What does Sheldon mean when he says it's a good idea for a T-shirt?

It's nothing. I just think it's a good idea to put it on a T-shirt.

If a photon hits a plane with two slits, then if a photon is guided through a plane.

If there is a slit with two slits and three slits are observed,

Then it does not pass through both slits at the same time.

If it cannot be observed, it will pass. If it is not observed, it will.

But if it is after leaving the plane, if it is observed after leaving the plane.

But before it hits the target,

Then it will not pass through both slits at the same time.

That's right. what are you trying to say？

Nothing, I just think it's a good idea for a T-shirt.

This is the original text. I hope it will help you and be adopted.