Question 1

How far is a light-second?

Accepted Answer

A light-second is 299,792 km. The Moon is 1.28 light-seconds from Earth. GPS satellites are about 0.07 light-seconds away.

Question 2

What can travel a light-second?

Accepted Answer

Light and radio waves travel 1 light-second (299,792 km) per second. Communication delay to the Moon is about 1.3 seconds each way.

Question 3

Is this conversion factor exact?

Accepted Answer

Metric-to-metric conversions are exact (1 km = 1000 m). Imperial-to-metric factors like 1 inch = 2.54 cm are exact by international agreement.

Question 4

Why do some countries use different units?

Accepted Answer

Historical reasons - the metric system spread from France after 1795. The US, UK, and a few others retained older systems. Science uses metric worldwide.

Light Seconds to Kilometers Converter

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