Between 2 and 3 years ago, I did a series of posts describing a science–fiction setting of my own invention. I was exploring different ways one might resolve the Fermi Paradox. For those unaware, the Fermi Paradox goes like this: We observe many places in the universe where technological life could appear and persist; but we have no evidence of alien visitors to Earth. Where is everybody?
The default solution to this paradox is to have technological life be rare in the universe. Other possible solutions include civilizations encountering various problems; barriers that prevent them from traveling or sending robotic emissaries across interstellar distances. So I call the setting “Fermi Problems” (geeky reference is geeky).
One situation I considered was life on a gas giant; specifically a hypothetical superjovian planet around HIP 66461, a G-type star 150 parsecs from the Sun. Since HIP 66461 is in the section of sky allocated to the constellation Ursa Major, I called these hypothetical aliens the ursians and the planet Ursa. I had thought that Ursa was a deep enough gravitational well that the ursians could never escape without outside intervention. I may have been wrong.
So, How Do You Escape From A Gas Giant?
To go into orbit around a gas giant with 2.8 times the mass of Jupiter, you have to acquire a speed of at least ~50 km/s. Escape velocity is twice the minimum orbital speed – i.e. ~100 km/s. That is very fast.
The Aeronaut’s Windlass is a new book from Jim Butcher (the author behind The Dresden Files) and it is nifty.
It’s also the first book in a planned nine-book series (called The Cinder Spires). My plan is to buckle in for a wild ride.
Also: not too many spoilers here, so go right on ahead.
So, I saw Mad Max: Fury Road recently. The story was pretty good, for the most part.
Naturally, I have some commentary.
And, you know… spoilers.
Why Is Mad Max In This Movie?
Thinking about the movie afterwards, Mad Max was entirely unnecessary. All the action sequences could be tweaked to not need the strange outsider. He’s peripheral, almost secondary. Furiosa is the real driving force behind the film. (Pun intended.)
Nonetheless, I think Max does serve an important role. As a drifter, he comes into town unfamiliar with the local politics, and serves in some sense as a stand-in for the audience. He asks the questions we’d want to know the answer to if we were there.
At least we’re not doing a Sharknado.
However, the tornado system that Furiosa and company drive through is intense. Multiple funnels extend from the clouds, colored by the ubiquitous dust, and the entire scene is lit by repeated flashes of lightning.
This sort of super-storm can happen, but it is unusual. (And terrifying. There’s also a weather phenomenon known as a haboob, which is basically a huge dust storm, and while these do occur in central Australia, they don’t involve the characteristic funnel of a tornado.)
The most intriguing bit is the part where Furiosa, driving a big rig, forces one of the smaller vehicles attacking her into the edge of one of the tornadoes, which then sucks it up while leaving the big truck safely on the ground.
Could that happen?
Checking out the Wikipedia page about tornadoes, it looks like a typical tornado is hundreds of meters across. That’s a lot bigger than the cloud Furiosa took advantage of; further, the most serious, big, scary, and dangerous tend to be wider “wedge” tornadoes, which can be up to a mile wide.
Nonetheless, it does say some strong-but-dissipating tornadoes can be sufficiently narrow.
But, can it still be strong enough to lift a car? According to the tornado intensity scales, it requires at least an F4, or EF4, “violent” “intense” tornado to pick up vehicles. Tornadoes are typically rating according to damage rather than wind speed, since the latter is difficult to actually measure in person for some reason; but it looks like wind speeds above 166 mph (or above about 74 m/s) are needed for a tornado of at least this strength, according to the Enhanced Fujita scale.
This leads up to the critical question: Can the high wind speeds for picking up one vehicle drop off fast enough for Furiosa’s rig to be safe while she pushes the other car in?
Even an EF2 tornado (with winds of 111-135 mph) can lift cars off the ground. Furiosa’s truck never leaves it during this escapade. The fact that it’s a big rig doesn’t necessary help: it’s the ratio of area to mass that’s really important, and the long, narrow tanker has quite a bit of area. It all depends on how heavily loaded she is. We know that Furiosa has a tanker full of water and other things, that helps.
Regardless, this implies that the winds of the tornado must drop from over 166 mph to under 111 mph over the span of perhaps 10 feet. That seems like a very fast drop over a very short distance to me; unfortunately, doing fluid dynamics to check this is tricky. However, there are reports of tornado damage with fairly sharp boundaries. You’ve probably heard the same stories about houses demolished next to houses that are essentially fine.
So, I’m going to put this down as maybe, but more plausible since that tank is full.
This book was fun. Or, rather, books; a colleague from work loaned me the whole triology in one volume (thanks, Unmesh!). Although there are many books in this series by Glen Cook, the trilogy includes The Black Company, Shadows Linger, and The White Rose.
The books follow the exploits of the eponymous Black Company, a group of highly skilled (and highly amoral) mercenaries.
As you might expect, the books have quite a bit of black and gray morality. It gets dark and gruesome. And, I’m going to spoil parts of the ending of the trilogy so… you know. You have been warned.
Inspired by reading The Three Body Problem recently, I decided to spend a few words on the central problem of that novel.
Specifically, the phenomenon of the alien invasion.
TVTropes as a nice do-it-yourself guide on the topic, but I’d like to confront one aspect that is rarely adequately addressed: