译文：但是,如果衰减不是指数的,那为什么实证结果所表明的并非如此?
这一句并无不妥,但若在why之前加上逗号,就会变得容易理
But if the decay is not exponential,
why the empirical results suggest otherwise?
（非物理学专业,此译只以英语角度理解.）
这一句是摘自《Quantum Theory of Tunneling》（量子穿隧理论）一书,以下是这句的上下文：
We begin our study of quantum tunneling by investigating as to why tunneling is exclusively a quantum phenomena and does not have a classical counterpart.Then we obtain a general result about the time dependence of the decay of a quasi-stationary system,and in particular the non-exponential nature of the decay.But if the decay is not exponential why the empirical results suggest otherwise?To explain this we study a solvable problem and show that an exponential decay,while is not exact,is a very good approximation.