Black Holes quiz

More questions about Black Holes

These visible examples show the question style. LearnClash turns the full topic into ranked duels and spaced repetition.

1. 1 Easy

   How do astronomers typically spot an invisible black hole in deep space?

   Answer: By its pull on nearby stars

   Why: The Milky Way's unseen central mass weighs 4 million Suns, and the star S2 laps it every 16 years at nearly 3 percent of light speed.

2. 2 Medium

   What is the name of the black hole at our galaxy's center?

   Answer: Sagittarius A*

   Why: The Event Horizon Telescope unveiled its first picture of it in May 2022, revealing about 4 million solar masses some 27,000 light years from Earth.

3. 3 Hard

   What is the settling vibration phase of a merged black hole called?

   Answer: Ringdown

   Why: During ringdown, the new black hole sheds its distortions at specific frequencies set entirely by its mass and spin.

4. 4 Easy

   What bends in general relativity to create a black hole's pull?

   Answer: spacetime

   Why: Matter warps space and time into a single fabric, so falling into a black hole is simply following curved paths inward.

5. 5 Medium

   How do astronomers detect black holes that are not actively feeding?

   Answer: Gravitational lensing

   Why: The one unambiguous isolated case, OGLE-2011-BLG-0462, took years of Hubble follow-up to confirm from the way it bent a background star's light.

6. 6 Hard

   What theory says black holes have no distinguishable outer features?

   Answer: No-hair theorem

   Why: Wheeler popularized the line that black holes have no hair; lacking a general proof, mathematicians still call it a conjecture.