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kqedscience:

Meet the First Woman to Win Math’s Most Prestigious Prize

As an 8-year-old, Maryam Mirzakhani used to tell herself stories about the exploits of a remarkable girl. Every night at bedtime, her heroine would become mayor, travel the world or fulfill some other grand destiny.

Today, Mirzakhani — a 37-year-old mathematics professor at Stanford University — still writes elaborate stories in her mind. The high ambitions haven’t changed, but the protagonists have: They are hyperbolic surfaces, moduli spaces and dynamical systems. In a way, she said, mathematics research feels like writing a novel. “There are different characters, and you are getting to know them better,” she said. “Things evolve, and then you look back at a character, and it’s completely different from your first impression.”

Learn more about Maryam Mirzakhani at wired.

(via mathmajik)

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Modern theories did not arise from revolutionary ideas which have been, so to speak, introduced into the exact sciences from without. On the contrary they have forced their way into research which was attempting consistently to carry out the programme of classical physics—they arise out of its very nature. It is for this reason that the beginnings of modern physics cannot be compared with the great upheavals of previous periods like the achievements of Copernicus. Copernicus’s idea was much more an import from outside into the concepts of the science of his time, and therefore caused far more telling changes in science than the ideas of modern physics are creating to-day.

Werner Heisenberg

(via scienceisbeauty)

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spaceplasma:

Tokamaks: the future of fusion energy

Fusion is the energy that powers our Sun and other stars.  It has been a goal of scientists around the world to harness this process by which the stars “burn” hydrogen into helium (i.e. nuclear fusion) for energy production on Earth since it was discovered in the 1940′s.

Nuclear fusion is the process by which light nuclei fuse together to create a single, heavier nucleus and release energy.  Given the correct conditions (such as those found in plasma), nuclei of light elements can smash into each other with enough energy to undergo fusion. The “easiest” (most energetically favorable) fusion reaction occurs between the hydrogen isotopes deuterium and tritium.  When the nucleus of a deuterium atom crashes into the nucleus of a tritium atom with sufficient energy, a fusion reaction occurs and a huge amount of energy is released, 17.6 million electron volts to be exact. 

Why fusion? To put this in terms of energy that we all experience; fusion generates more energy per reaction than any other energy source.  A single gram of deuterium/tritium fusion fuel can generate 350 million kJ of energy, nearly 10 million times more energy than from the same amount of fossil fuel!

Fusion power has the potential to provide sufficient energy to satisfy mounting demand, and to do so sustainably, with a relatively small impact on the environment. Nuclear fusion has many potential attractions. Firstly, its hydrogen isotope fuels are relatively abundant – one of the necessary isotopes, deuterium, can be extracted from seawater, while the other fuel, tritium, would be bred from a lithium blanket using neutrons produced in the fusion reaction itself. Furthermore, a fusion reactor would produce virtually no CO2 or atmospheric pollutants, and its other radioactive waste products would be very short-lived compared to those produced by conventional nuclear reactors.

Fusion reactions require so much energy that they must occur with the hydrogen isotopes in this plasma state. Plasma makes up all of the stars, and is the most common form of matter in the visible universe. Since plasmas are made of charged particles every particle can interact with every other particle, even over very long distances. The fact that 99% of the universe is made of plasmas makes studying them very important if we are to understand how the universe works.

How do we create fusion in a laboratory? This is where tokamaks come in. In order for nuclear fusion to occur, the nuclei inside of the plasma must first be extremely hot, like in a star. Unfortunately, no material on Earth can withstand these temperatures so in order to contain a plasma with such high temperatures, we have to be creative. One clever solution is to create a magnetic “bottle” using large magnet coils to capture the plasma and suspend it away from the container’s surfaces. The plasma follows along the magnetic field, suspended away from the walls. This complex combination of magnets used to confine the plasma and the chamber where the plasma is held is known as a tokamak. Tokamaks have a toroidal shape (i.e. they are shaped like a donut) so they have no open ends for plasma to escape. Tokamaks, like the ASDEX Upgrade (pictured above), create and contain the hottest materials in the solar system. The aim of ASDEX Upgrade, the “Axially Symmetric Divertor Experiment”, is to prepare the physics base for ITER.

ITER (International Thermonuclear Experimental Reactor and Latin for “the way” or “the road”) is an international nuclear fusion research and engineering project, which is currently building the world’s largest experimental tokamak nuclear fusion reactor. The ITER project aims to make the long-awaited transition from experimental studies of plasma physics to full-scale electricity-producing fusion power plants.

Further readings:

(via likeaphysicist)

77 notes

Do Black Holes Explode When They Die?

thecosmosmadeconscious:

image

A new theory suggests that black holes might die by transforming into a ‘white hole,’ which theoretically behave in the exact opposite manner as a black hole - rather than sucking all matter in, a ‘white hole’ spews it out.

The theory, as first reported by Nature.com, is based on the speculative quantum theory of gravity. Scientists believe it may help determine the great debate over black holes about whether they destroy the things they consume.

According to the theory, a ‘white hole’ would explosively expel all the material consumed by a black hole.

Read More

(Source: Daily Mail)

470 notes

skunkbear:

MIT researchers have reconstructed the sound of speech by analyzing a high speed video of the minute vibrations of a nearby chip bag. They reconstructed “Mary Had A Little Lamb” from the vibrations of the leaves of houseplant. They reconstructed Queen’s “Under Pressure” from a video of earbuds. That’s a cool trick (with some interesting surveillance and forensic implications).

"This is totally out of some Hollywood thriller," says Alexei Efros, an associate professor of electrical engineering and computer science at the University of California at Berkeley. “You know that the killer has admitted his guilt because there’s surveillance footage of his potato chip bag vibrating.”
If you want to really see sound waves check out our video.

skunkbear:

MIT researchers have reconstructed the sound of speech by analyzing a high speed video of the minute vibrations of a nearby chip bag. They reconstructed “Mary Had A Little Lamb” from the vibrations of the leaves of houseplant. They reconstructed Queen’s “Under Pressure” from a video of earbuds. That’s a cool trick (with some interesting surveillance and forensic implications).

"This is totally out of some Hollywood thriller," says Alexei Efros, an associate professor of electrical engineering and computer science at the University of California at Berkeley. “You know that the killer has admitted his guilt because there’s surveillance footage of his potato chip bag vibrating.”

If you want to really see sound waves check out our video.

51 notes

Interview with P. A. M. Dirac By Thomas S. Kuhn and Eugene Paul Wigner At Wigner’s home, Princeton, New Jersey April 1, l962

scienceisbeauty:

Mandatory reading for anyone interested in modern physics, the vision of one of its main precursors, Paul Dirac, interviewed by Thomas Kuhn and Eugene Wigner, nothing less.

About Dirac I always recomend this wonderful book from Graham Farmelo: The Strangest Man: The Hidden Life of Paul Dirac, Mystic of the Atom, and alternatively, this conference by the author:

h/t TRF

43 notes

spherical-harmonics:

Quantum bounce could make black holes explode

If space-time is granular, it could reverse gravitational collapse and turn it into expansion.

One of the leading approaches to merging quantum theory and gravity, pioneered by, among others, theoretical physicist Carlo Rovelli of Aix-Marseille University in France, posits that it is not just gravity but space-time itself that is quantized, woven from tiny, individual loops that cannot be subdivided any further. The loops in this ‘loop quantum gravity’ — a theoretical attempt that has yet to find experimental support — would be so tiny that to any observer space-time looks smooth and continuous. In the new work1, Rovelli and his Aix-Marseille colleague Hal Haggard have calculated that the loop structure would halt the collapse of a black hole.
The collapsing star would reach a stage at which its inside can shrink no further, because the loops cannot be compressed into anything smaller, and in fact they would exert an outward pressure that theorists call a quantum bounce, transforming a black hole into a white hole. Rather than being shrouded by a true, eternal event horizon, the event would be concealed by a temporary ‘apparent horizon’, says Rovelli. (Theoretical physicist Stephen Hawking of the University of Cambridge, UK, has recently suggested that true event horizons would be incompatible with quantum physics.)

spherical-harmonics:

Quantum bounce could make black holes explode

If space-time is granular, it could reverse gravitational collapse and turn it into expansion.

One of the leading approaches to merging quantum theory and gravity, pioneered by, among others, theoretical physicist Carlo Rovelli of Aix-Marseille University in France, posits that it is not just gravity but space-time itself that is quantized, woven from tiny, individual loops that cannot be subdivided any further. The loops in this ‘loop quantum gravity’ — a theoretical attempt that has yet to find experimental support — would be so tiny that to any observer space-time looks smooth and continuous. In the new work1, Rovelli and his Aix-Marseille colleague Hal Haggard have calculated that the loop structure would halt the collapse of a black hole.

The collapsing star would reach a stage at which its inside can shrink no further, because the loops cannot be compressed into anything smaller, and in fact they would exert an outward pressure that theorists call a quantum bounce, transforming a black hole into a white hole. Rather than being shrouded by a true, eternal event horizon, the event would be concealed by a temporary ‘apparent horizon’, says Rovelli. (Theoretical physicist Stephen Hawking of the University of Cambridge, UK, has recently suggested that true event horizons would be incompatible with quantum physics.)

277 notes

scienceisbeauty:

CERN announces LHC restart schedule:
2 June 2014 - Restart of the Proton Synchrotron Booster
18 June 2014 - Restart of the Proton Synchrotron (PS)
Early July - Powering tests at the Super Proton Synchrotron (SPS)
Mid-July - Physics programme to restart at the ISOLDE facility and at the PS
Mid-August - Antimatter Physics programme to restart at the Antiproton Decelerator
Mid-October - Physics programme to restart at the SPS
Early 2015 - Beam back into the Large Hadron Collider (LHC)
Spring 2015 - Physics programme to restart at the LHC experiments

scienceisbeauty:

CERN announces LHC restart schedule:

(via spherical-harmonics)