What 100 year flood means

“And this is where you first start getting a sense that maybe engineering hydrology isn’t the most exact of sciences. …none of the Imperial units for these values agree, but if you do the math, the conversion factor is just about one, so we ignore it. We just leave it off! This is not something we take out to the fifth decimal place.”

SpaceX does it again

Another Falcon9 successfully landed on a moving barge this morning.

In order to make the economics work, these birds do a ballistic reentry, essentially falling out of the sky and making a corrective landing burn at the last possible minute. Since this Falcon was delivering a Japanese communications satellite to high orbit, the lifter fell a lot further than the last one did, ending up going twice as fast and requiring a 12-G final burn before touching down softly on the recovery vessel Of Course I Still Love You.

Congratulations to Elon Musk and the SpaceX team, who are among the many people who don’t read this blog.

Radioactivity Art

Greenpeace photographer Greg McNevin has created a beautiful series of photographs based on walking around areas formerly contaminated by the ongoing Chernobyl and Fukushima nuclear disasters with an LED stick connected to a geiger counter. It’s unfortunate that most people won’t be able to see the art past the politics, but I think it has value in both spheres.

SpaceX lands at sea

A little late with the news, but anyway the SpaceX’s Falcon-9 has successfully landed on the drone barge “Of Course I Still Love You”. The landing deck is 170 by 300 feet long, and the Falcon’s legs stand 60 feet apart. As you can see by the whitecaps, the sea was very rough with high altitude crosswinds of 50 mph and low altitude winds of 25 mph.

For true space geeks, the beautifully produced full 18 minute video:

Orbital ATK Cygnus 6 space truck

The unmanned Cygnus cargo mission OA-6 went up Saturday on a Russian/American Atlas V, successfully delivering a new 3d printer to the International Space station. The ISS crew snagged the Cygnus today with their robotic arm.

Interesting side note on this mission, before Cygnus 6 plunges to its fiery reentry doom it’s going to test artificial gecko feet and be used for a fire-in-space experiment.

$1 million Google Tiny Box prize won

Belgian contenders The Red Electrical Devils have won the $1,000,000 Google Tiny Box prize.

There’s a .pdf of the paper describing their design here, but don’t bother trying to read it if the word “schematic” means nothing to you.

Google’s challenge was for a tiny, lightweight device that converts DC (the type of electricity that batteries and solar panels put out) to AC (the type of electricity that is most useful for doing work). Such devices are called “inverters” and improvements in inverter technology would obviously be useful for electric cars, home solar power systems, and many another thing.

The winning team exceeded Google’s minimum requirements to win by three times, creating a device that is ten times smaller than existing technologies while meeting all of Google’s other restrictions (such as 95% or better efficiency, air cooling, &etc.) It’s extremely impressive work.

Mansplaining manspreading

Jason Kottke referred to this as “hilarious mansplaining about manspreading” but I thought it was interesting.

In an extremely crowded subway car or airport trolley, I’ll end up sitting with my legs at a 45 degree angle to one side and my back curled so that my chest is nearly touching my thighs, or even in a complete fetal position with my feet on the seat and my arms wrapped around my legs. The passages between seats are so narrow in American mass transit that I can’t have my legs stick straight out, because my knees will be battered into pulp by passersby with briefcases and purses, and the people on either side of me (especially if they are men) won’t have room for their shoulders if I lean back in my also-too-narrow seat.

It turns out there’s a reason for this, it’s basically because I’m shaped like most men – I have longer thighs and wider shoulders than the reedy eloi the seats were apparently designed for.

new discovery in science of blowing up stuff

Alkali metals can react explosively with ​water and it is textbook knowledge that this vigorous behaviour results from heat release, steam formation and ignition of the ​hydrogen gas that is produced. Here we suggest that the initial process enabling the alkali metal explosion in ​water is, however, of a completely different nature. High-speed camera imaging of liquid drops of a ​sodium/potassium alloy in ​water reveals submillisecond formation of metal spikes that protrude from the surface of the drop. Molecular dynamics simulations demonstrate that on immersion in ​water there is an almost immediate release of electrons from the metal surface. The system thus quickly reaches the Rayleigh instability limit, which leads to a ‘coulomb explosion’ of the alkali metal drop. Consequently, a new metal surface in contact with ​water is formed, which explains why the reaction does not become self-quenched by its products, but can rather lead to explosive behaviour.

water droplet included for comparison

Audi e-Diesel

Audi and Sunfire have invented a robot plant. With a dumb name.

The Dresden energy technology corporation sunfire is Audi’s project partner and the plant operator. It operates according to the power‑to‑liquid (PtL) principle and uses green power to produce a liquid fuel. The only raw materials needed are water and carbon dioxide. The CO2 used is currently supplied by a biogas facility. In addition, initially a portion of the CO2 needed is extracted from the ambient air by means of direct air capturing, a technology of Audi’s Zurich‑based partner Climeworks.