Popular Mechanics- Like the one in your car, Johannes Roßnagel's engine is a four-stroke. In four steps it compresses and heats, then expands and cools. And as with any other engine, this cycle is repeated over and over again—transforming the changing temperature into mechanical energy.
The supermassive black hole is 40 million times as massive as the sun and powers a quasar that existed 700 million years after the Big Bang.
Vision Pro is here and it’s a surprisingly capable device. Apple has also loaded the headset with a ton of options and features that aren’t obvious at first glance.
Engineers expect to lose contact with the private US moon lander Odysseus on Tuesday, cutting short the mission after its sideways touchdown last week.
