What's the greatest invention of all time? It's a loaded question, sure, but allow us to tackle it.

The microchip and the computer are up there. Both pretty much make the modern world go round.

The airplane and the automobile, of course. And during this summer, we can't help but love air conditioning. Which leads us to the refrigerator.

But maybe we should look at medicine. As much as we love air conditioning, it doesn't exactly save too many lives. As opposed to the polio vaccine. Or aspirin. Or penicillin.

Yes, penicillin just has to be near the very top. The miracle drug was discovered by Alexander Fleming, but it was the work of Ernst Chain, Jew, and Howard Florey that led to its wide use. The trio received the Nobel for their efforts.

So, yes, penicillin. Hard to go wrong with that.

Oh, and the toilet! How can we forget the toilet...