So in the first half of the 20th century we thought it was a great idea to use asbestos in our buildings. In the last half of the 20th century we decided that wasn’t such a great idea and at great expense we’ve been doing our best to get rid of it.
At one time we thought the Milky Way galaxy was it. We now know there’s billions of galaxies out there.
What makes us so cock sure that we have physics right? We know what gravity does but we don’t know why gravity does what it does. We know it’s there and we know why it’s there but we don’t know how it’s there.
