Uncategorized
- Anthropology
Ancient Lure of the Lakes: Early Americans followed the water
Archaeological investigations in Chile indicate that beginning around 13,000 years ago, early American settlers lived at high altitudes during humid periods, when they could set up hunting camps on the shores of lakes.
-
19147
I am concerned about this article. It addresses the mass of fissile materials needed to “make a bomb,” yet it’s clear that the critical masses given–10 kilograms for plutonium-239, 50 kg for uranium-235, and 60 kg for neptunium-237–are for bare spheres with no neutron moderation, reflection, or other factors contributing to going critical. Consider that […]
- Physics
Neptunium Nukes? Little-studied metal goes critical
Researchers have measured with far greater accuracy than ever before how much neptunium it would take to make a bomb.
