Talk-Polywell.org

Past rates of sea level rise have little to do with what has started to happen. That's because something is (or at least could be) happening now, that was not happening in the past. It is the fundamental risk incurred by projecting into the future past trends. All bets are off if something changes, ...

I see people picking and choosing pieces of physics to support pre-existing politics. I don't see much in the way of response to actual observations and effects. Nowhere in this entire conversation thread. I find that completely alarming. Ice on the ground or the ocean surface melts when ambient tem...

Look, in the real world, there are a lot of effects going on. It's not linear cause and effect from one piece of physics. But one at a time, we can understand the effects of the pieces. There is such a thing as the greenhouse effect, which you can demonstrate for yourself with glass bell jars, therm...

If you ditch the ideologies and just look at what works, and at what our cultural traditions have been going back to the Roman Republic, I think you will find that it is extremism itself that is the bad actor. This is true whether it is political extremism or religious extremism that we talk about. ...

I would venture a prediction about China. They will probably overexpand and overextend themselves into an economic implosion in a very few years, one that lasts about a decade or so, just like the Japanese did about 25 years ago. Once they come out of it, they will take a less arrogant approach to t...

As I recall, Pluto was a belly-scoop ramjet with wings and conventional tail group. It resembled a very large Snark, Matador, or Mace. My father remembered this project at what used to be Chance Vought in Dallas. They were the airframe prime for it. That was substantially before my time. Some but no...

Timberwind sounds about as bad as the Pluto nuke ramjet. The core assembly supports ran about 10 F from meltpoint. Nonmaneuvering low altitude M3 cruise missile. It spewed a lot of hard radiation in ground tests. The jet was pretty loud, too. Its shock wave plus jet noise was calculated to be lethal...

I knew about DUMBO. It's actually pretty close to what I had in mind. That's a completely different fuel element design geometry, and as I understand it, requires a different nozzle design as well. That's OK, it's a good solid core design, and needs a few tests to verify effectiveness, with NERVA as...

My 6000 sec figure dates from some old mission studies from about 1969 or 1970, about the time containment and gas fission controllability were being verified in bench tests. They did understand two limits, but these were very fuzzy. One was a cooling limit: heavy radiator necessary above 2000-2500 ...

I see the problem. Try this

http://exrocketman.blogspot.com

Now that I've done this, I will return to cheaper access to LEO for a while. The post for the Mars mission on "exrocketman" is for Dec 20 2010.

I had been working on ways and means to do Mars exploration without a heavy-lift rocket. Think I found a way to do it. I wrote it up and posted it over at http://exrocketman.blogspot.com. Enjoy.

Spacex may or may not ever solve first stage recovery and reuse. I hope they do, but at about 10% or less inert weight in the stage, it's pretty fragile for ocean impact, parachutes notwithstanding. That's not a high-pressure solid like the shuttle SRB's, that's a relatively low-pressure liquid tank...

Anybody get a kick out of Spacex's success with the Dec 8 flight test of Falcon-9/Dragon? I kinda think that's the next generation of manned spaceflight, and for cargo, especially bigger payloads. This thing is roughly equivalent to the old Saturn-1. It's a heavy lifter. They did good with the test....

Think about this: special relativity describes what inertially-moving object A looks like to an static observer in inertial reference frame B. That's almost exactly what Einstein's paper said, except his language was a whole lot more technical. The operative word in my description is "looks like". T...

I was taught that photons are massless, but of nonzero momentum. That's why they do travel at lightspeed, yet can have an impact force against solar sails or other objects. And they do seem to have such impact.