Best way to boil water, according to physicist
Physicist Tom Murphy calculated how much of the energy of various methods went to heating the water, versus dissipating along the way. With the largest gas stovetop burner on full-blast and no lid, about 15% of the natural gas being burned was converted to heat in the water. With a lid and a small burner, the gas stove reaches about 30% efficiency. The microwave hit 43%. Kettles reached 70% efficiency.
The pleasure of that cold glass of water
The pleasure that comes with a drink of water after a hike isn’t linked to your actual need for a drink. A study in the journal Neuron reports that the neural systems related to the feeling of reward work independently of those involved in monitoring water intake. Gulping tells the brain that liquid has been consumed, but that happens whether it was water or oil. The body also tracks water in the gut, and when water is not arriving, thirst returns. Neuroscientist Yuki Oka reported that injecting water into the stomachs of mice quenched thirst, but it was only when mice drank water normally that a flood of dopamine resulted. So hydration by itself isn’t rewarding. Still, that blissful feeling that comes with a cold glass of water is very real.