I mean, it's gold, so I know I got 79 plus here. And I've got 2 plus. And I've got a 79 plus. What would be the size of the sphere of 79 plus that would deflect something of 2 plus through this angle? So that's Marsden. It's not bad for a kid that's been out of school for a couple of years. That's his problem. So he did. He did the calculation. He did the calculation and Marsden figured out that the radius of the nucleus to the radius of the atom is on the order of about 1 to 10,000.
That means most of the gold foil is void. Most of the gold foil is nothing. And you've got all this mass, highly dense, concentrated here. So this is the Rutherford model, which was called the nuclear model. This was proposed by Rutherford because it has such a thing is a nucleus. He coined the term, nucleus. So that's a big step forward from this thing here.