Physics boffins measure smallest known gravitational field (so far)
Millimetre-sized masses: Physics boffins measure smallest known gravitational field (so far)
It might not have occured to rock lugging early humans in the Stone Age that gravity is a relatively weak force, but it is.
Throughout their evolution, humans have become accustomed to living on the surface of a ball with a mass of around 6 × 1024 kg, and our planet being this size makes gravity on Earth a real visceral experience for such sentient bipeds.
Fast-forward a few millennia, and we now know gravity as the weakling of the fundamental forces, which also include weak and strong nuclear interactions and electromagnetic force. Gravity is, for example, about 36 orders of magnitude weaker than the electromagnetic force.
Measuring gravitational forces between less-than-planet-sized objects has always been tricky, and limited to a few kilograms, but research published in Nature shows it can be achieved between two gold spheres with a mass of about 90 milligrams, and a radius of 1mm. That’s about the mass of an average-sized worker bee (although its body takes up a lot more space with a length of around 15mm).
Continued https://www.theregister.com/2021/03/16/measuring_the_gravity_between_houseflies/
