Arr, the Mysteries of the Briny Deep

This Creeping Underwater Ice Tornado Kills Everything It Touches

Brinicles are columns of ice that form under very calm ocean conditions, when there’s a big differential between the water temperature (around -1.9C) and the air temperature about the sea ice (below -20C). The warmer sea flows up to the air, freezing into new ice. According to the BBC, “the salt in this newly formed ice is concentrated and pushed into the brine channels. And because it is very cold and salty, it is denser than the water beneath.” This makes it fall down into the water, creating an ice plume that grows into the brinicle.

When it gets to the ground, it starts to expand, killing everything it touches. The whole process takes five to six hours, according to the team, which is surprisingly fast.

Too Late for Turkey-Day

You can’t wow the family for Thanksgiving, but maybe the gang is still around, or you can store these away for a future family gathering.

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From 10 quirky science stunts

One step better would be an explanation for the inevitable “How does that work?” (or similar) question that arises, so here’s a quick explanation of the physics-y ones. The ping-pong ball tends to stay in the column of air owing to Bernoulli’s principle — pressure decreases the faster the air moves, so there is lateral pressure gradient which gives you a restoring force. The coin and card trick works because the force on the card is probably larger than the force on the coin, and even if they are comparable, card is less massive so it undergoes a much larger acceleration. Consequently, it moves away much faster than the coin, so the coin doesn’t get displaced very far.

Jabbing a sharp pencil through a bag tends to form a hole that conforms to the pencil, and water seals small gaps at low pressure owing to the surface tension. Straws are stronger along their length and covering then end with your thumb means air can’t escape; the increased pressure from the potato being forced into it makes it even stronger against collapsing. Matches burning heat up air and make it expand, so the density is lower than outside. When the matches go out the air cools, lowering the pressure. The egg provides a good seal, and the outside pressure forces the egg inside.

The others have elements of chemistry biology/physiology. So I will pass on those explanations.

I Had No Choice but to Post This

What Does Determinism Have In Common With Gods, The Flying Spaghetti Monster And Pink, Invisible Unicorns?

A common misconception by many lay-determinists (non-physicists) is that Heisenberg’s uncertainty principle describes a technical problem of our measurements rather than a principle of the universe. However, Stephen Hawking predicted the radiation named after him as stemming from virtual particle/antiparticle pairs being generated by quantum vacuum fluctuations right at the event horizon of black holes. A similar effect was claimed to have been observed in the lab. Just this week, another effect having to do with quantum fluctuations in a vacuum generating particle/antiparticle pairs has been observed. Forty years ago it was predicted that these same fluctuations which are thought to give rise to Hawking Radiation should become ‘real’, i.e., visible photons when they hit a mirror which moves at a significant fraction of the speed of light. It is this generation of photons which was directly observed and reported in the paper cited above.

It's a Trick Question

How Does Faster-Than-Light Quantum Communication Work?

Every so often, I ask readers to submit their sci/tech questions, so that I can go pester people until I have some answers that I can share with the rest of the class. One recent question was: “How does faster-than-light quantum communication work?” Short answer: it doesn’t. But of course there’s more to it than that.

Bonus: entanglement explained correctly, for which I am thankful

No, That's Not It

A number of stories have come out about how OPERA has “confirmed” the faster-than-light finding that was reported recently. Well, not really — they used shorter pulses to address one of the concerns: that the very wide (~10,000 nanosecond) pulses might have given a misleading result when the curve-fitting took place. So they shortened the pulse width, and got the same 60-nanosecond offset. But this doesn’t address other systematics that might be responsible, so it doesn’t really count as a confirmation. Validation will only come when different setups, with different systematics, agree. (The Bad Astronomer has made a similar observation)

There are also reports about how the FTL result has been refuted: Study rejects “faster than light” particle finding

That’s not quite right, either. The model says that FTL neutrinos should lose energy, in a process analogous to Cerenkov radiation that is emitted by charged particles. But since we’re talking about new physics, theory is no proof of anything. Proof (scientific proof, that is) comes from experimental confirmation. Nature has the final say. So this model is no more a refutation of the FTL neutrinos than relativity is — they are both good reason to suspect the result and demand a very high standard of evidence, but they do not constitute a true rejection of the phenomenon.

Similarly, I could (and would) dismiss idle claims of perpetual motion based on the laws of thermodynamics, but if someone were to build an actual perpetual motion device, there would be ways to test it, and very stringent testing would be demanded. And nobody would be surprised when the device ultimately failed. But if the device somehow worked, all the fingers in the world pointing to a thermodynamics textbook wouldn’t change that. Another example (from my field of work) would be laser cooling, when experiment contradicted the prevailing theory, which is a strong parallel to what is happening with the neutrino saga.

There’s also this bit that I noticed:

The September announcement of the finding, backed up last week after new studies, caused a furor in the scientific world as it seemed to suggest Albert Einstein’s ideas on relativity, and much of modern physics, were based on a mistaken premise.

The test was not backed up, as I have already written, and I wouldn’t characterize this as a furor. I haven’t seen any protests about this (the Nobel riots notwithstanding); there don’t seem to be any moves to “occupy CERN” of which I am aware.

Here’s a similar take on the “refutation”

The Devil is in the Details

Breakthrough material is barely more than air

Researchers at HRL Laboratories, the California Institute of Technology, and the University of California at Irvine have created what they say is the lowest-density material, a lattice of hollow tubes of the metal nickel.
Its volume is 99.99 percent air, and its density is 0.9 milligram per cubic centimeter–not including the air in or between its tubes. That density is less than one-thousandth that of water.

… of if this Paper Has One Side, and Whether Pigs Have Wings!

Of Mobius Strips and the Shape of Things

[E]ven though Earth is (roughly) spherical, the directions you travel can be broken down into two directions: North-South (longitude lines) and East-West (latitude lines). However, there are two places where the latitude-longitude coordinate system breaks down: the North and South Poles, where a single latitude corresponds to all the longitudes simultaneously. In fact, no coordinate system can describe the surface of a sphere without a breakdown at at least one point! It’s not for lack of trying, it’s just a mathematical fact. (There are coordinate systems that break down at only one point, but they’re less useful for cartography.)

Arguments about Möbius are always so one-sided.