¿Qué es la materia oscura?

The video explains the concept of dark matter, which is invisible yet more common than visible matter. It discusses how gravity holds galaxies together despite the insufficient gravitational force of visible stars. The Doppler effect is introduced as a method to measure the speed of stars in galaxies, using the analogy of a police siren's changing pitch. The video emphasizes using observable phenomena to infer the existence of unseen elements like dark matter.

What is the term used for the unseen matter that is more common than visible matter in the universe?

• Dark matter

• Antimatter

• Dark energy

• Neutrinos

Why do physicists believe that dark matter exists?

• Because it emits light

• Due to its gravitational effects

• Due to its magnetic properties

• Because it can be seen with telescopes

What analogy is used to describe the role of gravity in holding galaxies together?

• A spinning top

• A swinging pendulum

• A rotating wheel

• A giant carousel

How do astronomers measure the speed of stars in distant galaxies?

• By measuring their size

• Using the Doppler effect

• Using gravitational waves

• By observing their brightness

What phenomenon causes the change in pitch of a police siren as it passes by?

• The Doppler effect

• The gravitational pull

• The speed of light

• The magnetic field