5 impossible things that are actually possible in physics. Einstein’s theory of general relativity is famous for its prediction of wormholes, which can connect spaces at different times to allow time travel. No one has actually seen a wormhole, and even if these wormholes do exist, there’s a heated debate over whether it’s safe to travel through. While we wait for future visitors to let us know that wormholes are possible, here are some things that are impossible in nature that may have already been proven to be possible.
perpetual motion machine
The idea of a machine or device that can move or do other useful work without the need for external force. Leonardo da Vinci worked on a variety of designs, and Robert Boyle imagined a funnel that operated on its own. Blaise Pascal wisely gave up the possibility of searching for perpetual motion and invented the roulette wheel.
Large perpetual motion machines violate various laws of physics, especially the laws of thermodynamics. But Nobel Prize winner Frank Wilczyk’s “time crystal,” a material that repeats forever without external energy, appears to be as close as it gets to a perpetual motion machine. However, recent “time crystals” in the lab haven’t done anything useful, so the mission continues.
Ever wished you could disappear above ground and reappear somewhere else in the distance? Strangely, there are no laws of physics to prevent this from happening. In his 2008 book “Impossible Physics,” physicist Michio Kaku called the telegraph a “type I impossibility,” meaning the technology is theoretically possible and could even be within our lifetimes exist.
Harry Potter‘s invisibility cloak is just a fictional costume that makes you disappear. But so-called metamaterials raise similar possibilities in real life.
The principle of a metamaterial cloak is simple: Light waves bend around objects in your field of vision, much like water folds around a boulder in a stream. In effect, completely new nanostructured materials must be developed that can bend light in unusual ways.
The first metamaterial was created in a laboratory in 2000, and basic cloaking devices were created soon after. Camouflage is impossible for human-sized objects, but that’s not much of a loss. Even if this were possible, you could only make certain wavelengths of light make invisible objects more visible. Instead, similar cloaking principles could be used to deflect seismic waves and isolate entire cities from earthquakes.
If you want to live in this universe, you’d better abide by its rules. Nothing can travel faster than the speed of light, and nothing can go below absolute zero.
Absolute zero, about -273°C, represents the temperature at which atoms stop moving. So logically, it cannot go below this temperature. In fact, as physicists demonstrated earlier this year, you simply can’t reach it.
According to the strict definition of thermodynamics, temperature is a measure of order: the quieter and more ordered something is, the cooler it is. So in 2013, physicists at Ludwig-Maximilians-University in Munich, Germany, took a logical leap: They collected some atoms cooled to almost absolute zero and created a technology with temperatures below absolute zero.
These states are not really practical. But they may help us study dark energy, the mysterious dark energy that divides the universe because, as some have suggested, it has a negative temperature.
matter and antimatter
Normally, when matter comes into contact with its antimatter counterpart, they are “annihilated” in a sudden burst of energy. Fortunately, we live in a universe with a lot of matter and a small amount of the mysterious antimatter.
But strangely, some matter can also be antimatter. So-called “Majorana fermions” are their own antiparticles, capable of self-annihilation under the right conditions. Physicists have long suspected that neutrinos might fall into this category, despite proving such a way to detect some of the rarest behaviors in the universe, with one occurring once every 100 trillion years.
At the same time, we have some similar reports in the laboratory. When an electron is ripped away from a superconductor, it leaves behind a hole, like a positively charged particle with exactly the same mass. If done in the right way, they can act like Majorana fermions.