At the upper limits of what's energetically possible, cosmic rays still persist. What happens if a human gets hit by the most energetic one?

Our great hope is that today's indirect, astrophysical evidence will someday lead to successful direct detection. What if that's impossible?

Just like animals, galaxies often have bizarre, unusual, or even unique properties. But finding many, all at once, really does raise alarms.

Even in an expanding Universe, we expect both redshifted and blueshifted galaxies. But nearly every one we see is redshifted. Here's why.

Many view the development of fringe, alternative theories as a useless waste of time. But when they can be tested, it shows what reality is.

Gravitational lenses arise when foreground masses and background light sources properly align. Einstein rings are rare, but crosses abound.

It's not about particle-antiparticle pairs falling into or escaping from a black hole. A deeper explanation alters our view of reality.

The VENUS survey isn't about planets at all, but about finding multiply-lensed supernovae. The ambition? To save the expanding Universe.

Back in 1604, Johannes Kepler discovered the Milky Way's last naked-eye supernova. Here's how NASA's Chandra sees it over the 21st century.

The seeds of cosmic structure that were planted back during the Big Bang grew into the cosmic web we see today. What is it telling us?

When objects are gravitationally bound, they cannot escape from one another's influence. How does that work within the expanding Universe?

Travel half the distance to your destination, and there's always another half to go. So how do you eventually arrive? That's Zeno's Paradox.

Even the youngest galaxies are often dust-rich, even with very low levels of heavy elements. Nearby dwarf galaxy Sextans A explains why.

Astronomers have found starless gas clouds before, but Cloud 9 might be the most pristine one of all, with big lessons for cosmic history.

Particles are everywhere, including particles from space that stream through the human body. Here's how they prove Einstein's relativity.

Perhaps the most remarkable fact about the Universe is simply that it, and everything in it, exists. But what's the reason why?

The highest-energy particles could be a sign of new, unexpected physics. But the simplest, most mundane explanation is particularly iron-ic.

While humanity has been skywatching since ancient times, much of our cosmic understanding has come about only recently. Very recently.

Our Universe doesn't just expand and cool, but the expansion itself is accelerating. Can stars form under such structure-erasing conditions?

Earth orbits the Sun while spinning on its tilted axis, with two annual occasions marking that maximal tilt. That's where solstices arise.

Big Think and the John Templeton Foundation gathered scientists, artists, and storytellers in Los Angeles to explore the power of awe.

Our Standard Model of the Universe, for both particle physics and cosmology, remains intact for now. When will its foundations crack?

Science isn't absolute. Its truths and discoveries enable us to approximate reality, but we must always remain open-minded to revisions.

The method you use to measure the expanding Universe determines which of two answers you'll get. Lensed supernovae can't resolve that issue.

Some vital, key ingredients must be in place for the Universe to make more matter than antimatter. The LHC took us one step closer in 2025.

As the lightest baryon in the Universe, the proton is thought by many to be eternally stable. But if it isn't, can we observe it decaying?

We have a picture of how and when it will all come to an end. These three big ideas could still profoundly change how our cosmos evolves.

Science has assembled an incredible story outlining our Universe's whole history. Despite its unrivaled success, 9 profound gaps remain.

Although American Thanksgiving only comes once a year, the scientific rules that make our Universe possible are always worth appreciating.

Everything ever seen — every star, mountain, and face — makes up less than 5 percent of the universe. Astrophysicist Janna Levin reminds us that the rest — dark matter and dark energy — is invisible, mysterious, and everywhere. We are the luminous exception in a universe of darkness.