Jennifer R. Vail

And that's why they really don't want trains to have to stop too often when they're those big freight trains.

But also, I think on the other aspect of it, how much friction is required to stop those trains.

And that's, of course, obviously where we really like friction when we're braking.

But goodness, that's a lot of friction and a lot of frictional heating to get those big heavy trains to stop.

Yeah.

So the science of where friction and lubrication is called tribology.

And that is actually a relatively new modern science, even though we've been contending with friction since we discovered fire.

The term was formalized in the 1960s because a group of engineers got together in England to

study a bunch of manufacturing failures that were happening.

And they thought it was because things weren't being lubricated well.

But when they looked at it, they realized it was a far more complex problem.

And so they actually went to the Oxford English Dictionary to ask the editor, hi, we need a term for this

you know, field that we've stumbled upon, what can you come up with?

And the editor suggested tribology, because things ending in ology tend to be well accepted in science.

And the Greek word tribos meant to rub.

And so it's really the science of rubbing things together.

That is a really great question.

And that stickiness, we would call that adhesion.

So that is separate but related because if you have tape that's stuck to the counter, but then you want to try to move the tape,

you will have friction and that's because adhesion is one of the mechanisms behind friction so in order for something to move if it's really sticky and really adhesive you're going to have to break those adhesive bonds which gives rise to friction when you're trying to move things so friction is then the force needed to overcome the bonds and enable motion okay so in all of the study of friction