50 mind-bending facts about the cosmos
Your free cheat sheet: 50 short, astonishing facts from the Big Bang to the bit — perfect to skim, share and remember.
Big Bang & Universe
- 1The universe is about 13.8 billion years old.
- 2With the Big Bang, space and time themselves began, not just matter.
- 3The oldest light, the background radiation, is today only 2.725 degrees above absolute zero.
- 4Only about 5 percent of the universe is ordinary matter.
- 5About 27 percent is invisible dark matter, around 68 percent dark energy.
- 6The universe is not only expanding, it does so ever faster.
- 7The first atomic nuclei formed within the first minutes after the Big Bang.
- 8Almost every atom in you was once inside a star.
- 9The Milky Way alone likely contains over 100 billion stars.
Black Holes
- 10A black hole is so dense that not even light escapes.
- 11The boundary of no return is called the event horizon.
- 12At the center of almost every large galaxy sits a giant black hole.
- 13Our Milky Way has one too, with about four million solar masses.
- 14Near a black hole, time passes more slowly.
- 15Black holes are not entirely black, they glow tinily via Hawking radiation.
- 16The first photo of a black hole was achieved in 2019.
- 17As matter falls in, the accretion disk shines brighter than a whole galaxy.
Quantum World
- 18A quantum particle can be in several states at once.
- 19Only measurement fixes a value; before that the possibilities exist side by side.
- 20Entangled particles affect each other instantly, no matter how far apart.
- 21Light is at once a wave and a particle.
- 22A particle's position and speed can never both be measured exactly.
- 23Every particle has an antiparticle with reversed charge.
- 24When matter and antimatter meet, they turn into pure energy.
- 25Quantum effects power everyday tech like lasers, chips and MRI.
Origin of Life
- 26All life on Earth uses the same genetic code.
- 27Simple gases and sparks can already form building blocks of life.
- 28Some meteorites contain over 90 different amino acids.
- 29Deep on the seafloor, life thrives entirely without sunlight.
- 30All living things trace back to a common ancestor called LUCA.
- 31Evolution works with random variation and directed selection.
- 32Earth is about 4.5 billion years old.
- 33Life has existed on Earth for about 3.5 billion years.
Stars & Exoplanets
- 34We already know more than 5,000 planets around other stars.
- 35The first planet around a Sun-like star was discovered in 1995.
- 36A light-year is a distance, not a time: about 9.46 trillion kilometers.
- 37In the habitable zone, liquid water would be possible.
- 38A neutron star is so dense that a teaspoon weighs billions of tons.
- 39Heavy elements like gold form when neutron stars merge.
- 40Even simple binoculars reveal the four large moons of Jupiter.
- 41The Andromeda Galaxy is 2.5 million light-years away and faintly visible to the naked eye.
Information, Bit & AI
- 42The physicist John Wheeler captured his idea in the phrase "It from Bit".
- 43A bit is the smallest unit of information: 0 or 1.
- 44A qubit can be 0 and 1 at once thanks to superposition.
- 45The holographic principle suggests a space can be described by its surface.
- 46Modern AI learns from data instead of following fixed rules.
- 47Large language models, at their core, only predict the next word.
- 48The AI AlphaFold predicts protein folding and won a Nobel Prize in 2024.
- 49A quantum computer is not a faster everyday machine, superior only for a few problems.
- 50In physics, information is considered indestructible, the core of the information paradox.
Newsletter · free
The cosmos in your inbox
Once a week: the best of the universe, made simple.
Welcome gift: a cheat sheet of 50 cosmic facts. Preview the 50 facts →
- Every week
- Always free
- No spam