This site is made possible by member support. 💞
Big thanks to Arcustech for hosting the site and offering amazing tech support.
When you buy through links on kottke.org, I may earn an affiliate commission. Thanks for supporting the site!
kottke.org. home of fine hypertext products since 1998.
Beloved by 86.47% of the web.
Observe sunspots by going to Grand Central Terminal?
The southern wall of the Grand Concourse, facing 42nd Street, has semicircular grills high up, with small curlicued spaces like those in a leafy tree. Many of those spaces act like the aperture of a pinhole camera, reflecting an image of the sun that, when it reaches the floor, will be 8 to 12 inches wide. The smaller grill spaces will produce dimmer but sharper solar images on your paper.
(via 92y blog)
From Harvard Magazine, an appreciation of the work that the Hubble telescope has done since its 1990 launch into orbit.
The “Pillars of Creation” may be the most iconic Hubble photograph ever taken. “Located in the Eagle Nebula, the pillars are clouds of molecular hydrogen, light years in length, where new stars are being born,” says Aguilar. “However, recent discoveries indicate these pillars were destroyed by a massive nearby super nova some 6,000 years ago. This is a ghost image of a past cosmic disaster that we won’t see here on Earth for another thousand years or so-and a perfect example of the fact that everything we see in the universe is history.”
The Hubble Space Telescope was launched into space 18 years ago and to celebrate, NASA has put up a photo gallery of merging galaxies, galaxies as in love with each other as NASA is with the Hubble. Aww.
A photograph of the newest possible moon, one that’s only about 15 hours old.
Finding the Moon when its slim crescent is still less than about 24 hours past the New Moon phase requires careful timing and planning, a challenging project even for experienced observers. In this sighting, only about 0.8 percent of the Moon’s disk appears illuminated.
(via airbag)
The Hubble telescope recently captured an image of a double Einstein Ring.
An Einstein Ring happens when two galaxies are perfectly aligned. The closer galaxy acts as a lens, magnifying and distorting the view of a more distant galaxy. But today astronomers announced that they’ve discovered a double Einstein Ring: three galaxies are perfectly aligned, creating a double ring around the lensing galaxy.
A list of the top 10 astronomy images of 2007, including entwined galaxies and a dying star.
On the origin of the Earth’s moon and how our planet would be different if we didn’t have a moon.
The Moon has been a stabilizing factor for the axis of rotation of the Earth. If you look at Mars, for instance, that planet has wobbled quite dramatically on its axis over time due to the gravitational influence of all the other planets in the solar system. Because of this obliquity change, the ice that is now at the poles on Mars would sometimes drift to the equator. But the Earth’s moon has helped stabilize our planet so that its axis of rotation stays in the same direction. For this reason, we had much less climatic change than if the Earth had been alone. And this has changed the way life evolved on Earth, allowing for the emergence of more complex multi-cellular organisms compared to a planet where drastic climatic change would allow only small, robust organisms to survive.
Comet Holmes brightened a millionfold late this week and has become visible to the naked eye, even in bright cities. The second chart on this page shows how quickly the comet shot up in brightness.
Using adaptive optics, which corrects for atmospheric distortion, some astronomers have modified a ground telescope to yield sharper images than the Hubble.
Hubble’s optics provide greater detail over a wider angle, while the Lucky camera as used at Palomar gives ultra-high resolution only for a tiny slice of the sky at one time.
This New Yorker article on light pollution makes mention of the Bortle Dark-Sky Scale, which is a measure of how bright the stars are in a particular part of the sky.
In Galileo’s time, nighttime skies all over the world would have merited the darkest Bortle ranking, Class 1. Today, the sky above New York City is Class 9, at the other extreme of the scale, and American suburban skies are typically Class 5, 6, or 7. The very darkest places in the continental United States today are almost never darker than Class 2, and are increasingly threatened. For someone standing on the North Rim of the Grand Canyon on a moonless night, the brightest feature of the sky is not the Milky Way but the glow of Las Vegas, a hundred and seventy-five miles away. To see skies truly comparable to those which Galileo knew, you would have to travel to such places as the Australian outback and the mountains of Peru.
Arecibo Observatory, the world’s largest radio telescope, is in danger of being shut down due to budget cuts. Arecibo could run for almost two years for the cost of a single F-16 fighter jet…to say nothing of the small fraction of the cost of the War in Iraq required.
Is the search for aliens such a good idea? If/when we find evidence of extraterrestrial intelligent life, will they welcome us as neighbors, treat us as vermin in their universe or something inbetween? “Jared Diamond, professor of evolutionary biology and Pulitzer Prize winner, says: ‘Those astronomers now preparing again to beam radio signals out to hoped-for extraterrestrials are naive, even dangerous.’”
Poor Pluto. First they demoted it from planet status and now it’s not even the biggest dwarf planet in the solar system.
Are there many small galaxies, like the one just discovered just outside our own, orbiting the larger visible galaxies?
Three trillion years from now, the universe will be observably static, the Milky Way alone, and scientists of the day likely won’t be able to “infer that the beginning involved a Big Bang”.
Closeup videos of the sun. The bottom one is especially mesmerizing.
How to survive a black hole. If you’re in a rocket ship about to fall into a black hole, you might live a bit longer if you turn on your engines. “But in general a person falling past the horizon won’t have zero velocity to begin with. Then the situation is different — in fact it’s worse. So firing the rocket for a short time can push the astronaut back on to the best-case scenario: the trajectory followed by free fall from rest.”
Scientists have found an Earth-like planet orbiting one of the closest stars to our solar system. “On the treasure map of the universe, one would be tempted to mark this planet with an X.”
For next time around, how to photograph a lunar eclipse. Here’s a list of upcoming eclipses. (via inmyallstars)
Nice composite photo of the lunar eclipse last night. We missed it because it was a bit cloudy and tall buildingy in NYC last night. (thx, ajit)
Update: Here’s another, another, and one more.
On tonight’s to-do list: total lunar eclipse. Totality occurs at 5:44pm ET and will last about an hour. On the east coast of the US, the moon will already be eclipsed when it rises. Best bet for seeing it is Africa, Europe, and the Middle East (see map).
Astronomers are tracking a 250-meter-wide asteroid called Apophis which will come within 30,000 km of earth in 2029. However, it’s too soon to tell if that near-miss will pull the asteroid into a collision course with the earth 7 years later. “Lu says the best way to deflect an asteroid is with a ‘gravity tractor’ — a spacecraft displacing about 1 metric ton that simply hovers near an asteroid and gently tweaks its orbit.”
Top 100 photos taken by the Hubble Space Telescope, a singularly talented photographer.
Woo, NASA finally decides to fix the Hubble, repairs that will keep it working until at least 2013. “Scientists expect an upgraded Hubble to continue to make groundbreaking discoveries.”
They shut all the lights off in Reykjavik last Thursday so that residents might see the stars without light pollution. What a lovely idea.
Is “dwarf planet” an ironym? “Pluto is a dwarf planet, but we are now faced with the absurdity that a dwarf planet is not a planet.” (thx, adriana)
After hearing the news that Pluto had been demoted from its full planetary status in the solar system, Meg and I decided to hold a contest to find a new mnemonic device for the planets, replacing the old “My very elegant mother just served us nine pizzas” (among others). The mnemonic could work for either the new 8 planet line-up, the 8 major + 3 dwarf planets, or the old 9 planet arrangement in protest of Pluto’s demotion. Thanks to everyone who entered; we received a bunch of great entries and it was hard to choose a winner. But first place goes to Josh Mishell for:
My! Very educated morons just screwed up numerous planetariums.
Josh’s protest mnemonic is memorable, topical, and goes beyond a simple description of the shameful proceedings in Prague to real-world consequences. As the winning entrant, Josh will receive a print from HistoryShots…we’re suggesting Race to the Moon. Congratulations to Josh.
Now, some runners-up. These came very close to winning:
Many Very Earnest Men Just Snubbed Unfortunate Ninth Planet (Dave Child)
“My vision, erased. Mercy! Just some underachiever now.” (Delia, as spoken by Pluto discoverer Clyde Tombaugh)
Most vexing experience, mother just served us nothing! (Bart Baxter)
There were several entries that referenced vegetarianism and veganism; this haiku by Evan Norris was my favorite:
most vegans envy
my jovian silhouette,
not usually
Update: A reader noted that Evan’s haiku incorrectly swaps the positions of Neptune and Uranus. Happily, “usually not” works just as well. (thx, peter)
The honorary mention for lack of sophistication goes to Andrea Harner and Jonah Peretti for:
Molesting Very Excitedly, Michael Jackson Sucks Underage Nipples
Best foreign language award goes to Bernardo Carvalho for his Portuguese mnemonic (remember, “Earth” is something like “Terra” in Portuguese so the t fits. And we’ll ignore the e too…):
minha velha, traga meu jantar: sopa, uva, nozes e pão (Translated: “Old woman, bring me dinner: soup, grapes, nuts and bread”)
And here are some of the best of the rest:
Mollifying voluminous egos means judiciously striking underappreciated named planetoid (Bruce Turner)
Most Virgins Eventually Marry Jocks So Unscrupulously Naughty (Aaron Arcello)
Morons Violate Every Map Just So UFOs Navigate Poorly (Sean Tevis)
My violin emits minimal joy since union nixed Pluto (C.D.)
Maximum velocity earns many joyous shouts, unless not planetary (Scott Tadman)
Thanks again to everyone who entered!
Socials & More