Phenomenal cosmic power, itty bitty living space

Wouldn’t it be great to take the universe in the lab? Astronomy is one of the most captivating parts of physics. I mean, one can’t scoff at the idea of unveiling the mysteries of the cosmos. Unfortuntely, galaxies and black holes don’t exactly cooperate as far as experimenting goes.

A group of physicists is working on a solution.

As it turns out, bottling the immense cosmos in a handful of atoms is but one of the amazing properties of graphene. Graphene is a very thin sheet of carbon, just a single atom thick, all arranged in hexagons like cells in a beehive. Normally, then, each cell has six atoms, but scientists can add or remove one here and there, making some cells with five or seven.

CC-BY-SA AlexanderAlUS via commons

The normal structure of graphene lets a few electrons (one per atom, precisely) rather free to roam around. Cells with one atom more or less mess up this nice order. Electrons can’t just skip around carefree, instead they are attracted to five-atom cells and repelled by seven-atom ones. This creates a little bit of electric current in the material.

Big whoop.

Here comes the cool part, though: this current seems to bend exactly as how spacetime does according to General Relativity. So, appropriately placing atoms, you could simulate fantastically large cosmic phenomena in teeny tiny devices.

An example of wormhole in two-dimensional space-time. credit: telegraph.co.uk

For example, the researchers connected two sheets of graphene to simulate a wormhole—the hypothetical tunnel connecting two far-apart regions of spacetime, like in Interstellar.

The research is still just theoretical, but a tangible prototype should be just around the corner. The researchers say that it should have plenty of applications for electronic devices.

Personally, I’m also interested in holding the (ok, simulated) forces of gravity in the palm of my hand.

If you want more
  • The study isn’t published on journals yet. As far as I understand it’s about to be, in the meantime you can find the manuscript here

Cover photo: CC-BY-SA Karl Wienand, (using felixioncool, WikiImages, skeeze)

Wormholes: digging tunnels through space

Sometimes science fiction tells us stories of technology we can almost grasp already, like traveling to Mars. Other times it’s much more far-fetched and outrageous stuff, like wormholes. Since general relativity doesn’t explicitly, entirely forbid them, they have fascinated scientists and authors alike.

An example of a wormhole connecting regions of two-dimensional space. credit: telegraph.co.uk

A wormhole is a tunnel, a shortcut between two far-apart regions in spacetime. The movie Interstellar had many flaws, but at least plausible science (thanks to the supervision of star physicist Kip Thorne). They also explain quite effectively the idea of wormholes: take a sheet of paper and fold it in half, then punch a hole through it. You just created a wormhole in your paper universe.

The entrance should look like a black hole, an inescapable sink where light and matter disappear forever. The exist should be the opposite: a source from which matter and light spring eternal—a white hole. Through a wormhole, you’d be able to cross immense distances in relatively short times. But, probably, not travel in time*.

So do they exist?

For sure we can’t make them. Making wormholes with paper is cute, but it only works because the sheet is two-dimensional and we are comfortable handling three. To create a real wormhole we’d need to work in four dimensions which is a non-starter for now.

It’s also unlikely that naturally-occurring, large wormholes exist. First, at least observing a white hole would give some indication of the existence of wormholes, but we’ve never seen them. Secondly, keeping a macroscopic wormhole open requires something that turns gravity from a force that pulls things together to one that pushes them apart. And we’ve never seen that either.

Still, I find really cool that we can imagine such an outlandish thing and actually reason about them, make sound arguments on how it could or could not work.

A simulation of what a wormhole from the university Tübingen (Germany) to the dunes of Boulogne (France) would look like. CC-BY-SA CorvinZahn/Gallery of Space Time Travel, via commons

If you want more
  • There’s plenty of semi-accurate explanations around about wormholes. But I liked this more serious one on Chalkdust
  • NASA does a great job seriously answering all sorts of wormhole questions on this page
  • Some say black holes are actually entrances of wormholes to other universes. Maybe, maybe not. Black holes are freakin’ weird.

* MINOR SPOILER: In Interstellar, Cooper does sort of travel in time, too. But that only happens after stepping into other dimensions: we’ve already crossed into magic.

Cover photo: CC0 Pexels/pixabay