Astronomers From The United States

"It is hoped that systematic study of the light changes of all the variables, nearly two thousand in number, in the two Magellanic Clouds may soon be undertaken at this Observatory."

"A determination of the visual magnitudes of the stars had a very large place in the work of the Observatory during the first half of Professor Pickering's directorate. As soon as the need of photographic magnitudes became urgent, the importance of a standard sequence, from which the photographic magnitudes could be derived for stars anywhere in the sky, became evident. A sequence of stars of varying magnitudes had been early selected near the North Pole, and the determination of the magnitudes of the stars involved was assigned to Miss Leavitt. This work was carried out with unusual originality, skill, and patience."

"I should be willing to pay thirty cents an hour in view of the quality of your work, although our usual price, in such cases, is twenty five cents an hour."

"About 1906 a Durchmustering of variable stars was proposed at the Harvard Observatory. Somewhat later this was undertaken on plates included in the Map of the Sky... A comparison of the photographs of a number of these regions by Miss Leavitt led to the discovery of several hundred variables and other special objects. Among them were a number of stars of the Algol type."

"It is to be hoped, also, that the parallaxes of some variables of this type may be measured."

"Since the Cepheid] variables are probably at nearly the same distance from the Earth, their periods are apparently associated with their actual emission of light, as determined by their mass, density, and surface brightness."

"A remarkable relation between the brightness of these Cepheid] variables and the length of their periods will be noticed. In H.A. 60, No.4, attention was called to the fact that the brighter variables have the longer periods, but at that time it was felt that the number was too small the drawing of general conclusions. The periods of 8 additional variables which have been determined since that time, however, conform to the same law. The relation is shown graphically in Figure 1... The two resulting curves, one for the maxima and one for the minima, are surprisingly smooth, and of remarkable form. In Figure 2, the abscissas are equal to the logarithms of the periods, and the ordinates to the corresponding magnitudes, as in Figure 1. A straight line can readily be drawn among each of the two series of points corresponding to the maxima and minima, thus showing that there is a simple relation between the brightness of the variables and their periods. The logarithm of the period increases by about 0.48 for each increase of one magnitude in brightness."

"One of the most striking accomplishments of Miss Leavitt was the discovery of 1,777 variable stars in the Magellanic Clouds. These results were [made] possible by photographs of long exposure made at Arequipa with the 24-inch Bruce refractor and forwarded to Cambridge. Some of these plates had exposures of from two to four hours and showed very faint stars, among which nearly all the variables are found. ...from a study of 25 of them, the important law was derived, that the length of period bears a definite relation to the absolute magnitude."

"It is worthy of notice that in Table VI the brighter variables have the longer periods. It is also noticeable that those having the longest periods appear to be as regular in their variations as those which pass through their changes in a day or two."

"The discovery of variable stars, at this Observatory and elsewhere, has progressed so rapidly during the last five years, that the difficulty of keeping pace in observing and discussing them has become very great. In the study of distribution now in progress here, the actual time devoted to the search for new variables is small, but thorough observation requires much time, while the discussion of results may be prolonged almost indefinitely. When new lists of variables are published, therefore, it should be remembered that their discovery does not interfere materially with the study of individual objects. The number of these is so large that the publication of full results for all must be greatly delayed."

"Apparently no sharp dividing line can be drawn between true Algol stars and those whose variations are continuous. Periods of nine variables in this region, which are of the Algol type or closely resemble it, have been determined and are here discussed."

"The range of H 1255 is only four tenths of a magnitude, and on account of its brightness it is difficult to observe on all plates except those taken with the 1-inch Cooke lens. It seemed necessary, therefore, to take unusual precautions in order to secure accurate observations, and to give each one its full weight. Accordingly, one hundred and thirty six photographs were selected, including nearly all of those taken with the Cooke lens, and also those taken with the 8 inch Bache Telescope on which the variable was certainly faint. Four independent estimates of brightness were made on each plate, and means were taken, thus reducing the probable error one half. The phase was computed for each observation, thus covering all parts of the light curve. ...H 1255 and H 1303 differ from the other variables in a marked degree as in each case the duration of the phase of minimum is very long in proportion to the length of the period. This fact led to considerable difficulty in determining their periods as they were apparently at their minimum brightness for some time before and after the actual minima occurred. In H 1255, the change in brightness is obviously continuous throughout the period, although it is much more rapid near minimum than near maximum. This is clearly seen in Plate IV, Figs. 5 and 6."

"Neutrinos are fundamental subatomic particles produced in nuclear reactions, like those in the sun. We always talk about the fact that we can’t see neutrinos or dark matter and that basically they’re invisible, but if you think about it from the other side, we’re also invisible to them."

"Nothing in nature or the cosmos is ever completely still — as I write this, several wild Mallards have returned to the Museum courtyard and are creating a frantic spectacle of water and wings as they dive and attack in their annual spring ritual. Further from home, a supermassive black hole at the center of a galaxy 56 million light years from Earth has recently been observed to be spinning at close to the speed of light."

"The Big Bang theory has been extremely successful in describing the history and evolution of the Universe, and new experiments and observations continue to confirm the basic predictions of this theory. But we do not yet know the answer to the question"

"Ibn al-Haytham was the first person ever to set down the rules of science. -S01E05"

"In this moment, I am euphoric. Not because of any phony god’s blessing. But because, I am enlightened by my intelligence"

"he does have that same passion to connect that is critical if you want to be a science communicator."

"Halley shattered their monopoly, beating them at their own game. A game that no scientist had ever played before: Prophecy. -S01E03"

"in Space where there ain't no gravity, helicopter dick really do be a way to travel."

"At least once a week, if not once a day, we might each ponder what cosmic truths lie undiscovered before us, perhaps awaiting the arrival of a clever thinker, an ingenious experiment, or an innovative space mission to reveal them. We might further ponder how those discoveries may one day transform life on Earth. Absent such curiosity, we are no different from the provincial farmer who expresses no need to venture beyond the county line, because his forty acres meet all his needs. Yet if all our predecessors had felt that way, the farmer would instead be a cave dweller, chasing down his dinner with a stick and a rock."

"... the anatomy of a sound bite is—it's gotta be interesting. And it's gotta be tasty. It should also be a little bit fun to hear ... so that you smile. And it's gotta have enough of all that to want to tell someone else that you just learned something. ... I have a master class on thinking like a scientist and how to communicate what you know in your expertise to others."

"If a huge genetic gap separated us from our closest relative in the animal kingdom, we could justifiably celebrate our brilliance. We might be entitled to walk around thinking we’re distant and distinct from our fellow creatures. But no such gap exists. Instead, we are one with the rest of nature, fitting neither above nor below, but within."

"Of all the sciences cultivated by mankind, Astronomy is acknowledged to be, and undoubtedly is, the most sublime, the most interesting, and the most useful. For, by knowledge derived from this science, not only the bulk of the Earth is discovered . . . ; but our very faculties are enlarged with the grandeur of the ideas it conveys, our minds exalted above [their] low contracted prejudices."

"The cosmic perspective flows from fundamental knowledge. But it’s more than about what you know. It’s also about having the wisdom and insight to apply that knowledge to assessing our place in the universe. And its attributes are clear: The cosmic perspective comes from the frontiers of science, yet it is not solely the provenance of the scientist. It belongs to everyone. The cosmic perspective is humble. The cosmic perspective is spiritual—even redemptive—but not religious. The cosmic perspective enables us to grasp, in the same thought, the large and the small. The cosmic perspective opens our minds to extraordinary ideas but does not leave them so open that our brains spill out, making us susceptible to believing anything we’re told. The cosmic perspective opens our eyes to the universe, not as a benevolent cradle designed to nurture life but as a cold, lonely, hazardous place, forcing us to reassess the value of all humans to one another. The cosmic perspective shows Earth to be a mote. But it’s a precious mote and, for the moment, it’s the only home we have. The cosmic perspective finds beauty in the images of planets, moons, stars, and nebulae, but also celebrates the laws of physics that shape them. The cosmic perspective enables us to see beyond our circumstances, allowing us to transcend the primal search for food, shelter, and a mate. The cosmic perspective reminds us that in space, where there is no air, a flag will not wave, an indication that perhaps flag-waving and space exploration do not mix. The cosmic perspective not only embraces our genetic kinship with all life on Earth but also values our chemical kinship with any yet-to-be discovered life in the universe, as well as our atomic kinship with the universe itself."

"Science is a cooperative enterprise spanning the generations. It's the passing of a torch from teacher to student to teacher; a community of minds reaching back to antiquity and forward to the stars. (From the first Cosmos: ASO episode, Standing Up in the Milky Way.)"

"Cosmologists have plenty of ego. How could you not when your job is to deduce what brought the universe into existence?"

"In our own solar system, for example, everything that is not the Sun adds up to less than one fifth of one percent of the Sun’s mass."

"The Theory of Evolution, like the Theory of Gravity, is a scientific fact. Evolution really happened. Accepting our kinship with all life on earth is not only solid science, in my view, it's also a soaring spiritual experience. (From the second Cosmos: ASO episode, Some of the Things That Molecules Do.)"

"If you want to assert a truth, first make sure it's not just an opinion that you desperately want to be true."

"What is NASA's mission? Is it to beat the russians? Is it to inspire?"

"All I can say is, the universe is in a good shape, it's earth that has all the problems."

"Other unrelenting skeptics might declare that “seeing is believing”—an approach to life that works well in many endeavors, including mechanical engineering, fishing, and perhaps dating. It’s also good, apparently, for residents of Missouri. But it doesn’t make for good science. Science is not just about seeing, it’s about measuring, preferably with something that’s not your own eyes, which are inextricably conjoined with the baggage of your brain. That baggage is more often than not a satchel of preconceived ideas, post-conceived notions, and outright bias."

"As important as Steve Jobs was, no doubt about it — [and] you have to add him to Bill Gates, because they birthed the personal computing revolution kind of together — here's the difference: Elon Musk is trying to invent a future, not by providing the next app."

"I could just tell you it's all bunk; but then you wouldn't be empowered to understand why. Other than to quote, "Oh, Doctor Tyson said..." And I never want you to quote me citing my authority as a scientist for your knowing something. If that's what you have to resort to I have failed as an educator. As an educator, it's my duty to empower you to think. So that you can go forth and think accurate thoughts about how the world is put together. Inoculating you against the [people] out there who will exploit your ignorance on anything they possibly can."

"If you start wielding a hammer, then all your problems look like nails. And maybe they’re not. Maybe it's more subtle than that. And so your toolkit has to be able to morph into what is necessary for what it is that you confront at that moment."

"Within one linear centimeter of your lower colon there lives and works more bacteria (about 100 billion) than all humans who have ever been born. Yet many people continue to assert that it is we who are in charge of the world."

"I am trying to convince people--not only the public, but lawmakers and people in power--that investing in the frontier of science, however remote it may seem in its relevance to what you're doing today, is a way of stockpiling the seed corns of future harvests of this nation... Advancing a frontier--history has shown--has advanced a culture ever since the industrial revolution got underway."

"Words that make questions may not be questions at all."

"The problem, often not discovered until late in life, is that when you look for things like love, meaning, motivation, it implies they are sitting behind a tree or under a rock. The most successful people recognize, that in life they create their own love, they manufacture their own meaning, they generate their own motivation. For me, I am driven by two main philosophies, know more today about the world than I knew yesterday. And along the way, lessen the suffering of others. You'd be surprised how far that gets you."

"Ignorance is the natural state of mind for a research scientist. People who believe they are ignorant of nothing have neither looked for, nor stumbled upon, the boundary between what is known and unknown in the universe. What we do know, and what we can assert without further hesitation, is that the universe had a beginning. The universe continues to evolve. And yes, every one of our body’s atoms is traceable to the big bang and to the thermonuclear furnaces within high-mass stars that exploded more than five billion years ago. We are stardust brought to life, then empowered by the universe to figure itself out—and we have only just begun."

"The universe is under no obligation to make sense to you."

"This universality of physical laws drives scientific discovery like nothing else."

"To the scientist, the universality of physical laws makes the cosmos a marvelously simple place. By comparison, human nature—the psychologist’s domain—is infinitely more daunting. In America, local school boards vote on subjects to be taught in the classroom. In some cases, votes are cast according to the whims of cultural, political, or religious tides. Around the world, varying belief systems lead to political differences that are not always resolved peacefully. The power and beauty of physical laws is that they apply everywhere, whether or not you choose to believe in them. In other words, after the laws of physics, everything else is opinion."

"Kids are never the problem. They are born scientists. The problem is always the adults. They beat the curiosity out of the kids. They out-number kids. They vote. They wield resources. That's why my public focus is primarily adults."

"Personally, I am quite comfortable with chemicals, anywhere in the universe. My favorite stars, as well as my best friends, are all made of them."

"When I pore over the data that establish the mysterious presence of dark matter and dark energy throughout the universe, sometimes I forget that every day—every twenty-four-hour rotation of Earth—people kill and get killed in the name of someone else’s conception of God, and that some people who do not kill in the name of God, kill in the name of needs or wants of political dogma."

"Within a month of opening day, I received a letter from an Ivy League professor of psychology whose expertise was in things that make people feel insignificant…He wanted to administer a before-and-after questionnaire to visitors, assessing the depth of their depression after viewing the show. Passport to the Universe, he wrote, elicited the most dramatic feelings of smallness and insignificance he had ever experienced. How could that be? Every time I see the space show (and others we’ve produced), I feel alive and spirited and connected. I also feel large, knowing that the goings-on within the three-pound human brain are what enabled us to figure out our place in the universe. Allow me to suggest that it’s the professor, not I, who has misread nature. His ego was unjustifiably big to begin with, inflated by delusions of significance and fed by cultural assumptions that human beings are more important than everything else in the universe. In all fairness to the fellow, powerful forces in society leave most of us susceptible. As was I, until the day I learned in biology class that more bacteria live and work in one centimeter of my colon, than the number of people who have ever existed in the world. That kind of information makes you think twice about who–or what–is actually in charge. From that day on, I began to think of people not as the masters of space and time but as participants in a great cosmic chain of being, with a direct genetic link across species both living and extinct, extending back nearly four billion years to the earliest single-celled organisms on Earth."

"The good thing about science is that it’s true whether or not you believe in it."

"My view is that if your philosophy is not unsettled daily then you are blind to all the universe has to offer."