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# The "Science and Space" Thread #2

Discussion in 'Random Discussion' started by lotuseclat79, Feb 15, 2010.

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Fill in the Blanks: Using Math to Turn Lo-Res Datasets Into Hi-Res Samples.

Compressed sensing was discovered by chance. In February 2004, Emmanuel Candès was messing around on his computer, looking at an image called the Shepp-Logan Phantom. The image &#8212; a standard picture used by computer scientists and engineers to test imaging algorithms &#8212; resembles a Close Encounters alien doing a quizzical eyebrow lift. Candès, then a professor at Caltech, now at Stanford, was experimenting with a badly corrupted version of the phantom meant to simulate the noisy, fuzzy images you get when an MRI isn&#8217;t given enough time to complete a scan. Candès thought a mathematical technique called l1 minimization might help clean up the streaks a bit. He pressed a key and the algorithm went to work.

Using a mathematical concept called sparsity, the compressed-sensing algorithm takes lo-res files and transforms them into sharp images. Illustration: Gabriel Peyre

-- Tom

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Physicists look for the arrow of time, biologists find it.

-- Tom

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Astronomically Large Lenses Measure the Age and Size of the Universe (w/ Video).

Using entire galaxies as lenses to look at other galaxies, researchers have a newly precise way to measure the size and age of the universe and how rapidly it is expanding, on a par with other techniques. The measurement determines a value for the Hubble constant, which indicates the size of the universe, and confirms the age of the universe as 13.75 billion years old, within 170 million years. The results also confirm the strength of dark energy, responsible for accelerating the expansion of the universe.

Oftentimes it is difficult for scientists to distinguish between a very bright light far away and a dimmer source lying much closer. A gravitational lens circumvents this problem by providing multiple clues as to the distance light travels. When a large nearby object, such as a galaxy, blocks a distant object, such as another galaxy, the light can detour around the blockage. But instead of taking a single path, light can bend around the object in one of two, or four different routes, thus doubling or quadrupling the amount of information scientists receive. As the brightness of the background galaxy nucleus fluctuates, physicists can measure the ebb and flow of light from the four distinct paths, such as in the B1608+656 system imaged above. Credit: Image courtesy of Sherry Suyu (University of Bonn)

-- Tom

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5. ### franca

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On a clear day

This mesmerising view of Earth is a montage of images taken by the Terra satellite orbiting 435miles above the planet's surface..

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Chilean Quake May Have Shortened Earth Days.

The Feb. 27 magnitude 8.8 earthquake in Chile may have shortened the length of each Earth day.

Interesting: The farther away from the equator and the steeper the fault the more effective (the fault is) in moving Earth's mass vertically and hence more effective in shifting Earth's figure axis (not the same as north-south axis).

-- Tom

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Measuring material hotter than the sun.

Three Vanderbilt physicists are members of the scientific team that have reported creating an exotic state of matter with a temperature of four trillion degrees Celsius. It's the hottest temperature ever achieved in a laboratory and 250,000 times hotter than the heart of the sun.

-- Tom

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NASA finds up to 1.3 trillion pounds of lunar ice.

Data gathered from a NASA radar on board an Indian spacecraft indicate that more than 40 craters permanently in shadows contain as much as 600 million cubic meters of ice.

A map of the north pole of the moon, showing the locations of the many craters that have now been determined to contain frozen water. (Credit: NASA)

-- Tom

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A measure for the multiverse.

When cosmologist George Ellis turned 70 last year, his friends held a party to celebrate.
...
For a start, Ellis's celebration at the University of Oxford lasted for three days and the guest list was made up entirely of physicists, astronomers and philosophers of science. They had gathered to debate what Ellis considers the most dangerous idea in science: the suggestion that our universe is but a tiny part of an unimaginably large and diverse multiverse.
...
Raphael Bousso of the University of California, Berkeley, has also been grappling with the multiverse, and in the past few months he has found a way round the troubling problem of unobservable universes.

Getting the measure of the multiverse: Traditional View; Casual Patch Measure; Holographic Multiverse

-- Tom

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Geophysicists push age of Earth's magnetic field back 250 million years.

Planetary shield formed soon enough to protect early life forms from harmful solar radiation

Shields up: Earth&#8217;s magnetic field protects life at the planet&#8217;s surface by holding the solar wind at bay, as shown in this artist&#8217;s illustration. New research suggests the magnetic field existed 3.45 billion years ago but was 30 to 50 percent weaker than it is today. Credit: NASA

-- Tom

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From two-trillion-degree heat, researchers create new matter -- and new questions.

A worldwide team of researchers have for the first time created a particle that is believed to have been in existence immediately after the creation of the universe - the so-called "Big Bang" - and it could lead to new questions and answers about some of the basic laws of physics because in essence, it creates a new form of matter.

The diagram above is known as the 3-D chart of the nuclides. The familiar Periodic Table arranges the elements according to their atomic number, Z, which determines the chemical properties of each element. Physicists are also concerned with the N axis, which gives the number of neutrons in the nucleus. The third axis represents strangeness, S, which is zero for all naturally occurring matter, but could be non-zero in the core of collapsed stars. Antinuclei lie at negative Z and N in the above chart, and the newly discovered antinucleus (magenta) now extends the 3-D chart into the new region of strange antimatter.

The Solenoidal Tracker at RHIC (STAR) is a detector which specializes in tracking the thousands of particles produced by each ion collision. The massive unit weighs 1,200 tons and is as large as a house. Credit: Photo courtesy of Brookhaven National Laboratory.

In a single collision of gold nuclei at RHIC, many hundreds of particles are emitted most created from the quantum vacuum via the conversion of energy into mass in accordance with Einsteins famous equation E = mc2. The particles leave telltale tracks in the STAR detector (shown here from the end and side). Scientists analyzed about a hundred million collisions to spot the new antinuclei, identified via their characteristic decay into a light isotope of antihelium and a positive pi-meson. Altogether, 70 examples of the new antinucleus were found.

-- Tom

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Transcendental Meditation activates default mode network, the brain's natural ground state.

A new EEG study conducted on college students at American University found they could more highly activate the default mode network, a suggested natural "ground state" of the brain, during their practice of the Transcendental Meditation technique. This three-month randomized control study is published in a special issue of Cognitive Processing dedicated to the Neuroscience of Meditation and Consciousness, Volume 11, Number 1, February, 2010.

These raw EEG tracings during eyes-closed rest (left) and Transcendental Meditation (right) represent 18 tracings over 6 seconds. The top tracings are from frontal sensors; the middle tracings are from central sensors; the bottom tracings are from parietal and occipital sensors (back). Note the high-density alpha activity in posterior leads during eyes-closed rest, and the global alpha bursts across all brain areas during Transcendental Meditation practice. Credit: Cognitive Processing, Volume 11 (2010), Issue 1

These are eLORETA images of sources of alpha EEG during TM compared to eyes-closed rest in the default mode network (the white areas). Credit: Cognitive Processing, Volume 11 (2010), Issue 1

-- Tom

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Herschel Finds Possible Life-Enabling Molecules in Space.

The Herschel Space Observatory has revealed the chemical fingerprints of potentially life-enabling organic molecules in the Orion nebula, a nearby stellar nursery in our Milky Way galaxy.

Data, called a spectrum, showing water and organics in the Orion nebula. The data were taken by the heterodyne instrument for the far infrared, or HIFI, onboard the Herschel Space Observatory, a European Space Agency-led mission with important participation from NASA. Image credit: ESA/NASA/JPL-Caltech

-- Tom

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First of Missing Primitive Stars Found.

Astronomers have discovered a relic from the early universe -- a star that may have been among the second generation of stars to form after the Big Bang.

The newly discovered red giant star S1020549 dominates this artist's conception. The primitive star contains 6,000 times less heavy elements than our Sun, indicating that it formed very early in the Universe's history. Located in the dwarf galaxy Sculptor some 290,000 light-years away, the star's presence supports the theory that our galaxy underwent a "cannibal" phase, growing to its current size by swallowing dwarf galaxies and other galactic building blocks. (Credit: David A. Aguilar / CfA)

-- Tom

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