Of all the weirdness in the universe, the quantum mechanics phenomenon called “entanglement” may be the most mind-boggling. Physicists have long shaken their heads at the theory that two particles that become entangled will always and instantly mirror each other’s properties, no matter how far they are separated, which seems to go against all other physical understanding. In the everyday world, objects can organize themselves in just a few ways. For example, two people can coordinate their actions by talking directly with each other, or they can both receive instructions from a third source…. But quantum mechanics allows for a third way to coordinate information [Nature News].

Einstein rebelled against the notion of quantum entanglement, derisively calling it “spooky action at a distance”  [LiveScience]. Entanglement would look a lot less spooky if we could prove that an entangled object releases an unknown particle or some other signal at high speeds to influence its partner, giving the illusion of a simultaneous reaction [LiveScience]. But a new study shows that if some hidden signal is passing between the separated particles, it would have to travel at 10,000 times the speed of light. As this explanation seems impossible, the research team favors the alternate, weirder idea: that a measurement on one photon instantly influences the other [New Scientist].

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A new study of a pair of neutron stars has proven that Albert Einstein got the details right on his theory of general relativity, which describes the interactions of gravity, space, and time in our universe. A team of astrophysicists examined two newly discovered neutron stars, the small and dense stellar bodies formed after a supernova collapses, and found that Einstein accurately predicted their movements more than 90 years before the unusual star system was first sighted.

In Einstein’s relativistic universe, matter curves space and slows down time, and the speed of light remains the only constant. But those are the big effects. The theory of relativity also includes some more esoteric details, one of which is called spin precession. The idea goes like this: Two massive bodies orbiting near each other will warp space enough to disturb the central axis around which both are moving, causing them to begin wobbling just like spinning tops. Strong gravity creates this so-called precession, and the more massive the objects, the easier the precession is to observe [ScienceNow Daily News].

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