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Comment Re:Game changing? (Score 1) 95

that wasn't even using LH2 which I hear is harder

You say that like it's a good thing. Methane is easier to handle and makes refurbishing the engine for reuse simpler, cutting costs all around.

I think the game-changing aspect is supposed to be a combination of low manufacture cost, low operation cost, high thrust, and very high reusabiity -- 25 missions. The idea is to be pretty good on every metric, not necessarily the best (e.g. highest thrust) in every metric. That's engineering for you: it involves making choices. And you can never be certain you made the right ones until the produce either succeeds or fails.

Comment Don't buy too MANY bitcoins... (Score 1) 51

You only need 1.21 gigawatts to travel back in time, buy Bitcoins at USD$0.008, become the most powerful company on the planet and simply buy out any and all competitors before they become a threat.

Don't buy too MANY of the Bitcoins. You might get back to now and find out that the market that drove their price up never developed and theyr're worth nothing.

Comment Sorry, doesn't work that way. (Score 3, Insightful) 51

What happens when Amazon or Google buy 1 GW of green power, does a coal plant gets shut down? No. What happen is that the typical home customer has its share of green power reduced from say, 4% to 3%. The production remains the same.

No.

What happens is, with a guaranteed customer with concentrated loads (and no need to cut a deal with a power distribution company to sell THEM the power), an investor builds renewable-energy plants near the Amazon or Google sites and starts selling them the power. So more generation DOES get built for the projects, and the consumers' mix is not impacted as you describe.

(In the short run such big projects may push the price of equipment up slightly, but in the long run they enable economy-of-scale manufacturing that brings the price down.)

Photovoltic panels, for instance, beat grid power once they cost less than a dollar per watt. Market price in 10-panel pallet loads was $0.33 last I looked, and even the domestic panel manufacturers who won the anti-dumping decision are only asking for a price floor of $0.78.

Comment Re:Good. (Score 2) 178

I once worked for a non-profit that funded scientific field research. Two of us were standing outside with a researcher who had just returned from spending months in one of those inflatable rainforest tree rafts, when a huge, iridescent staghorn beetle landed right at our feet.

The scientist shoved us back. "Don't step on it!"

The other staffer I was with gave him a totally uncomprehending look, and I had to explain to the researcher: "The kind of people who work here don't step on weird looking bugs. They pick them up and play with them."

Comment Re:Gotta be water, not air (Score 1) 81

This just like setting up an inertial platform in the ocean. You tow the long tube out horizontally and then flood one end of it. The flooding end sinks while the not-flooded-yet end pops up.

If you divided the platform into two watertight segments, you could flood just one of the compartments and it would flip up to a vertical orientation with part of the non-flooded compartment below the waterline. You then position the tower where you want it, and flood the upper compartment just enough to settle it on the sea floor with enough force to keep it in place. It remains in part supported in its upright position by bouyancy. The flooded section is under compression; the part with air is under tension up to the displacement point of the above-water part.

Comment Macbook keyboards are interesting. (Score 1) 527

I can't comment on recent ones, but I have a 2011 17" MBP in the kitchen doing light duty. I picked it up cheap because it wouldn't boot. The problem was a bad keyboard, which I replaced.

The keyboard, at least on the old MBPs, feels very solid, but when you get the replacement it's incredibly thin and flimsy; the metal body is little more than foil. You could easily fold it in half like a piece of paper. It's basically a flimsy dome switch keyoboard with a mechanical gizmos added to the key to give it a crisper feel. This also means its unlikely to be a piece of dust causing your problems -- unless the dust was put there in the factory. The business parts of the switch are safely under a silicone membrane.

What give the installed keyboard its solid feel is that it is screwed into the very sturdy aluminum laptop chassis with dozens of tiny screws. What you feel when you type on it is not the solidity of the keyboard, but of the heavy sheet of aluminum it is very firmly attached to. This is how the engineers got the machine to feel sturdy and light at the same time.

My advice is if the key seems mechanically good but doesn't register, first test an external keyboard to make sure it's not some kind of software issue, then replace the whole keyboard. It's not a particularly complicated repair, but be advised the screws are tiny, about the size of coarsely ground coffee. A fine jeweler's phillips head screwdriver, strong magnifier, and a large expanse of uncluttered workspace is recommended. The screws are small enough you can't just put them into the hole. You have to nudge them into the hole and hope they go in business end first, which takes several tries.

Also: given the severe abuse keyboards get in normal use, I recommend using an external keyboard whenever you can; that way you can just toss the keyboard when it breaks. Only use the laptop keyboard when you're on the road. This also gives you the chance to get a keyboard that you really like.

Comment Re:Whew (Score 2) 106

Is this [HL-60] the one that contaminated everything? /i?

I am not a biiochemist, but... That seems to be a human leukemia line.

Are you maybe thinking of HeLa - the very hardy immortalized cervical cancer cell line that was the first to be successfully grown in bulk?

I hear there was a model for the progression of cancer that had to be scrapped, because it was really the result of HeLa cells, escaped into laboratory environments, eventually contaminating virtually any cancer cell culture experiment and replacing the intended cells.

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