Phycists have understood at least theoretically, that there may be higher dimensions, besides our normal three. The first clue came in 1905 when Einstein developed his theory of special relativity. Of course, by dimensions we’re talking about length, width, and height. Generally speaking, when we talk about a fourth dimension, it’s considered space-time. But here, physicists mean a spatial dimension beyond the normal three, not a parallel universe, as such dimensions are mistaken for in popular sci-fi shows.

Even if there are other dimensions somewhere out there in our universe or in others, should we travel to a place which includes them, scientists aren’t so sure we could even experience them. Our brains may be incapable. Mathematically, we can describe the 4^th dimension but we may never experience it in the physical realm.

Even so, that hasn’t stopped us from looking for evidence of higher dimensions. One model which helps us conceive of it easier and understand it better is a tesseract or hypercube. This is a cube within a cube. Though a helpful metaphor, it doesn’t actually exist in the real world. So how might scientists actually detect the 4^th dimension? Two separate research teams, one in the US and one in Europe have completed dual experiments, to do just that.

Both of these were 2D experiments which hinted at a 4D world, utilizing a phenomenon known as the quantum Hall effect. The Hall Effect is when you have an electrically conducive material, say a sheet of metal or a wire, which you pass current through. The electrons move in one direction. Place a magnetic field perpendicular to the material and instead of electrons get diverted to the left or right, by what’s called the Lorentz force.

Find a good explanation of the Hall effect and quantum Hall effect here:

The result of the Hall effect is that electrons get stuck within a 2D system. They can then only move in two directions. The quantum Hall effect occurs at the quantum level, either when the material is at very low temperatures, or is subject to a very strong magnetic field. Here, an additional thing happens. The voltage doesn’t increase normally but instead, jumps up in steps. By restricting electrons with the quantum Hall effect, you can also measure them.

Follow the math and you’ll realize that the quantum Hall effect is also detectable within a 4D system. Professor Mikael Rechtsman of Penn State University was part of the American team. He told Gizmodo, “Physically, we don’t have a 4D spatial system, but we can access 4D quantum Hall physics using this lower-dimensional system because the higher-dimensional system is coded in the complexity of the structure.”

We ourselves as 3D objects cast a 2D shadow. A 4D object should then cast a 3D shadow.  We can learn something about a 3D object by studying its shadow. So it stands to reason that we could also gain knowledge about a 4D object from its 3D shadow. Both teams in these experiments did something of that kind. They used lasers to catch a glimpse of the 4^th dimension. The results of each experiment were published in two reports, both in the journal Nature.

In the European experiment, scientists took the element rubidium and cooled it down to absolute zero. Then, they trapped atoms there within a lattice of lasers, creating what researchers describe as, “an egg-carton-like crystal of light.” Next, they introduced more lasers to excite the atoms, creating what’s known as a quantum “charge pump.” Though atoms themselves don’t have a charge, here they simulated the transport of electrical charges. Subtle variations in the atoms’ movements coincided with how the quantum Hall effect would play out in the 4^th dimension.

In the US experiment, glass was used to control the flow of laser light into the system. This was basically a rectangular glass prism with a series of channels within it, which looked like a number of fiber optic cables stuck inside, running the length of the box and terminating at both ends. Researchers were able to manipulate the light using these channels as wave guides, in order to make it act like an electric field. When light jumped from opposite edges into the corners, researchers knew they had observed the quantum Hall effect, as it would occur in a 4D system.

Scientists at ETH Zürich, a university in Switzerland, conducted the European experiment. Researcher Oded Zilberberg was among them. He said that before these experiments, observing actions occurring in the 4^th dimension seemed more like science fiction.

“Right now, those experiments are still far from any useful application,” he said. Yet, physics in the 4^th dimension could be influencing our 3D world. As for applications Rechtsman said, “Maybe we can come up with new physics in the higher dimension and then design devices that take advantage the higher-dimensional physics in lower dimensions.”

In these experiments, the photons and electrons didn’t interact. In the next, scientists believe it might be interesting to see what happens when they do. Rechtsman claims we could gain a better understanding of the phases of matter by investigating the 4^th dimension. Say we get a healthy grasp of it, is that the end? Certainly not. Theoretical physicists believe there may as many as 11 dimensions.

To learn about the 4^th dimension from Carl Sagan himself, click here:

Scientists said on Thursday they recorded particles travelling faster than light – a finding that could overturn one of Einstein’s fundamental laws of the universe. Antonio Ereditato, spokesman for the international group of researchers, said that measurements taken over three years showed neutrinos pumped from CERN near Geneva to Gran Sasso in Italy had arrived 60 nanoseconds quicker than light would have done.

“We have high confidence in our results. We have checked and rechecked for anything that could have distorted our measurements but we found nothing,” he said. “We now want colleagues to check them independently.”

If confirmed, the discovery would undermine Albert Einstein’s 1905 theory of special relativity, which says that the speed of light is a “cosmic constant” and that nothing in the universe can travel faster. That assertion, which has withstood over a century of testing, is one of the key elements of the so-called Standard Model of physics, which attempts to describe the way the universe and everything in it works. The totally unexpected finding emerged from research by a physicists working on an experiment dubbed OPERA run jointly by the CERN particle research centre near Geneva and the Gran Sasso Laboratory in central Italy.

A total of 15,000 beams of neutrinos – tiny particles that pervade the cosmos – were fired over a period of three years from CERN towards Gran Sasso 730 (500 miles) km away, where they were picked up by giant detectors. Light would have covered the distance in around 2.4 thousandths of a second, but the neutrinos took 60 nanoseconds – or 60 billionths of a second – less than light beams would have taken.

“It is a tiny difference,” said Ereditato, who also works at Berne University in Switzerland, “but conceptually it is incredibly important. The finding is so startling that, for the moment, everybody should be very prudent.”

Ereditato declined to speculate on what it might mean if other physicists, who will be officially informed of the discovery at a meeting in CERN on Friday, found that OPERA’s measurements were correct.

“I just don’t want to think of the implications,” he said. “We are scientists and work with what we know.”

Much science-fiction literature is based on the idea that, if the light-speed barrier can be overcome, time travel might theoretically become possible. The existence of the neutrino, an elementary sub-atomic particle with a tiny amount of mass created in radioactive decay or in nuclear reactions such as those in the Sun, was first confirmed in 1934, but it still mystifies researchers.

It can pass through most matter undetected, even over long distances, and without being affected. Millions pass through the human body every day, scientists say. To reach Gran Sasso, the neutrinos pushed out from a special installation at CERN – also home to the Large Hadron Collider probing the origins of the universe – have to pass through water, air and rock.

The underground Italian laboratory, some 120 km (75 miles) to the south of Rome, is the largest of its type in the world for particle physics and cosmic research. Around 750 scientists from 22 different countries work there, attracted by the possibility of staging experiments in its three massive halls, protected from cosmic rays by some 1,400 metres (4,200 feet) of rock overhead.

What has happened at CERN?
Scientists say they have clocked neutrinos – tiny particles smaller than atoms – travelling at 300,006 kilometres per second, slightly faster than the speed of light.

What does that mean?
Einstein’s theory of special relativity says nothing can travel faster than the speed of light in a vacuum, because photons – light particles – have no mass. Proof that neutrinos, mysterious subatomic particles which have a tiny amount of mass, can travel faster would be inconsistent with Einstein’s theory.

What are the knock-on effects?
Einstein’s theory is critical to the Standard Model of physics that helps explain everything we know about how the universe works, from black holes to the big bang. If it is shown to be flawed, virtually everything in modern physics and the fundamental laws of nature would have to be rethought.

Have the results been proven?
The findings were such a shock that CERN’s scientists spent months checking their data before making their announcement. But they have asked American and Japanese teams to confirm the results before they are declared an actual discovery. The data will also be put online overnight so that it can be scrutinised by experts across the world.

Does this mean E does not equal MC squared?
The theory of special relativity was used to spawn the theory that energy is equal to mass multiplied by the speed of light squared. It is premature to discount the most famous equation of all time, but the latest discovery suggests one key assumption it relies on – that nothing can accelerate faster than light – may not be wholly accurate.