Super Spooky

Entanglement in the Macro World

By linking the electrical currents of two superconductors large enough to be seen with the naked eye, researchers have extended the domain of observable quantum effects. Billions of flowing electrons in the superconductors can collectively exhibit a weird quantum property called entanglement, usually confined to the realm of tiny particles, scientists report in the Sept. 24 Nature.

That sounds pretty cool, though they don’t go into any details about why exposing the currents to microwaves would entangle them. If the microwaves were linearly polarized, and the current loops are acting as antennae, I can see this; linear polarization can be expressed as a superposition of right- and left-circular polarization, so that might do the trick.

However, I have some objections to the reporting.

After interacting in a certain way, objects become mysteriously linked, or entangled, so that what happens to one seems to affect the fate of the other.

This is ambiguous, so I’m not sure if it fall into the trap of the “doing something to one changes the other” error, but even ambiguous is bad. Entanglement means knowing the state of one tells you the state of the other. And the real kicker here is “mysteriously,” which implies that nobody knows what the heck is going on. There are unanswered questions in entanglement, as there are in all areas of science, but it’s not the same as scientists fumbling and bumbling around, saying, “OMG! WTF?” Entanglement is a prediction of quantum mechanics, and the fact that people are exploiting it shows that it’s not really Sphinx-y (terribly mysterious) at all. Physics ain’t easy, but there’s no need to hamstring the understanding of it by selling it as mysterious.

In the new study, researchers used a microwave pulse to attempt to entangle the electrical currents of the two superconductors. If the currents were quantum-mechanically linked, one current would flow clockwise at the time of measurement (assigned a value of 0), while the other would flow counterclockwise when measured (assigned a value of 1), Martinis says. On the other hand, the currents’ directions would be completely independent of each other if everyday, classical physics were at work.

This can’t be right. If they are independent of each other you expect the currents to have no correlation, so half the time they should be in the opposite direction — so simply measuring currents in the opposite direction is not an indication that they are entangled. That could hold only if classically you always expected them to be in the same direction. The indication that they are entangled is the much higher incidence of finding the opposite currents, as was observed.

Part of the Problem

STUDY: U.S. subsidises fossil fuels 2.5 times more than renewables

Fossil fuels were given about $72 billion during the seven years, while renewable fuels got just $29 billion. The money the U.S. spends on renewables isn’t all that great, either. Of the $29 billion, $16.8 billion went to producing corn-based ethanol. Just two tax credits – the Foreign Tax Credit and the Credit for Production of Nonconventional Fuels – account for about $30 billion.

To be fair, normalized to the amount of energy, renewables probably win, but this still seems backwards. Weaning ourselves from foreign oil and reducing CO2 emissions isn’t going to be painless. I think it’s time that we recognize that, stop being like children afraid of getting a shot at the doctor’s office, and suck it up a little bit.

Free Parking

Get Out of Jail Free: Monopoly’s Hidden Maps

During World War II, as the number of British airmen held hostage behind enemy lines escalated, the country’s secret service enlisted an unlikely partner in the ongoing war effort: The board game Monopoly.

It was the perfect accomplice.

Included in the items the German army allowed humanitarian groups to distribute in care packages to imprisoned soldiers, the game was too innocent to raise suspicion. But it was the ideal size for a top-secret escape kit that could help spring British POWs from German war camps.

The British secret service conspired with the U.K. manufacturer to stuff a compass, small metal tools, such as files, and, most importantly, a map, into cut-out compartments in the Monopoly board itself.

Yummy, Tasty, Packingfraction-Ohs

Volume Packing of Breakfast Cereal

With Raisin Bran, I tend to fill the bowl with cereal, then add milk, and when I finish the cereal, there’s only a small amount of milk left. With Cheerios, on the other hand, after I finish all the cereal from a full bowl plus milk, there’s still rather a lot of milk left. I generally put in another half-bowl (maybe two-thirds) worth of cereal, and finish that, too.

Being a physicist (and, as noted earlier, a gigantic dork), it occurs to me that this can probably be explained by the different volume packing factors for the different shapes. Raisin Bran is mostly flat flakes, which Cheerios are little toroids. Those two shapes will fill space very differently.

Photon Overlap

The Overlap of Two Photons

To measure ultrafast phenomena, researchers often use repetitive trains of very short laser pulses. For example, they can create two pulse trains from the same source and send them along different paths. To measure the length of the pulses within the trains, they shine both at a “nonlinear” crystal. The crystal produces extra light with double the original frequency when two pulses are present simultaneously. By changing the path followed by one train, perhaps making it a micron or so longer, researchers create a delay of a few femtoseconds. As they increase the extra path length, pulses from the two trains become out of sync, which reduces the crystal’s output and indicates the length of the pulses.

Nothing to do with Dogs

Out, Damn’d Spot!

The Poisson/Arago/Fresnel spot, which is a great example of the predictive requirement of science; this one being a binary condition. One implication of the hypothesis is that there will be a spot. Either there isn’t a spot, or there is, and that will or will not falsify the hypothesis.

“If Fresnel’s idea is correct, then the edges of a circular obstruction will act as sources of light waves. Most of these will cancel out and produce a shadow behind the object, as expected. But because the path length from the edge to the middle of the shadow is equal no matter where on the edge you start, the cancellation can’t happen and there has to be a bright spot right in the middle of the shadow. This is self-evidently bogus.”

OMG, We're All Going to Die!


But not because of this.

Movie Theaters Will Fry Us All with Infrared to Stop Pirates

Fry us all? Oh, please.

Sharp, at the request of Japan’s National Institute of Informatics, has developed a method to ruin the camcorder footage shot by pirates in movie theaters. By placing mega IR lights behind the screen (which are invisible to the human eye, of course), the light can tunnel through tiny holes that are already in screens for the passage of sound.

CCDs are sensitive to IR, which is why there is usually a filter in place (unless you remove it). But the filter isn’t perfect, so adding more IR should screw up the picture. Until someone figures out that they can put another (perhaps better) IR filter on the lens. Oh, crap, did I say that out loud?

Bonus picture (I know Matt did this already, but I finally had my camera at a place with an electric stove). The burner was still black to the naked eye when this image was recorded.

burner IR 1