How do you find the pewter museum of science in heart gold?

There is no "Pewter Museum of Science" in Pokemon HeartGold. There is, however, a Pewter City Museum, but it doesn't have anything to do with science!

The Pewter City Museum is located in the northeastern part of the city. It is a small building next to the gym. Inside the museum, you can find an exhibit about the history of the gym and Brock's family. There is also a special exhibit in the museum about the history of the Gym Leader, Brock, himself, in a museum exhibit, as well as a rare Pokemon, Omanyte, that you can catch here.

Is there anything else you'd like to know about Pewter City or Pokemon HeartGold?