black holes Flashcards
What powerful force allows black holes to absorb light?
Gravity
How do scientists know that black holes exist?
By observing objects and light around black holes
How do black holes form?
When giant stars explode
Where do super massive black holes likely exist?
At the center of galaxies
True or False: Black holes are invisible because they don’t reflect light.
TRUE
What do we call the boundary around a black hole where nothing can escape its gravity?
Event horizon
What is the center of a black hole called?
Singularity
What is it called when an aging star explodes?
Supernova
True or False: Black holes were first discovered by Ancient Egyptian astronomers around 3000 BCE.
FALSE
What makes the gravity of a black hole so strong?
Its small size and large mass
The Event Horizon Telescope captured the now-iconic image of the M87 black hole. Why is it called that?
- It is at the centre of the galaxy Messier 87, named after astronomer Charles Messier
- Its mass is roughly 87 solar masses
- It spins at 87 rotations per microsecond
- It is 87 million light years from Earth
- No one knows for sure
It is at the centre of the galaxy Messier 87, named after astronomer Charles Messier
How many times more massive than our Sun is the M87 black hole?
6 billion times
How far away from Earth is the M87 black hole?
55 million light years
The Event Horizon Telescope required multiple telescopes, with split-second synchronization, to capture the image of the M87 black hole. How many telescopes were used?
Eight
What quantity of stuff falls inexorably past the event horizon of the M87 black hole, never to be seen again, during the span of a single day?
The equivalent of 90 Earths
The M87 black hole is supermassive, but relatively compact for its mass. What size does it occupy?
It is roughly the size of our solar system
Over time, a black hole will evaporate via a process called Hawking radiation. How long will it take for the M87 black hole to fully evaporate?
Much longer than the current age of the universe
If the black hole image captured by the Event Horizon Telescope had been egg-shaped instead of round, what could it mean?
That Einstein was wrong about general relativity
Roughly how small would you have to squish the Earth for it to become a black hole?
The size of a wedding ring
About how long will it take for our Sun to turn into a black hole?
It won’t – it’s too small
If photons (light) have no mass, how can they be trapped by the gravitational field of a black hole?
Mass is actually linked to space, and the density of a black hole curves the space around it to an extreme degree
