Proving 2 temperatures coexist — disrupting thermodynamics.
Stuart Wolpert.
According to the basic laws of thermodynamics, if you leave a warm apple pie in a winter window eventually the pie would cool down to the same temperature as the surrounding air.
For chemists and physicists, cooling samples of charged particles, also called ions, makes them easier to control and study. So they use a similar approach — called buffer gas cooling — to lower the temperature of ions by trapping them and then immersing them in clouds of cold atoms. Collisions with the atoms cool the originally hot ions by transferring energy from the ions to the atoms — much the same way a warm pie is cooled next to the cold window, said Eric Hudson, associate professor of physics at UCLA.
But new research by Hudson and his team, published in the journal Nature Communications, demonstrates that ions never truly cool to the temperature of the surrounding gas. Also, very surprisingly, they discovered that under certain conditions, two final temperatures exist, and the temperature that the ions choose depends on their starting temperature.