The Boston Citgo sign, all 3,600 square LED feet of which has served as the backdrop to Red Sox games since 1965, is now officially a "pending landmark."

Spanish Surrealist Salvador Dalí spent much of the 1940s in the U.S., avoiding World War II and its aftermath. He was a well-known fixture on the art scene in Monterey, Calif. — and that's where the largest collection of Dalí's work on the West Coast is now open to the public.

Copyright 2016 Fresh Air. To see more, visit Fresh Air.

The middle of summer is when the surprises in publishing turn up. I'm talking about those quietly commanding books that publishers tend to put out now, because fall and winter are focused on big books by established authors. Which brings us to The Dream Life of Astronauts, by Patrick Ryan, a very funny and touching collection of nine short stories that take place in the 1960s and '70s around Cape Canaveral, Fla.

When the United Kingdom voted to leave the European Union last month, the seaside town of Port Talbot in Wales eagerly went along with the move. Brexit was approved by some 57 percent of the town's residents.

Now some of them are wondering if they made the wrong decision.

The June 23 Brexit vote has raised questions about the fate of the troubled Port Talbot Works, Britain's largest surviving steel plant — a huge, steam-belching facility that has long been the town's biggest employer.

Solar Impulse 2 has landed in Cairo, completing the penultimate leg of its attempt to circumnavigate the globe using only the power of the sun.

The trip over the Mediterranean included a breathtaking flyover of the Pyramids. Check it out:

President Obama is challenging Americans to have an honest and open-hearted conversation about race and law enforcement. But even as he sits down at the White House with police and civil rights activists, Obama is mindful of the limits of that approach.

"I've seen how inadequate words can be in bringing about lasting change," the president said Tuesday at a memorial service for five law officers killed last week in Dallas. "I've seen how inadequate my own words have been."

Mice watching Orson Welles movies may help scientists explain human consciousness.

At least that's one premise of the Allen Brain Observatory, which launched Wednesday and lets anyone with an Internet connection study a mouse brain as it responds to visual information.

The FBI says it is giving up on the D.B. Cooper investigation, 45 years after the mysterious hijacker parachuted into the night with $200,000 in a briefcase, becoming an instant folk figure.

"Following one of the longest and most exhaustive investigations in our history," the FBI's Ayn Dietrich-Williams said in a statement, "the FBI redirected resources allocated to the D.B. Cooper case in order to focus on other investigative priorities."

This is the first in a series of essays concerning our collective future. The goal is to bring forth some of the main issues humanity faces today, as we move forward to uncertain times. In an effort to be as thorough as possible, we will consider two kinds of threats: those due to natural disasters and those that are man-made. The idea is to expose some of the dangers and possible mechanisms that have been proposed to deal with these issues. My intention is not to offer a detailed analysis for each threat — but to invite reflection and, hopefully, action.

Pages

Can You Be In Two Places At Once? Let's Find Out!

Jan 23, 2013

It is rather rough to see that we are still in the stage of our swaddling clothes, and it is not surprising that the fellows struggle against admitting it (even to themselves).

This is how Einstein closed his letter of December 22, 1950, to physicist Erwin Schrödinger — one of the architects of quantum mechanics. The "fellows" were Bohr, Heisenberg, Dirac and the majority of other physicists who embraced the so-called Copenhagen Interpretation of quantum mechanics which, among other things, restricted how much we could know of reality: there is an insurmountable barrier, summarized in Heisenberg's Uncertainty Principle, that states that we can't know both the position and the velocity of a quantum object (an electron, a proton, an atom) with arbitrary precision. This is not a technological limitation, but a matter of principle; it's how Nature is.

There is more. A quantum object can be in two places at once; it can go across obstacles, like a ghost; it can be dead and alive at the same time, like Schrödinger's unfortunate cat.

Are these things for real? Is this the world you live in?

Einstein and Schrödinger would have none of that. They would accept that reality is stranger than fiction, that the quantum world is different from our everyday reality. But they would hold that this is a temporary setback; we just have to find the right theory and we are back at being able to determine things as comfortably as we can with the motion of a falling rock.

Although the back and forth between the two groups is a fascinating chapter in the history of science, the answer is in the experiments. And it is here that the amazing reality of the quantum shows up without any signs of abating.

Behind the mystery is the infamous (or some may say beautiful) wave-particle duality, that things, especially little things, can and should be viewed as being both a particle — thus limited in space — and a wave — thus spread out in space. Unless you are a Taoist, to be two opposite things at once is very weird, like being hot and cold, light and dark or tall and short.

Heisenberg and Bohr claimed that it's not the quantum world fault, it's ours; electrons are neither particles nor waves; these are images we construct from our everyday experience, and such intuitions are inappropriate to describe what really goes on down there. The math, though, is crystal clear. We can compute at will, finding out the various properties of electrons, atoms and molecules with remarkable accuracy. A probabilistic theory doesn't imply in a flaky theory.

This all started in 1924, when Louis de Broglie conjectured that electrons and all bits of matter display both particle and wave properties. Einstein loved the idea, initially. In 1927, Clinton Davisson and Lester Germer observed electrons diffracting off a nickel crystal, something that only waves can do: de Broglie was right, electrons can behave as waves. Passing through two small slits, they interfere with one another, creating a light and dark interference pattern on a screen. Bullets wouldn't do that; they'd pile up on the screen right behind the holes.

In 1989, Akira Tonomura from Hitachi in Japan managed to make single electrons interfere, bringing the notion that matter particles behave like waves to unprecedented clarity. A single electron passes through two slits at the same time in order to create an interference pattern; this is why people say that in the quantum world things can be in two places at once.

What about bigger objects? Is there a limiting size beyond which this peculiar quantum behavior is lost? Can we interfere as waves? Due to amazing technological advances, diffraction experiments have been performed with neutrons (two thousand times heavier than electrons), atoms and even molecules hundreds of times larger than electrons. An amazing example is the 1999 experiment by Anton Zeilinger and his group at the University of Vienna, where interference was achieved for buckyballs, the large (60 carbon atoms) soccer-ball-shaped molecules that look like Buckminster Fuller's geodesic domes.

The bigger the object the harder it is to demonstrate self-interference. Imagine a soccer ball scoring two goals at once!

The next step is to attempt interference experiments with viruses; and then with actual living things. How does life respond to quantum interference? Can something interfere with itself and remain alive? It's a long shot from "beam me up, Scotty"; but we will only manage to do that in 2260 if scientists keep pushing the boundaries now.


You can keep up with more of what Marcelo is thinking on Facebook and Twitter: @mgleiser

Copyright 2013 NPR. To see more, visit http://www.npr.org/.