Jon Stewart just went down a couple points in my book when I saw this clip:
What he says in that clip is that, at their core, science and religion are very similar because he thinks they both require you to take things on faith. Jon says religion asks you to believe in a supernatural being that you can’t see, and that you should just believe he is there. Similarly, Jon thinks science asks you to believe that the universe is composed largely of a type of matter that you can’t see, and you should just believe it’s there.
The difference, of course, is that dark matter can actually be measured even though you can’t see it. For example, you might not be able to see the bottom of a deep well, but you can measure it by dropping a rock down there. In the same way, dark matter can be measured through its gravitational influence on other matter.
I’ve always thought of Jon as a very smart guy and continue to think that, but this was kind of painful to watch. Looks like some other people agree as well.