Category: At the seaside
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The painful search for gravitational waves
Gravitational wave detectors have a sorry history of disappointing results. Joseph Weber at the University of Maryland first claimed to have spotted these waves in 1969. He did it by listening to the way a giant cylindrical bars vibrate, thinking that passing gravitational waves would cause them to ring like a bell. Nobody has been…
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Why small black holes cannot grow
Quantum mechanics places a fundamental limit on the minimum quanta of energy that can be associated with a bit of energy. It’s about 10^-50 Joules, which ain’t much. That has important implications for black holes, says Scott Funkhouser, a physicist at The Citadel, the military college of South Carolina, in Charleston. As black holes accretes…
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Musical relativity
Here’s a neat idea for a concert that’s going to blow a few minds if it ever takes to the stage. A combination of three or more notes played together is called a chord. We know that certain musical chords sound happy while others sound sad (although nobody knows why). The mood of a piece…
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The science of the Grateful Dead
Good to see that Deadheads are alive and well at Los Alamos National Laboratory in New Mexico. In the heart of one of the world’s most secret weapons labs, these guys are hard at work developing a science of the Grateful Dead, the 60s psychedelic band that played together until 1995. Today, they take the…
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How to build a warp drive
Is faster than light travel allowed by the laws of physics? There’s no harm in speculating, right? In 1994, Michael Alcubierre, a physicist at the National Autonomous University of Mexico in Mexico City, put warp drive on a firm (-ish) theoretical footing for the first time. His thinking was that what relativity actually prevents…
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If invisibility cloaks don’t work, try the invisibility sheet
When it comes to invisibility cloaks, nobody has done more to advance the field than John Pendry, a theoretical physicist at Imperial College, London. It was he who suggested the idea in the first place and mapped out how one could be built in theory. He even got his hands dirty by collaborating with the…
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Surfing solves puzzle of water snail locomotion
Snails move using a mechanism called adhesive locomotion. Through muscular contraction and expansion of their foot, they transmit a force to the ground through a thin layer of mucus which is adhesive at low strains but otherwise flows like a liquid. But what of water snails that move upsidedown along the underside of a liquid…
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First test of exotic space thruster ends in explosion
In 2006, Mason Peck at Cornell University in Ithaca dreamt up with an entirely new way to control satellites orbiting planets that have a magnetic field. The idea is based on the Lorentz force: that a charged particle moving through a magnetic field experiences a force perpendicular to both its velocity and the field. So…
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Why ET will phone using neutrinos not photons
The search for extraterrestrial intelligence assumes that ET will be communicating using photons. But despite decades of listening out, we’ve heard nothing. But today, John Learned from the University of Hawaii and pals say forget photons. We should be looking for evidence of ET using neutrinos. The reason is that any civilisation advanced enough to…
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Phobos could form Saturn-like ring around Mars
The martian moon Phobos is spiralling towards Mars at a rate of 20 cm a year. (That compares with our own moon which is spiralling away from us at about 4cm per year). The question is when will it hit. On the arxiv today, Bijay Kumar Sharma calculates that we have about 11 million years…