⬛ DARK MATTER: THE INVISIBLE UNIVERSE
PAGE 1 OF 5 — THE INVISIBLE GLUE
27% OF THE UNIVERSE
IT IS THERE. BUT YOU CANNOT SEE IT.
About 27 percent of the entire universe is made of something that does not emit light, does not absorb light, and does not interact with ordinary matter at all. We cannot see it with any telescope. We cannot touch it. We cannot detect it with any instrument we currently possess. Yet we know with certainty it exists, because its gravity holds galaxies together and shapes the entire large-scale structure of the cosmos.
🤔 THE INVISIBLE MAJORITY
Everything you have ever seen, touched, or detected, every star, planet, gas cloud, and black hole, makes up only 5 percent of the universe. Dark matter is five times more abundant than ordinary matter, yet completely invisible to us.
INVISIBLE!
NO SIGNAL
🔮 Does not emit any form of electromagnetic radiation
⚡ Does not absorb or reflect light of any wavelength
⛔ Passes straight through ordinary matter with no interaction
⚡ Does not absorb or reflect light of any wavelength
⛔ Passes straight through ordinary matter with no interaction
ONLY GRAVITY
⚡ Gravity is the only way it interacts with anything
🌌 Forms an invisible scaffold around every galaxy
🔗 Without it, galaxies would fly apart at their rotation speeds
🌌 Forms an invisible scaffold around every galaxy
🔗 Without it, galaxies would fly apart at their rotation speeds
PAGE 2 OF 5 — THREE PROOFS IT EXISTS
GALAXY ROTATION CURVES
THE STARS SPIN TOO FAST
Stars at the edge of a galaxy should orbit slowly, like outer planets in our Solar System orbit the Sun slowly. But observations show they spin just as fast as stars near the centre. The only explanation: a vast invisible halo of matter surrounds every galaxy, its gravity keeping those outer stars in orbit. Astronomer Vera Rubin proved this beyond doubt in the 1970s, and it changed physics forever.
TOO FAST!
BULLET CLUSTER
💥 Two galaxy clusters collided at 10 million kilometres per hour
🌝 The gas (normal matter) slowed down and separated
⬛ The dark matter halo passed straight through, detected by gravitational lensing
🌝 The gas (normal matter) slowed down and separated
⬛ The dark matter halo passed straight through, detected by gravitational lensing
GRAVITATIONAL LENSING
🔭 Massive objects bend light from galaxies behind them
🔮 The amount of bending reveals more mass than we can see
✨ The extra mass is dark matter: detected purely by its gravity
🔮 The amount of bending reveals more mass than we can see
✨ The extra mass is dark matter: detected purely by its gravity
COSMIC WEB
🌟 Computer simulations with dark matter reproduce the universe perfectly
🔗 Without dark matter, models produce a smooth, featureless universe
🌌 Filaments and voids only form when dark matter is included
🔗 Without dark matter, models produce a smooth, featureless universe
🌌 Filaments and voids only form when dark matter is included
PAGE 3 OF 5 — THE SCIENTISTS WHO FOUND IT
FRITZ ZWICKY · 1933
🔮 Measured the speeds of galaxies in the Coma Cluster
⚡ They moved far too fast for the visible matter to hold them
🤔 Called it dunkle Materie (dark matter): decades ahead of his time
⚡ They moved far too fast for the visible matter to hold them
🤔 Called it dunkle Materie (dark matter): decades ahead of his time
VERA RUBIN · 1970s
🏔 Measured rotation curves of hundreds of spiral galaxies
📊 Flat rotation curves proved invisible mass in every galaxy
🥇 Her work made dark matter a central pillar of cosmology
📊 Flat rotation curves proved invisible mass in every galaxy
🥇 Her work made dark matter a central pillar of cosmology
THE DARK MATTER HALO
EVERY GALAXY WEARS AN INVISIBLE HALO
Every galaxy, including our Milky Way, is surrounded by a vast spherical halo of dark matter many times larger than the visible galaxy itself. Our dark matter halo extends at least 200,000 light-years from the galactic centre, compared to the 100,000 light-year disc of visible stars. The halo's gravity is what makes galaxies stable and gives them the structure they have today.
🏠 OUR OWN DARK MATTER HALO
Right now, as you read this, roughly 1 billion dark matter particles are passing through your body every second. Each one is passing through the Earth, the Sun, and out the other side without interacting with a single atom.
HALO!
PAGE 4 OF 5 — WHAT COULD IT BE?
THE CANDIDATES
WE KNOW WHAT IT IS NOT. WE DO NOT YET KNOW WHAT IT IS.
Dark matter is not black holes, not neutron stars, not planets, not any known particle of the Standard Model of physics. Physicists have proposed dozens of candidates. The most promising are new types of particles that interact only via gravity and possibly the weak nuclear force. After decades of searching with the world's most sensitive detectors, none have been found yet. This is one of the greatest unsolved problems in all of science.
MYSTERY!
WIMPs
⚛️ Weakly Interacting Massive Particles: the leading candidate
🔮 Mass of 10 to 10,000 times a proton
🔍 Underground detectors search for rare WIMP collisions with atomic nuclei
🔮 Mass of 10 to 10,000 times a proton
🔍 Underground detectors search for rare WIMP collisions with atomic nuclei
AXIONS
🔮 Extremely light hypothetical particles
⚡ Would convert to photons in strong magnetic fields
🔭 Microwave cavity detectors actively searching in the lab
⚡ Would convert to photons in strong magnetic fields
🔭 Microwave cavity detectors actively searching in the lab
OTHER IDEAS
⬛ Primordial black holes: formed in the early universe before stars
🤔 Sterile neutrinos: a heavier cousin of the known neutrino
🔮 Modified gravity theories: perhaps gravity itself behaves differently
🤔 Sterile neutrinos: a heavier cousin of the known neutrino
🔮 Modified gravity theories: perhaps gravity itself behaves differently
PAGE 5 OF 5 — THE SEARCH CONTINUES
THE LEGACY
THE HUNT FOR THE UNIVERSE'S BIGGEST SECRET
Physicists are searching for dark matter using three strategies simultaneously. Direct detection: deep underground laboratories shield sensitive detectors from cosmic rays, waiting for a dark matter particle to collide with an atom. Indirect detection: space telescopes look for gamma rays produced when dark matter particles annihilate each other in dense regions. Particle colliders: the Large Hadron Collider smashes protons together hoping to create dark matter particles.
🛰 RUBIN SPACE TELESCOPE
The Vera Rubin Observatory in Chile will photograph 20 billion galaxies over 10 years, creating the most detailed map of dark matter's distribution ever made by measuring gravitational lensing on an unprecedented scale.
SEARCHING!
COSMIC WEB TODAY
🌟 Dark matter forms the cosmic web's invisible skeleton
🌌 Galaxies form where dark matter filaments intersect
🔗 Without dark matter the universe would be smooth and empty
🌌 Galaxies form where dark matter filaments intersect
🔗 Without dark matter the universe would be smooth and empty
REMEMBER THIS
📌 KEY FACTS
⬛ Dark matter: 27% of the universe, five times more than normal matter
⛔ Cannot be seen, touched, or directly detected
⚡ Only interacts through gravity
🔮 Proven by galaxy rotation curves, lensing, and the Bullet Cluster
❓ Its identity remains the greatest unsolved mystery in physics
⛔ Cannot be seen, touched, or directly detected
⚡ Only interacts through gravity
🔮 Proven by galaxy rotation curves, lensing, and the Bullet Cluster
❓ Its identity remains the greatest unsolved mystery in physics
🧠 DARK MATTER QUIZ
TEST YOUR KNOWLEDGE · 5 QUESTIONS
QUESTION 01
How does dark matter interact with ordinary matter?
QUESTION 02
What was the key observation that proved dark matter exists in galaxies?
QUESTION 03
What did the Bullet Cluster observation prove about dark matter?
QUESTION 04
Which astronomer first measured flat galaxy rotation curves, providing strong evidence for dark matter?
QUESTION 05
What percentage of the universe is made of dark matter?
0/5
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