"Wherever I go in the world people ask me “Do aliens exist?” It’s a good question because it cuts to the heart of how we see our place in the Universe. Are we alone in our small round blue ball? I think probably not, because of one fact: The Universe is BIG.. Really big. Our planet is just one of eight in orbit around our sun, which itself is hardly special being one of about 200 billion stars in a vast spiral, our galaxy the Milky Way. So big sometimes I find it hard to comprehend, but even the Milky Way is just a tiny drop in the Cosmic ocean. Just one of 100 billion galaxies, formed into an enormous web stretching away in all directions. At this scale, each point of light is an entire galaxy, which not only puts our little world in perspective but also makes it difficult to believe we really are alone. So to my mathematical brain.. the numbers alone make thinking about aliens perfectly rational"
Stephen Hawking - “Into The Universe” (via ikenbot