Dark Matter and Dark Energy

A set of flashcards reviewing key concepts, historical findings, and numerical data regarding dark matter, dark energy, and normal matter based on the lecture.

What percentage of the universe is made up of normal matter?

Less than 5%

What are the basic building blocks of normal matter?

Atoms

Why is dark matter invisible?

It is likely made of complicated particles that do not reflect light.

How do scientists know that dark matter exists if it cannot be seen directly?

Through its gravitational effects on visible objects and light.

Which astronomer studied galaxy movement and matter calculations in 1933?

Fritz Zwicky

What surprising finding did Fritz Zwicky uncover in 1933?

There was a large amount of unaccounted-for mass, and visible normal matter was insufficient to hold galaxies together.

Why would objects in a galaxy fly apart without dark matter?

The gravitational force coming from visible objects is not strong enough to hold them together.

What observable effect occurs when light passes through areas with a high concentration of dark matter?

The passing light bends around those areas.

What percentage of the universe is made up of dark matter?

About 27%

What percentage of the universe is composed of dark energy?

68%