It's fun to think about how we know stuff. For instance, the sun has a mass of about 2 x 10 30 kilograms. That is such an enormous mass that it's difficult to comprehend. And if it's so difficult for ...
Physicist Markus Aspelmeyer vividly remembers the day, nearly a decade ago, that a visitor to his lab declared the gravitational pull of his office chair too weak to measure. Measurable or not, this ...