After breathing a deep sigh, I feel better — don’t you? It’s relaxing. And it turns out there’s a good reason why we feel relief after big breaths. It comes down to a special fluid inside our lungs. The liquid — pulmonary surfactant — helps our lungs work. Without it, we’d be in serious trouble. But researchers at ETH Zurich, a university in Switzerland, found that deep breaths have an interesting effect on how this fluid interacts with the lungs. The new research was published in the journal Science…
