Showing posts with label escape. Show all posts
Showing posts with label escape. Show all posts

Friday, June 10

Why do bees die after stinging you?

Honey bee stings have a barbed ratchet mechanism that pulls the stinger into the initial wound. This didn’t evolve as a suicide mechanism – honey bees can pull their stings out after stinging other insects. It’s meant to drive the stinger in as deep as possible; it just happens that mammal skin is too fibrous to release the sting, so the abdomen is torn open when the bee tries to escape afterwards. Honey bees are the only species to suffer this fate, but the cost to the hive of losing some workers is worth it for an improved ability to repel honey thieves.

Sunday, April 5

HOW DO GRAVITONS ESCAPE FROM A BLACK HOLE?

In Einstein’s theory of General Relativity, the force of gravity around a black hole is described solely by the warping or curvature of ‘space-time’. However, many scientists believe we can also describe gravity, just like the other forces of nature, as the exchange of ‘virtual’ particles – in the same way that particles of light, photons, carry the electromagnetic force. Unfortunately there is, as yet, no such quantum theory of gravity that would describe how it works at this level, although we have some clues as to what it might look like. But crucially, these ‘virtual’ gravitational particles (called ‘gravitons’) aren’t bound by the normal rules of physics. They can pretty much do what they like, including travelling faster than light, as long as they do it before we notice them! Consequently, a black hole’s event horizon presents no barrier to gravitons and hence their communication with the outside Universe.