Here’s the blog for you. It’s a good guide for IDing creepy crawlies.
[Update a few minutes later]
Not related, and yet it sort of is. How did pterosaurs get into the air?
Category Archives: Science And Society
In The Eye Of The Beholder
The science of attractive faces.
A Critical Space Technology Issue
Would entry heating from orbit pop a kernel of popcorn?
I don’t really have time to think about it much right now, but the answer is (as is often the case), it depends…
Man Bites Dog
Here are two stories that are kind remarkable, in terms of their locale. First, the Huffpo, of all places, says that Al Gore is a scam artist:
You are probably wondering whether President-elect Obama owes the world an apology for his actions regarding global warming. The answer is, not yet. There is one person, however, who does. You have probably guessed his name: Al Gore.
Mr. Gore has stated, regarding climate change, that “the science is in.” Well, he is absolutely right about that, except for one tiny thing. It is the biggest whopper ever sold to the public in the history of humankind.
Contemplate it for a moment, even go read it in whole, before considering the second, a protest of thousands of people supporting Israel…in Paris.
Unfortunately, it was still smaller than the pro-terrorist crowds.
Free Fall
As Clark notes, here is a very nicely written piece on parabolic flight and weightlessness. Rare is the reporter (even science reporters) who get the physics right on this, because (as he points out) they get confused by the phrase “zero gravity,” which doesn’t really exist anywhere in the universe. Only one quibble:
Each period of ‘weightlessness’ is limited to half a minute or so; otherwise we ‘zeronauts’ would continue freefalling right into the Nevada desert at 600mph. As it is, during half-a-minute’s power- dive we drop nearly 20,000ft – although inside the plane we are completely unaware of this.
This gives the impression that weightlessness only occurs when you “drop” (i.e., descend in altitude). But it actually happens on the way up as well. In both cases, you are “falling” (in the sense that there is no force acting on you other than gravity). First you fall up, then hit the top of the trajectory, then fall down, weightless all the while, and unable to discern your direction of motion. If this seems counterintuitive, it is. But consider an elliptical orbit. As you approach perigee you’re heading down (toward the earth), and once you reach it, you start heading back up (away from the earth) to apogee, but you’re in orbit, and free fall the entire orbit. A parabola in an aircraft is an orbit that, if continued, would intersect the earth’s surface (which is why it is wise to not continue it). And of course, to be more technical yet, it is only parabolic in an approximate sense (assuming flat earth). In reality, it is a tiny section of an ellipse, because the contents of the aircraft are (briefly) in orbit, within the atmosphere.
I should also note that the phrase “power dive” is also misleading. “Power dive” implies that you are diving with engines at full thrust to get down as fast as possible, but in fact, the engines are barely running above idle throughout (until the pullout). Their only function is to overcome wind resistance so that the aircraft can approximate a cannon ball falling in vacuum.
Twelve Elegant Examples
…of evolution.
Death From The Heavens
Was there a major meteoritic strike 13,000 years ago in North America?
That wasn’t very long ago (compared to, say, the sixty-five million years ago that the Yucatan was hit). Evidence continues to accumulate that we get hit a lot more than people have previously imagined. We really need to develop the capability to do something about it. We have technology in hand to do so, but apparently lack the will to deploy it. This by itself is reason enough to make the investment to become a real spacefaring civilization, but pork and maintaining existing jobs remain more important.
Smarter Now?
John Tierney wonders if Dr. Holdren learned anything from his misguided bet with Julian Simon:
Dr. Simon’s victory was not (as some Lab readers suggested) a fluke based on exceptionally lucky timing, as you can see from this Wikipedia graph showing the inflation-adjusted prices for the five metals in the bet from 1950 to 2002. (Since 2002, metal prices rose sharply for several years but have since plummeted back to familiar levels.) Prices do sometimes shoot up for natural resources, but people react by finding new sources and substitutes, and prices come back down. If you look back over the past several centuries, as Dr. Simon demonstrated in his book, “The Ultimate Resource,” you’ll see that the trend was downward long before 1950, too.
What lessons Dr. Holdren learn from that bet? The only one I’m aware of is: Don’t test your theories by betting on them. After Dr. Simon collected his winnings in 1990, he offered to make another bet not just on natural resources but also on any measure of human welfare, like life expectancy or food per capita. Once again, Dr. Simon predicted that humans would adapt to new problems (like global warming) and end up better off in the future — by any measure at any future date that Dr. Holdren or Dr. Ehrlich cared to name. They refused his offer. They did, however, go on making more gloomy predictions and calculations about the problems of sustainability, as in this 1995 essay discussing how to avert future shortages of resources.
I find this particular appointment disquieting. As one of my commenters said earlier, I’d much prefer a “science advisor” who sees technology as a solution, rather than a problem. And, again, I have no idea what the implications of this pick are for space policy.
Doing The Right Thing Wrong
Mike Thomas has a misguided rant over at the Orlando Sentinel, bashing NASA and its supposed desire to go to Mars (something that is hard for me to discern, based on what it’s actually doing).
There are, broadly, two classes of NASA critics: those who think that it’s doing the wrong thing, and those who think that it’s doing the thing wrong. I fall into the latter camp, but Mr. Thomas is clearly one of the former. But his position seems to be incoherent. He thinks that NASA is supposed to be doing science (as indicated by his final words), and if so, he’s correct that manned spaceflight, as currently performed, contributes very little to it. But he doesn’t seem to think that it should be engaged in space science. He (like too many) thinks that NASA’s job is to heal the planet. My biggest fear of an Obama administration (at least in terms of space policy) is that they will agree, and divert it from its original role as an agency that looks outward, to one that looks instead inward.
Whether one believes that we should be doing more about climate change or not, Mike Griffin is correct that it is not within NASA’s charter to do the heavy (or even any) lifting in that regard. It was a heartburn that I always had with things like the Ride Report, and “Mission To Planet Earth.” If these are important things to do, then set up an agency to do them, but don’t defocus and distract NASA with them. In fact, it is much more a job for NOAA. The problem is that NOAA has no history of developing satellites, and has traditionally relied on NASA to do it for them. Perhaps that ought to change.
If NASA improperly gets assigned the task of healing the planet, it is inevitable that it will make it even harder for it to properly explore and develop space, which is what it was established to do. Now frankly, given how wrongly NASA has been doing the right thing, I’m not sure that it would be all that much of a tragedy if we were to end its manned spaceflight program. But unlike Mr. Thomas, I’d rather see it starting to do it right.
Better Climate Control
Through nanotech. J. Storrs Hall (aka JoSH) has some ideas. I have a problem with this one, though:
So you have this balloon and it floats up there twenty miles. They all have a little GPS and receiver so they can turn themselves. That’s all there is to it. What can you do with a machine like this? The machine is essentially a programmable greenhouse gas. If you set the mirrors facing the sun, it reflects all the sunlight back. If you set them sideways, it allows the sunlight to come through, and similarly for the longwave radiation coming from the back side of the earth at night.
He seems to be implying that GPS can be used to determine attitude. It can’t. It only provides velocity and position. Now it may want to know that information for other purposes, but there will have to be some other means of attitude knowledge. It seems to me the simplest way would be to just measure the sunlight hitting the mirror (which would actually be a solar cell). As you adjust your attitude, the power available will grow or shrink, and it can use the rate to control the angle. As for how to physically control the attitude, I would guess that little reaction wheels would do the job.
Of course, many of the warm mongers hate technical solutions like this, because they don’t require us to piously tighten up our hair shirts, and they don’t allow for sufficient control of the global economy.