pigboy

Out of all those advanced civilizations in the universe, what fraction use electromagnetic radiation for communication? We are like ants waiting for other civilizations to communicate with us using pheromones.

The statement "space is cold" doesn't make much sense, since space, being a vacuum, is lacking any _thing_ to have a temperature at all. What little matter does exist in the vacuum of space is not going to conduct any significant heat from your warm body. An ordinary "space blanket" would keep you quite warm. Until you suffocated, of course.

I love this, but I would like to be able to return to my solved puzzles after I've done them (assumed that's what the "Save" button did).

Quite happy to finally get level 11 done.

That used to motivate me too. But when I found myself in a job where my work no longer made that happen, I quit and changed careers (mid-40s). I just turned 50 and I am in my third year teaching high-school math, physics and computer science. It's like being born again.

Energy density is a critical issue for aircraft because lift/drag ratios are capped at around 15 to 30. For every 15-30 N of fuel weight, you must supply at least 1 N of additional thrust (which translates to power, once you multiply by speed).

Cars, on the other hand, experience a combination of aerodynamic and powertrain drag and rolling resistance, of which only (mostly?) the rolling resistance depends on mass. The typical coefficient of rolling resistance is about 10x better than the typical L/D ratio for aircraft (if I believe Wikipedia). Hence, road vehicles are 10x less sensitive to energy density than aircraft.

So a statement that electric vehicles won't work is nonsense, without considering how sensitive the different vehicles are to fuel mass.

I'm finding I generate very few "personal files" these days, compared with, say, ten years ago. Most personal files are produced/archived with Google Docs.

Yes, that is scary.

I also have 100 GB or so of archived photographs and videos that I back up with a mixture of Ubuntu One (videos and assorted files from 10 years ago) and Rackspace Cloudfiles (photos). I wrote my own Python scripts for backing up and verifying photos on Cloudfiles.

The capsule and heat shield do deplete virtually all of its speed. With Mars' thin atmosphere, the terminal velocity is still quite high and the parachute/rocket combination is needed to take it all the way down. AFAIK this is a relatively conventional system, with the exception of the very last moment of touchdown, which uses descent rockets and the sky crane.

Perhaps the most similar landing was by Viking, which made the final descent on rockets. Those thrusters were expressly designed (that is, compromised) to produce as little disturbance of the landing site as possible. The only thing Curiosity is doing that is really new is the sky crane. If there are any errors in understanding the dynamics of rocket plus lengthening pendulum in Mars gravity, then all is lost. I think it is likely that some extra attention has been paid to this part of the mission.

Anouncing: the Chromebook of media players!

I started using Opera in the days when its free version was supported by adware (I actually purchased a license). It was always a technical innovator, so the question of why it failed to garner market share is a good one. The answer, of course, is that technical superiority is never a prerequisite for commercial success. Marketing trumps engineering every time.

American "free enterprise" at work. Why some people worship this nonsense is beyond me.

Principal Software Designer for embedded systems at Simplex Time Recorder, a subsidiary of Tyco International.

The dot-com bubble involved more than Internet companies as Tyco's stock crashed amid scandal involving its CEO. For me this led to downsizing, layoffs, a year of consulting, three of working under lousy conditions and finally a complete career change to teaching.

Lesson learned? The free enterprise system is seriously flawed. I watched a thriving, innovative American business get eaten alive by Tyco. A handful got filthy rich while thousands of workers lost their jobs as production moved overseas. Shameful..