No, the terms "virtual particles" and "tachyons" do not mean the same thing. They are distinct concepts in particle physics with different characteristics and roles.
Virtual Particles: In quantum field theory, virtual particles are mathematical constructs used to describe interactions between particles. They are not directly observable or detectable like real particles, but they play a crucial role in the calculations of particle interactions. Virtual particles are temporary excitations or fluctuations in quantum fields that arise due to the uncertainty principle. They can mediate forces between real particles and contribute to processes such as particle scattering. However, they do not exist as independent entities with well-defined properties and cannot be directly measured or observed.
Tachyons: Tachyons, on the other hand, are hypothetical particles that have a peculiar property of moving faster than the speed of light. According to special relativity, particles with mass cannot reach or exceed the speed of light, as it would violate causality and lead to paradoxes. Tachyons, if they existed, would have imaginary mass and would always move faster than light. However, there is no experimental evidence supporting the existence of tachyons, and they are not part of the currently accepted particle physics framework.
In summary, virtual particles are mathematical constructs used in quantum field theory to describe particle interactions, while tachyons are hypothetical particles that, if they existed, would travel faster than the speed of light.