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Comment Re:Great, now all we need to do... (Score 3, Interesting) 239 239

Interesting fact: at ~0.7c, the kinetic energy is equal to the rest mass of the ship. So if you have a photon drive running off of a perfectly efficient total conversion engine, you'll have fed more than half your ship to the converter by then.

Comment Re:New proposal. (Score 1) 164 164

Since Sieverts are a measure of ionizing radiation, then obviously the background levels I mentioned are ionizing radiation.

Certainly the physical distribution of the radiation sources are important, but I didn't think that was worth mentioning in a simple summary comparison. Sieverts already attempt to correct for biological effects, but yes, if the radiation source is something that can internally bioaccumulate, it will have more complex and serious effects. That is beyond a simple single-measurement comparison, however.

Comment Re:This is disputed (Score 1) 380 380

Solar is dead. Most of the US doesn't get enough sun to make solar feasible.

This article has a good solar efficiency study for the entire US. In summary, there's not a lot of difference in the contiguous US - about the only place where solar is significantly worse off is Alaska.

Comment Re:From Someone Who Works in Boulder (Score 1) 85 85

I was around on my bicycle yesterday and today; the flooding didn't seem too bad west of Broadway, except for the creek path, but there's more low-lying buildings east of there. Nothing of note on the main CU campus. Although it appears that Boulder Creek was quite a bit higher late last evening than it was when I was there. Very high debris marks and silt all over, including through a lot of the downtown streets. Also a mudslide early this morning at the opening of the canyon.

I have a number of pictures here (somewhat low quality), and several short videos from the same areas.

Whenever people agree with me, I always think I must be wrong. - Oscar Wilde