Dark energy
Around 1912, with early studies on the expansion of the universe.
When did scientists start studying dark energy?
Why is dark matter called dark
It is invisible to telescopes
How much of the universe is dark matter?
27%
What is the universe’s expansion?
space itself is stretching, causing galaxies to move away from each other over time.
Who was alexander Friedman?
Russian astronomer who conversed about galaxy drifting and expansion of the universe
She connected the brightness and luminosity of Cepheid stars, helping measure cosmic distances.
What did Henrietta Swan Leavitt contribute?
What is gravitational lensing
Dark matter’s gravity that can bend light from surrounding universes, distorting the light wave.
What is baryonic matter?
Normal matter made of protons, neutrons, and electrons
What evidence shows the universe is expanding? Who first observed it?
The redshift of light from distant galaxies, first observed by Edwin Hubble.
What is quintessence?
theory that dark matter a liquid
What did Vesto Slipher discover?
Using spectrographs, he found that galaxies were moving away from us, showing redshift — evidence of an expanding universe.
Does dark matter interact with light?
NO
What is non baryonic matter
Matter not made of atoms
What is redshift?
when light from an object moving away shifts to longer (redder) wavelengths.
What is vacuum energy
Energy found in empty space
What did the 1998 Nobel Prize-winning team discover?
the universe is expanding faster over time, confirming the presence of dark energy.
Who was Vera Rubin and what did she discover?
In the 1970s, Vera Rubin noticed that outer stars in galaxies moved too fast, suggesting dark matter was holding them in place.
What are WIMPs?
Weakly Interacting Massive Particles
What is Hubble’s Law?
galaxies farther away move faster from us
Does dark matter take up space?
yes
What is dark energy and what does it do?
Dark energy drives the acceleration of the expansion of the universe. It makes up 68% of the universe.
Is dark matter hot or cold?
It is cold because of its slow moving particles
In 2006 observations about a galaxy cluster led to direct evidence about the existence of dark matter.
What is the Bullet Cluster?
What is the “Hubble tension”
A disagreement between different measurements of the universe’s expansion rate.
Does dark matter hold mass?
yes