Carl Sagan

Carl Sagan

This a collection of almost everything including stories, lessons, short quotes which I will keep updating often. Happy Learning!

To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.

The universe is a pretty big place. If it’s just us, seems like an awful waste of space.

That’s here. That’s home. That’s us. On it, everyone you love, everyone you know, everyone you have ever heard of, every human being who ever was, lived out their lives…[E]very king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every revered teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species lived there–on a mote of dust suspended in a sunbeam.

Feel free to jump anywhere,


Modern science has been a voyage into the unknown, with a lesson in humility waiting at every stop. Our common sense intuitions can be mistaken. Our preferences don’t count. We do not live in a privileged reference frame. If we crave some cosmic purpose, then let us find ourselves a worthy goal.

What an astonishing thing a book is. It’s a flat object made from a tree with flexible parts on which are imprinted lots of funny dark squiggles. But one glance at it and you’re inside the mind of another person, maybe somebody dead for thousands of years. Across the millennia, an author is speaking clearly and silently inside your head, directly to you. Writing is perhaps the greatest of human inventions, binding together people who never knew each other, citizens of distant epochs. Books break the shackles of time. A book is proof that humans are capable of working magic.

From this distant vantage point, the Earth might not seem of any particular interest. But for us, it’s different. Consider again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there-on a mote of dust suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot.

Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.

It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.

Long ago, when an early galaxy began to pour light out in to the surrounding darkness no witness could have known that billions of years later. Some remote clumps of rock and metal, ice and organic molecules would fall together to form a place that we call earth. And surely nobody could have imagined that life would arise, and thinking beings evolve who would one day capture a fraction of that light and would try to puzzle out what sent it on its way.

We can recognize here a shortcoming, in some circumstances serious, in our ability to understand the world. Characteristically, willie-nilly we seem compelled to project our own nature onto nature. Man in his arrogance thinks himself a great work worthy of the interposition of a deity. Darwin wrote in his notebook, more humble, and I think truer to consider himself created from animals.

How is it that hardly any major religion has looked at science and concluded, “This is better than we thought! The Universe is much bigger than our prophets said, grander, more subtle, more elegant?” Instead they say, “No, no, no! My god is a little god, and I want him to stay that way.” A religion, old or new, that stressed the magnificence of the Universe as revealed by modern science might be able to draw forth reserves of reverence and awe hardly tapped by the conventional faiths.

You’re an interesting species. An interesting mix. You’re capable of such beautiful dreams, and such horrible nightmares. You feel so lost, so cut off, so alone, only you’re not. See, in all our searching, the only thing we’ve found that makes the emptiness bearable, is each other.

We sometimes hear of things that can travel faster than light. Something called ‘the speed of thought’ is occasionally proffered. This is an exceptionally silly notion especially since the speed of impulses through the neutrons in our brain is about the same as the speed of a donkey cart.

There is a wide yawning black infinity. In every direction the extension is endless, the sensation of depth is overwhelming. And the darkness is immortal. Where light exists, it is pure, blazing, fierce; but light exists almost nowhere, and the blackness itself is also pure and blazing and fierce. But most of all, there is very nearly nothing in the dark; except for little bits here and there, often associated with the light, this infinite receptacle is empty. This picture is strangely frightening. It should be familiar. It is our universe.

Even these stars, which seem so numerous, are, as sand, as dust, or less than dust, in the enormity of the space in which there is nothing. Nothing! We are not without empathetic terror when we open Pascal’s Pensées and read, “I am the great silent spaces between worlds.


We are a way for the cosmos to know itself.

The nature of life on Earth and the search for life elsewhere are two sides of the same question - the search for who we are.

Imagination will often carry us to worlds that never were. But without it we go nowhere.

It pays to keep an open mind, but not so open your brains fall out.

Extraordinary claims require extraordinary evidence.

Science is not only compatible with spirituality; it is a profound source of spirituality.

If you wish to make an apple pie from scratch, you must first invent the universe.

We are like butterflies who flutter for a day and think it is forever.

I don’t want to believe. I want to know.

Books permit us to voyage through time, to tap the wisdom of our ancestors.

We’re all time travelers—at a rate of exactly one second per second.

Science has taught us that we are not the measure of all things.

Science is more than a body of knowledge, it’s a way of thinking.


I went to the librarian and asked for a book about stars … And the answer was stunning. It was that the Sun was a star but really close. The stars were suns, but so far away they were just little points of light … The scale of the universe suddenly opened up to me. It was a kind of religious experience. There was a magnificence to it, a grandeur, a scale which has never left me. Never ever left me.

Neil deGrasse Tyson: On Carl Sagan

It was almost like a dispatch from another planet: the invitation to the young astronomer to leave Brooklyn and visit the lakes and gorges of upstate New York. In 1975, Sagan, who was already famous at that time, was so impressed by Tyson’s college application that he personally reached out to him, hoping to convince the high school student to attend Cornell. He even offered to personally show Tyson around his lab.

You can read Sagan’s letter, dated November 12, 1975, below.

Dear Neil:

Thanks for your letter and most interesting resume. I was especially glad to see that, for a career in astronomy, you intend to do your undergraduate work in physics. In this way, you will acquire the essential tools for a wide range of subsequent astronomical endeavors.

I would guess from your resume that your interests in astronomy are sufficiently deep and your mathematical and physical background sufficiently strong that we could probably engage you in real astronomical research during your undergraduate career here, if the possibility interests you. For example, we hope to be bringing back to Ithaca in late calendar year 1976 an enormous array of Viking data on Mars both from the orbiters and from the landers.

I would be delighted to meet with you when you visit Ithaca. Please try and give as much advance notice of the date as you can because my travel schedule is quite hectic right now and I really would like to be in Ithaca when you drop by.

With all good wishes,

Carl Sagan

Tyson was deeply moved by Sagan’s kindness and sincerity. He did venture out to Ithaca from the Bronx on a snowy afternoon. As Tyson recalled years later, “I thought to myself, who am I? I’m just some high school kid.” In the end, Sagan’s personal plea wasn’t quite enough to convince young Tyson to attend his school. As you can read in his response below, dated April 30, 1976, Tyson decided to go to Harvard.

Dear Prof. Sagan

Thank you for your offer concerning the Viking Missions. After long thought and decision making I have chosen to attend Harvard University this September. I chose it not simply because of its “valuable” name but because they have a larger astronomy department in addition to the Smithsonian Astrophysical Observatory, so while I am majoring in physics I will have more surrounding me in the way of on-going research in astronomy.

I want to say that I did enjoy meeting you and I am very grateful for your hospitality and the time you spent with me while at Cornell. I will throughout my undergraduate years keep you informed on any noteworthy news concerning astronomy-related work that I’m involved in. I do plan to apply again for the Viking Internship next summer.

Thanks again

Neil D. Tyson

He(Carl) was nothing I was like drinking buddies with them but we were sort of a generation separate but I was applying to colleges in high school and I already knew I wanted to do to study the universe at age 17 because I knew at age 9. So my applications were dripping with the universe, I was accepted at Cornell and it’s time to decide what school you go to and a set of other schools as well. The admissions office unknown to me sent my application to Carl Sagan, he who’s already famous, he was already on Johnny Carson’s Tonight Show set to get him to just comment on it. Carl Sagan then sent me a letter hand sign saying, “I understand you Mike you’re considering Cornell, if you come by and visit I’d be happy to show you the lab” and I said, “Is this Carl Sagan?” I showed it to mom dad is this, could this be and it was! I wrote back and I said, “y’all go up in two weekends”. He met me on a Saturday morning in the snow gave me a tour of his lab. I’m in his office he reaches back pulls out one of his books signs it to me. At the end of the day, he drove me back to the bus station. The snow was falling harder. He wrote his phone number, his home phone number, on a scrap of paper. And he said, “If the bus can’t get through, call me. Spend the night at my home, with my family.” I thought to myself “Who am I?”, I’m just some high school kid. I already knew I wanted to become a scientist, but that afternoon I learned from Carl the kind of person I wanted to become. He reached out to me and to countless others. Inspiring so many of us to study, teach, and do science. Science is a cooperative enterprise, spanning the generations. To this day I have this duty to respond to students who are inquiring about the universe as a career path, to respond to them in the way that Carl Sagan had responded to me.

And just watch this!

Neil book