Physics – Page 95

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Early Magnetic Galaxies Surprise Astronomers

July 17, 2008

Astronomers reported in Nature that early galaxies have normal magnetic fields.1 That is surprising because magnetic fields were supposed to start small and strengthen over billions of years. The team tried to be careful to distinguish intervening magnetic signatures from those in quasars. Their measurements indicated that “organized fields of surprisingly high strengths […]

Solar System

Saturn Rings: F is for Flamboyant

July 2, 2008

Cassini provides additional evidence that Saturn's F-ring is young.

Cosmology

Cosmology at the Outer Limits

June 30, 2008

Those who think cosmology could not get any weirder than it already is (01/15/2008) may want to take note of recent pronouncements by the gurus of universal physics. Physics teachers in particular may feel an obligation to state Bob Berman’s disclaimer (10/06/2004) before class: viz, “Warning: The following contains contemporary cosmology. Reading it can produce […]

Physics

Hopes Die for Enceladus Longevity

June 19, 2008

Ever since Enceladus, the little 300-mile-across moon of Saturn was found in 2005 to be erupting out its south pole, scientists have tried to explain how it could be possible. They have looked high and low for an energy source to power the geysers of the little moon dubbed “Cold Faithful” for billions of years. […]

Cosmology

Divining the CMB

June 12, 2008

What do you see in this pattern? Look very closely. The Cosmic Microwave Background (CMB) is a faint glow of electromagnetic radiation that pervades the universe. What it means is a matter of intense and sometimes bizarre speculation by cosmologists. The spectrum of the CMB matches almost perfectly that of an ideal radiator, […]

Intelligent Design

Alien Messages via Neutrinos

June 6, 2008

Three scientists are suggesting that SETI researchers comb neutrinos for alien messages. Nothing natural could produce high-energy neutrinos, they said in Science,1 so aliens may use their cosmic accelerators to send neutrino packets across the intergalactic internet. They suggested watching for them in the neutrino detector at the South Pole. 1. Random Samples, Science, Volume […]

Cosmology

Cosmology in Crisis Over Dark Energy

May 21, 2008

Ten years ago, cosmologists invented dark energy to explain certain features of the expansion of the universe that could not be reconciled with observations of supernova magnitudes. Now, reported National Geographic News, dark energy remains the most profound problem in physics. It’s like theory and observations are refusing to cooperate with an arranged marriage. […]

Astronomy

Hubble Snaps Colliding Galaxies

April 24, 2008

A new catalog of colliding galaxy images has been released by the Hubble Space Science Institute. The 59 images show “close encounters that sometimes end in grand mergers and overflowing sites of new star birth as the colliding galaxies morph into wondrous new shapes.” The release coincided with the 18th anniversary of the Hubble Space […]

Health

Mars Lacks Safety Shield for Humans

April 3, 2008

Forget all those optimistic, futuristic sci-fi tales of humans landing on Mars. It isn’t safe, said Space.com. NASA’s space radiation program doubts that a human body could survive prolonged exposure to space. This is a problem for long stays on the moon, too. “The magnetic field of Earth protects humanity from radiation in […]

Amazing Facts

Seeing Vision in a New Light

March 31, 2008

The eye is like a camera, right? That picture is way too simplistic. The eye-brain visual system does image processing and gleans information from photons in diverse and remarkable ways. Here are some recent findings by scientists: Upward mobility: A team of Harvard scientists found some retinal ganglion cells that sense upward motion. Writing in […]

Origin of Life

Enceladus: Hotter Chemical Plume Found

March 26, 2008

Initial results of Cassini’s March 12 flyby of Enceladus have been published. You can watch a replay of today’s press briefing, read the blog, and read illustrated bulletins about the organic material, chemical signatures, hot spot locations, the stellar occultation (see also the Quicktime animation). Another article shows the plume locations. An astrobiologist (Chris McKay) […]

Physics

Crater Dater Deflator: Impactors Can Be Recycled

March 25, 2008

They came from outer space – that was the old paradigm about impactors that made craters on planetary bodies. Then, we learned how secondary craters can confuse a surface’s history (06/08/2006, 09/25/2007). Now, two papers in Icarus show that moons can do a lateral pass. Alvarellos et al,1 showed that Jupiter’s moon Io […]

Astronomy

How to Avoid Dark Energy

March 15, 2008

Who needs dark energy? Copernicus? George Ellis (U. of Cape Town) said we could get rid of dark energy by throwing the Copernican Principle overboard. Writing in Nature,1 he said that dark energy may simply be an artifact of the geometry of space-time. Copernicus did not invent the Copernican Principle. He was just […]

Physics

Falling Rocks Leave Holes in Science

March 13, 2008

Hard data in astronomy is hard to come by, except when it comes by special delivery – as with meteorites. If there is any class of phenomena that should be well understood, it should be space debris and the craters they form, because the processes involved can be watched in real time. Meteorites adorn many […]

Astronomy

Is Cosmology Getting Wimp-y?

February 28, 2008

Physics and astronomy are usually thought of as the “hard” sciences, where empiricism is king. Read the following excerpts from a story on the BBC News science page with that in mind (suggestion: replace “dark matter” with “mysterious unknown stuff”). The first stars to appear in the Universe may have been powered by dark matter, […]

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