Scientists have now observed quantum effects at the macro level, in a laboratory experiment involving entanglement. This is a fairly big deal, not only because of what it tells us about the strange ways matter relates to matter, but because of what technology might come of it, especially with quantum computing:

He doubts that there will be any immediate applications for the technique, partly because the entanglement is very short-lived. “I am not sure where this particular work will go from here,” says Cleland. “I can’t think of a particular use for entanglement that lasts for only a few picoseconds” (10^-12 seconds).

But Walmsley is more optimistic. “Diamond could form the basis of a powerful technology for practical quantum information processing,” he says. “The optical properties of diamond make it ideal for producing tiny optical circuits on chips.”

Entanglement is one of the most bizarre aspects of quantum theory. In essence, it involves two objects that become “entangled” with each other, which is to say develop a relationship such that anything that happens to one happens to the other simultaneously, no matter how far apart they are. Einstein, who struggled to accept this, called it “spooky action at a distance.” How does this happen? Scientists don’t know. But they’ve observed it many, many times. Earlier this year, the quantum physicist Vlatko Vedral wrote a great cover story for Scientific American (behind the paywall, alas) talking about how scientists are now looking at evidence for quantum processes at work in the macro world (previously it was believed that quantum effects only worked at the subatomic level). For example, it’s hypothesized that quantum effects may explain how birds navigate. Here’s the lead of Vedral’s piece, the only bit that’s available for free:

According to standard physics textbooks, quantum mechanics is the theory of the microscopic world. It describes particles, atoms and molecules but gives way to ordinary classical physics on the macroscopic scales of pears, people and planets. Somewhere between molecules and pears lies a boundary where the strangeness of quantum behavior ends and the familiarity of classical physics begins. The impression that quantum mechanics is limited to the microworld permeates the public understanding of science. For instance, Columbia University physicist Brian Greene writes on the first page of his hugely successful (and otherwise excellent) book The Elegant Universe that quantum mechanics “provides a theoretical framework for understanding the universe on the smallest of scales.” Classical physics, which comprises any theory that is not quantum, including Albert Einstein’s theories of relativity, handles the largest of scales.

Yet this convenient partitioning of the world is a myth. Few modern physicists think that classical physics has equal status with quantum mechanics; it is but a useful approximation of a world that is quantum at all scales. Although quantum effects may be harder to see in the macroworld, the reason has nothing to do with size per se but with the way that quantum systems interact with one another. Until the past decade, experimentalists had not confirmed that quantum behavior persists on a macroscopic scale. Today, however, they routinely do. These effects are more pervasive than anyone ever suspected. They may operate in the cells of our body.

Here’s Vedral’s Five Books interview.  Excerpt:

Does it lead you to believe that maybe people go into quantum physics to prove an idea that they’ve already had?

That’s an interesting point. It’s difficult to tell what comes prior to what, right? In a way we do have these inner feelings, all of us, as to what we think the world should be like. And we usually carry this prejudice with us into our research as well, so it’s not clear whether you come with a prejudice and then you’re trying to use this theory to confirm what you already thought the world was like prior to that. In this kind of interview it’s easy to expose these kinds of things: you can see that people started with some ideas and then maybe changed them or didn’t change them as they did research.

All these unifying theories that quantum mechanics proves, seem to have already been posited in literature or religion or whatever. 

Yes, I don’t think there is anything really distinctly novel that was brought there philosophically by quantum mechanics. The key tenet I would say is this randomness that is at the core of our interaction with the world: there is an element that you can never make more deterministic. And, of course, randomness as a way of looking at the world existed for a long time. If you go back to the ancient Greeks I think you will see a spectrum of all of these world views already present there.

What’s most interesting to me about quantum theory? The philosophical idea that consciousness is involved at some mysterious (that is, observed but not understood) level with determining outcomes in the material world — that is, that there is no bright, clean barrier between objectivity and subjectivity.