Space & Cosmos
What Is a White Hole? Real Math That Nature Never Built
What is a white hole? It is a black hole with time reversed: a region nothing can enter. Real math, badly unstable, and never once seen in the sky.
Space & Cosmos
Black holes, stars, planets, and the scale of everything.
Space & Cosmos
Is the Universe Infinite? Space Is Flat, and That Settles Nothing
Is the universe infinite? Space measures flat to within a fraction of a percent, which permits an endless cosmos but cannot prove one. Here's why.
Space & Cosmos
Why is Mars red? It is rusting, and that is a clue to its watery past
Why is Mars red? The planet is coated in iron oxide dust, the same stuff as rust. A 2025 study points to a water-bearing mineral, hinting Mars was once wet.
Space & Cosmos
How Big Is the Biggest Star Compared to the Sun? Up to 2,000+ Times Wider
How big is the biggest star compared to the sun? The largest known stars are roughly 1,500 to 2,100+ times the Sun's radius, big enough to swallow the inner planets.
Space & Cosmos
What Would Happen If the Moon Crashed Into Earth? It Would Shatter First
What would happen if the moon crashed into earth? It would break apart into a ring long before impact, when it crossed Earth's Roche limit. And it can't happen.
Space & Cosmos
How Long Would It Take to Drive to the Sun? About 177 Years
How long would it take to drive to the sun? At a steady 60 mph nonstop, about 177 years. Light makes the same trip in 8 minutes, and one NASA probe in 9 days.
Space & Cosmos
What Is on the Other Side of a Black Hole? Honestly, Nobody Knows
What is on the other side of a black hole? Likely a singularity we can never see, while white holes and wormholes stay math, not proof. Here is the honest answer.
Space & Cosmos
How Many Earths Can Fit in the Sun? About 1.3 Million
How many earths can fit in the sun? About 1.3 million by volume, or roughly 960,000 packed as solid spheres, with 109 lined up across its face.
Space & Cosmos
How cold is space? Colder than almost anywhere, but not how you think
How cold is space? Empty space sits at about -270C, just above absolute zero. But a vacuum has no real temperature, and you would overheat before you froze.
Space & Cosmos
What does space smell like? Astronauts say seared steak
What does space smell like? Astronauts describe seared steak, hot metal, and gunpowder clinging to suits after spacewalks. Here is the chemistry behind it.
Space & Cosmos
Why is Pluto not a planet? The vote that demoted a world
Why is Pluto not a planet? In 2006 astronomers voted it a dwarf planet for failing one rule: it never cleared its orbit. The story, and the man who killed it.
Space & Cosmos
Where Does Gold Come From? The Cosmic Catastrophe Behind Every Wedding Ring
Where does gold come from? The gold in your jewelry was forged in a neutron star collision billions of years ago. Here's the wild physics behind it.
Space & Cosmos
How Do Black Holes Die? The Slow Fade of the Darkest Things
How do black holes die? Through Hawking radiation, they slowly evaporate over almost unimaginable spans of time. Here's how the universe's darkest objects end.
Space & Cosmos
How Big Is the Universe? (And Does It Have an Edge?)
How big is the universe? The observable universe spans 93 billion light-years, but the whole thing may be infinite. Here's what 'size' even means in space.
Space & Cosmos
What Happens When the Sun Dies?
What happens when the sun dies? In 5 billion years it swells into a red giant, swallows the inner planets, and fades to a white dwarf. Here's the timeline.
Space & Cosmos
Why Do Stars Twinkle but Planets Don't?
Why do stars twinkle while planets shine steadily? The answer is our turbulent atmosphere bending starlight, and a surprising trick of distance and size.