Black Holes are heavenly objects with masses so large (> 1.4 times Solar Mass, termed the Chandrasekhar Limit) that even light cannot escape from their gravitational pull. As a consequence, a black hole cannot be directly seen. However, it can be indirectly detected by a) observing the motion of a neighboring/orbiting star or planet, b) detecting the light (e.g. X-Rays) emitted by the matter falling into the black hole. Recently, University of Michigan scientists, using the orbiting Chandra telescope, have found peculiar X-Ray emissions from a black hole which indicates that it has a mass of about 10,000 Suns. Such intermediate mass black holes have been theorized to exist, but this is the first time one has been detected.

ULX black hole in galaxy M74 (Courtesy: University of Michigan)
At the larger end, scientists have previously detected black holes a billion times the mass of the Sun (at the center of galaxies like our Milky Way). At the smaller end, there is strong evidence for the existence of black holes with about 10 solar masses. This is the first time an intermediate mass black hole has been found.
Lead researcher Jifeng Liu and his colleagues used Chandra to observe a black hole in the galaxy M74, which is about 32 million light years from Earth in the constellation Pisces. They found that this source exhibits strong, nearly periodic variations in its X-ray brightness every two hours, providing an important clue to the black holes’ mass. The black hole also fell into a class of sources called ultraluminous X-ray sources (ULXs) because they radiate 10 to 1000 times more x-ray power than Neutron stars and stellar mass black holes.
There are no convinciing explanation (yet) of how these black holes are formed. Some theories under consideration are that intermediate-mass black holes form as dozens or even hundreds of black holes merge in the center of a dense star cluster, or that they are the remnant nuclei of small galaxies that are in the process of being absorbed by a larger galaxy.

Cosmic Rays are high energy particles that bombard the Earth from outer space. These particles are often accelerated to high velocities (and hence the high energy) by Gamma Rays from supernovae explosions, pulsars, quasars and massive star forming regions. Now astrophysicists using the HESS (High Energy Stereoscope System) array of telescopes in Namibia in Africa have detected eight new sources of gamma rays from the center of our galaxy (The Milky Way) including two sources which are a totally new phenomenon.

Milky Way Center (Courtesy: University of Tennessee)The results could shed new light on the origin of the cosmic sources in the universe. Two of the sources are of a totally new kind, as they have no counterparts at radio, optical or X-ray wavelengths. According to the researchers, these sources could be a new class of "dark" cosmic accelerators. Interestingly enough, the main particles accelerated in these objects are nucleons (protons and neutrons) rather than electrons as in the more conventional sources :).
Scientists are not sure about the processes that would selectively accelerate nucleons, and leave the lighter electrons (or other particles) behind. However, this adds another piece to the puzzle that is our galaxy, The Milky Way. Such heavy particles can help scientists compose a picture of the dust-laden core of our galaxy, perhaps providing new details about its origin and composition.

Gregor Johann Mendel is often described as the Father of Genetics. His discoveries regarding the inheritance of pea plants laid a solid foundation for the idea that genetic traits propagate from parents to children (generally) through dominant and recessive genes. Most of us have studied Mendel's work in our biology textbooks, and now it looks like some portions of it have to be rewritten :). It looks like contrary to inheritance laws the scientific world has accepted for more than 100 years, some plants revert to normal traits carried by their grandparents, bypassing genetic abnormalities carried by both parents.

Mutant plant inherits traits from grandparents (Courtesy: Purdue University)According to Robert Pruitt, a Purdue Department of Botany and Plant Pathology molecular geneticist, the mutant parent plants (Arabidopsis) apparently have hidden templates that contain genetic information from the previous generation! This information can be passed along to the offspring, and if the offspring finds that the genes from both its parents are abnormal/mutated, it might choose to use the template genes from its grandparents.
In this research, if both the parents have a mutation (the flowers were fused into tight balls), the child plant still can have a normal flower, inherited from the grandparent plants through template genes passed through its parents.
Even though a phenomenon called atavism has similar expressions (for example, a child might have his grandmother's nose), there is a big difference between the two. Atavistic genes are recessive genes that got suppressed in the parents due to the presence of a dominant gene, but were expressed in a child which lacks the dominant gene. In the case of the Arabidopsis plant, the grandparent genes are kept in a separate location in the parent, and are used in the child in case the parent genes are mutated/damaged.
This obviously introduces extra complexity into Mendel's Laws. If such behavior is found in animals as well, it is possible that it will be an avenue for gene therapy to treat or cure diseases. The study is published in the March 24 issue of the journal Nature.

Scientists at the Los Alamos National Laboratory have developed a novel method for detecting fingerprints based on the chemical elements present in fingerprint residue. The technique is called Micro-X-Ray Fluorescence (MXRF), and has the potential to help expand the use of fingerprinting as a forensic investigation tool. The technique detects fingerprints by an X-Ray analysis of the chemical residue left behind (salts, such as Sodium Chloride and Potassium Chloride, excreted in sweat). Current forensic techniques often involve a physical interaction with the print (treating the suspect area with powders, liquids, or vapors); so this X-Ray method is a superior one.

X-Ray images of fingerprints (Courtesy: Los Alamos National Laboratory)MXRF detects the elements (Sodium, Chlorine, Potassium, and others) present in the fingerprint. Many fingerprints leave a chemical trace behind, and it takes really small amounts for it to be detected by MXRF.
However, scientists assert that it is not a panacea, since some fingerprints will not contain enough chemicals to be seen. Also, bacteria/nature might destroy some fingerprints (especially if they are old). But MXRF does offer a non-invasive way of detecting a fingerprint, which leaves it pristine for other techniques, notably DNA extraction. It is also faster than other fingerprinting techniques, and therefore can be a useful tool since time is often the most important factor in solving any crime.

Somehow, to me, this post seems strangely appropriate, given that this is the 100th anniversary of Einstein's seminal papers, and (if I may be so conceited!) my 50th post in this blog :-). This year is also the 50th anniversary of Einstein's death.
Albert Einstein is one physicist who defined and dominated the 20th century. His papers on Special and General Relativity, Brownian Motion, and Photoelectric Effect single-handedly transformed our view of the world and how it operates.

Albert Einstein (1879-1955)As part of the celebrations of Einstein's famous discoveries in 1905 the British Library has released a CD (here) containing various speeches and radio broadcasts by Einstein. The CD begins with a discussion of his most famous equation E=mc². However, most of the CD is devoted to his speeches and talks on international affairs, and the fate of the Jewish people.
The centerpiece of the CD is a 25 minute eulogy to Einstein by the Irish playwright George Bernard Shaw. Says Shaw: There are great men who are great men amongst small men, but there are also great men who are great amongst great men, and that is the sort of great man whom you have amongst you here tonight. Men like Einstein are not makers of empires, but they are makers of universes. And when they have made those universes, their hands are unstained by the blood of any human being on earth.
Einstein was a great physicist, but he was a greater humanitarian. One week before his death Einstein signed his last letter. It was a letter to Bertrand Russell in which he agreed that his name should go on a manifesto urging all nations to give up nuclear weapons. It is fitting that one of his last acts was to argue, as he had done all his life, for international peace. Perhaps while celebrating his science, we could also pay tribute to this giant of a man by taking steps to honor his vision of a nuclear-free world, a world he (unwittingly) played such a large part in creating? I sure hope so.

A number puzzle first proposed by the brilliant mathematician Srinivasa Ramanujan (1887-1920) has finally been solved. Karl Mahlburg, A graduate student at the University of Wisconsin at Madison has submitted a 10-page paper of his results to the Proceedings of the National Academy of Sciences.

Srinivasa Ramanujan (1887-1920)All natural numbers (1,2,3,4,...) can be broken down into sums. For example, the number 4 can be broken down in 5 ways (called partitions): 4, 3+1, 2+2, 2+1+1 and 1+1+1+1. Ramanujan realized that curious patterns - called congruences, existed for some numbers: for example, the number of partitions for any number ending in 4 or 9 is divisible by 5 (The number 4 can be broken down into 5 partitions, as shown above). He also discovered that for some other numbers, the number of such partitions is divisible by 7 or 11. No one knew why!
In the 1940s, physicist Freeman Dyson discovered a rule, called a 'rank', explaining the congruences for 5 and 7. Mathematician George Andrews was able to explain (in the 1980s) the case (called a 'crank' ;-)) involving the number 11. Then in the late 1990s, Mahlburg's advisor, Ken Ono, stumbled across an equation in one of Ramanujan's notebooks that led him to discover that any prime number - not just 5, 7, and 11 - had congruences! This was totally unexpected. But again it was unclear why. It was Mahlburg who was able to prove why it was so.
Such a study into the nature of numbers might seem esoteric. But the solution may one day lead to advances in particle physics and computer security. As Mahlburg noted, such partitions have been used previously in understanding the various ways particles can arrange themselves, as well as in encrypting credit card information sent over the internet.

Neandertal (Homo Neanderthalensis) was a cousin species of modern humans that inhabited Europe and parts of western Asia from about 230,000 to 29,000 years ago during the Middle Palaeolithic (early Stone) age. Considerable debate in the recent years have been focussed on the similarities between Neandertal and modern human physiology and anatomy. Recently, some scientists have claimed that the Neandertals had a strong, yet high-pitched, voice that they used for both singing and speaking. It is also possible that some of our ancestors might have interbred with the Neandertals when the two species perhaps met in the Western Europe. The fact that such issues are being discussed is partly because of our extreme fascination with our closest (extinct) relatives.

Neandertal skeleton (Courtesy: National Geographic)Now, another team of scientists have constructed the first fully articulated, or jointed, Neandertal skeleton using castings from real Neandertal bones. The team included G.J. Sawyer from American Museum of Natural History (AMNH), and Blaine Maley, a graduate student in the Department of Anthropology at Washington University in St. Louis, Missouri. The bones were casted from those of a skeleton called La Ferrassie 1, which was discovered in France in 1909. This skeleton is fairly complete, but it lacks a complete rib cage, vertebral column, and pelvis. The researchers obtained these parts from other individual skeletons. This is the first time a full skeleton of the Neandertal has been constructed/assembled.
The skeleton stands 5.4 feet tall, and is currently on display at the Dolan DNA Learning Center in Cold Spring Harbor, New York. It will be permanently moved to AMNH in New York City.
The reconstruction could provide researchers valuable details about the Neandertals, and aid future work in comparative anatomy of humans and Neandertals.