like CDF receive lots of invitations but it is hard to get chosen by our speakers committee for the most prestigious events.
Cheers,
T.
"Theory predicts, and observations confirm, that the mass we can see is just 4.507034% of the total."
Does this 4.5% figure come from GM=tc^3 ? If so, what values are you using for t and for observed density? I can't see why you are quoting the percentage to 7 significant figures when even the value of G is uncertain to that precision and certainly the Hubble constant and density estimates shouldn't be quoted beyond two significant figures or they will imply a precision unwarranted by the error bars.
According to general relativity with critical density but no cosmological constant, the age of the universe is t = (2/3)/H, where H is Hubble constant.
The 2/3 ratio is for gravitational deceleration without a cosmological constant to offset it.
Because Einstein/Friedmann supposed that critical density was slowing down the expansion, general relativity (no cosmological constant) predicted age of universe t = (2/3)/H. The identity R = c/H is based on t = 1/H, not t = (2/3)/H. If we use t = (2/3)/H, then R = ct = {2/3}c/H, the factor of {2/3} being the factor by which the expansion is slowed down by gravity from what it would be without gravity. Putting R = {2/3}c/H into
M = (4/3)Pi*(R^3)Rho
= (1/2)(R^3)(H^2)/G
= (4/18)(c^2)R/G
= (2/9)(c^2)R/G
(This is directly analogous to the fact that in a free very high pressure supersonic shock wave in a uniform fluid, the deceleration due to the shock wave continuously hitting, engulfing more air and heating it etc, ensures that the velocity U = (2/5)R/t where R is shock radius and t is time, see my proof at http://glasstone.blogspot.com/2006/03/analytical-mathematics-for-physical.html , so for a shock wave being decelerated by hitting and engulfing air, R = (5/2)Ut, which is a direct analogy to Einstein's or rather Friedmann's R = {2/3}c/H where the multiplier is caused by deceleration due to gravity, rather than hitting, engulfing, and compressing fluid. The multiplier is bigger than 1 because the earlier expansion was faster, because deceleration causes a progressive slow down.)
However, as observations by Perlmutter in 1998 showed, the actual expansion shows no such deceleration: R = c/H (Hubble's law) is correct for some reason. The issue is that Einstein's/Friedmann's "explanation" of Hubble's law changes it from R = v/H where v {is much smaller than} c (small distances), to R = {2/3}v/H at immense (relativistic) distances where v ~ c. Perlmutter was trying in 1998 to confirm this prediction when he disproved it. There is only one explanation which accurately predicts why Friedmann's solution is wrong: quantum gravity, redshift of gauge bosons preventing deceleration of extremely rapidly receding galaxies and supernovae, because the redshift of gravity causing radiation (and other gravity mechanism phenomena, such as gravity being due to surrounding recession, not independent of it) prevent deceleration from occurring at extreme redshifts.
Hi Louise, nice post!
I like the regerence to the BBC
You could also have used the link to ESA Portal news Black hole boldly goes where no black hole has gone before
PS - Happy New Year!
Hi Nigel, this does tell us about the structure. If the Universe is approximately spherical, then volume $V = [2 \pi^2 (ct)^3]^{-1}$. Initial density $\rho_i$ for a mass M before matter formation is just M/V, where M = tc^3/G. We then have $\rho_i = (2 \pi^2*\ G t^2)^{-1}$.
Stable density $\rho_0$ after matter formation is $(6 \pi G t^2)^{-1}$. Difference between those is 4.507034% taken to as many decimals as you like. If the Universe were a different shape, or R were some other multiple of ct, density would be very different.
Q9, I will use British and European results whenever possible. It is Americans who claimed inflation and "dark energy." Many physicists, like Roger Penrose, don't necessarily believe the Americans. When Planck results are announced around 2010, they may have very different conclusions.
The Planck spacecraft promises to measure $\rho_0$ to an accuracy of +/- 0.1%, which will allow us to check the first two significant figures. At our late cosmological time the figure 4.507034% is nearly constant, since nearly all the matter has formed.
Hi Louise, everybody.
The new site is ready for visitors at last (Visual Physics). Not all content is in place yet, lots of "stub" articles, but it's a good start. You are all invited to browse and contribute. Cheers!
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