Researchers in Spain have created a tiny magnetic wormhole for the first time ever, and they’ve used it to connect two regions of space so that a magnetic field can travel ‘invisibly’ between them.

Before you get too excited, this isn’t the same as the gravitational wormholes that allows humans to travel rapidly across space in science fiction TV shows and films such as Stargate, Star Trek, and Interstellar, and it’s not able to transport matter. But the physicists managed to create a tunnel that allows a magnetic field to disappear at one point, and then reappear at another, which is still a pretty huge deal.

A wormhole is effectively just a tunnel that connects two places in the Universe. So far scientists have simulated this process, but are nowhere near creating a gravitational wormhole, as it would require us to create huge amounts of gravitational energy – something we don’t yet know how to do.

But what physicists are good at is generating and manipulating electromagnetic energy, and so the team from the Autonomous University of Barcelona decided to see if they could build a magnetic wormhole in the lab instead.

Last year they managed to create tunnels that directed magnetic fields from one place to another, but these weren’t true wormholes because they didn’t keep the magnetic field undetectable or magnetically ‘invisible’ while it was travelling inside the tunnel.

This is something they’ve now finally managed to overcome, by using metamaterial and metasurfaces to build their tunnel. That meant that they could make the magnetic field from a source, such as a magnet or an electromagnet, appear at the other end of the wormhole with no trace of it in between.

This created the illusion that the magnetic field must be travelling through some kind of extra dimension. Oddly enough, it also meant that an isolated magnetic monopole – a magnet with only one pole, North or South – appeared randomly at the end of the tunnel.

“This result is strange enough in itself, as magnetic monopoles do not exist in nature,” a press release explains. “The overall effect is that of a magnetic field that appears to travel from one point to another through a dimension that lies outside the conventional three dimensions.”

To be clear, the wormhole in this experiment isn’t really invisible to the human eye – it’s a sphere made up of an outer ferromagnetic surface, an inner superconducting layer, and then a ferromagnetic sheet rolled into a cylinder internally – but the way that it’s been designed means that it, and its contents, is totally undetectable magnetically. In other words, it’s magnetically invisible from the outside, but to us it looks more like this:

Wormhole2Jordi Prat-Camps/Autonomous University of Barcelona

And while the tunnel isn’t anywhere near to the kind of wormhole that would take us across space, it does have a lot of features in common. “[It] changes the topology of space, as if the inner region has been magnetically erased from space,” lead researcher Àlvar Sánchez explains.

The research will have practical applications in areas that use magnetic fields – for example, it could lead to the creation of MRI machines that don’t require people to lie inside the claustrophobic machine, or more targeted MRI scans.

But importantly, it also teaches us more about ways we can tunnel our way through space – an endeavour that holds countless exciting possibilities.

http://www.sciencedaily.com/releases/2015/09/150903081506.htm

http://www.nature.com/articles/srep12488

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Time travel has been simulated by Australian physicists

SCIENCEALERT STAFF 23 JUN 2014
Physicists at the University of Queensland in Australia have used photons – single particles of light – to simulate quantum particles travelling through time and study their behaviour.

They were hoping to find out more about whether time travel would be possible at the quantum level – a theory first predicted in 1991.

In the study, the researchers simulated the behaviour of a single photon that travels through a wormhole and interacts with its older self. This is known as a closed timelike curve – a closed path in space-time that returns to the same starting point in space but at an earlier time. Their study is published in Nature Communications.

They did this by making use of a mathematical equivalence between two cases, lead author Martin Ringbauer told The Speaker.

In the first case, photon one “travels trough a wormhole into the past, then interacts with its older version,” Ringbauer explained. And in the second case, photon two travels through normal space-time, but interacts with another photon that is trapped inside a closed timelike curve forever.

“We used single photons to do this but the time-travel was simulated by using a second photon to play the part of the past incarnation of the time travelling photon,” said University of Queensland physics professor Tim Ralph.

The research will hopefully help researchers bridge the gap between two critical theories, said Ringbuaer.

“The question of time travel features at the interface between two of our most successful yet incompatible physical theories – Einstein’s general relativity and quantum mechanics,” Ringbuaer explained.

“Einstein’s theory describes the world at the very large scale of stars and galaxies, while quantum mechanics is an excellent description of the world at the very small scale of atoms and molecules,” he added.

According to Einstein’s theory, it could be possible to travel back in time by following a closed timelike curve. However physicists and philosophers have struggled with this theory given the paradoxes such as the grandparents paradox, where a time traveller could prevent their grandparents from meeting, thus preventing the time traveller’s birth in the first place.

But in 1991 it was suggested that time travel in the quantum world would avoid these kinds of paradoxes because the properties of quantum particles are “fuzzy” and “uncertain” – and this is the one of the first times anyone has simulated the behaviour of such a scenario.

“We see in our simulation (as was predicted in 1991) how many effects become possible, which are forbidden in standard quantum mechanics,” said Ringbauer. “For example it is possible to perfectly distinguish different states of a quantum system, which are usually only partially distinguishable. This makes quantum cryptography breakable and violates Heisenberg’s uncertainty principle. We also show that photons behave differently, depending on how they were created in the first place.”