Soldiers could one day conduct covert operations in complete secrecy, now that Pentagon-backed physicists have figured out how to mask entire events by distorting light.

A team at Cornell University, with support from Darpa, the Pentagon’s out-there research arm, managed to hide an event for 40 picoseconds (those are trillionths of seconds, if you’re counting). They’ve published their groundbreaking research in this week’s edition of the journal Nature.

This is the first time that scientists have succeeded in masking an event, though research teams have in recent years made remarkable strides in cloaking objects. Researchers at the University of Texas, Dallas, last year harnessed the mirage effect to make objects vanish. And in 2010, physicists at the University of St. Andrews made leaps towards using metamaterials to trick human eyes into not seeing what was right in front of them.

Masking an object entails bending light around that object. If the light doesn’t actually hit an object, then that object won’t be visible to the human eye.

Where events are concerned, concealment relies on changing the speed of light. We can see actions happening when, and because, light from those actions reaches our eyes. Usually, the light arrives on an ongoing basis. What Cornell researchers did, in simple terms, is tweak that flow of light — just for a mere instant — so that an event could transpire without being observable. They split apart a beam of light, making half the beam move extremely quickly and the other half more slowly. The “gap” between those speeds is where the event in question is hidden.

The entire experiment occurred inside a fiber optics cable. Researchers passed a beam of green light down the cable, and had it move through a lens that split the light into two frequencies, one moving slowly and the other faster. As that was happening, they shot a red laser through the beams. Since the laser “shooting” occurred during a teeny, tiny time gap, it was imperceptible.

Sure, the team’s got a ways to go before they’re able to mask 30 seconds of action, let alone several minutes. But the research certainly opens up new possibilities. For one, masking super-quick events, like those that occur with data transmission, could help conceal covert computer operations.

In the words of Nature editors, the research marks “a significant step towards full spatio-temporal cloaking.” But it could be decades before military personnel will basically be able to zap history, as it happens: According to Cornell scientists, it’d take a machine 18,600 miles long to produce a time mask that lasts a single second.

Awesome and terrifying at the same time.

I have been enjoying Adam Hochschild’s To End All Wars: A Story of Loyalty and Rebellion, 1914-1918, which covers the British role in World War I.  My favorite section details how the British responded when it turned out they had a drastic shortage of binoculars, which at that time were very important for fighting the war.  They turned to the world’s leading manufacturer of “precision optics,” namely Germany.  The German War Office immediately supplied 8,000 to 10,000 binoculars to Britain, directly intended and designed for military use.  Further orders consisted of many thousands more and the Germans told the British to examine the equipment they had been capturing, to figure out which orders they wished to place.

The Germans in turn demanded rubber from the British, which was needed for their war effort.  It was delivered to Germany at the Swiss border.

What are the possible theories?

1. It was a two-front war, and thus the British could offer the Germans a deal, knowing part of the costs of the rubber supply would fall on the combatants at the Eastern front, or perhaps even other combatants at the Western front.

2. The deal may have appealed to commercial interests in each country.

3. Politicians may have expected to survive the war, and to have their country survive the war, and in the meantime they wanted the war for their side to go better rather than worse, for reasons of public relations or to appeal to their military lobbies.

4. The traders may have disagreed about the relative merits of what they were exchanging, as is the case on Wall Street every day.

What else?

Marx is laughing right now.