Conny Aerts

So if you have no information, what can you do?

Well, you think, well, it won't be that different.

Well, the stars have many more surprises than us astrophysicists have imagination.

What a smack.

Yes, I always say the stars are right, the theory is wrong if it doesn't match with each other, right?

So thanks to the frequency shifts of these waves, we can now measure how stars rotate around.

And why is that important?

Well, if they rotate faster or slower, then their material gets mixed in a different way.

That's also something you can imagine if you take the analogy with coffee drinkers.

If you like coffee with milk, you pour milk into your coffee and you don't wait until everything is mixed because then the coffee is cold and it doesn't taste well anymore.

No, you take a spoon and you rotate your coffee.

In my terminology, that is saying you bring angular momentum to the coffee cup.

And why do you do that?

That's what everybody does without saying it.

And that's because everybody prefers well-mixed coffee with milk.

Well, we could do an experiment of how people do that.

But, you know, the diversity of human beings taking their spoons will be large.

And in stars...

There's a whole range of internal rotation frequencies that we have measured.

We have about 2000 stars now for which this has been measured by many groups in the world with astro seismologists.