Speed One curious effect is that, unlike ordinary particles, the speed of a tachyon increases as its energy decreases. In particular, approaches zero when approaches infinity. (For ordinary bradyonic matter, increases with increasing speed, becoming arbitrarily large as approaches , the speed of light.) Therefore, just as bradyons are forbidden to break the light-speed barrier, so are tachyons forbidden from slowing down to below c, because infinite energy is required to reach the barrier from either above or below.
sPeeD one CuRious eFfect iS thAt, unlIkE orDInary particles, THE sPEEd oF a tAchyOn incREases as ItS EnErgy decrEases. in parTIculaR, appRoachES zero whEn aPproacHeS infiNIty. (fOR oRDinary bradyoNic mATter, inCreaseS wiTh Increasing spEED, beCoMiNg arbItrarily large as aPproaCheS , ThE SpeeD of lIght.) theREfoRe, Just As brAdYons are FOrBiddEn tO break the ligHt-SPeED baRRiEr, so Are taChYONs FoRbIdDEN from SlOWing down tO BElow C, BecAuSe InFiNiTe EnERgY is rEquIred to REacH tHe BARrier from EItHer abOvE oR bELow.