Tag Archives | Physics
“It would be a pretty amazing thing to show that we have actually made physical contact in another universe. It’s a long shot, but it would by very profound for physics” (Prof. Efstathiou). Via BBC:
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The idea that other universes – as well as our own – lie within “bubbles” of space and time has received a boost.
Studies of the low-temperature glow left from the Big Bang suggest that several of these “bubble universes” may have left marks on our own.
This “multiverse” idea is popular in modern physics, but experimental tests have been hard to come by.
The preliminary work, to be published in Physical Review D, will be firmed up using data from the Planck telescope.
For now, the team has worked with seven years’ worth of data from the Wilkinson Microwave Anisotropy Probe, which measures in minute detail the cosmic microwave background (CMB) – the faint glow left from our Universe’s formation.
Major disappointment, from some jerk scientists who don’t seem to know when to keep their results to themselves. Via Discovery:
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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.
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.
Ah, now we know why the Doctor visits our planet so often. Via NASA’s website:
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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.
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.
The ever lucid Phil Plait writes on Bad Astronomy:
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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.
It really is a strange universe out there. Marcus Chown writes in New Scientist:
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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.