Search found 102 matches

by taniwha
Fri Mar 05, 2010 11:47 pm
Forum: General
Topic: Jones: No Warming For 15 Years
Replies: 72
Views: 9998

Come back here and fight like a man! I'll bite your leg off!
by taniwha
Fri Mar 05, 2010 12:17 pm
Forum: News
Topic: Polywell FOIA
Replies: 475
Views: 103418

The first three questions can be answered with 99% certainty without an experiment, i.e. cheap and quick, because they are based on best-case assumptions and well-understood physical processes. The fourth one is a computational grand challenge, and even with massive theoretical effort, you are like...
by taniwha
Thu Mar 04, 2010 11:56 am
Forum: General
Topic: There Was Once a Lot More CO2 In The air
Replies: 40
Views: 4143

Thank you. Very interesting! (over 300% gain!?!)
by taniwha
Thu Mar 04, 2010 10:30 am
Forum: News
Topic: Water on the moon
Replies: 23
Views: 3888

If they're small enough.

If they're big enough, they might make reasonable "private islands".

It's the ones in the middle that might be too much of a PITA to do anything with.

Hmm, Goldilocks and the Three Asteroids?
by taniwha
Thu Mar 04, 2010 8:32 am
Forum: News
Topic: Water on the moon
Replies: 23
Views: 3888

Capturing an asteroid of worthwhile size will take decidedly non-trivial power-plant and drives. However, as a very large number of asteroids are available within Jupiter's orbit (and don't forget the Trojans), they're close enough that fusion powered ships might be able to do the trip without worry...
by taniwha
Wed Mar 03, 2010 12:44 pm
Forum: News
Topic: Water on the moon
Replies: 23
Views: 3888

Ok :) (I'm prone to both reading and typing mistakes, so it could have been either).
by taniwha
Wed Mar 03, 2010 12:00 pm
Forum: News
Topic: Water on the moon
Replies: 23
Views: 3888

Take a closer look. That's GW, not MW. Even more power :). 120MW won't get you anywhere all that fast (though it will get you far if you are very patient, so long as you're already in orbit). However, even with only 120MW, no need to collect space icebergs: that much power should do a nice job of Lu...
by taniwha
Wed Mar 03, 2010 11:48 am
Forum: General
Topic: VASIMR
Replies: 127
Views: 14330

Giorgio: Please read this (and the rest of the site). You might like the liquid droplet radiators :) What it boils down to is that unless you have no other option (admittedly, our current situation), thermal energy production in space just doesn't make sense. You lose too much energy to Carnot. That...
by taniwha
Wed Mar 03, 2010 11:21 am
Forum: General
Topic: VASIMR
Replies: 127
Views: 14330

One of the most useful things about a pBj Polywell is that the waste heat can be rejected at high temperatures. And secondly it is not a thermal machine. So on the generation side it is not limited by Carnot. There are of course other problems. Yeah, and the biggest one is shielding for the side-re...
by taniwha
Wed Mar 03, 2010 11:16 am
Forum: News
Topic: Water on the moon
Replies: 23
Views: 3888

One perfectly good use for the oxygen: reaction mass. At the same specific impulse in an ion engine, oxygen (single electron removal) requires 1/16th the current as hydrogen to produce the same thrust, though the drive voltage will need to be 16 times that of hydrogen. (603kA, 187kV vs 9.6MA, 11.7kV...
by taniwha
Tue Mar 02, 2010 1:01 pm
Forum: General
Topic: Earth's magnetic reversals, and risks..
Replies: 31
Views: 2978

Well, not having the link handy (dig through the general forum archives, it's in one of the AGW threads), I tried some googling and found this. It seems it may not have been one killer asteroid, but two, along with volcanoes spurred on by the second.
by taniwha
Tue Mar 02, 2010 12:24 pm
Forum: General
Topic: Earth's magnetic reversals, and risks..
Replies: 31
Views: 2978

The dinosaurs were done in by external events (asteroid). Their demise is rather irrelevant. Scientific hypotesis range from asteroid to vulcanic activity. For what I know up to today there is no relevant proof for one or the other. I read recently that it actually was proven (crater found, even). ...
by taniwha
Tue Mar 02, 2010 11:03 am
Forum: General
Topic: Earth's magnetic reversals, and risks..
Replies: 31
Views: 2978

In addition, the last reversal was about 780000 years ago: long after our ancestors evolved. Also, the flip seems to take 100s-1000s of years. (info from wikipedia.

I think asteroids are a much bigger worry.
by taniwha
Tue Mar 02, 2010 10:34 am
Forum: General
Topic: Earth's magnetic reversals, and risks..
Replies: 31
Views: 2978

The dinosaurs were done in by external events (asteroid). Their demise is rather irrelevant. Successful is as simple as "can breed fast enough for its population to grow". Back to cosmic rays: first, it seems I was wrong about "solar cosmic rays". I have to agree, it's a horrible name. As for the ra...
by taniwha
Mon Mar 01, 2010 1:06 pm
Forum: General
Topic: Earth's magnetic reversals, and risks..
Replies: 31
Views: 2978

It's not just a misnomer, they don't exist. Cosmic rays, by definition, come from outside the solar system (thus "cosmic"). In which case, I guess the magnetic field does protect us from solar cosmic rays, along with the hard vacuum of space. However, see below for a more serious treatment. The magn...