In a loving tribute to her father, Sasha Sagan remembers how she came to learn about death. She describes an exchange in which she asked Carl if he would ever see his deceased parents again. He responded that “there was nothing he would like more in the world than to see his mother and father again, but that he had no reason — and no evidence — to support the idea of an afterlife, so he couldn’t give in to the temptation”:

Then he told me, very tenderly, that it can be dangerous to believe things just because you want them to be true. You can get tricked if you don’t question yourself and others, especially people in a position of authority. He told me that anything that’s truly real can stand up to scrutiny. As far as I can remember, this is the first time I began to understand the permanence of death. As I veered into a kind of mini existential crisis, my parents comforted me without deviating from their scientific worldview.

“You are alive right this second. That is an amazing thing,” they told me. When you consider the nearly infinite number of forks in the road that lead to any single person being born, they said, you must be grateful that you’re you at this very second.

Think of the enormous number of potential alternate universes where, for example, your great-great-grandparents never meet and you never come to be. Moreover, you have the pleasure of living on a planet where you have evolved to breathe the air, drink the water, and love the warmth of the closest star. You’re connected to the generations through DNA — and, even farther back, to the universe, because every cell in your body was cooked in the hearts of stars. We are star stuff, my dad famously said, and he made me feel that way.

Meanwhile, Jason Koebler explains the latest Hubble photo, pictured above:

What you’re seeing is a cross-section of the universe, showcasing objects that are one billion times fainter than those that you can see with your naked eye. Most of the things that look close are actually billions of light years apart, and most of them are billions of light years away from us. Check out the ultra high-res version here.

(Image by the NASA/ESA Hubble Space Telescope)