Here is a nice photo taken from below of a Liquid Robotics Wave Glider. We have about 100 of these self swimming robots already roaming the ocean, including 4 that just recently swam themselves from San Francisco to Hawaii on their way across the Pacific Ocean. Here’s a nice article describing what we are doing with these robots.
A few weeks ago it was announced that most stars have orbiting planets, and that there are likely more than 100 billion habitable planets in our galaxy. So life at least has the opportunity to be commonplace in our galaxy. But this brings up a nagging question (first posed by Enrico Fermi): why don’t we see any signs of other advanced civilizations in our galaxy? It is not for lack of looking. The Search for Extraterrestrial Intelligence (SETI) project has for over 25 years been actively searching for radio and other signals that would presumably be emitted by intelligent civilizations. There has to date been no such sign.
One possibility of course is that life itself is rare. Maybe the Earth is just a special place, and life doesn’t even exist on other planets. This runs counter to the Copernican revolution, which over the centuries has demoted the Earth from being the center of the universe to being an average planet orbiting an average star on the outskirts of an average galaxy. If there are a multitude of places where life can thrive, why should life only have arisen on Earth?
Some have speculated that life is commonplace, but that advanced civilizations do not survive long because they also develop advanced weapons and they kill themselves off in great wars. But there is another possibility. Perhaps some natural process prevents civilizations from surviving long enough to be able to broadcast their presence. Instead of civilizations knocking themselves out, maybe they simply lack the foresight to protect themselves from natural disasters.
It turns out that there is actually good reason to suspect this is the case. The majority of these recently discovered planets orbit their respective stars as part of multi-planet systems, almost certainly along with leftover material that did not manage to coalesce into planets. This debris, otherwise known as asteroids, will on occasion collide with the planets at great speed, just as it does here in our own solar system.
If a large enough asteroid hits a planet, nearly all life on that planet can be exterminated, just as happened when a 10km asteroid struck the Earth wiping out the dinosaurs. But an asteroid does not need to be nearly that big to collapse a technically advanced civilization. One paradox is that as societies become more advanced, they become more interdependent and in many ways more fragile. Witness the worldwide economic and societal impacts of the recent Japan earthquake and of Hurricane Katrina in 2005 (both of which were relatively small events in the grand scheme of things). On Earth, the impact of only a 1km asteroid is generally considered large enough to end human civilization. That is because in addition to the direct devastation, it would throw up enough dust into the upper atmosphere to end growing seasons worldwide for a few years. Given we only have a few months of food stockpiled worldwide, this clearly bodes badly for civilization as we know it. After an impact like this, civilization would likely need to start over. Impacts of 1km asteroids happen on Earth about once per million years. Smaller impacts are even more frequent, and the global consequences are even harder to predict. I would submit though that allowing even a 500 meter asteroid to hit the Earth, i.e. one we don’t believe to be large enough to end civilization, is not an experiment we want to conduct.
That means that between large asteroid impacts, there is a race of sorts. Any civilization on any planet in our galaxy must develop the technology to prevent asteroid impacts and/or the ability to withstand them, or the civilization on that planet will be eventually be reset to a more primitive state. We could consider this a test. If a civilization advances fast enough, and has the foresight to confront this problem, it may ensure its long term survival. If not, the consequences of orbital mechanics may wipe it out. Perhaps this is why we don’t see any signs of other advanced civilizations. This is also a warning to us. Human civilization is only a few tens of thousands of years old, and the clock is ticking. Will we pass the test? www.b612foundation.org
The real NCAA tournament is taking place right now in St. Louis (not that silly basketball stuff). That’s right, the NCAA Division 1 Wrestling Tournament is going on, and after the semi-finals, Cornell University is in 2nd place with 3 guys in the finals!
Go Big Red!
I spent the other afternoon flying around the skies chasing and trying to shoot down my friends. I’ve been learning the ins and outs (and ups and downs) of how to fly aerial combat in a Russian built Yak-52 aircraft. The Yak-52 is a 9-cylinder 360HP radial engine aircraft mostly used for military and aerobatic training. It is a great airplane (tough like Russian Bear!).
This dogfighting video was taken (on a different day) by my friend Freezer. I’m still learning, and I’ve noticed how much more he makes use of the 3rd dimension, i.e. going vertically (up or down). I still fly a bit like Khan in the old Star Trek movie “Wrath of Khan” where his weakness like mine is that he doesn’t think 3-dimensionally. The other day I was often in the situation where I needed to increase the turn rate of the aircraft (i.e. needing to pull back on the stick harder to come around behind the other aircraft) but couldn’t because I was running out of airspeed. Freezer was trying to coach me to bank the aircraft more to bring the nose downwards and using gravity to increase my airspeed thus allowing me to keep the airplane above stall speed while still increasing my pull on the stick (and my resultant turn rate). Then once I’d caught up to the other aircraft in the turn I can climb back upwards to pull in behind them and shoot them down.
How better to spend a Sunday afternoon?
I gave a talk today at Sandia Labs about the B612 Foundation. One of the things we discussed was asteroid 2011 AG5, which has a 1 in 600 chance of hitting Earth on February 5, 2040 at around 4AM GMT. If it hits, it will have an explosive energy of about 100 Megatons, which is about double the largest nuclear weapon ever tested, or equivalently about 7000 times larger than the Hiroshima bomb. There is currently some controversy over whether or not we should do some detailed analysis to figure out when our last chance to divert this asteroid is, should future observations not be able to rule out an impact. We won’t be able to see the asteroid again for about another year and a half, so rather than sit around doing nothing, why not do some preparation work? I can’t imagine why we wouldn’t do some more detailed engineering analysis work now (it’s cheap) just to get ahead of things in the tiny chance it does turn out to be on a collision course. We don’t need to build anything to divert the asteroid yet (that would be expensive), but why not hedge our bets and do some advance planning now? It is of course overwhelmingly likely that this asteroid will NOT strike the Earth, but my feeling is we should be prepared if it will.
Asteroid AG5 is not a cause for alarm, but rather a wake up call.
I asked the crowd the question, if we had a 100 megaton nuclear weapon that had a 1 in 600 chance of accidentally exploding in 2040, would we take measures now to make sure that didn’t happen? Of course we would.
How is the situation with AG5 any different?
These recent videos of the Earth viewed from the International Space Station bring back great memories. When I flew aboard the ISS in 2003, we didn’t have the low light cameras used to make these videos, so seeing these now is a real treat. One of my favorite time-off things to do on the dark side of the Earth was to turn off all the lights in the Docking Compartment, let my eyes dark adapt, and just enjoy the view!
Did you know your odds of being killed in a car accident tomorrow are the same as the Earth suffering an asteroid impact tomorrow of greater than 100 Megatons? 100 Megatons is many times larger than all the bombs used in WWII. But while your death in a car accident would be a tragedy, the difference with an asteroid impact is that we are all riding in the same car!
By the way, the statistic mentioned above is not in dispute. It comes from a combination of counting craters on the moon, directly counting meteors in the sky, and using our limited telescopes on Earth to search small regions of the sky for asteroids. Take a look at the chart below (from the National Research Council Report Defending Planet Earth). 100 Megatons by the way is nothing close to the scale of something that would wipe out all life on Earth. In fact it may even result in quite limited damage if it hits in a suitably desolate spot (like northern Canada or Siberia). Of course if it hits the wrong spot, things could be pretty bad. Is this a risk we want to take?
Do you wear a seatbelt? Do you have an airbag in your car? Why aren’t we taking the same precautions with
our own planet? We should be searching the skies, finding and mapping all asteroids that could hit the Earth so
we can deflect them as needed. There are a number of ways to deflect asteroids that we are confident would work (a subject for a later post). The harder thing may actually be getting people to take the problem seriously enough to spend the relatively small amount of money needed to find and track asteroids ahead of time so we have advance notice of a threat. Take a look at what we are doing about the problem at the B612 Foundation.
The amazing thing is that we as a species have developed the tools to slightly change the evolution of our solar system, and to prevent our planet from being hit by asteroids. Now if we only had the wisdom to deploy these tools. Drive safely!
I gave a talk yesterday at Google about protecting humanity. We had a good discussion about
the best way to fund projects that are trying to ensure the long term survival of humanity.
Corporations are in general bad at funding projects with benefits that are potentially
off in the distant future. And governments are bad at funding such projects too when there
isn’t a concrete threat (i.e. with known time/place etc) and there isn’t
a natural constituency that directly benefits from the program.
For example, I made the argument that work such as what we are doing at the B612 Foundation (www.b612foundation.org) may actually be amongst the most important works on Earth, but does not have any government or corporate support.
Nine years ago today, the Space Shuttle Columbia disintegrated on reentry, killing seven close friends. One of the astronauts aboard Columbia was Ilan Ramon. In the months leading up to the final flight of Columbia, I had been holding a running discussion with Ilan about how we should get our families together for dinner. But life was busy. His flight was upcoming, and I was training for an upcoming Space Station mission. With my travel schedule and his, we always found an excuse to put off our family dinner. A few weeks before his flight we ran into each other in the hallway of the astronaut office, and we swore we would have our long awaited dinner right after his flight. Obviously that never happened, and one my true regrets is that we never got to enjoy that time together because life got in the way. If there is one thing I’ve learned, it is that Tomorrow isn’t certain. Don’t put thngs off!
Every year on the last week in January, NASA remembers our fallen comrades from Apollo 1, Challenger, and Columbia. This is video taken of the T-38 missing man formation over Johnson Space Center. RIP Rick, Willie, Kalpana, Dave, Mike, Laurel, and Ilan.