Avi Loeb

Right.

And we know that from various techniques that we are using.

For example, when a planet passes in front of the face of the star, we see diminution, a decrease in the brightness.

My audience knows transiting, they know.

Exactly, the transit method.

We also see, I mean, some planets are detected by the fact that they...

gravitation attract the the star to move back and forth as they move around it so these are mainly jupiters and there is also the possibility of direct imaging and there is the method that i proposed when i was a postdoc at princeton that since then became a whole field of research and that's using gravitational lensing so basically you have a star that is lensing by gravity the light coming from a star behind it far away

and that could magnify the background star for a short period of time when it passes behind the lens.

So just the force of gravity, and Einstein predicted it back in 1940, he didn't expect it to be discovered, but we now know of lots of micro, we call it micro because it's a star doing the lensing.

There are also lensing effects of galaxies that are much bigger.

But the point is that if the light from the background star is passing near a planet, then the planet can do additional lensing on top of what the lens star is doing.

And I realized, so the story is very funny.

My next door neighbor, when I was at Princeton, the Institute for Advanced Studies, I knew nothing about astronomy when I came in.

So I realized he's writing papers about gravitational microlensing by stars.

And I went to his office.

His name is Andy Gould.

And I said, Andy, what if there is a planet next to the star?

Wouldn't that introduce a nice bump on the light curve of the background star?

And he said, no, it wouldn't work because planets are much less massive than the star, which is true that the Earth is tiny.

But there still must be some wobble, no?