Interesting science

*   It seems sperm whales told each other how to avoid whalers in 19th century Pacific Ocean:

Using newly digitised logbooks detailing the hunting of sperm whales in the north Pacific, the authors discovered that within just a few years, the strike rate of the whalers’ harpoons fell by 58%. This simple fact leads to an astonishing conclusion: that information about what was happening to them was being collectively shared among the whales, who made vital changes to their behaviour. As their culture made fatal first contact with ours, they learned quickly from their mistakes.

“Sperm whales have a traditional way of reacting to attacks from orca,” notes Hal Whitehead, who spoke to the Guardian from his house overlooking the ocean in Dalhousie, Nova Scotia, where he teaches. Before humans, orca were their only predators, against whom sperm whales form defensive circles, their powerful tails held outwards to keep their assailants at bay. But such techniques “just made it easier for the whalers to slaughter them”, says Whitehead....

Sperm whales are highly socialised animals, able to communicate over great distances. They associate in clans defined by the dialect pattern of their sonar clicks. Their culture is matrilinear, and information about the new dangers may have been passed on in the same way whale matriarchs share knowledge about feeding grounds. Sperm whales also possess the largest brain on the planet. It is not hard to imagine that they understood what was happening to them.

The hunters themselves realised the whales’ efforts to escape. They saw that the animals appeared to communicate the threat within their attacked groups. Abandoning their usual defensive formations, the whales swam upwind to escape the hunters’ ships, themselves wind-powered. ‘This was cultural evolution, much too fast for genetic evolution,’ says Whitehead.

*   Quanta has an article that is relatively easy to follow, about a paper showing that imaginary numbers are essential in quantum physics:

... physicists may have just shown for the first time that imaginary numbers are, in a sense, real.

*   They have measured a tiny amount of gravitational attraction:

An experiment shows that Newton’s law of gravity holds even for two masses as small as about 90 milligrams. The findings take us a step nearer to measuring gravitational fields that are so weak that they could enter the quantum regime.

 Still, sounds hard to believe it could lead to this:

The next step is to push on to even smaller masses — Westphal et al. suggest that gravitational fields of masses of the order of 10^–8 kg could eventually be measured. However, much work will need to be done to achieve this goal. The first task will be to substantially reduce damping of the oscillations of the torsion balance, which won’t be easy. But if it can be done, then perhaps quantum gravitational effects will finally be observed.