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Sun, 19 May 2013 12:56:52 -0400

New principle may help explain why nature is quantum Like small...

Tue, 14 May 2013 20:28:35 -0400

New principle may help explain why nature is quantum

Like small children, scientists are always asking the question ‘why?’. One question they’ve yet to answer is why nature picked quantum physics, in all its weird glory, as a sensible way to behave. Researchers Corsin Pfister and Stephanie Wehner at the Centre for Quantum Technologies at the National University of Singapore tackle this perennial question in a paper published today in Nature Communications.

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minus229k1: thanks to #IFLS this guy is clearly a...

Sat, 11 May 2013 16:58:31 -0400

minus229k1:

thanks to #IFLS

this guy is clearly a maths-freak,and i appreciate that:
http://bit.ly/176k5db

Scinerds: What is a Quantum?

Thu, 09 May 2013 18:03:49 -0400

Scinerds: What is a Quantum?: thatscienceguy: Today the science world is full of the word quantum...

fashionablephysicists: Taking physics to a whole new level.

Tue, 07 May 2013 16:34:51 -0400

fashionablephysicists:

Taking physics to a whole new level.

Two Scoops. Get Huge.: There Is No Such Thing as Cardio (Actual Science)

Tue, 07 May 2013 00:20:51 -0400

Two Scoops. Get Huge.: There Is No Such Thing as Cardio (Actual Science):...

ikenbot: Antimatter and Fusion Drives Could Power Future...

Mon, 06 May 2013 10:09:10 -0400

ikenbot:

Antimatter and Fusion Drives Could Power Future Spaceships

Nuclear fusion reactions sparked by beams of antimatter could be propelling ultra-fast spaceships on long journeys before the end of the century, researchers say.

Image: Comparison of Daedalus spacecraft and Saturn V rocket.

A fusion-powered spacecraft could reach Jupiter within four months, potentially opening up parts of the outer solar system to manned exploration, according to a 2010 NASA report.

A number of hurdles would have to be overcome—particularly in the production and storage of antimatter—to make the technology feasible, but some experts imagine it could be ready to go in a half-century or so.

It’s “probably not a 40-year technology, but 50, 60? Quite possible, and something that would have a significant impact on exploration by changing the mass-power-finance calculus when planning,” Jason Hay, a senior aerospace technology analyst for consulting firm The Tauri Group, said during an Aug. 29 presentation with NASA’s Future In-Space Operations working group.

The power of fusion

The fuel for such a fusion-driven spaceship would likely consist of many small pellets containing deuterium and tritium—heavy isotopes of hydrogen that harbor one or two neutrons, respectively, in their nuclei. (The common hydrogen atom has no neutrons.)

Inside each pellet, this fuel would be surrounded by another material, perhaps uranium. A beam of antiprotons—the antimatter equivalent of protons, sporting a net electrical charge of minus-1 rather than plus-1—would be directed at the pellets.

When the antiprotons slammed into uranium nuclei, they would annihilate, generating high-energy fission products that ignite fusion reactions in the fuel.

Such reactions—for example, deuterium and tritium nuclei merging to create one helium-4 atom and one neutron—throw off huge amounts of energy that could be harnessed to propel a spacecraft in several different ways.

“The energy from these reactions could be used to heat a propellant or provide thrust through magnetic confinement and a magnetic nozzle,” states the 2010 report, called “Technology Frontiers: Breakthrough Capabilities for Space Exploration,” which NASA produced with the help of The Tauri Group and other experts.

The basic idea is not new: Project Daedalus, a study conducted by the British Interplanetary Society in the 1970s, proposed using a fusion rocket to power an interstellar spacecraft. Daedalus’ fusion reactions would be sparked by electron beams rather than antiproton beams, however.

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Materials scientist creates world's toughest fiber

Wed, 01 May 2013 12:08:00 -0400

Phys.org —Italian materials scientist Nicola Pugno has realized amazing gains in adding toughness to...

the-star-stuff: By Ricardo Cid (See more here)

Fri, 26 Apr 2013 15:44:58 -0400

the-star-stuff:

By Ricardo Cid (See more here)

IceCube detects the highest energy Neutrinos ever

Fri, 26 Apr 2013 08:35:00 -0400

Phys.org - Researchers at the Antarctic research station IceCube are reporting that they’ve...

astronemma: Einstein’s Gravity Theory Passes Toughest Test...

Fri, 26 Apr 2013 08:18:00 -0400

astronemma:

Einstein’s Gravity Theory Passes Toughest Test Yet

An extreme pair of superdense stars orbiting each other has put Einstein’s general theory of relativity to its toughest test yet, and the crazy-haired physicist still comes out on top.

About 7,000 light-years from Earth, an exceptionally massive neutron star that spins around 25 times a second is orbited by a compact, white dwarf star. The gravity of this system is so intense that it offers an unprecedented testing ground for theories of gravity.

Scientists know general relativity, proposed by Albert Einstein in 1915, isn’t the complete story. While it does very well describing large, massive systems, it’s incompatible with quantum mechanics, which governs the physics of the very small. For something extremely small, yet extremely massive — such as a black hole — the two theories contradict each other, and scientists are left without a physical description.

Rare systems like this binary star pair offer a chance to probe the boundary between the two theories, and search for possible openings toward new physics that could reconcile them.

“We thought this system might be extreme enough to show a breakdown in general relativity, but instead, Einstein’s predictions held up quite well,” Paulo Freire, an astronomer at the Max Planck Institute for Radio Astronomy in Germany, said in a statement.

The white dwarf in the pair represents the remains of an aging star that lost its atmosphere and is gradually cooling down. Its companion, the neutron star, is much more massive and is so dense that the protons and electrons in its atoms have collapsed to form neutrons. Created in a supernova explosion that marked the death of a star, the neutron star contains twice the mass of the sun packed into an area just 12 miles (19 kilometers) wide. On the surface of this star, gravity is 300 billion times stronger than on Earth.

The neutron star is what’s called a pulsar, because it gives off a beam of light that appears to pulse on and off as it rotates past Earth.

The gravitational field created by the pulsar is so strong that the scientists suspected they might notice deviations from the predictions of general relativity in the motions of the white dwarf around it. General relativity posits that massive objects warp the space and time around them, causing other objects, and even light, to travel along curved paths when they pass nearby.

General relativity also predicts that a close binary system such as this one will radiate gravitational energy in the form of ripples in space-time called gravitational waves. This loss of energy would cause the orbital period of the system to change slightly over time. Alternative theories of gravity offer slightly different predictions for the white dwarf’s motions.

“Our radio observations were so precise that we have already been able to measure a change in the orbital period of 8 millionths of a second per year — exactly what Einstein’s theory predicts,” said Paulo Freire, another team member at the Max Planck Institute.

Though the results don’t help physicists solve the fundamental gravity quandary, they do confirm that current efforts to detect gravitational waves, based on Einstein’s predictions, are on the right track. Several Earth-based tests are underway to look for perturbations in space-time distances caused by passing gravitational waves.

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subatomiconsciousness:

Mon, 22 Apr 2013 12:09:11 -0400

subatomiconsciousness:

understandingtheuniverse: altoidyoda: Actual 4th grade science...

Mon, 22 Apr 2013 12:08:57 -0400

understandingtheuniverse:

altoidyoda:

Actual 4th grade science test from a school in South Carolina.

jtotheizzoe: feezix: Pages from Albert Einstein’s notebook

Sun, 21 Apr 2013 07:42:51 -0400

jtotheizzoe:

feezix:

Pages from Albert Einstein’s notebook

approachingsignificance: When Criminologists do IT, the law has...

Sun, 14 Apr 2013 21:59:31 -0400

approachingsignificance:

When Criminologists do IT, the law has been broken.

Sociologists do IT in groups.

Psychologists do IT in their heads.

Seen on I Fucking Love Science.

What else ya got for our social sciences?

sincerelyscience: ikenbot: breakingnews: Hawaii approves...

Sun, 14 Apr 2013 16:02:11 -0400

sincerelyscience:

ikenbot:

breakingnews:

Hawaii approves permit for world’s largest telescope

Pacific Business News: A permit for the $1.3 billion Thirty Meter Telescope was approved by the Hawaii Board of Land and Natural Resources on Friday.

The telescope will be built on the summit of the volcano Mauna Kea by a group of research universities primarily from California and Canada.

Researchers believe the telescope will produce images three times sharper than those produced by optical telescopes today.

Read more: http://bit.ly/112KHWk

Illustration courtesy TMT Observatory Corp

Nice!

I live in Hawaii and when they’re designing it I will be graduated from engineering school :D I really hope I can work on this project

scinerds: Scientists can now turn brains invisible Say hello...

Sun, 14 Apr 2013 09:29:58 -0400

scinerds:

Scientists can now turn brains invisible

Say hello to the stunning results of CLARITY — a new technique that enables scientists to turn brain matter and other tissues completely transparent. It’s already being hailed as one of the most important advances for neuroanatomy in decades, and it’s not hard to see why.

Cut off a mouse’s head. Carefully remove its brain, wash it gently, and you’ll wind up with something resembling the sample pictured above, on the left. Grey matter, it so happens, lives up to its name. Due in large part to molecules known as lipids, organs like the brain are usually opaque. Lipids comprise cell membranes and provide structural support to a variety of organs and tissues throughout the body – but they also scatter light. As a result, most microscopes are lucky if they can peer even a millimeter into biological matter before images in the viewfinder get blurry.

One of the more popular techniques scientists use to get around this hangup is called “sectioning.” It’s brutally straightforward in practice: a researcher will freeze a chunk of tissue (a mouse brain, for example) in liquid nitrogen, and then slice it into scores of little sheets, each one just a fraction of a millimeter thick. This turns a single 3-dimensional problem (otherwise inscrutable, due to its non-transparent nature) into a series of 2-dimensional ones. Go through a brain layer by layer, and you can cobble together a volumetric picture of everything from cellular structure, to the spatial distribution of proteins, to the various connections that form between neurons. But the tradeoff is substantial. You’re literally cutting your sample into a bunch of tiny little pieces. With every slice, tissue is deformed, connections are severed, information is lost.

CLARITY does away with the slicing and dicing entirely. The technique, described in the latest issue of Nature by a team led by Stanford researchers Kwanghun Chung and Karl Deisseroth, works by stripping away all of a tissue’s light-scattering lipids, while leaving everything else right where it belongs. You’ll recall, however, that lipids play an important structural role in organs like the brain; if you remove them, everything else falls apart — a fact that has plagued past attempts at making tissues see-through. But that’s where CLARITY is different.

CLARITY works by virtue of a bait and switch. In their study, Chung and Deisseroth submerge a mouse brain in a mixture of formaldehyde and acrylamide. The former attaches important cellular structures and components to the latter, which solidifies into a gel when heated. An electrical current is then coursed through the gel, stripping it of anything not hanging on. The lipids go bye-bye, and the brain goes clear as Jell-O. More importantly: all of its significant structures remain intact and in place. Neurons, synapses, proteins, DNA. Every last component is exactly where it should be.

The ability to strip a brain of its lipids and nothing else gives rise to remarkable research possibilities. In the image above, a mouse brain turned transparent with CLARITY has been made visible again by labeling specific neurons with a fluorescent marker that glows green. Researchers have been using this technique (called “immunolabeling”) to highlight certain molecular and structural features for years, but with CLARITY, labeled cells can be seen in three dimensions, all at once.

In fact, the process of removing the brain’s lipids actually makes the tissues more permeable, making it easier to not only tag them with fluorescent markers in the first place, but untagthem and then tag them again with an entirely different label. What’s more, the fact that you don’t have to cut a brain up to see how it was stained means that you can add more tags to the same brain. The picture below shows a region of the brain known as the hippocampus that has had its different neurons labeled in a variety of fluorescent colors. A brain that was once impermeable to light has been made invisible, only to be made visible again – but this time with remarkable specificity.

There’s nothing that says this technique couldn’t be used on human brains, so long as you have the time. Coloring-in a clarified brain like the one above requires soaking it in solution with the fluorescent labels you want to tag it with. For a mouse brain, that can take a month or more. For a brain as voluminous as a human’s, it would take much longer. (While Chung and Deisseroth did demonstrate their technique could be used on human brains, they did so with a small block of tissue, not an entire brain.)

Likewise, there’s nothing that says CLARITY could not be used on tissues besides the brain, though the organ certainly shows the most immediate promise. The ability to visualize the neuronal connections throughout a transparent brain, for example, could spur incredible growth in the field of connectomics, which seeks to map the brain’s neuronal wiring. In neuroscience, few tools are as coveted as those that enable you to see the part and the whole simultaneously – CLARITY could enable researchers to study the structure and distribution of individual neurons in the context of the whole brain. “This is the kind of innovation that will slingshot neuroscience far beyond today,” said Henry Markram, leader of Europe’s recently unveiled Human Brain Project, in an interview with NatGeo’s Ed Yong. “This new method of whole-brain imaging across all levels of the brain provides a way to acquire much of the key data we will need.”

Full Article

newsweek: Hidden deep in Obama’s Fiscal Year 2014 Budget is...

Wed, 10 Apr 2013 12:01:40 -0400

newsweek:

Hidden deep in Obama’s Fiscal Year 2014 Budget is this item: “Begins work on a mission to rendezvous with—and then move—a small asteroid.”

See what else you can find that’s particularly noteworthy, and tell us.

I think we should start calling climate deniers "Climate Satirists."

Sun, 07 Apr 2013 17:54:28 -0400

I think we should start calling climate deniers "Climate Satirists.":...

Population Stabilization by 2050?

Sun, 07 Apr 2013 16:07:43 -0400

Population Stabilization by 2050?