Comment: Notice that Earth's atmosphere is very thin (relatively speaking, no thicker than the outer skin of an apple). Earth appears very fragile and precious. No national borders can be seen; all humanity occupies a common biosphere; we are all in this world, together. Some observers have labeled this the Overview Effect.
As the astronomers unanimously teach, the circuit of the whole earth, which to us seems endless, compared with the greatness of the universe has the likeness of a mere tiny point.
The spacecraft was a long way from home, beyond the orbit of the outermost planet and high above the ecliptic plane which is an imaginary flat surface that we can think of as something like a racetrack in which the orbits of the planets are mainly confined. The ship was speeding away from the Sun at 40,000 miles per hour. But in early February of 1990, it was overtaken by an urgent message from Earth.
Obediently, it turned its cameras back toward the now-distant planets. Slewing its scan platform from one spot in the sky to another, it snapped 60 pictures and stored them in digital form on its tape recorder. Then, slowly, in March, April, and May, it radioed the data back to Earth. Each image was composed of 640,000 individual picture elements ("pixels"), like the dots in a newspaper wire-photo or a pointillist painting. The spacecraft was 3.7 billion miles away from Earth, so far away that it took etch pixel 5.5 hours, traveling at the speed of light, to reach us. The pictures might have been returned earlier, but the big radio telescopes in California, Spain, and Australia that receive these whispers from the edge of the Solar System had responsibilities to other ships that ply the sea of space among them, Magellan, bound for Venus, and Galileo on its tortuous passage to Jupiter.
Voyager 1 was so high above the ecliptic plane because, in 1981, it had made a close pass by Titan, the giant moon of Saturn. Its sister ship, Voyager 2, was dispatched on a different trajectory, within the ecliptic plane, and so she was able to perform her celebrated explorations of Uranus and Neptune. The two Voyager robots have explored four planets and nearly sixty moons. They are triumphs of human engineering an. one of the glories of the American space program. They will be in the history books when much else about our time forgotten.
The Voyagers were guaranteed to work only until the Saturn encounter. I thought it might be a good idea, just after Saturn, to have them take one last glance homeward. From Saturn, I knew the Earth would appear too small for Voyager to make out any detail. Our planet would be just a point of light, a lonely pixel, hardly distinguishable from the many other points of light Voyager could see, nearby planets and far-off suns. But precisely because of the obscurity of our world thus revealed, such a picture might be worth having.
Mariners had painstakingly mapped the coastlines of the continents. Geographers had translated these findings into charts and globes. Photographs of tiny patches of the Earth had been obtained first by balloons and aircraft, then by rockets in brief ballistic flight, and at last by orbiting spacecraft giving a perspective like the one you achieve by positioning your eyeball about an inch above a large globe. While almost everyone is taught that the Earth is a sphere with all of us somehow glued to it by gravity, the reality of our circumstance did not really begin to sink in until the famous frame-filling Apollo photograph of the whole Earth, the one taken by the Apollo 17 astronauts on the last journey of humans to the Moon.
It has become a kind of icon of our age. There's Antarctica at what Americans and Europeans so readily regard as the bottom, and then all of Africa stretching up above it: You can see Ethiopia, Tanzania, and Kenya, where the earliest humans lived. At top right are Saudi Arabia and what Europeans call the Near East. Just barely peeking out at the top is the Mediterranean Sea, around which so much of our global civilization emerged. You can make out the blue of the ocean, the yellow-red of the Sahara and the Arabian Desert, the brown-green of forest and grassland.
And yet there is no sign of humans in this picture, not our reworking of the Earth's surface, not our machines, not ourselves: We are too small and our statecraft is too feeble to be seen by a spacecraft between the Earth and the Moon. From this vantage point, our obsession with nationalism is nowhere in evidence. The Apollo pictures of the whole Earth conveyed to multitudes something well known to astronomers: On the scale of worlds (to say nothing of stars or galaxies) humans are inconsequential, a thin film of life on an obscure and solitary lump of rock and metal.
It seemed to me that another picture of the Earth, this one taken from a hundred thousand times farther away, might help in the continuing process of revealing to ourselves our true circumstance and condition. It had been well understood by the scientists and philosophers of classical antiquity that the Earth was a mere point in a vast encompassing Cosmos, but no one had ever seen it as such. Here was our first chance (and perhaps also our last for decades to come).
Many in NASA's Voyager Project were supportive. But from the outer Solar System the Earth lies very near the Sun, like a moth enthralled around a flame. Did we want to aim the camera so close to the Sun as to risk burning out the spacecraft's vidicon system? Wouldn't it be better to delay until all the scientific images from Uranus and Neptune, if the spacecraft lasted that long, were taken?
And so we waited (and a good thing too) from 1981 at Saturn, to 1986 at Uranus, to 1989 when both spacecraft had passed the orbits of Neptune and Pluto. At last the time came but there were a few instrumental calibrations that needed to be done first, and we waited a little longer. Although the spacecraft were in the right spots, the instruments were still working beautifully, and there were no other pictures to take, a few project personnel opposed it. It wasn't science, they said. Then we discovered that the technicians who devise and transmit the radio commands to Voyager were, in a cash-strapped NASA, to be laid off immediately or transferred to other jobs. If the picture were to be taken, it had to be done right then. At the last minute actually, in the midst of the Voyager 2 encounter with Neptune, the then NASA Administrator, Rear Admiral Richard Truly, stepped in and made sure that these images were obtained. The space scientists Candy Hansen of NASA's Jet Propulsion Laboratory (JPL) and Carolyn Porco of University of Arizona designed the command sequence and calculated the camera exposure times.
So here they are, a mosaic of squares laid down on top of the planets and a background smattering of more distant stars. We were able to photograph not only the Earth, but also five other of the Sun's nine known planets. Mercury, the innermost, was lost in the glare of the Sun, and Mars and Pluto were too small, too dimly lit, and/or too far away. Uranus and Neptune are so dim that to record their presence required long exposures; accordingly, their images were smeared because of spacecraft motion. This is how the planets would look to an alien spaceship approaching the Solar System after a long interstellar voyage.
From this distance the planets seem only points of light, smeared or unsmeared, even through the high-resolution telescope aboard Voyager. They are like the planets seen with the naked eye from the surface of the Earth, luminous dots, brighter than most of the stars. Over a period of months the Earth, like the other planets, would seem to move among the stars. You cannot tell merely by looking at one of these dots what it's like, what's on it, what its past has been, and whether, n this particular epoch, anyone lives there.
Because of the reflection of sunlight off the spacecraft, the Earth seems to be sitting in a beam of light, as if there were some special significance to this small world. But it's just an accident of geometry and optics. The Sun emits its radiation equitably in all directions. Had the picture been taken a little earlier or a little later, there would have been no sunbeam highlighting the Earth.
And why that cerulean color? The blue comes partly from the sea, partly from the sky. While water in a glass is transparent, it absorbs slightly more red light than blue. If you have tens of meters of the stuff or more, the red light is absorbed out and what gets reflected back to space is mainly blue. In the same way, a short line of sight through air seems perfectly transparent. Nevertheless, something Leonardo da Vinci excelled at portraying, the more distant the object, the bluer it seems. Why? Because the air scatters blue light around much better than it does red. So the bluish cast of this dot comes from its thick but transparent atmosphere and its deep oceans of liquid water. And the white? The Earth on an average day is about half covered with white water clouds.
We can explain the wan blueness of this little world because we know it well. Whether an alien scientist newly arrived at the outskirts of our solar system could reliably deduce oceans and clouds and a thickish atmosphere is less certain. Neptune, for instance, is blue, but chiefly for different reasons. From this distant vantage point, the Earth might not seem of any particular interest.
But for us, it's different. Look 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, ever 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 rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become momentary masters of a fraction of a dot. Think of the endless visited by the inhabitants of one corner of this pixel the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.
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.
"Because of the reflection of sunlight off the spacecraft, the Earth seems to be sitting in a beam of light, as if there were some special significance to this small world. But it's just an accident of geometry and optics. The Sun emits its radiation equitably in all directions. Had the picture been taken a little earlier or a little later there would have been no sunbeam highlighting the Earth."
When I was a child, I was taught the Christmas greeting "peace on Earth and good will to all men". In my adult years I became aware of the fact that this was a poor translation of "peace on Earth to men of good will". This means that this greeting-blessing "is conditional" based upon the behavior of the recipient (are you a person of good will?). As the song says, we will get the Christmas we deserve based upon our personal and collective actions. Individually we must care for others as well as the Earth. Collectively we must vote for peacemakers while advocating for non-violence.
Every December, many in the western world will read or watch "A Christmas Carol" by Charles Dickens then will kick back and congratulate themselves for not being cold-hearted like Ebenezer Scrooge. And yet, the actions of extreme capitalists are the moral equivalent of Scrooge with one exception: unlike Scrooge, they will never realize the error of their ways. In order to maximize their profit, activist hedge funds demand that large companies outsource work to locations where wages, taxes, and regulations are the lowest. If they had their way, businesses would not offer pensions, benefits or paid holidays. If they had their way, businesses would be money printing machines with no employees.
Americans are always banging on about Adam Smith and "the invisible hand of the market" which is attributed to his second book "The Wealth of Nations". But Adam Smith (who called himself a moral philosopher) wrote an earlier book titled "The Theory of Moral Sentiments" which Americans ignore. Germans called this "Das Adam Smith Problem"
The “Adam Smith Problem” is the name given to an argument that arose among German scholars during the second half of the nineteenth century concerning the compatibility of the conceptions of human nature advanced in, respectively, Adam Smith's Theory of Moral Sentiments (1759) and his Wealth of Nations (1776). During the twentieth century these arguments were forgotten but the problem lived on, the consensus now being that there is no such incompatibility, and therefore no problem. Rather than rehearse the arguments for and against compatibility and incompatibility, this paper returns to the German writers of the 1850s–1890s and demonstrates that their engagement in this argument represents the foundation of modern Smith scholarship. It is shown that the “problem” was not simply a mistake best forgotten, but the first sustained scholarly effort to understand the importance of Smith's work, an effort that lacked any parallel in English commentary of the time. By the 1890s British writers, overwhelmingly ignorant of German commentary, assumed that there was little more to be said about Smith's work. Belated international familiarity with this German “Problem” played a major role in transforming Smith from a simple partisan of free trade into a theorist of commercial society and human action.
By scientific definition, the solar system only extends as far as our Sun's heliosphere. The boundary is known as the heliopause and is past the orbit of Pluto (reclassified from a planet to a Kuiper Belt object in 2006).
It’s alive! By firing a set of thrusters that have been gathering dust for more than 3 decades, NASA has extended the lifetime of the Voyager 1 mission by a few years.
The interstellar probe is 13 billion miles away, moving at a speed of over 17 kilometres per second, but it still manages to send messages back to Earth. In order to do that, it needs to keep its antenna pointed towards us.
After 40 years in space, the thrusters that orient the spacecraft and keep its antenna aiming in the right direction have started to break down.
NASA engineers decided to try firing the craft’s backup thrusters, which have been dormant for 37 years. Then, they had to wait 19 hours and 35 minutes to get a signal from Voyager 1 at the edge of our solar system. The long shot worked, and NASA scientists plan to fully switch over to the backup thrusters in 2020.
The Voyager flight team dug up old records and studied the original software before tackling the test. As each milestone in the test was achieved, the excitement level grew, said propulsion engineer Todd Barber. “The mood was one of relief, joy and incredulity after witnessing these well-rested thrusters pick up the baton as if no time had passed at all,” he said in a statement.
By switching out the thrusters, Voyager 1 may be able to keep sending us messages for a little while longer, until around 2025. Launched in 1977, Voyager 1 is the only spacecraft travelling through interstellar space, the region beyond our solar system. Voyager 2 is close on its heels, nearly 11 billion miles from Earth. The thruster test worked so well that NASA expects to try it on Voyager 2 in the future.Read more at NewScientist magazine: