The periodic table remains essential after 150 years

It’s another raw day in St. Petersburg, Russia, but the man striding down the University Embankment along the Neva River isn’t pondering how the icy wind off the Gulf of Finland chills his bones or whether Emperor Alexander II’s reforms will increase salaries for professors like him. Instead, Dmitrii Mendeleev is imagining how he could reveal the chemical underpinnings of the universe on a single page.