Quotes by Astrophysicists

Advances in medicine and agriculture have saved vastly more lives than have been lost in all the wars in history.
Carl Sagan
Let us begin with the fine-structure constant. ... The fine-structure constant is really the ratio of two natural units or atoms of action. ... We obtain action when we multiply energy by time. ... We are challenged to find a unified theory of electric particles and radiation in which the electrostatic type of action and the quantum type of action are traced to their source.
Arthur Stanley Eddington
Our television signals leave this planet and go out into space...the signals spread out from the earth in spherical waves, a little like ripples in a pond. They travel at the speed of light, 186,000 miles a second, and essentially go on forever. The better some other civilizations receivers are, the farther away they could be and still pick up our tv signals. Even we could detect a strong tv transmission from a planet going around the nearest star.' President: 'You mean everything? You mean to say all that crap on television - the car crashes, wrestling, the porno channels, the evening news?
Carl Sagan
Even if we ourselves are not personally scandalized by the notion of other animals as close relatives, even if our age has accommodated to the idea, the passionate resistance of so many of us, in so many epochs and cultures, and by so many distinguished scholars, must say something important about us. What can we learn about ourselves from an apparent error so widespread, propagated by so many leading philosophers and scientists, both ancient and modern, with such assurance and self-satisfaction? One of several possible answers: A sharp distinction between humans and "animals" is essential if we are to bend them to our will, make them work for us, wear them, eat them--without any disquieting tinges of guilt or regret. With untroubled consciences, we can render whole species extinct--for our perceived short-term benefit, or even through simple carelessness. Their loss is of little import: Those beings, we tell ourselves, are not like us. An unbridgeable gap gas thus a practical role to play beyond the mere stroking of human egos. Darwin's formulation of this answer was: "Animals whom we have made our slaves, we do not like to consider our equals.
Carl Sagan
At the heart of science is an essential balance between two seemingly contradictory attitudes--an openness to new ideas, no matter how bizarre or counterintuitive they may be, and the most ruthless skeptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense.
Carl Sagan
In choosing a hypothesis there is no virtue in being timid. I clearly would have been burned at the stake in another age.
Thomas Gold
Before we invented civilization our ancestors lived mainly in the open out under the sky. Before we devised artificial lights and atmospheric pollution and modern forms of nocturnal entertainment we watched the stars. There were practical calendar reasons of course but there was more to it than that. Even today the most jaded city dweller can be unexpectedly moved upon encountering a clear night sky studded with thousands of twinkling stars. When it happens to me after all these years it still takes my breath away.
Carl Sagan
The hole in the ozone layer is a kind of skywriting. At first it seemed to spell out our continuing complacency before a witch's brew of deadly perils. But perhaps it really tells of a newfound talent to work together to protect the global environment.
Carl Sagan
One of the great commandments of science is, 'Mistrust arguments from authority'. (Scientists, being primates, and thus given to dominance hierarchies, of course do not always follow this commandment.)
Carl Sagan
Washburn has reported that infant baboons and other young primates appear to be born with only three inborn fears -of falling, snakes, and the dark-corresponding respectively to the dangers posed byNewtonian gravitation to tree-dwellers, by our ancient enemies the reptiles, and by mammalian nocturnal predators, which must have been particularly terrifying for the visually oriented primates.
Carl Sagan
Russell commented that the development of such gifted individuals (referring to polymaths) required a childhood period in which there was little or no pressure for conformity, a time in which the child could develop and pursue his or her own interests no matter how unusual or bizarre.
Carl Sagan
We tend to hear much more about the splendors returned than the ships that brought them or the shipwrights. It has always been that way. Even those history books enamored of the voyages of Christopher Columbus do not tell much about the builders of the Nina the Pinta and the Santa Maria or about the principle of the caravel. These spacecraft their designers builders navigators and controllers are examples of what science and engineering set free for well-defined peaceful purposes can accomplish. Those scientists and engineers should be role models for an America seeking excellence and international competitiveness. They should be on our stamps.
Carl Sagan
The gravitational waves of the first detection were generated by a collision of black holes in a galaxy 1.3 billion light-years away, and at a time when Earth was teeming with simple, single-celled organisms. While the ripple moved through space in all directions, Earth would, after another 800 million years, evolve complex life, including flowers and dinosaurs and flying creatures, as well as a branch of vertebrates called mammals. Among the mammals, a sub-branch would evolve frontal lobes and complex thought to accompany them. We call them primates. A single branch of these primates would develop a genetic mutation that allowed speech, and that branch—Homo Sapiens—would invent agriculture and civilization and philosophy and art and science. All in the last ten thousand years. Ultimately, one of its twentieth-century scientists would invent relativity out of his head, and predict the existence of gravitational waves. A century later, technology capable of seeing these waves would finally catch up with the prediction, just days before that gravity wave, which had been traveling for 1.3 billion years, washed over Earth and was detected.Yes, Einstein was a badass.
Neil deGrasse Tyson
The near side of a galaxy is tens of thousands of light-years closer to us than the far side; thus we see the front as it was tens of thousands of years before the back. But typical events in galactic dynamics occupy tens of millions of years, so the error in thinking of an image of a galaxy as frozen in one moment of time is small.
Carl Sagan
You will understand the true spirit neither of science nor of religion unless seeking is placed in the forefront.
Arthur Stanley Eddington
I'm frequently asked, "Do you believe there's extraterrestrial intelligence?" I give the standard arguments- there are a lot of places out there, the molecules of life are everywhere, I use the word billions, and so on. Then I say it would be astonishing to me if there weren't extraterrestrial intelligence, but of course there is as yet no compelling evidence for it.Often, I'm asked next, "What do you really think?"I say, "I just told you what I really think.""Yes, but what's your gut feeling?"But I try not to think with my gut. If I'm serious about understanding the world, thinking with anything besides my brain, as tempting as that might be, is likely to get me into trouble. Really, it's okay to reserve judgment until the evidence is in.
Carl Sagan