The health advisory limits are in the part per quadrillion.

健康咨询限度以千万亿分之为单位。

The nucleus of an atom is tiny-only one millionth of a billionth of the full volume of the atom-but fantastically dense, since it contains virtually all the atom's mass.

子核很小——只有子全部容量的千万亿分之，但密度极大，它实际构成了子的全部物质。

Part per quadrillion is one thousandth of that.

千万亿分之个数字的千分之。

The laser energy used to move the muon up to that unstable state can be used to calculate the radius of the helium nucleus, which is 1.67824 femtometers—one femtometer being one quadrillionth of a meter.

用于将μ子提升到不稳定状态的激光能量可以用来计算氦核的半径，其大小为1.67824飞米——飞米等于千万亿分之米。

They are tiny, septillions  of times smaller than an atom – and they explode with the power of a trillion supernovae  in a trillionth of an octillionth of a second.

它们微小到比子小千万亿倍——并且在千万亿分之秒内爆发出相当于千万亿颗超新星的能量。

So, you know, we got this back of the eye that responds to 1 ten trillionth of electromagnetic radiation in our world.

因此，我们的视网膜仅对世界中电磁辐射总量的千万亿分之产生反应。