# Particles travelling faster than the speed of light?

• Physonic
In summary: Tachyons are hypothetical particles that travel faster than the speed of light, but they have never been observed in nature and their existence is not supported by current scientific evidence. They are an interesting concept in theoretical physics, but their existence remains unproven.

#### Physonic

hi, I just heard about particles traveling faster than speed of light and somthing about cerenkov radiation. Is it possible for some subatomical particles to overcome speed of light? if yes, doesn't it contradicts einsteins relativity? I'm pretty confused please help.

Particles going faster than light in vacuum do not exist. Overcoming speed of light means a violation of causality (even if possible formulations of relativity in this case exist and the corresponding field theories describe the so called tachyonic excitations, but these imply a vacuum instability and then they are never observed in nature).

Cerenkov radiation appears when a particle moves faster than the speed of light in the given medium (not vacuum). In a medium the speed of light is given by v=c/n being n the refraction index of the medium itself and so v is smaller than c. A particle can travel faster than v in the medium producing electromagnetic radiation much in the same way of the sonic bang of an aircraft moving faster than the sound speed in air.

Jon

Lester said:
Particles going faster than light in vacuum do not exist. Overcoming speed of light means a violation of causality (even if possible formulations of relativity in this case exist and the corresponding field theories describe the so called tachyonic excitations, but these imply a vacuum instability and then they are never observed in nature).

Cerenkov radiation appears when a particle moves faster than the speed of light in the given medium (not vacuum). In a medium the speed of light is given by v=c/n being n the refraction index of the medium itself and so v is smaller than c. A particle can travel faster than v in the medium producing electromagnetic radiation much in the same way of the sonic bang of an aircraft moving faster than the sound speed in air.

Jon

Thanks a lot! Now I am happy again!

And what about tachyons? Do they "exist"?

Only in the minds of some theorists.

## 1. What are particles travelling faster than the speed of light?

Particles travelling faster than the speed of light are hypothetical particles that are thought to travel faster than the speed of light, which is the maximum speed at which any form of matter or information can travel according to the theory of relativity. These particles are not confirmed to exist and are still a topic of scientific research.

## 2. Is it possible for particles to travel faster than the speed of light?

According to the theory of relativity, it is not possible for particles with mass to travel faster than the speed of light. However, some theories, such as the Alcubierre drive, propose ways in which objects could theoretically travel faster than light by manipulating space-time. However, these theories are still speculative and have not been proven.

## 3. What would happen if particles could travel faster than the speed of light?

If particles could travel faster than the speed of light, it would fundamentally change our understanding of the laws of physics. Time and space would behave differently, and the concept of cause and effect could be altered. It could also potentially open up the possibility of time travel and other science fiction concepts.

## 4. How are scientists studying particles travelling faster than the speed of light?

Scientists are studying the possibility of particles travelling faster than the speed of light through experiments and theoretical models. Some experiments, such as the Large Hadron Collider, aim to recreate conditions similar to the early universe to observe the behavior of particles. Theoretical models, such as quantum mechanics and string theory, also explore the possibility of particles travelling faster than light.

## 5. Why is the speed of light considered the universal speed limit?

The speed of light, which is approximately 299,792,458 meters per second, is considered the universal speed limit because it is the maximum speed at which energy, matter, and information can travel according to the theory of relativity. This speed is also the same in all frames of reference, meaning it is constant regardless of how fast an observer is moving. This concept has been confirmed through countless experiments and observations in the field of physics.