Posts by Semianonymous Megacoward

About that crater erasure

Not only erosion and volcanism can obscure craters; consider the dino-killing Chicxulub impact crater, buried under sedimentary rock. Also, most asteroid strikes on Earth will occur in oceans, and the ocean floor is vigorously recycled into the mantle via subduction. The average age of the ocean floor is only about one sixth the age of the Cryogenian, and none of the ocean floor is as old as old as the impacts discussed in this article. So evidence of bombardment from 800 million years ago would likely be indirect, such as layers of shocked quartz in sedimentary rock.

Incidentally, the current interpretation of Martian history has the red planet dry, frozen and (relatively) airless before the impacts described here ( https://en.wikipedia.org/wiki/Geological_history_of_Mars ). Researchers from Elon Musk's Mars colonists might look for a spike in crater ages around 800 million years ago.

The money is spent on Earth

Amazon's difficult working environment is well-known. Is the same true of Blue Origin?

The money is being spent on this planet and is buying groceries and making house payments for the engineers, machinists, managers, and others employed at Blue Origin. Are they being pushed as hard as Amazon employees? If they are, then how the money is distributed between companies is a bit of a wash. If they're not, then there's an even stronger argument for the editorial's thesis.

Minor Correction

"Kubrick's masterpiece followed closely in the wake of Gene Roddenberry's Star Trek on US TV network CBS in 1966."

Star Trek is currently owned by CBS but was first broadcast by NBC. See

https://en.wikipedia.org/wiki/Star_Trek:_The_Original_Series

Pedantic point

Launch windows to Mars occur roughly every 26 months, not every 18 as implied by the article. A window opens not when Earth and Mars are closest, but when the target planet will be located at the far end of the spacecraft's most efficient transfer orbit.

e.g., https://www.nasa.gov/centers/kennedy/launchingrockets/launchwindows.html

Chris Rea's Texas

Great song. First heard it in Glasgow before being posted to Texas -- 26 years ago.

https://www.youtube.com/watch?v=GMk208Op1Jc

https://en.wikipedia.org/wiki/Chris_Rea

Regarding driving in Texas, robo-cars can't be worse than those piloted by the meat sacks in the state.

Everybody has an opinion

Here's a perspective from someone who worked in scientific/engineering (not IT) positions in industry. Oddly enough, I was introduced to Macs by BP, which originally used them for user desktops before Windows PCs. We used assorted mainframes and DEC machines for scientific and engineering work, and the minicomputers were replaced by Unix workstations around 1990. Unix had a steep learning curve, but it was also very stable compared to Windows back then. For business applications, PCs replaced the Macs, and after a few more years Linux boxes replaced the Unix workstations for technical work. Both changes were cost-driven: PCs were cheaper than Macs, and Linux machines were cheaper than Unix machines.

Folks working in big companies often have little choice of the hardware and operating system they're made to use, but scientists in academia may have more freedom to choose. Old-time scientific types invested in Unix had two choices when migrating off proprietary (Sun, IBM, H-P, etc.) Unix workstations: Linux or Mac OS X. The Apple logos seen at JPL and the like reflect the choice of Mac OS X. They got to keep the Unix environment they were already familiar with, plus get Microsoft Office and a consistent GUI. IT types may have been more likely to choose Linux, but scientists were less likely to do so because they didn't want to get involved with configuring and tweaking their computers.

I suspect that zealotry often results from defensiveness; folks who are heavily invested in a particular way of doing things will defend their turf loudly when they feel threatened, especially when they're in the minority. It's just human nature.

It's elementary

Picking nits here: the material is carbonaceous -- carbon-rich -- and probably not carboniferous, the word used in the article. Carboniferous means "coal-bearing" and was a geologic time period ending about 300 million years ago, much younger than cometary material. Coal-bearing comets would be pretty cool, but the only fossils I've seen in comets or meteorites to date have been in science fiction stories.

Carbonaceous chondrites are a carbon-rich class of meteorites, some of which contain inclusions predating our solar system. Carbonaceous chondrites presumably derive from C-type asteroids.