Half the universe was missing... until now

The video explores the missing baryon problem, explaining that while baryonic matter should make up 5% of the universe, only 2.5% is observed. It discusses the formation of elements post-Big Bang and the use of cosmic microwave background radiation to estimate baryon density. The search for missing baryons involves quasars and the Lyman Alpha forest, revealing that much baryonic matter is in the warm hot intergalactic medium (WHIM). Fast radio bursts help detect ionized baryons, confirming the WHIM's role. The video concludes with reflections on scientific discovery.

What percentage of the universe is expected to be made up of baryonic matter?

• 2.5%

• 68%

• 5%

• 27%

Why is the density of baryonic matter important in the early universe?

• It changes the gravitational constant.

• It affects the rate of fusion reactions.

• It alters the cosmic microwave background.

• It determines the speed of light.

What role do quasars play in the search for baryonic matter?

• They serve as backlights to detect neutral hydrogen.

• They emit X-rays that illuminate dark matter.

• They create new baryonic matter.

• They produce gravitational waves.

What is the Lyman Alpha forest?

• A series of absorption lines from neutral hydrogen.

• A cluster of quasars.

• A collection of galaxies in the early universe.

• A type of dark matter.

What is the warm-hot intergalactic medium (WHIM)?

• A form of dark matter.

• A cluster of stars.

• Ionized particles between galaxies.

• A type of dark energy.

How do fast radio bursts help in finding missing baryons?

• They create new baryonic matter.

• They alter the cosmic microwave background.

• They provide a dispersion measure to estimate baryon density.

• They emit visible light that illuminates baryons.

What percentage of baryonic matter is found in the WHIM?

• 20%

• 10%

• 50%

• 75%

What surprised the narrator about the distribution of baryonic matter?

• Most baryonic matter is in stars and galaxies.

• Only a small fraction is in stars and galaxies.

• Baryonic matter is evenly distributed.

• Baryonic matter is mostly in black holes.

What is a key difference between scientists and non-scientists according to the narrator?

• Non-scientists enjoy being wrong.

• Scientists prefer being wrong to learn new things.

• Scientists dislike unexpected results.

• Non-scientists seek new physics.

What validates the computer simulations run decades ago?

• The confirmation of the WHIM's existence.

• The discovery of new galaxies.

• The detection of dark matter.

• The measurement of cosmic microwave background.