Tuesday, November 09, 2010
Galactic black holes, cosmic ray bubbles... and more science
First, when you see twin lobes of high energy, extending from the poles of a spinning stellar object, then it is a dead giveaway. This happens when matter that's been captured by a black hole or neutron star spirals inward, via a swirling skirt called an Accretion Disk. As this matter pulverizes, compresses and heats up, the resulting super-energized plasma gets channeled into intense magnetic fields. While some of the matter falls all the way into the singularity, some of the rest escapes via the only path available...
...straight up and out of the singularity's north and south poles. We've seen this happening in many parts of the universe, especially in light from galaxies in the wild early days of the cosmos. So what does this have to do with today's "gamma ray bubble"?
The twin lobes we observe are fat spheroids, not narrow jets. But that could have simply resulted from the jets striking matter as they speared outward from some event at the galactic center. What event? Well... clearly... the black hole down there had something to EAT, maybe 30,000 years ago!
We know all about the black hole, by the way. It was only guessed-about, just 20 years ago. Now we know its mass and location in exquisite detail, even though - because it is now quiet - it cannot be seen. Because a dozen nearby stars are whirling around a particular point in space, like mad dervishes. The BH has a mass millions of times that of our sun... because it has had millions of meals before. And, apparently, it had another, pretty recently. About the time painters were drawing mastadons on the caves of Lasceaux.
I just got off the phone with Gregory Benford, who knows the galactic center better than almost anybody on Earth, having studied it as an astronomer and written the classic "Galactic Center" series of science fiction novels. (Greg told me "you have it entirely right on all counts, David." Cool! ;-) He also said that there is plenty of other evidence, supporting the supposition that the Black Hole gobbled up something big, a few tens of thousands of years ago.
=== MORE SCIENCE! =====
A NASA spacecraft sped past a small comet Thursday, beaming pictures back to Earth that gave scientists a rare close-up view of its rocky nucleus. (Once again proving my doctoral dissertation was correct!)
Since late last month, the world supply of Viagra ads and other e-mail spam has dropped by an estimated one-fifth. But with 200 billion spam messages in circulation each day, there is still plenty to go around. Moscow police authorities said Mr. Igor Gusev, 31, a suspected spam kingpin, was a central figure in the operations of SpamIt.com, which paid spammers to promote online pharmacies, sometimes quite lewdly. SpamIt.com suddenly stopped operating on Sept. 27. With less financial incentive to send their junk mail, spammers curtailed their activity by an estimated 50 billion messages a day.
Fermilab is building a holometer (holographic interferometer) to determine if all reality is really an illusion – that the universe is really two dimensional, and the third dimension is an illusion. “The universe-as-hologram theory is predicated on the idea that spacetime is not perfectly smooth, but becomes discrete and pixelated as you zoom in further and further, like a low-res digital image.”
A water dance: a mesmerizing slow motion video of water droplets bouncing off an array of hydrophobic (water-repelling) carbon nanotubes. Watch the climax as two drops collide and merge.
For a bit of humor: an ordinary day obeying the laws of physics, like it or not
From memristors to artificial cells to the semantic web. Fifty ideas to change science forever: Cast your vote for which will most profoundly affect our future:
It’s not quite Star Wars, but science fiction is changing the modern battlefield: with the advent of spy saucers, big dogs, stealth ships, nuke proof tanks, airborne lighsaber, and a flying humvee.
A global gender gap: how do countries worldwide compare in empowering women? Based on data on wages, literacy, leadership and health, Yemen scores at the bottom, Norway at the top. Overall, gaps in health and education have narrowed more quickly than those in leadership & economic power.
A mathematician weighs in on the contrasts between stories and statistics. Stories tend to focus on atypical individuals, peculiar circumstances, random occurrences… and the occasional improbable coincidence (or even a deux ex machina). And yet the author tries to populate stories with realistic details and true-to-life characters – to help the reader suspend disbelief.
Twenty fictional librarians who save the world.
A few ‘forgotten’ classics of science fiction. The list includes some of my favorites... and some lost classics of science fiction that I never read, or never even heard of. I have a few lost classics of my own, such as THE AGE OF THE PUSSYFOOT, by Frederik Pohl, which contains the only pre-1980 futuristic portrayal of citizens carrying around (very) smart computer phones in their pockets. Others would include Poul Anderson's BRAIN WAVE, and John Boyd's THE LAST STARSHIP FROM EARTH.
=== AND NOW EVEN MORE SCIENCE ===
From The Economist: a report on smart systems: “What if there were two worlds, the real one and its digital reflection? The real one is strewn with sensors, picking up everything from movement to smell. The digital one, an edifice built of software, takes in all that information and automatically acts on it. If a door opens in the real world, so does its virtual equivalent…..The real and digital worlds are converging, thanks to a proliferation of connected sensors and cameras, ubiquitous wireless networks, communications standards and the activities of humans themselves.”
Project M may put Avatars on the Moon: A rogue group of NASA engineers proposes landing a humanoid robot on the moon in 1000 days – for a fraction of a manned mission cost. The bot - controlled by scientists on earth using telepresence suits - may be a version of Robonaut2 set for launch to the ISS. No life support or return trip necessary. Two legs may not be the best design -- lower to the ground may be more stable
Ten strange and mind-boggling things about the universe: Negative energy, frame dragging, relativity of simultaneity, black strings, geon, Kerr black hole, quantum tunneling, cosmic strings, antimatter retrocausality….
Eight ways in which the human condition is improving: World GDP per capita is increasing, the number of people in extreme poverty is decreasing; life expectancy is steadily increasing; infant mortality is declining….
Five misconceptions about the CERN Large Hadron Collider.
=== AND FINALLY ===
The $1.1 million “Hundred Year Starship” project is a yearlong study for a multigenerational mission which is yet to be named … and for which humans might need to be re-engineered. Pete Worden, director of NASA’s Ames Research Center, created a stir last month at a conference sponsored by the Long Now Foundation when he mentioned that the space agency was kicking in an extra $100,000 to the project, sponsored by the Pentagon’s Defense Advanced Research Projects Agency.
Why a newfound love of of science fiction might help Africa to transform itself.
...and this vital reminder...
"I believe in humanity. We are an incredible species. We're still just a child creature, we're still being nasty to each other. And all children go through those phases. We're growing up, we're moving into adolescence now. When we grow up – man, we're going to be something!"
- Gene Roddenberry, Hollywood Blvd. "Star" ceremony acceptance speech, 9/4/85