Understanding Light and Space

The video explains that nothing can travel faster than light, which moves at 300 million meters per second. Astronomers use light years to measure vast distances in space, as using meters or kilometers is impractical. Light takes 8.3 minutes to travel from the Sun to Earth, meaning we see events with a delay. Proxima Centauri, the nearest star after the Sun, is 4.2 light years away, so its light takes 4.2 years to reach us. Observing space is essentially looking back in time due to the vast distances involved.

Why do astronomers prefer using light years over kilometers to measure distances in space?

• Kilometers are too small for vast distances.

• Kilometers are not accurate enough.

• Light years are easier to calculate.

• Light years are a universal standard.

How long does it take for light to travel from the Sun to Earth?

• 5 minutes

• 8.3 minutes

• 10 minutes

• 12.5 minutes

What is the significance of the 8.3-minute delay in observing the Sun from Earth?

• It measures the Earth's distance from the Sun.

• It reflects the Sun's gravitational pull.

• It indicates the time light takes to travel from the Sun.

• It shows the speed of Earth's rotation.

How far is Proxima Centauri from Earth?

• 2.5 light years

• 5.6 light years

• 3.8 light years

• 4.2 light years

What does observing stars tell us about time?

• We see stars in real-time.

• We see stars as they are in the present.

• We see stars as they were in the past.

• We see stars as they will be in the future.