Encore: The Deepest Picture Ever
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Encore: on Wednesdays, we repost the best posts from previous months. To comment, please see the original post. My favorite astronomy picture is the Hubble Ultra Deep Field image (HUDF). NASA has released its ultimate version, called XDF, a couple of years ago. Whether it is the original version of the HUDF or the XDF version, I find both absolutely breathtaking. Let me explain a little bit to help you appreciate them. The field of view is tiny: if you wanted to cover the whole sky with a grid of similar images you would have to make 16 million of them! It would not be very practical because the Hubble Space Telescope (HST) had enough trouble taking this one picture. It took it about a month of accumulated gazing at one spot in the sky to obtain just one image. Not in a million years (literally) could the HST cover the whole sky with such images! What was the point … Continue reading

Encore: Inflation
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Encore: on Wednesdays (or *ahem* sometimes Thursday’s), we repost the best posts from previous months, and make them publicly available. To comment, please see the original post. It was Einstein who first hypothesized that the universe is homogeneous and looks the same in all directions (isotropic). A century later this hypothesis still holds, and yet we do not know exactly why this should be the case. By describing the universe as homogeneous and isotropic, Einstein did not mean to say, for example, that a small town in India will look the same as a small town Indiana. Rather, Einstein’s hypothesis refers to the fact that the patterns that millions of galaxies make on the sky look similar in all directions. So the pattern that one million galaxies makes on the sky looks the same as the pattern that a different one million galaxies will look like in a different direction of the sky. How can this be? Astronomers do not … Continue reading

Encore: Across the Universe: What’s in a Name?
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Encore: on Wednesdays, we repost the best posts from previous months, and make them publicly available. To comment, please see the original post. (A column from The Tablet, first published in March, 2004) On the other side of Neptune live the Trans-Neptunian Objects, or TNOs. They are worlds so faint that to measure their colors, we use a mirror nearly two meters across to gather their light, which we focus into a spot of only a few hundreds of a millimeter, collecting it with an ultra-sensitive electronic chip, over a five-minute time exposure. They move – more than five minutes and the spot turns into a streak. But take enough exposures over a few hours and you can plot their motions against the background stars and galaxies. The TNOs are thought to be the home of a class of comets, and they may represent material that’s been kept in “deep freeze” since the solar system was first formed. Though theorized … Continue reading

Encore: On Seeing the Great Wall of China from the Moon
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Encore: on Wednesdays, we repost the best posts from previous months, and make them publicly available. To comment, please see the original post. Urban legend buffs are familiar with the claim that the Great Wall of China can be seen from the Moon (or somewhere else in outer space). Nobody knows quite where this idea comes from. I’ve been reading One Man Caravan by Robert Edison Fulton, Jr. published in 1937 by Harcourt, Brace, and Company. Departing London in 1932, Fulton rode around the world on a motorcycle, or anyway, he covered 40,000 miles through Europe, the Middle East, India, Indonesia, Indochina, China, Japan, and the United States, relying on steamships for the wetter parts of the world. Good book. I was interested in him because he later invented the Airphibian flying car and the bizarre Fulton Skyhook rescue device. See his obituary for more. While reading, I was startled to find a reference to the Great Wall space myth … Continue reading

Encore: On Evolution as a “Bad Word”
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Encore: on Wednesdays, we repost the best posts from previous months, and make them publicly available. To comment, please see the original post. Recently, a fellow member of the Warren Astronomical Society was giving a lecture about stars to a church group (the WAS does quite a bit of outreach at churches and similar venues). When he mentioned the words “Stellar Evolution,” some audience members got VERY upset, and he was literally forced to quit his lecture, pack-up and leave. I have since modified my lecture about stars to use the words “Stellar Life-Cycle” instead. When did the word “Evolution,” used in any form, become a “Bad Word?” Everything evolves, Everything. All the time… Galaxies, stars and star systems, planets, life, ecosystems, intelligence, cities, cultures, societies, technology, data, thought… the whole of the Cosmos. Evolution is NOT a “Bad Word” – it’s about as bad as the word “Mauve.” My wife is a middle-school Science teacher; every time she covers … Continue reading

Encore: “And Do Not Return There till They Have Watered the Earth:” Wondering about Hebrews & Hydrology
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Encore: on Wednesdays, we repost the best posts from previous months, and make them publicly available. To comment, please see the original post. I am wondering about something that is not astronomical, but it does concern the sky. As a lector in my parish on 11 January, I read aloud a passage from Isaiah, chapter 55, verses 1 through 11. I became curious about verses 10 and 11, which contain a simile about rainfall. Yet just as from the heavens the rain and snow come down And do not return there till they have watered the earth, making it fertile and fruitful, Giving seed to the one who sows and bread to the one who eats, So shall my word be that goes forth from my mouth; It shall not return to me empty, but shall do what pleases me, achieving the end for which I sent it. That water allows plants to grow, and is thus essential to fertility … Continue reading

Encore: SDO Shows the Sun in a New Light
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Encore: on Wednesdays, we repost the best posts from previous months, and make them publicly available. To comment, please see the original post. I have a lecture about the Sun – during my presentation, I show this video from the NASA’s Solar Dynamics Observatory – the audience never fails to =gasp!= or =wooh!= when they see this! I showed this to a classroom full of 90 3rd grade students, and their eyes nearly popped out of their heads! I show a couple other video too, like this one showing beautiful Coronal Loops: and this one, showing a very active region of the Sun: The SDO website has “The Sun Now” – a section that shows the Sun in near real-time, in several different frequencies. The images below are live from the SDO site: You can also create your own movies of the Sun from the SDO site! Go HERE, pick your desired date range, select a frequency, select a resolution, … Continue reading