Top 10 Things Faster than Light
Suggested by SMSFans of science fiction know about warp drive. A spacecraft that was equipped with warp drive could warp the space around it and enable it to travel faster than the speed of light. Traveling faster than the speed of light may be a staple of science fiction, but it’s also a frequent topic for actual scientists. Albert Einstein, in his special theory of relativity, said a particle would need an infinite amount of energy to travel faster than the speed of light, but he didn’t forbid it as impossible. From super-fast particles to hopping outside of gravity, from instantaneous communication to warping space like an ocean wave, here are 10 ideas or examples of traveling faster than light.
10. Heim Theory
Like string theory, Heim theory was intended to try reconciling quantum mechanics with the general theory of relativity. German physicist Burkhard Heim suggested that generating enough of an electromagnetic field could “pop” an object out of a gravitational pull and ultimately out of 3-dimensional space itself. Without the encumbrances of gravity and the regular dimensions we know, a spacecraft could conceivably travel in another dimensional space at a rate that is faster than light. Heim’s theory depends on creating huge amounts of electromagnetic force, and to do that, we’d need materials with a density greater than anything we have available. That means Heim’s theory can’t be tested at this point. The theory has been getting more attention from scientists, though, so it remains to be seen how the theory can be tweaked in the future.
9. EPR Paradox
It’s not always matter than can travel faster than light, but also communication. The EPR Paradox (named for Albert Einstein, Boris Podolsky, and Nathan Rosen) was a thought experiment designed to challenge quantum mechanics and highlight what they thought of as inadequacies. The idea stems from the uncertainty that is fundamental to quantum physics. A particle’s position, momentum, and spin are physically present but unknown at first. When particles first interact but then separate, they are considered connected – or entangled – and properties that are identified for one would become true for the other, even if the properties are inverted. The EPR paradox showed that, under quantum physics, regardless of how much distance two paired particles travel away from each other, when physical properties are measured and described for one of them, the other one will instantaneously adopt those properties, which would amount to communication being passed faster than light. The EPR Paradox as originally intended to criticize quantum mechanics, but the notion of entanglement and the sharing of properties have been shown to be experimentally valid.
8. Virtual Particles
In quantum physics, there’s an idea known as quantum tunneling, which allows for a particle to pass through a barrier that it previously couldn’t. One of the major players in quantum tunneling is the virtual particle, which exists for only a limited time and in a limited space, and can pass through any barrier at a constant speed, regardless of the barrier’s thickness. Virtual particles also describe probable paths that a particle could take. For instance, in one such thought experiment, two prisms are placed with a gap between them. Because of the gap, light would not pass through in a straight line, but would be refracted, as is the norm with prisms. Any single photon (or light particle), however, could simply pass straight through, even though the sum of the particles – the light wave – would be refracted. Since the photon, which in this illustration was understood as a virtual photon, traveled the gap in a straight line rather than being refracted, then it would have crossed the gap earlier than the light wave and thus traveled faster than light. This is known as the Hartman effect, since it was first described by Thomas Hartman in 1962.
7. Distant Galaxies Moving Apart
The idea of distance and relative velocity applies in the reverse, too. The effects of the Big Bang are still around. The universe is still moving, and matter even as large as galaxies are moving away from each other. As the distance between galaxies grows, the relative velocity appears to increase to third-party observers. We understand space as curving around objects, which forms the basis for gravity. One object is drawn to another when is within the curvature of space that leads to the center of that object. The farther away objects become, the less influential the curvature of space is – the less powerful gravitational pull is – and the faster objects can move. As objects move farther and farther apart, if their velocities are within the same frame of reference, then their velocities interact until the relative velocity passes the speed of light. Relative velocity like this can only be noticed as an observer. If we look at galaxies moving away from our own, it will appear to us that we are stationary and the other galaxy is moving, so there is only one velocity that we’ll consider. When we watch two objects moving apart, though, independent of our movement, we witness both velocities, and that’s when relative velocity becomes a factor.
6. Shadows on Distant Objects
Another way to view faster-than-light speed from a mindset of relativity is by measuring the speed of shadows moving on distant objects. Imagine you are casting a shadow of your finger on a distant object. When you move your finger, your shadow does not move exactly the same distance that your finger moved; it will have covered a greater distance on the surface of the object on which its cast. Even though it covers a greater distance, it will travel in the same amount of time as your finger. Traveling more distance in the same amount of time means it is moving at a faster velocity. Now imagine you can move an shadow-casting object at the speed of light. We can see that the shadow would be moving faster than light. The greater the distance between your finger and the light, and the greater the distance between your finger and the object on which the shadow is cast, the faster the shadow will move.
5. Closing Speed
One possible way to measure faster-than-light speed is to approach it from the viewpoint of relative velocity. Think of it this way: if Car A is moving toward Car B, but Car B is motionless, then the velocity you would see as an outside observer, is simply the velocity of Car A. The distance between Car A and Car B is being traveled only as fast as Car A is moving. On the other hand if Car B is also moving toward Car A, then then distance between them is being traveled faster than either car is moving individually. Since both cars are moving, the distance either car has to travel to reach the other car is constantly decreasing at a rate that is faster than each car is moving. We call this closing speed. It’s not simply the speed an object is moving, but the speed with which one object can reach another object.
Now if you have two objects moving toward each other at near the speed of light – or even exactly the speed of light – their closing speed would theoretically be faster than the speed of light. Although this is not an example of an object or information moving faster than light, it is an example of measuring faster-than-light speed. Relative velocity is part of Einstein’s special theory of relativity, so it doesn’t violate any physical properties. The speed at which the two objects are moving may not be faster than light, but the speed at which we observe them moving toward each other would be faster than light.
4. The 10th Dimension
String theory was a model for theoretical physics that imagined the universe as subatomic strings that vibrate in multiple dimensions. It was conceived as a way of reconciling the physical properties of subatomic particles, which is informed by quantum mechanics, and the physical properties of large objects, which falls under Einstein’s general theory of relativity. Quantum mechanics seemed to contradict the general theory of relativity, so string theory sought to bring them together under one framework.
M-theory is the next generation of string theory, which suggests that all of those strings vibrate in a 10th dimension. Some scientists think this is the key to faster-than-light travel. For an object to move that fast, tremendous amounts of energy are required. For instance, scientists have stated that moving a 30 foot by 30 foot by 30 foot spacecraft faster than light would take an amount of energy equivalent to the entire mass of Jupiter if it were converted into pure energy. Harnessing that much energy, some scientists believe, can be achieved by manipulating the mysterious dark energy, which would happen by manipulating the 10th dimension where all matter is vibrating at once.
This idea of manipulating dark energy by altering the 10th dimension is based on Alcubierre’s vision for warping space. Dark energy is a theoretical form of energy that is thought to accelerate the expansion of the universe. By manipulating dark energy in the 10th dimension, we would manipulate the expansion of space-time, and that could enable us to move an object faster than light.
3. The Big Bang
The Alcubierre drive is a theoretical way of moving a spacecraft, but it’s possible the universe showed a similar method shortly after it was born. The Big Bang is widely regarded as a highly plausible origin story for the universe. The theory states that all the matter of the universe was compressed into the tiniest particle. Because so much matter and so much mass was compressed into such a small space, the amount of pressure and heat was extraordinary. It’s more than we can even fathom outside of a mathematical equation. At some point, the pressure resulted in an explosion – the Big Bang – and all the matter of the universe began to rapidly expand outward from that original point. The force that would have resulted from that explosion, and the force necessary to propel all that matter as wide as the universe that we know, was so immense that some scientists think the speed at which matter was moving shortly after the Big Bang was actually faster than light. Since the Big Bang resulted in space-time moving and the physical forces of the universe being set into motion, this is similar to the Alcubierre drive. Space-time itself was moving in chunks. We don’t know with any certainty that this is how things happened, but several models of the Big Bang have space-time moving at faster-than-light speed.
2. Alcubierre Drive
In 1994, a Mexian theoretical physicist named Miguel Alcubierre proposed a radical idea for traveling faster than light. His idea is similar to warp drive. Rather than thinking about space and time as static and unmoving and trying to propel a spacecraft through it at a faster-than-light speed, Alcubierre imagined space and time as helping the craft along by thinking of it as a wave. Just like in the ocean, where waves are created when the water contracts and then expands, waves in the space-time continuum are created when space-time contracts on one end of a spacecraft and expands on the other. Space-time would, in effect, give a boost to the craft, like a special acceleration – an Alcubierre drive – to propel the craft faster than light. Of course, this is still theoretical. Achieving Alcubierre drive would require changing the properties of space-time in an imbalanced way, so that space-time is contracting on one end of the craft and expanding on the other.
1. Neutrinos
We’ve all learned about protons, neutrons, and electrons in school as the particles that make up atoms. A neutrino is a different particle that is smaller than an atom and, like neutrons, carry no electrical charge. Without electrical charge, the neutrino is unaffected by the electromagnetic forces and are only impacted by the weakest of the forces. Neutrinos are extremely tiny. Though most scientists agree that neutrinos do have mass, their mass has never been accurately measured. As a result of all of these characteristics, neutrinos are able to travel long distances and through all types of matter without being impeded by the stronger forces that interact with other subatomic particles. This made neutrinos a great candidate to break the faster-than-light speed barrier, and in 2011, it appears they were shown to achieve the feat.
Scientists in Italy and Switzerland had collaborated to measure the speed at which one type of neutrino – the muon neutrino – traveled between two points. What they found is that the muon neutrino arrived at the finish line 60 nanoseconds faster than the speed of light. They actually measured this phenomenon on two separate occasions. Nevertheless, not all scientists agree. Some have said that faulty fiber optic cables gave false results. The controversy was enough to make the lead scientist who revealed the faster-than-light results to resign from his post. Still, the dissent is still a hypothesis and until proven otherwise, the muon neutrino is still on the books as faster than light.
