Monday, January 31, 2011
Tigers Tigers Everywhere
On December 26, 2004 there was a magnitude 9.3 earthquake in the Indian Ocean, off the coast of Sumatra. It caused a powerful tsunami that devastated the coastal regions of several countries and killed 240,000 people. News of the tsunami's destructive powers quickly made the rounds in the news media. We watched in horror and dismay the extent of the devastation. The earthquake registered 9.3, stronger than the one in Maule, Chili in February 2010, which was registered at 8.8. The 8.8 Chili quake was so strong that it shifted the Earth's crust, redistributing mass on such a scale that, according to NASA, it caused a shift in the Earth’s axis! The shift has been estimated at 8 centimeters, which affected the rate of the Earth's rotation and shortened the length of our day by some 1.26 microseconds.
As tremendous as the Chili quake was, the 2004 quake was stronger. But far stranger and much less reported—forty-four hours after the quake, NASA's newly launched Swift satellite, the Very Large Array, and other observatories picked up the arrival of a powerful gamma ray burst. A hundred times stronger than any gamma burst previously recorded, this one was as bright as a full moon, but radiated most of its energy in gamma wavelengths. This gamma burst temporarily altered the shape of our ionosphere and distorted radio transmissions. We tracked this gamma burst to activity in the neutron star SGR 1806-20, a soft gamma ray repeater, in the constellation Sagittarius, approximately 10 degrees northeast of the Galactic Center or about 45,000 light years from us.
Less than forty-eight hours after the biggest earthquake in twenty five years, a very intense gamma ray burst hit our planet! This gamma burst was 100 times brighter than anything we had seen in the twenty-five year history of gamma ray observation. Were these two highly unusual events related? We don't know how or why they would be, though it has been postulated that gravitational waves might have been a factor that set the earthquake into motion. Perhaps the gamma rays, that we monitored, were slowed down by scattering off dust particles, cosmic rays and such, making them proportionately slower than unimpeded gravitational waves that they might have been traveling with. Or perhaps the gravitational waves were going at superluminal speed—also a possibility—hitting the earth and setting off the quake and tsunami before the gamma rays could catch up. At this point who knows?
Regardless whether the two events were related or it was just an astronomical coincidence, both events triggered alarmists theories and thoughts of the end of the world. The familiar cries is God punishing us? and the Earth is upset and trying to kill us! was heard again and again. Unfortunately science and the media did not take the opportunity to explain and educate the masses on what just had happened. Nothing was said that would explain to them that plate tectonics are necessary for the continuance of life on our planet, and that the same forces that made that neutron star behave like that made us, and if those forces didn't exist and continue to function, we wouldn't be here at all.
Scientists have discovered about a dozen magnetic neutron stars, which they like to call magnetars. The magnetic field around magnetars is about 1,000 trillion gauss, strong enough to strip information from a credit card at a distance halfway to the moon or 192,000 km. Ordinary neutron stars measure just a trillion gauss; to give you an idea the sun has around 1 gauss and the magnetic field around the Earth around 0.5 gauss. Yet the diameter of SGR 1806-20 is not more than 20 kilometers, that's how dense it is!
There are a few magnetars which are called soft gamma repeaters, because they flare up randomly. Each event emits about 10^30 to 10^35 watts for about a second. For a tenth of a second, the flare on SGR 1806-20 unleashed energy at a rate of about 10^40 watts. This is more than the total energy produced by the Sun in 150,000 years! Had this happened within a dozen light years from here, it would have fried us. Fortunately, however, all the magnetars, that we know of, are much farther away than that.
Interesting stuff, yet the way science is taught us is often dry and uninteresting, and too much out of date. For example, schools often teach Newton's ideas of gravity and ignore Einstein altogether, so most of us don't have a clue—then to add insult to injury, science is propagated on television and the Internet with an alarmist air. The media is continuously feeding us stories that the sky is falling or is soon about to. Watching science channels, I have lost count how many times I've seen a show depicting how the Earth will end, never failing to warn me that it isn't if it will happen but when. First there was Frankenstein, the War Of The Worlds, Klaatu's dire warnings; in the cinema and on television, even on the radio we learn that the end is near, remember In The Year 2525? When we grow tired of the admonitions, or too numb to listen anymore, the old stories are replaced with new ones: disintegration by antimatter, microscopic black holes, the shutting down of the Earth's magnetic sphere, planetary pole reverse, super volcanoes, gigantic comets and asteroids, et cetera. Unfortunately, a significant part of the scientific community is complacent about propagating science in this way, it's good for funding. But this thinking is self-defeating, it works for awhile, but in the end it just turns people off.
I heard an old Buddhist koan told to me by one of the more eccentric professors when I was in university, which I never forgot. It goes something like this. A monk was walking through a dense forest when he noticed a hungry tiger stalking him. He hurried along but inadvertently fell off a cliff. Luckily the monk caught hold of a branch temporarily staving off what would have been a disastrous fall. Hanging by the branch he looked up to see the tiger peering down at him licking its chops. He looked down, to his surprise, another tiger was at the bottom of the cliff looking up at him, also licking its chops. Under his weight the branch started to give way and break. Just then the monk saw a wild strawberry growing in the crevice of a rock next to him. The monk picked the strawberry and popped it in his mouth, and that strawberry was the sweetest tasting strawberry he ever had. Pause, think, reflect...
In the month of December 2004, two tigers were at our door. One proved deadly enough and caused us a lot of grief, yet had the other tiger (SGR 1806-20) been closer to us, it could have been way more destructive. That's not the point. The point is is that the universe in 2004 had two tigers who were fascinating animals. They had—and still have a lot—to teach us. Both events were part of the ongoing story of the evolution of our galaxy; both events were bodies dealing with their own mass and conserving energy—one a star the other a planet. Perhaps we ought to start looking at the universe with more stoicism and curiosity. I'm not suggesting that we ignore the threats, nor to not take action when action is warranted, but we ought not worry so much, there are tigers out there, there are lions, and bears too; some may want to have us for dinner. But that's the beauty of it, isn't it? That most of the universe is 99.9999% not friendly to us, but all of it together as a coherent, harmonious system seems to be; as the anthropic theorists have stated, the cosmos seem to have been created to be perfect for human life. Or at least perfect enough to make it interesting.
Posted by Wayne Ferrier at 12:05 AM | Permalink