Originally, scientists thought this might be because they were firing a lot of electrons toward the screen at one time, and maybe some of the electrons were crashing into each other on the other side of the barrier, canceling each other out and not making it to the screen. By 1974 they were finally able to develop a way to fire one electron at a time at the screen, so there was no way possible for them to interfere with each other. But they still got an interference pattern.

(To watch a short and well-done animated video of this Double Slit experiment from What the Bleep!? – Down the Rabbit Hole, click here.)

How is that possible? How is it possible to send one tiny particle of “matter” at a time through two slits and have it form a wave interference pattern?

There was only one explanation that made any sense: An electron is a wave rather than a particle; it is not a solid piece of matter as we have always thought!

More recent experiments have discovered the same thing holds true for the nucleus of an atom, not just the electrons.

“Matter is not what we have long thought it to be. To the scientist, matter has always been thought of as sort of the ultimate in that which is static and predictable…. We like to think of space as empty and matter as solid. But in fact, there is essentially nothing to matter whatsoever; it’s completely insubstantial. Take a look at an atom. We think of it as a kind of hard ball. Then we say, ‘Oh, well no, not really…it’s this little tiny point of really dense matter right at the center….’ But then it turns out that that’s not even right. Even the nucleus, which we think of as so dense, pops in and out of existence just as readily as the electrons do.”8

So the very building blocks of what we call our “physical universe” – the nucleus and electrons of atoms – are not just particles of matter, but in fact exist as waves. In quantum physics this is called “wave-particle duality.”

That blew everybody’s mind; but it’s not the end of the story….