DNA' nebula found in Milky Way

From: http://edition.cnn.com/2006/TECH/space/03/16/helix.picture.reut/index.html
The elongated double helix nebula stretches 80 light years in length.

Thursday, March 16, 2006 Posted: 1818 GMT (0218 HKT)

WASHINGTON (Reuters) -- Cosmic nebulae usually look like blobs in space, but astronomers using the Spitzer Space Telescope reported on Wednesday they have found a nebula twisted like the double helix of DNA.

"Nobody has ever seen anything like that before in the cosmic realm," said Mark Morris of the University of California, Los Angeles.

Most nebulae are "formless, amorphous conglomerations of dust and gas," Morris said in a statement, adding that this one "indicates a high degree of order."

The discovery of the twisted nebula, which stretches across 80 light-years at the center of the Milky Way, the galaxy that includes Earth, was reported in the current edition of the journal Nature.

A light-year is about 6 trillion miles (10 trillion kilometers), the distance light travels in a year.

"We see two intertwining strands wrapped around each other as in a DNA molecule," said Morris, lead author of the Nature article.

DNA, which forms the basic material in chromosomes, has a molecule that looks like a twisted ladder, known as a double helix.

The strands of the nebula may be torqued by twisted magnetic fields at the Milky Way's center, Morris said by telephone.

These magnetic fields are indirectly spawned by the gaping black hole at the galactic heart, he said. Black holes are massive matter-sucking drains in space, pulling in everything around them so powerfully that not even light can escape.

Black Holes

But before the matter falls into the black hole, it swirls around its edges. This rotation twists the magnetic fields, which in turn twist the nebula's strands, Morris said.

The nebula is relatively close to the black hole, just 300 light-years away. Earth is more than 25,000 light-years away.

NASA's Spitzer Space Telescope detects the infrared energy emitted by objects in space with high sensitivity and resolution, enabling it to clearly see the nebula's distinctive shape.

http://meta-religion.com/Astronomy/Nebulas/dna_nebula.html

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Self-assembling Nano-ice Discovered -- Structure Resembles DNA

From: http://www.sciencedaily.com/releases/2006/12/061213123744.htm

Dec 12, 2006

excerpt;

Zeng, post-doctoral student Jaeil Bai and doctoral candidate Jun Wang reported their findings in the Dec. 11-15 online edition of the Proceedings of the National Academy of Sciences.

Zeng and his colleagues use powerful computers to model how materials behave at the nanoscale (where measurements are made in billionths of meters) under extremes of temperature, pressure and confinement. The team found the self-assembling double helix of nano-ice following a months-long experiment on UNL's PrairieFire supercomputer.

The experiment was a follow-up on a 2001 discovery through computer modeling by Zeng and another team of four new kinds of one-dimensional ice inside carbon nanotubes. Scientists elsewhere later confirmed through laboratory experiment the existence of three of the new nano-ices. One result in particular intrigued Zeng, Bai and Wang. Scientists at Argonne National Laboratory near Chicago confirmed the existence of a chain of octagon-shaped ice crystals inside a 1.4-nanometer carbon tube, just as Zeng and company expected. But the Argonne group also found an additional, unexpected chain of water molecules inside the octagon.

Zeng said that report inspired his team to take another look at one-dimensional ice, but this time with a PrairieFire that was 20 times more powerful that it had been five years earlier. The 2001 results were achieved at atmospheric pressures, but PrairieFire's added processing power enabled Zeng, Bai and Wang to design simulations that greatly increased the pressure on the water molecules.

"We were shocked to see these molecules arrange themselves in this way," said Zeng, university professor of chemistry. "We thought it would be like two tubes, one inside the other, but it didn't do that.

It was helical, like DNA. I'm just speculating, but maybe the helix is a way for molecules to arrange themselves in a very compact, efficient way under high pressure.

"This ice formation can be viewed as a self-assembling process, and self-assembly is a way for molecules to bond together through weak hydrogen bonds. One example of a self-assembling material is protein. Proteins can self-assemble into structures like amyloid fibrils that can build up in the brain to cause Alzheimer's disease or prions that cause mad cow disease."

Another implication, Zeng said, is that these self-assembling helical ice structures may give scientists and engineers a different way to think about weak molecular bonds and the self-assembly process as they try to develop ways to direct self-assembly in making new materials. He said that while scientists have a good understanding of covalent bonds (the strong type of bonding where atoms share electrons), knowledge is not as complete about the weak bond, such as hydrogen bonds, that are essential to the self-assembly process. In weak bonding, atoms don't share electrons.

"We're happy to see potential applications that can maybe advance some fundamental science," Zeng said. "We're not engineers in direct contact with technology, but if our research can make some contribution, we're happy."

Zeng and his colleagues achieved their results by running four series of molecular dynamics simulations on PrairieFire and Department of Chemistry computers, using simulated carbon nanotubes ranging in diameter from 1.35 to 1.9 nanometers. They used Earth-like temperatures ranging from 117 degrees Fahrenheit to 9 degrees below zero F., but with pressures ranging from 10 to 40,000 atmospheres, with each series lasting no more than a few 10s of nanoseconds.

Most of the experiments produced the expected tubular structures, but in a simulation in a 1.35-nanometer tube at minus-9 degrees F. and 40,000 atmospheres, the ice transformed into a braid of double helix that resembles DNA in structure and in the weak bonds between the helixes. Additionally, in a simulation in a 1.9-nanometer tube at the same temperature, pressure on the confined liquid water was instantly raised from 10 atmospheres to 8,000. The confined liquid froze spontaneously into a high-density, triple-walled helical structure.

This research was funded by the Department of Energy, the National Science Foundation, the Nebraska Research Initiative and the John Simon Guggenheim Foundation.

http://meta-religion.com/Physics/Other_subjects/nano_ice.htm