What would scientists say about their understanding...?

I don't know about a percentage, but the more you know, the more you know you don't know.

I think that 0% of scientists have a compete understanding of the universe. We do not have the information available at this time to know anything about the universe with 100% certainty.

We know a great deal about our planet and this solar system, however.

I don't know anyone, with a functioning brain, who will say with certainty that God exists or does not exist.

a decimal point, infinite zeros and then a 1

Traveler, your second part is a plee for scientific understanding of the supernatural. Unfortunately, there is no validation in science for something that shows no experimental evidence. Therefore, you will not prove God with science.

Scientists understand a minute amount of the universe...

"For the scientist who has lived his dream by faith in the power of reason, the story ends like a bad dream. He has scaled the mountains of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been sitting there for centuries." - Robert Jastrow (astronomer and physicist)

We don't know what we don't know, so how can you give a percentage?