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What is dark matter?. 96% of the universe is missing In fact, all of the stuff we can detect in the universe: All of the matter All of the energy Only seems to account for 4% of the total size of the universe . Scientists have been measuring the movements of millions of stars and galaxies
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96% of the universe is missing • In fact, all of the stuff we can detect in the universe: • All of the matter • All of the energy • Only seems to account for 4% of the total size of the universe
Scientists have been measuring the movements of millions of stars and galaxies • And the way light bends on its way to us from distant galaxies billions of light years away • The results say the same thing again and again • There is a lot more out there than we see
The straight answer: we don’t know • Whatever it is, it doesn’t emit or absorb light like normal matter • So we’re call it dark matter • We think it accounts for 23% of all the matter in the universe Pie of matter and energy [NASA]
It’s invisible, but its gravity gives it away by bending passing light, like a lens • The cluster of galaxies in the front of this image, called Abell 1698, is bending the light from galaxies behind, making the curved streaks • Abell 1698 must contain dark matter to bend the light this much Galaxy Cluster [NASA]
This map shows dark matter has been around since as far back as we see, around 13.4 billion years billion years • It’s scattered all through the universe, like an invisible skeleton holding normal matter in the shapes we see Dark matter map [NASA]
Invisible astronomical objects called Massive Compact Halo Objects - MACHOS - may explain some of it • MACHOS are things like neutron stars and black holes, which have huge masses but give out no light • But most dark matter is probably made from something completely mysterious [CERN]
Dark matter might also be made of a completely undiscovered kind of subatomic particle • These particles are called supersymmetric particles, or sparticles for short • Some are weakly interacting massive particles: WIMPS • Top of the list of suspected dark matter WIMPS are neutralinos
Making sparticles, like neutralinos, needs more powerful particle accelerators than ever before • The LHC will be able to collide particles with enough energy to make them • We won’t see them directly, but the huge detectors at the LHC may pick up hints of their existence [CERN]
The biggest machine on Earth • To glimpse a shadow world of particles • That most of the matter in the universe is made from… [CERN]