Cosmology

______ is the study of the universe.

Cosmology

The dying star

The big bang

Black holes

How old is the universe?

13.772 billion years

13 billion years

13 years

13.772 million years

Many astronomers think the Universe is flat, Why do they think this?

They think the Universe contains lots of dark matter and energy so that the density = the critical density

They see no bending of light

They can see an edge to space, proving it is not curved

What is a scientific theory?

An observation of what happens

A best guess hypothesis

A opinion

A well tested observation over a long time

General relativity predicts that black holes have:

Infinite volume

Infinite density

Infinite mass

When stars die, they become black holes if they have masses of at least:

1/2 the mass of the sun

3x the mass of the sun

Twice the mass of the sun

What is a scientific law?

A proven theory

An explanation of why something happens

An opinion

A observation of what happens

What would change if our Sun was suddenly replaced by a black hole of the same mass?

Earth would be sucked into the black hole

The planets would no longer have the same orbit

We would die

Only the temperature on Earth would change

How do astronomers know when they are observing a black hole?

When they see the light emitted from nearby dust and gas being sucked into the black hole

When they hear the screams of people falling into the black hole

When everything in that region of space is completely black

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