Gravitational Lensing: What It Is And How It Is Helping Us Discover New Galaxies

The video explores the concept of lenses, focusing on gravitational lensing, a phenomenon where gravity acts as a lens to bend light from distant galaxies. This is rooted in Einstein's theory of general relativity, which suggests that massive objects distort space-time, affecting light paths. Gravitational lensing allows astronomers to discover new galaxies and study dark matter, which is invisible but has mass. The video also discusses the Einstein ring, a visual effect of perfect alignment in gravitational lensing, and highlights ongoing studies like the Dark Energy Survey to map dark matter in the universe.

What is a common characteristic of all lenses mentioned in the introduction?

• They are all used in scientific research.

• They are all made of glass.

• They all distort the view of objects behind them.

• They all magnify objects.

What is the primary cause of gravitational lensing?

• The rotation of galaxies.

• The presence of dark matter.

• The gravitational field of massive objects.

• The expansion of the universe.

According to Einstein's theory, what does gravity do to light waves?

• It accelerates them.

• It bends them.

• It splits them.

• It absorbs them.

What phenomenon occurs when the source, lens, and observer are perfectly aligned?

• A supernova explosion.

• An Einstein ring.

• A black hole formation.

• A solar eclipse.

What was the source of light in the first observed Einstein ring?

• A black hole.

• A dark dwarf satellite galaxy.

• A cluster of galaxies.

• A supernova.

How does dark matter interact with light?

• It reflects light.

• It bends light.

• It absorbs light.

• It emits light.

What is the goal of the Dark Energy Survey in relation to dark matter?

• To map the distribution of dark matter.

• To measure the temperature of dark matter.

• To eliminate dark matter from the universe.

• To convert dark matter into energy.