Yes, trains!

Maybe in a very, very large circular track. A huge circle.

And fast. Super fast. Make them faster by making them lighter. Smaller. Super tiny. So light and fast.

A teeny, tiny, light train going super duper fast in a very large circle.

Sure hope it doesn’t smack into anything while going top speed. Or maybe it does, so long as we measure it.

I like trains.

We already have plenty of trains in Switzerland, they’re just expensive to ride

There’s this (true) anecdote that precision measurements at CERN/LHC need to take into account the schedule of high-speed trains in the area because they cause tiny, yet measurable disturbances in the power grid.