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Monthly Archives: August 2013

An international team of researchers, led by physicists from Lund University in Sweden, have confirmed the existence of what is considered a new element with atomic number 115. The experiment was conducted at the GSI research facility in Germany. The results confirm earlier measurements performed by research groups in Russia.

UUP_Element_115

By bombarding a thin film of americium (atomic number 95) with calcium ions, the research team was able to measure photons in connection with the new element’s alpha decay. Certain energies of the photons agreed with the expected energies for x-ray radiation, which is a ‘fingerprint’ of a given element.

The new super-heavy element has yet to be named officially, but is known as ununpentium (from its atomic number, 115). A committee comprising members of the international unions of pure and applied physics and chemistry will review the new findings to decide whether to recommend further experiments before the discovery of the new element is acknowledged.

The original press release may be found here. The results were published in the journal Physical Review Letters.

NASA has just released new photos and video animations depicting the agency’s planned initiative to find, capture, redirect, and study a near-Earth asteroid. The images depict crew operations including the Orion spacecraft’s trip to and rendezvous with the relocated asteroid, as well as astronauts maneuvering through a spacewalk to collect samples from the asteroid.

Part of President Obama’s FY 2014 budget request for NASA, the asteroid initiative capitalizes on activities across the agency’s human exploration, space technology, and science programs. NASA is enhancing its ongoing efforts to identify and characterize near-Earth objects for scientific investigation, and to find potentially hazardous asteroids and targets appropriate for capture and exploration.

arv-orion

Credit: NASA

The mission is still just at the concept stage, but it is expected to employ advanced solar electric propulsion technology as a power source for its Orion spacecraft.

Read  the full press release here, or link straight to the images and video.

Physicists at the International Bureau of Weights and Measures (BIPM) in Sèvres, France, used a torsion balance to measure Newton’s constant of gravitation, G. Their new combined result, using two independent methods is

G = 6.67545(18) × 10−11 mkg−1 s−2

with an uncertainty of 27 parts per million. This is 241 parts per million above the 2010 value recommended by the international Committee on Data for Science and Technology (CODATA), quoted in Appendix 2A. Their paper will be published in Physical Review Letters.

3565107900

Credit: BIPM

 

(See also ‘A Closer Look 5.3’ and ‘Figure It Out 5.2,’ both on p. 110.)

A recent article in the New York Times highlights the ongoing debate among theoretical cosmologists about what happens when you enter a black hole, the so-called “Firewall Paradox”. At stake are some of the basic tenets of modern science, in particular Einstein’s general theory of relativity, the theory of gravity, on which our understanding of the Universe is based.

The traditional view holds that an astronaut falling into a black hole would not be physically aware of crossing the point of no return, known as the event horizon. (Of course, he or she will inevitably be crushed by the monstrous gravitational forces…)

In 1974, British cosmologist Stephen Hawking theorized, using general relativity and quantum theory (the laws which govern behaviors on the smallest, subatomic scales) that black holes, could leak particles and radiation back into space. This in itself generated a 30-year debate, and a famous wager with Caltech physicist John Preskill, on whether such escaping particles would carry some quantum information with them or not. In 2004, Hawking conceded that such information could survive.

A group of researchers at the University of California, Santa Barbara studying how information escapes a black hole’s clutches have presented the “Firewall Paradox”: that having information flowing out of a black hole is incompatible with having an otherwise smooth space-time at its boundary, i.e. the traditional event horizon. Instead there would be a discontinuity in the vacuum that would manifest itself as energetic particles — a literal “firewall” — lurking just inside the black hole.

If the firewall argument proves to be correct, one of three ideas that lie at the heart of modern physics, must be wrong. Either information can be lost in a black hole after all; Einstein’s principle of equivalence is wrong; or quantum field theory, which describes how elementary particles and forces interact, is wrong and needs fixing.

To find out more about possible solutions to this problem, read Dennis Overbye’s full New York Times article here.

p. 277: A Closer Look 10.2. Solar Eclipses of 2013

The two eclipses shown, both from Australia, are actually November 14, 2012, for the total solar eclipse and May 10, 2013, for the annular eclipse.

New observations from the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile have given astronomers the best view yet of how vigorous star formation can blast gas out of a galaxy and starve future generations of stars of the fuel they need to form and grow. Dramatic new images show enormous outflows of molecular gas ejected by star-forming regions in the nearby Sculptor Galaxy. These new results help to explain the strange paucity of very massive galaxies in the Universe. The study was published in the journal Nature on 25 July 2013.

The Sculptor Galaxy, also known as NGC 253, is a spiral galaxy located in the southern constellation of Sculptor. Lying at a distance of around 11.5 million light-years from our Solar System it is one of our closer intergalactic neighbors, and one of the closest ‘starburst galaxies,’ those which produce at an exceptionally high rate. Using ALMA, astronomers have discovered billowing columns of cold, dense gas fleeing from the center of the galactic disc. These results may help to explain why astronomers have found surprisingly few high-mass galaxies throughout the cosmos.

Credit: ALMA (ESO/NAOJ/NRAO)/Erik Rosolowsky

See the full ESO press release here, including links to more images and movies.