Two cosmic anomalies tell us that something big is missing from our model of the Universe. First, stars in the outer regions of a typical galaxy are orbiting the centre too fast for the galaxy's gravity to hold onto them. By rights, they should fly off into intergalactic space.
The second anomaly is that you are reading these words that is, galaxies like the Milky Way, and therefore you, exist. According to the standard picture of galaxy formation, regions of the cooling debris of the Big Bang that were slightly denser than average would have had slightly stronger gravity and pulled in material faster, enhancing their gravity so they pulled in matter even faster, and so on. But this process akin to the rich getting ever richer - could not have built galaxies as big as our Milky Way in the 13.8 billion years that the Universe has existed.
Confronted with these anomalies, most astronomers postulated that the Universe contains about five times as much invisible matter as visible stars and galaxies. It is the extra gravity of such 'dark matter', they claim, that holds onto stars in galaxies and sped up galaxy formation. However, an equally logical possibility is that, on cosmic scales, gravity is stronger than Newton would have predicted.
Bu hikaye BBC Science Focus dergisinin August 2022 sayısından alınmıştır.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber ? Giriş Yap
Bu hikaye BBC Science Focus dergisinin August 2022 sayısından alınmıştır.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber? Giriş Yap
CHANGE THE (BODY) CLOCKS
Why the end of British Summer Time can be a wake-up call for our circadian health
ARE OCTOPUSES SENTIENT?
If you've watched the Netflix documentary My Octopus Teacher or been lucky enough to encounter an octopus in the wild, you'll know there's something special about them.
THE MEXICAN MOLE LIZARD
Imagine what would happen if an earthworm, a lizard, a snake and a mole went on a night out, had too much too much tequila and let their guard down.
Do we finally know how the Egyptian Pyramids were built?
A number of breakthrough studies are beginning to paint a picture of how these wonders of the world were built, but much of the story still remains a mystery...
ECLIPSES ON DEMAND
Inside an unassuming building, behind a damp car park in Antwerp, Belgium, scientists are teaching two spacecraft to be dance partners for a performance that will take place in front of the Sun.
How light's 'secret code' reveals the story of the cosmos
The starlight we can see tells us alot about the Universe, but it's the parts we can't see that contain the biggest revelations
An artificial heart inspired by plumbing
Mechanical circulation could revolutionise transplant design and reduce waiting lists
Major Stonehenge discovery deepens mystery around ancient monument
New findings suggest a key six-tonne stone came from over 450 miles north of the circle
THE UNEXPECTED RETURN OF PNEUMATIC TUBES
Once a pioneering technology that revolutionised deliveries, pneumatic tubes had all but disappeared. Now they're back and enjoying a resurgence
LIVING FOSSILS
FOR SOME CREATURES ALIVE TODAY TIME HAS ALMOST STOOD STILL. MEET THE 'LIVING FOSSILS' THAT GIVE US A GLIMPSE INTO LIFE IN THE DISTANT PAST