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Comment: Re:Dimmable LEDs (Score 1) 187

by Geoffrey.landis (#47430539) Attached to: My most recent energy-saving bulbs last ...

Without dimmers, I've been hard pressed to see the difference between brands.

The differences are not easily visible from the outside. Some brands have gone through some pretty rigorous lifetime testing-- humidity, voltage variation, temperature-- while others are just "as long as it works long enough for the consumer to throw away the receipt" made, but you can't really tell by just looking at them.

Also, Lumens per watt can vary quite significantly from one to another.

Comment: HOW hot? (Score 0) 228

by Geoffrey.landis (#47363929) Attached to: Nathan Myhrvold's Recipe For a Better Oven

at 400 C, radiant energy starts doing a fair amount of the heat transfer. At 800 C, radiation overwhelms convection.

800 degrees C??? That's 1470 degrees F! Who has an oven that goes that high? That will turn just about anything into charcoal in under a minute.

Even 400 C-- 750 degrees F-- is quite a bit hotter than most ovens.

Comment: Longevity (Score 0) 196

by Geoffrey.landis (#47360195) Attached to: The lightbulb I've most recently acquired ...

Following on from the current poll: How long did your last energy saving bulb last ? 0-1 months; 2-4; 5-8; 9-14; 15-23; 2 years; 2-3 years; 4+ years

If "last" means "most recently purchased", how do you answer for a bulb purchased two years ago that's still working? Or, for that matter, a bulb purchased last month?

Comment: LED bulb replacement (Score 0) 196

by Geoffrey.landis (#47360161) Attached to: The lightbulb I've most recently acquired ...

My answer to this question is rather variable-- I've been changing out pretty much all of my bulbs for LED lamps. And I don't necessarily buy the cheapest ones. However, as it turns out, the ones I bought most recently were a couple of candelabra LED bulbs for the front entry chandelier, and they were pretty cheap. I was, however, also looking at LED strips to replace 4-foot fluorescent tubes-- if that had been my purchase, it would definitely have hit the "over twenty dollar" mark. (EarthLED has these. Some of these require rewiring to remove the ballast, although the Philips ones apparently are drop-in replacements)

I replaced the kitchen lights with LEDs. About $22 a pop. These are the larger lights, not the incandescent sized bulbs.

Excellent application for LEDs-- omni bulbs are far less efficient in that application than LED spots. (Any place where the required light is not omnidirectional is a good application for LEDs.)

Comment: Climate is long term, weather is short term (Score 2) 190

by Geoffrey.landis (#47353679) Attached to: NASA Launching Satellite To Track Carbon

It's not, and it also annoys me when people say that.

No single hurricane, heat wave, tornado, flood, wildfires due to drought, storm surge, hot summer, rainy winter is due to global warming, just as no single cold snap, hurricane free season, unseasonably cool spring, early winter storm is evidence that global warming isn't real.

Those are all weather. Climate is long term.

Comment: Re:Orders of magnitude (Score 1) 190

by Geoffrey.landis (#47353625) Attached to: NASA Launching Satellite To Track Carbon

Trivially, no single car trip has an effect on global carbon dioxide. It's a collective effect. Being a collective effect does not make it nonexistent, but it does make it a problem hard to solve, since the problem is distributed.

So, here's an interesting question-- and I'm not being sarcastic here, I'm being real. Given that no one car trip has an effect on global carbon dioxide, but a hundred billion car trips do have an effect, what would be an appropriate approach to addressing this impact?

Comment: Jurassic Earth [Re:Ordovician] (Score 1) 190

by Geoffrey.landis (#47352365) Attached to: NASA Launching Satellite To Track Carbon

Wait, doesn't your rebuttal show that the earth's temperature will not spiral out of control leading to the death and destruction predicted? :P

I don't recall ever making such a prediction.

To be honest you make great points for the view that we are really in a geologic cold period and global warming is just returning us to average temperatures for geologic time frames.

Yep, that's pretty much correct. The Earth is, on the average, quite a bit cooler than it has been in the geological past. It does not always have ice caps.

It happens that this is the climate that we humans are used to, and we've rather built our habitats and our agriculture around. But, on a geological scale, a few degrees of warming, and melting the polar ice caps. is no big deal. It's not the end of the world.

--unfortunately, when we return the planet to the climate conditions of the Jurassic, we probably don't get the dinosaurs back. But then, if biological research keeps on track, we'll just make new ones.

Comment: Orders of magnitude (Score 1) 190

by Geoffrey.landis (#47351947) Attached to: NASA Launching Satellite To Track Carbon

What about the amount of pollutants released with the launch of this satellite? Solid rockets and hydrazine aren't exactly environmentally friendly when you burn a million pounds in 12 minutes. The production of H2 and LOX is pretty dirty also, even if the final product is water.

OK, what about it?

I have a challenge for you. Using google, or your other favorite index-search tool, find out how much carbon dioxide is released by a single Delta-II launch. Then, look up how much carbon dioxide is put into the atmosphere per year by fossil fuel burning. Compare these two numbers. Do they differ by orders of magnitude? How many orders of magnitude?

Based on your findings, do you think that a rocket launch has a significant impact on global carbon dioxide levels? Do you think it has a measureable impact?

"Right now I feel that I've got my feet on the ground as far as my head is concerned." -- Baseball pitcher Bo Belinsky

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