Ultracold atoms in space will let us stress test Einstein’s relativity

Potassium and rubidium atoms aboard the International Space Station have been cooled almost to absolute zero to put a fundamental principle of Einstein’s theory of general relativity to the ultimate test

​Potassium and rubidium atoms aboard the International Space Station have been cooled almost to absolute zero to put a fundamental principle of Einstein’s theory of general relativity to the ultimate test Potassium and rubidium atoms aboard the International Space Station have been cooled almost to absolute zero to put a fundamental principle of Einstein’s theory of general relativity to the ultimate test