Tag Archives | Physics

Time Travel Proved Impossible

timetravel2Major disappointment, from some jerk scientists who don’t seem to know when to keep their results to themselves. Via Discovery:

Hong Kong physicists say they have proved that a single photon obeys Einstein’s theory that nothing can travel faster than the speed of light — demonstrating that outside science fiction, time travel is impossible.

The Hong Kong University of Science and Technology research team led by Du Shengwang said they had proved that a single photon, or unit of light, “obeys the traffic law of the universe.”

The possibility of time travel was raised 10 years ago when scientists discovered superluminal — or faster-than-light — propagation of optical pulses in some specific medium, the team said. It was later found to be a visual effect, but researchers thought it might still be possible for a single photon to exceed light speed.

Du, however, believed Einstein was right and determined to end the debate by measuring the ultimate speed of a single photon, which had not been done before.

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Space-Time Cloak Possible, Could It Make Events Disappear Too?

4467116919_603041818fCould an entire bank heist take place at an open bank with no one seeing it? The National Geographic reports:
It's no illusion: Science has found a way to make not just objects but entire events disappear, experts say. According to new research by British physicists, it's theoretically possible to create a material that can hide an entire bank heist from human eyes and surveillance cameras. "The concepts are basically quite simple," said Paul Kinsler, a physicist at Imperial College London, who created the idea with colleagues Martin McCall and Alberto Favaro. Unlike invisibility cloaks — some of which have been made to work at very small scales — the event cloak would do more than bend light around an object. Instead this cloak would use special materials filled with metallic arrays designed to adjust the speed of light passing through.
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NASA: There Is A Space-Time Vortex Around Earth

Doctor Who VortexAh, now we know why the Doctor visits our planet so often. Via NASA’s website:

Einstein was right again. There is a space-time vortex around Earth, and its shape precisely matches the predictions of Einstein’s theory of gravity.

Researchers confirmed these points at a press conference today at NASA headquarters where they announced the long-awaited results of Gravity Probe B (GP-B).

“The space-time around Earth appears to be distorted just as general relativity predicts,” says Stanford University physicist Francis Everitt, principal investigator of the Gravity Probe B mission.

“This is an epic result,” adds Clifford Will of Washington University in St. Louis. An expert in Einstein’s theories, Will chairs an independent panel of the National Research Council set up by NASA in 1998 to monitor and review the results of Gravity Probe B. “One day,” he predicts, “this will be written up in textbooks as one of the classic experiments in the history of physics.”

Time and space, according to Einstein’s theories of relativity, are woven together, forming a four-dimensional fabric called “space-time.” The mass of Earth dimples this fabric, much like a heavy person sitting in the middle of a trampoline.

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Physicists Create Heaviest Form of Antimatter Ever Seen

Smashing TimeStephen Battersby writes on New Scientist:
A newly created form of antimatter is the heaviest and most complex anti-thing ever seen. Anti-helium nuclei, each containing two anti-protons and two anti-neutrons, have been created and detected at the Relativistic Heavy Ion Collider (RHIC) in Upton, New York. Anti-particles have the opposite electrical charge to ordinary matter particles (anti-neutrons, which are electrically neutral, are made up of antiquarks that have the opposite charge to their normal quark counterparts). They annihilate on contact with matter, making them notoriously tricky to find and work with. Until recently, the most complex unit of antimatter ever seen was the counterpart of the helium-3 nucleus, which contains two protons and one neutron. But experiments at RHIC are changing that. RHIC collides heavy atomic nuclei such as lead and gold to form microscopic fireballs, where energy is so densely packed that many new particles can be created.
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Phil Plait: No, The “Super-Moon” Didn’t Cause the Japanese Earthquake

Moon's Apogee and Perigee.

Moon's Apogee and Perigee.

The ever lucid Phil Plait writes on Bad Astronomy:

Japan suffered a massive earthquake last night, measuring nearly magnitude 9. This is one of the largest quakes in its history, causing widespread and severe damage. Before I say anything else, I’m greatly saddened by the loss of life in Japan, and I’ll be donating to disaster relief organizations to help them get in there and do what they can to give aid to those in need.

While there isn’t much I can do to directly help the situation in Japan, I do hope I can help mitigate the panic and worry that can happen due to people blaming this earthquake on the so-called “supermoon” — a date when the Moon is especially close to the Earth at the same time it’s full. So let me be extremely clear:

Despite what a lot of people are saying, there is no way this earthquake was caused by the Moon.

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Two Planets Found Sharing One Orbit

Two Planets in One OrbitIt really is a strange universe out there. Marcus Chown writes in New Scientist:

Buried in the flood of data from the Kepler telescope is a planetary system unlike any seen before. Two of its apparent planets share the same orbit around their star. If the discovery is confirmed, it would bolster a theory that Earth once shared its orbit with a Mars-sized body that later crashed into it, resulting in the moon’s formation.

The two planets are part of a four-planet system dubbed KOI-730. They circle their sun-like parent star every 9.8 days at exactly the same orbital distance, one permanently about 60 degrees ahead of the other. In the night sky of one planet, the other world must appear as a constant, blazing light, never fading or brightening.

Gravitational “sweet spots” make this possible. When one body (such as a planet) orbits a much more massive body (a star), there are two Lagrange points along the planet’s orbit where a third body can orbit stably.

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Thunderstorms Generate Antimatter Beams

Antimatter Cloud (NASA)

Antimatter Cloud (NASA)

It sounds like the stuff of science fiction, but scientists are reporting that they have seen antimatter beams emitted from thunderstorms. Jonathan Palmer has the story at BBC News:

A space telescope has accidentally spotted thunderstorms on Earth producing beams of antimatter.

Such storms have long been known to give rise to fleeting sparks of light called terrestrial gamma-ray flashes. But results from the Fermi telescope show they also give out streams of electrons and their antimatter counterparts, positrons.

The surprise result was presented by researchers at the American Astronomical Society meeting in the US.

It deepens a mystery about terrestrial gamma-ray flashes, or TGFs — sparks of light that are estimated to occur 500 times a day in thunderstorms on Earth. They are a complex interplay of light and matter whose origin is poorly understood.

Thunderstorms are known to create tremendously high electric fields — evidenced by lightning strikes.

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Observatory 1.5 Miles Deep Under Antarctic Ice

Photo: The National Geographic

Photo: The National Geographic

Some secrets of the universe may be found by looking underground. Under the South Pole to be exact. There, under the ice, is the world’s largest neutrino observatory used to find clues to cosmic mysteries and subatomic particles that can travel through almost any matter. Via The National Geographic:

An IceCube sensor is dropped into 1 of 86 holes drilled into the Antarctic ice in a December 2010 picture.

To reach the icy depths, scientists designed and built the Enhanced Hot Water Drill, which can penetrate more than 1.2 miles (2 kilometers) of ice in less than two days. The team then fed the IceCube detector—86 cable strings that each contain 60 neutrino sensors—into the holes.

Each cable is equipped with another four sensors at the surface, which together make up one IceCube array. The detector and arrays combine to make the IceCube Neutrino Observatory.

Situated at the geographic South Pole, the U.S.

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