Mysteries of the Dark Cosmos

TL;DR

Astrophysicists explore the existence and properties of dark matter and dark energy, which make up 95% of the universe but remain largely unknown.

Transcript

hello my name is Roberto Trotter and I'm a professor of Astro statistics at Imperial College London and visiting professor of cosmology at Gresham College today we're going to talk about the mysteries of the dark cosmos and as we all know the cosmos is a infinite source of fascination for many of us if we look up at the night sky on a dark night wh... Read More

Key Insights

• 🕶️ Dark matter and dark energy make up 95% of the universe's composition, but their fundamental nature remains unknown.
• 🕶️ Dark matter is necessary to explain the gravitational effects observed in galaxy clusters and the rotation curves of galaxies.
• 🕶️ Dark energy, discovered through observations of supernovae, drives the accelerated expansion of the universe.
• 🕶️ Multiple lines of evidence, such as gravitational lensing and cosmic microwave background radiation, support the existence of dark matter and dark energy.
• 🕶️ Supersymmetry, a theoretical framework, offers a potential explanation for dark matter but has yet to be confirmed by experiments like the Large Hadron Collider.
• 👨‍🔬 Scientists are utilizing various observational and experimental techniques to search for and better understand dark matter and dark energy.
• 🕶️ The upcoming Vera Rubin Observatory will provide valuable data for mapping the distribution of dark matter and dark energy in the universe.

Questions & Answers

Q: How did astronomers first discover the existence of dark matter?

Astronomer Fritz Zwicky observed the Coma Cluster in 1933 and calculated that there must be unseen mass (dark matter) keeping the galaxies within the cluster gravitationally bound together.

Q: What evidence supports the existence of dark matter in galaxies?

Observations of galaxy rotation curves by Vera Rubin and others showed that the velocities of stars did not decrease with distance from the center, indicating the presence of additional unseen matter like dark matter.

Q: How was dark energy discovered?

Astronomers studying distant supernova explosions found that the universe's expansion was accelerating instead of slowing down, indicating the presence of an unknown form of energy (dark energy) driving this expansion.

Q: What are some ways scientists are currently searching for dark matter?

Scientists are using gamma-ray telescopes and underground detectors to search for signals that may be produced by interactions between dark matter particles and normal matter. The Large Hadron Collider is also being utilized to search for supersymmetric particles, which could be a component of dark matter.

Summary & Key Takeaways

• The cosmos is a source of fascination, but visible matter is only a small part of the universe's composition.

• Dark matter was theorized in 1933 as an unseen source of gravity necessary to keep galaxies together in clusters.

• Dark energy was discovered in the late 90s and is responsible for the accelerated expansion of the universe.