Quote by benk99nenm312
√(1 v2/c2) has two solutions, just like every other square root. It would be possible to get a negative solution.

Yes … so
slowerthanlight particles can travel either forward
or backward in time.
But tachyons can't … their time dilation is imaginary (and minus imaginary is still imaginary
)
As I stated, tachyons have some odd properties. One, they go backwards in time

No they don't …
If we see a tachyon going
from A
to B, another observer may see it go
from B
to A … that's all!
Two, they accelerate when they lose energy. How would this exotic property be possible without going backwards in time?

Nooo … energy = m
_{0}/√(1  v
^{2}/c
^{2}), so either the energy of tachyons is also imaginary, or their restmass is.