Fat atoms

Dr. Jennifer Pore

How big is an atom? Obviously they are very small, but remember there is huge variation in their sizes! Imagine that you are a hydrogen atom, just with a single proton, you wouldn’t want to get caught in a dark alley with a Uranium atom. Uranium has 92 protons and over 200 neutrons! That wouldn’t be a fair fight!

The heaviest atoms live on the absolute brink of existence. They can teach us about the limitations of all matter in the universe! The problem is, we barely know anything about them! We don’t even know how big they are! I’ll tell you a secret .  . . scientists have been guessing their masses! Highly-educated guesses, of course, but guesses never the less. How can we expect to unravel the greatest mysteries of the universe if we can’t even figure out how many protons and neutrons are in an atom?

My team and I built the first ever device capable of weighing these fat atoms. The atoms fly into our device and then they take these unique two-looped paths before landing on our detector. These two-looped paths are dependent on that atom’s mass, so I can tell you how much that atom weighs just from where it landed on the detector.

Now, the heaviest atoms do not exist naturally on earth. We have to make them, one atom at a time! Here is a recipe for making a very heavy atom. Take two kinda-heavy atoms and then slam them into each other with a ton of energy, hoping that they fuse into a single atom. Unfortunately, this barely ever works. 99.9% of the time the two atoms will just blow each other apart into pieces.

For our experiment we ran 30 days straight, 24/7, and we had to sit and wait for the heavy atom. And we had to wait . . . . and we had to wait . . .and then suddenly, there it was! We had created the heavy atom! It flew into our device, it took its two loops, and then it landed on the detector! Exactly where we expected it too! We had weighed the heaviest atom ever to be weighed! Not only had we confirmed that atom’s mass, but we confirmed that there must be fundamental forces in the universe that are strong enough to hold these fat atoms together.

So, how big was the atom? I’ll conclude just by saying this, those protons sure did make that mass look big.