What’s Going On With Black Holes?

Should I consider it ominous that, for the past week, my most popular post has been something I wrote 17 months ago about two black holes colliding in space?

Apparently, if this were to happen,

….space and time shift, density becomes infinite and time can come to a standstill.

Folks, it only feels like that sometimes.  But if you’re having black hole collision panic, let me know and we can discuss it.

Dinosaurs: Hard to Kill

It took a lot more than just one meteor slamming into Mexico to wipe out the big lizards, it turns out:

There’s growing evidence that the dinosaurs and most their contemporaries were not wiped out by the famed Chicxulub meteor impact, according to a paleontologist who says multiple meteor impacts, massive volcanism in India, and climate changes culminated in the end of the Cretaceous Period.

The Chicxulub impact may, in fact, have been the lesser and earlier of a series of meteors and volcanic eruptions that pounded life on Earth for more than 500,000 years, say Princeton University paleontologist Gerta Keller and her collaborators Thierry Adatte from the University of Neuchatel, Switzerland, and Zsolt Berner and Doris Stueben from Karlsruhe University in Germany. A final, much larger and still unidentified impact 65.5 million years ago appears to have been the last straw, exterminating two thirds of all species in one of the largest mass extinction events in the history of life. It’s that impact — not Chicxulub — which left the famous extraterrestrial iridium layer found in rocks worldwide that marks the impact that finally ended the Age of Reptiles.

“The Chicxulub impact could not have caused the mass extinction,” says Princeton University paleontologist Gerta Keller, “because this impact predates the mass extinction and apparently didn’t cause any extinctions.”

deccan-flood-basalts.jpgThe climate changes, caused in part by greenhouse gases released from “prolonged and massive eruptions” of the Deccan Flood Basalts in India, were pretty extreme: Oceans 3 or 4 degrees warmer, and land temperatures 7 or 8 degrees warmer, 20,000 years before, and 100,000 years after, the Chicxulub meteor struck. Marine life was affected by growing smaller and reproducing more offspring — to increase the odds for survival. Tropical species were on the edge of extinction. Then there was another huge meteor impact, comparable to the first. Where did that meteor strike? Scientists don’t know, although some are suggesting a 500-kilometer-wide crater in India might be a remnant of it.

You Are There…When Two Galaxies Collide and a Million Stars are Born

“This new NASA Hubble Space Telescope image of the Antennae galaxies is the sharpest yet of this merging pair of galaxies,” according to Universetoday.com. “During the course of the collision, billions of stars will be formed. The brightest and most compact of these star birth regions are called super star clusters.”

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The two spiral galaxies started to interact a few hundred million years ago, making the Antennae galaxies one of the nearest and youngest examples of a pair of colliding galaxies. Nearly half of the faint objects in the Antennae image are young clusters containing tens of thousands of stars. The orange blobs to the left and right of image center are the two cores of the original galaxies and consist mainly of old stars criss-crossed by filaments of dust, which appears brown in the image. The two galaxies are dotted with brilliant blue star-forming regions surrounded by glowing hydrogen gas, appearing in the image in pink.

Just…wow.

Nothing Better than Griffith Observatory

Is there any public space in Los Angeles more wonderful than Griffith Observatory? griffith5.jpg

It is an architectural gem set against a cliff overlooking a vast expanse of Los Angeles. It is a celebration of a branch of science, astronomy, to which Southern California can stake a proud claim. In a few weeks, it will reopen after a five-year renovation project, but because our friends Todd & Robin Mason have gained the affection of both the scientific and science-history communities in this area, they were invited to a preview opening Sunday morning — and let my wife and me tag along.

The Masons are finalizing a documentary, “Journey to Palomar,” the story of George Ellery Hale’s creation of the Mt. Wilson and Palomar Telescopes that profoundly expanded humankind’s understanding of the universe, beginning with Edwin Hubble’s first observations of  the universe’s expansion, which led to the development of the Big Bang theory that is now almost universally accepted. The Mason’s documentary will be one of the films you can see at the Leonard Nimoy Event Horizon, a new theater that the “Star Trek” actor and his wife made possible.

As will the public after November 3, we met a shuttle bus on the Orange Street side of Hollywood and Highland and presented our tickets there. The Observatory will accept visitors via a registration system, but as before the renovation, admission will be free. Waiting for the bus gave us a minute to check out the old Grauman’s Chinese Theater:gloria-swansons-handprints.jpg

We arrived to hear a talk from a volunteer who was clearly excited and proud of what had been done to bring the observatory back — and asked us not to take pictures of the few still-uncompleted details. Rather than going into the front door, which is what past visitors are familiar with, we were guided down a flight of stairs on the observatory’s west side, which leads to a new exhibit area — the Gunther Depths of Space, which covers a lot of information — our solar system and what we know about each of the planets; the stars, galaxies and nebulae; and “The Big Picture,” a 152 x 20 foot image of the “cosmic wilderness” — the Virgo cluster of stars and galaxies.

Here is what the Gunther room looks like:

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And here is a detail from “The Big Picture,” which in its entirety shows you a million stars. Each lighted object on this image represents not a star, but an entire galaxy:

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Upstairs, you’ll find some of the exhibits you recall, such as Foucault’s Pendulum, and the arresting murals in the rotunda, all nicely restored and probably augmented. But for me, when I got to this floor, I was less focused on the scientific information, and more on the sheer artistry of the building, indoors and out:

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You probably remember this monument that depicts Gallileo and Copernicus and other early explorers of the heavens:

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…and the walkways around the domes, up on the roof, opening up fantastic views of the city…

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…as well as beautiful little architectural details like this:

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I am really grateful we got to see this. It felt like a pilgrimage to the L.A. of old, the city and region with a spirit of adventure and discovery–a better place and a better time than L.A. now. But Griffith Observatory is here now, so the present-day is ennobled by it.

(Photo credits: From the top, #1 and #9 are by Todd Mason; #2-8 and #10 are by yours truly. And I hope the volunteers at Griffith Observatory will note that everything shown here is ready for public consumption!)

Ball of Fire*

A big meteorite hit Norway last week — with a force equivalent to the first atomic bomb dropped on Hiroshima. From Aftenposten:

A-Meteoritt_6sek_j_410790h.jpgAt around 2:05 a.m. on Wednesday, residents of the northern part of Troms and the western areas of Finnmark could clearly see a ball of fire taking several seconds to travel across the sky.

A few minutes later an impact could be heard and geophysics and seismology research foundation NORSAR registered a powerful sound and seismic disturbances at 02:13.25 a.m. at their station in Karasjok.

Farmer Peter Bruvold was out on his farm in Lyngseidet with a camera because his mare Virika was about to foal for the first time.

"I saw a brilliant flash of light in the sky, and this became a light with a tail of smoke," Bruvold told Aftenposten.no. He photographed the object and then continued to tend to his animals when he heard an enormous crash.

"I heard the bang seven minutes later. It sounded like when you set off a solid charge of dynamite a kilometer (0.62 miles) away," Bruvold said.

Very little news about this, even on the long-tailed Internet. Sure, Troms is a remote area, north of the Arctic Circle. But: It's one planet. While a meteorite landing two-thirds of a mile from a farmer in the frozen north might seem like a faraway event, something like this could happen, and a global catastrophe would be the result.

If an asteroid crashes into the Earth, it is likely to splash down somewhere in the oceans that cover 70 percent of the planet's surface. Huge tsunami waves, spreading out from the impact site like the ripples from a rock tossed into a pond, would inundate heavily populated coastal areas. A computer simulation of an asteroid impact tsunami developed by scientists at the University of California, Santa Cruz, shows waves as high as 400 feet sweeping onto the Atlantic Coast of the United States.

The researchers based their simulation on a real asteroid known to be on course for a close encounter with Earth eight centuries from now. Steven Ward, a researcher at the Institute of Geophysics and Planetary Physics at UCSC, and Erik Asphaug, an associate professor of Earth sciences, report their findings in the June issue of the Geophysical Journal International.

March 16, 2880, is the day the asteroid known as 1950 DA, a huge rock two-thirds of a mile in diameter, is due to swing so close to Earth it could slam into the Atlantic Ocean at 38,000 miles per hour. The probability of a direct hit is pretty small, but over the long timescales of Earth's history, asteroids this size and larger have periodically hammered the planet, sometimes with calamitous effects. The so-called K/T impact, for example, ended the age of the dinosaurs 65 million years ago.

"From a geologic perspective, events like this have happened many times in the past. Asteroids the size of 1950 DA have probably struck the Earth about 600 times since the age of the dinosaurs," Ward said.

Here's a link to the simulation. Have a nice day!

*UPDATE 6-12-06: The "Hiroshima" comparison was made by an astronomer at the University of Oslo, Knut Jørgen Røed Ødegaard. However, another Norwegian scientist disputes him:

Truls Lynne Hansen of the Northern Lights Observatory (Nordlysobservatoriet) in Tromsø disputes Røed Ødegaard's description, calling it an exaggeration.

"Our atmosphere is peppered with small stones from outer space all the time," Hansen told newspaper Aftenposten. "Most burn up and disappear, but some land here."

He thinks that what hit northern Norway last week was a stone weighing around 12 kilos (about 26 pounds). "Out in space it generated enormous speed, but after entering our atmosphere its tempo eased," Hansen said. "This kind of meteorite isn't radioactive and it's not glowing when it hits the ground."

 

In the same article, Aftenposten runs a somewhat inscrutable photo of the supposed impact site:Norway meteorite impact site.jpg

Surf’s Up

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If you ponder the mysteries of the universe, check out morning’s LA Times story about LIGO – the Laser Interferometer Gravitational-Wave Observatory Caltech operates in Hanford, Washington and an identical twin managed by MIT in Livingston, Louisiana — which scientists hope will allow them to demonstrate the truth of Einstein’s theory that “large bodies moving through space would give off waves of gravity, traveling at light speed, that would shrink and expand space-time itself.”

After Einstein, our conception of the universe changed. It is not empty space, it is a fabric. Space, and everything occupied by space, can be bent and stretched by waves of gravity, which Times’ author John Johnson Jr. likens to the ripples from a spoon stirring milk, or the indentation a bowling ball would make on a trampoline.

Today, such waves exist only in theory, the product of cosmic events like supernovas or pairs of neutron stars whipping through each others’ orbit and then smashing into each other.

According to theory, if our planet came close to the source of a gravitational wave, Earth would stretch to twice its normal size, then shrink in half before returning to its original shape — a scenario worthy of a Road Runner cartoon. Have no fear, however. The waves that could reach Earth are very weak, too weak to be measured — until last November when LIGO “reached a level of sensitivity at which (Caltech physicist Kip S. Thorne) and other experts believe they might detect waves.”

Here’s how Johnson describes what’s involved for LIGO to measure gravitational waves:

Down a twisting side road, LIGO appears out of the Russian cheatgrass and mustard plants, a bulky apparition with two tubes extending at right angles into the desert.

LIGO sites.jpgThe 2.4-mile-long tentacles are the heart of LIGO. They are at right angles so that incoming gravity waves will shrink one arm while lengthening the other. An identical facility sits in a forest in southern Louisiana, so that the readings made at one observatory can be cross-checked almost 2,000 miles away.

(snip)

Inside the arms is a laser interferometer, which works by splitting a laser beam and sending one of the two resulting beams down each arm. The beams then bounce around 100 times on a set of mirrors before being sent back to a photodetector.

The two beams should recombine at exactly the same time since they travel an identical distance.

But if a gravity wave passes by, the beams will be thrown off as the arms are alternately stretched and squeezed.

Detecting such a minute signal has required extraordinary steps.
Because the site had to be as flat as possible, satellites were used to survey the land, which was eventually graded to within three-eighths of an inch over five miles.

To get around the problem of air molecules shaking the mirrors, workers sucked the air out of the tubes down to a billionth of an atmosphere. But that still wasn’t good enough to make sure the speed of light would be constant throughout the tubes. So the team had to get the tubes down to a trillionth of an atmosphere.

The surface of the four 10-inch mirrors in the arms is so smooth it doesn’t vary by more than 30-billionths of an inch. Thirty control systems keep the lasers and mirrors in alignment. The vibration isolation system is so sophisticated, the only thing approaching it is the mechanics used by semiconductor chip makers to etch circuits on the chips.

Read the whole thing.