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Comment Not a bad guess (Score 1) 163

Human population has expanded tremendously in the last part of those 800,000 years, and all of us consume oxygen. It probably can't explain the first 700,000 years, though, since total global hominid population was probably fairly constant, with one species supplanting another.
But what about methane? We know it leaks from places like hydrate ices underwater, especially when there is an earthquake and landslide, and of course since it exists underground as natural gas, we know it can leak from there, too, if an earthquake happens to rupture the ground enough. Methane is a light gas that will rise toward the stratosphere, and likely react in the ozone layer. I'm talking about a long term slow thing, not fast enough to deplete ozone as fast as solar ultraviolet makes more from atmospheric oxygen. But the reaction produces water and CO2, and takes oxygen out of the air.

Comment Re:The New Invasive Species (Score 1, Insightful) 231

Regardless of what Captain Kirk might do, it is silly to think that potentially habitable planets are not already microbial hosting life-forms. All the data about early life on Earth indicates we got it almost as soon as the planetary crust cooled enough for life to be possible. It seems more likely that life arrived from elsewhere (panspermia) than thinking it evolved here --not enough time to evolve. Plus, we have data indicating that life may have existed even before the Earth existed. Therefore we should expect every planet that can possibly support life to already have it.

Comment Two more problems with Venus (Score -1) 211

On Earth it appears that the oceans put enough water into the crust as to make plate tectonics possible (the water lubricates fault lines. If Venus ever had plate tectonics, it probably stopped when the water evaporated. And then there is the fact that Venus is tide-locked between the Sun and Earth (always has the save face toward Earth when the two planets are closest together). Earth's magnetic field exists partly because of its rotation, and that magnetic field helps protect its atmosphere. Venus hasn't got the necessary rotation rate.
I once speculated about a way to make Venus habitable. Like many good tricks, it can mostly be done with mirrors. :)

Comment Re:Read some Engels (Score 4, Interesting) 519

It seems to me that the article focused on Communism because it is simpler and easier to model than Capitalism. This does not mean that it cannot be done for Capitalism. It also does not automatically mean Communism is better than Capitalism. On the other hand, Capitalism does seem to have a problem, in that the evidence indicates it helps the rich get richer while everyone else gets poorer. If that "seem to have a problem" could be proved mathematically, then perhaps Capitalist economies might consider some sort of modification to be appropriate. Perhaps the ideal economic system has some Capitalist characteristics and some Communist characteristics. But we won't know until they all get mathematically modeled.

Comment Re:It runs on... (Score 2) 110

Photons. Photons carry energy, as proved by solar cells. It is simply that you can't collect a lot of energy with low-frequency photons like those associated with RF. But "not a lot" of energy is not the same thing as "no" energy. Any device with an appropriately small energy need (the classic device is the crystal radio set), can be powered by RF photons. So, anyone promoting the powering of a modern device by RF photons merely has to show that the device needs an appropriately small energy supply. If it needs too much, it won't work. But if it can collect enough RF photons, then it should work just fine.

Comment Re:HOW OFTEN (Score 1) 331

It is possible that one must eventually stop switching languages. A major reason to acquire knowledge is to use it. If you are constantly learning stuff, how much using are you accomplishing? About 1974 I had a FORTRAN class in college. There was a mainframe with keypunch machines and punch cards to feed into the computer. I never got to use FORTRAN for anything after college, but must have remembered some basics, because when home computers started being popular in the early 1980s, they all had BASIC and I learned that language very quickly, self-taught. A couple years after that, and there was more I wanted to do than the computer's memory could hold, so I got a book on 6809 Assembly Language and taught myself that. I happened to like that language it a lot, and did some fun projects like modifying the computer's ROM code (it could be EPROMmed) so that a full-screen editor replaced the wimpy line-editor that came with the computer, my new code fitting in the same space as the old code. That was all hobby-type stuff, and then a friend suggested I could help his small business if I learned a BASIC-like language called "CLIPPER", which was designed for database management in the days before SQL, and competed with languages like dBase III and FoxPro. That was interesting and fun; I figured out a way to put CLIPPER code inside a database, and get the program to pull blocks of its own code from the database as needed, and run them. We stopped worrying about the overall size of the program and memory limitations ("640K ought to be enough for anyone", hah!), after that. But the small business was too small and didn't survive, so when another friend mentioned a programming job if I learned C, I got the Kernighan and Ritchie book from the library and taught myself that. Since they say C has all of the advantages and all the disadvantages of Assembly, I liked that language a lot, too. I could reminisce more, but instead I'll just mention some more languages I've used to some degree or other, over the years: QBASIC, Delphi (aka Object Pascal), C++, C#, SQL, 8086 Assembly, GAP, HTML/CSS, PHP, and JavaScript. Sometimes I feel a bit like the character Rufo in Heinlein's "Glory Road", who said something like, "I've forgotten how many languages I know, but when I hear one, I speak it." Nowadays I'm back to hobbyist programming. If any nerds out there are interested in a few rather mental but free JavaScript games and puzzles, built into web pages so accessible by any Operating System on any device that has a modern standards-compliant browser , go here. I'll be adding more in due course, including some multiplayer games.

Comment Re:Except for FAA regulations (Score 2) 156

Distance matters. What if drones were combined with automated delivery trucks? The truck carries a lot of mail for many addresses in an area, and carries it to that area; drones carries mail from the trucks to the addresses. The drones can re-charge at the trucks, and each truck might have several drones making simultaneous deliveries. None of these drones need fly especially high or far, to make its delivery.

Comment Re:oxygen is the new lead (Score 1) 630

In other words, every form of electrochemical energy storage involves three things, which we can call "fuel" and "oxidizer" and "product". In a typical storage battery/cell, the fuel and oxidizer react to yield product and electricity until consumed, and then electricity must be fed into each cell to separate the accumulated product back into fuel and oxidizer. 100% of the total weight must always be carried around.
In a hydrogen fuel cell, the oxidizer is atmospheric oxygen and the product is water, which can be dumped as fast as it is produced. Only the fuel need be carried around, and its weight diminishes as the fuel tank empties. Conversion of product back into fuel and oxygen takes place outside the confines of the fuel cell, and so refilling a vehicle's fuel tank is equivalent to "recharging" it.
The original post has a point that hydrogen is bulky. However, that is now, and not necessarily going to be true in the future. One technology exists that could shrink the size of a hydrogen fuel tank enormously. Perhaps some day it can be mass-produced. See, the commonest type of an ordinary hydrogen molecule has two protons and two electrons and qualifies as a "boson". It is known that Bose-Einstein Condensates can put a lot of atoms into each-other's/same space...and the molecules remain gaseous the whole time. :)

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