Eroom’s Law

I only heard about this counterpart to Moore’s law recently (Eroom is Moore spelled backwards). Drug development has become more expensive at a relatively constant rate over time. Dollars are adjusted for inflation.

Details on USA legal limits of commercial space-based imaging

These rules only apply to entities licensed through the USA.

1. Google Maps often doesn’t use satellite images over cities. It often uses images taken from airborne platforms (Wikipedia):
“Although Google uses the word satellite, most of the high-resolution imagery of cities is aerial photography taken from aircraft flying at 800 feet (240 m) to 1,500 feet (460 m); however, most of the other imagery is from satellites.”

2. There are legal limits on what image resolution can be marketed commercially (book):
Ground sample distance (GSD) of 0.5 meters can be marketed generally by USA-authorized entities. GSD greater than 0.25 meters requires special permision.

3. Commercial entities can only take low-resolution space-based images of Israel (NOAA):
No USA entity can distribute high-resolution satellite photos of Israel. According to the Kyl-Bingaman Amendment requires “department or agency of the United States may issue a license for the collection or dissemination by a non-Federal entity of satellite imagery with respect to Israel only if such imagery is no more detailed or precise than satellite imagery of Israel that is available from commercial sources.”

Good post on a good energy blog


His claims of useful energy conversion efficiency:
40% fancy solar cell for spacecraft
35% fossil fuel power plant
28% all electric car (80% battery * 35% power plant)
15-25% human metabolism
15-25% burning gasoline for locomotive power
15% mass-market polycrystalline solar cell
5% photosynthesis

He claims 15% efficiency of solar panels is pretty good. I agree.