Just by studying mathematics we can hope to make a guess at the kind of mathematics that will come into the physics of the future... If someone can hit on the right lines along which to make this development, it may lead to a future advance in which people will first discover the equations and then, after examining them, gradually learn how to apply them... My own belief is that this is a more likely line of progress than trying to guess at physical pictures.

Testing shows the presence, not the absence of bugs.

An idea can be tested, whereas if you have no idea, nothing can be tested and you don't understand anything. The molecule that you make when you are getting sunburned or when you eat a lot of food is part of the same molecule that contains an endorphin or an opiate. No one has ever had a hypothesis about why the two are together.

You can't even begin to understand biology, you can't understand life, unless you understand what it's all there for, how it arose - and that means evolution.

Some claim evolution is just a theory. As if it were merely an opinion. The theory of evolution, like the theory of gravity, is a scientific fact. Evolution really happened. Accepting our kinship with all life on Earth is not only solid science. In my view, it’s also a soaring spiritual experience.

There's something really beautiful about science, that human beings can ask these questions and can answer them. You can make models of nature and understand how it works.