  An exact solution of the Einstein--Maxwell equations yields a general
relativistic picture of the tachyonic phenomenon, suggesting a hypothesis on
the tachyon creation. The hypothesis says that the tachyon is produced when a
neutral and very heavy (over 75 GeV/c^2) subatomic particle is placed in
electric and magnetic fields that are perpendicular, very strong (over 6.9 x
10^17 esu/cm^2 or oersted), and the squared ratio of their strength lies in the
interval (1,5]. Such conditions can occur when nonpositive subatomic particles
of high energy strike atomic nuclei other than the proton. The kinematical
relations for the produced tachyon are given. Previous searches for tachyons in
air showers and some possible causes of their negative results are discussed.
Experiments with the use of the strongest colliders and improvements in the air
shower experiments are suggested. An unfortunate terminology is also discussed.
