Ivana Hughes

Nuclear weapons are different from conventional weapons in many ways.

One of the things that I like to say is that they really defy the kind of concept of both space and time.

And let me explain what I mean by that.

If you have a conventional weapon and you explode it over a city or wherever,

that explosion is going to have an impact in that local place.

And it's going to have that impact in time.

And then you could come back and clean up the area and rebuild and so on.

Nuclear weapons are not like that.

A nuclear explosion in one place, in one location, and in one split moment of time can have both global effects and it can have impacts over actually even thousands of years through the effects of radiation and the kind of radioactive isotopes that get deposited in the environment.

But there are sort of a number of ways in which even a single nuclear weapon explosion can be incredibly dangerous and devastating.

And then there are a number of impacts in which a nuclear war, in which many nuclear weapons are used, can be...

obviously quite clearly much more devastating.

So the thing that people know about nuclear weapons is that one nuclear weapon can be much more powerful than any kind of chemical explosion.

So for example, the atomic bombings of Hiroshima and Nagasaki

80 years ago.

80 years ago, almost exactly, had what's called energy yields of 15 and 21 kilotons of TNT.

Now, these bombs were made out of uranium and plutonium, uranium for the Hiroshima bomb.

and plutonium for the Nagasaki bomb.

But when we describe their energy yield, we describe it in terms of the equivalent amount of chemical explosive that you would need.

So that's where the 15 kilotons, 15,000 tons of TNTs, how much you would have needed of chemical explosive to produce the energy equivalent to that explosion.