jijopaul said:I'm a fresher in PF. If I'm posting indecently, please forgive..
Vacuum is something empty. It contains nothing. Then why should it have properties like permeability, permittivity etc.?
There is not a definite line differentiating virtual particles from real particles — the equations of physics just describe particles (which includes both equally). The amplitude that a virtual particle exists interferes with the amplitude for its non-existence; whereas for a real particle the cases of existence and non-existence cease to be coherent with each other and do not interfere any more. In the quantum field theory view, "real particles" are viewed as being detectable excitations of underlying quantum fields. ... In this sense, virtual particles are an artifact of perturbation theory, and do not appear in a non-perturbative treatment.
Vacuum is considered empty space because it contains no matter, such as particles or atoms. It is a region in space that is devoid of any material content, making it an ideal environment for experiments and observations.
Although vacuum may seem empty, it still has properties such as pressure, density, and energy. These properties arise from the interactions of virtual particles, which are constantly popping in and out of existence due to quantum fluctuations.
Temperature is a measure of the average kinetic energy of particles in a substance. Since vacuum contains no particles, it also has no temperature. However, the objects placed in a vacuum can have a temperature, which can affect the properties of the vacuum itself.
Vacuum refers to the absence of matter, while outer space refers to the vast expanse beyond Earth's atmosphere. Outer space contains various particles and forms of radiation, while vacuum is completely devoid of any matter.
In a vacuum, there is no medium for sound to travel through, so it cannot be heard. Light, on the other hand, can travel through a vacuum at its maximum speed, making it the fastest way to transmit information or energy through space.