Light seconds, light years, light centuries: How to measure extreme distances - Yuan-Sen Ting
TED-Ed・2 minutes read
Light, the fastest entity known, measures distances by its travel time, such as a light year being 6 trillion miles and the Moon one light-second away. Astrophysicists use parallax and standard candles like cepheid variables and type 1a supernovae to determine the distances of stars and galaxies, helping decode the universe's history and our origins.
Insights
- Light travels at an incredible speed, allowing us to measure distances in light years, revealing the vastness of space. The use of standard candles like cepheid variables and type 1a supernovae helps astrophysicists determine distances to stars and galaxies, providing crucial insights into the universe's history and our origins.
- By observing distant objects and decoding the information carried by light, astrophysicists can look back in time, unraveling the mysteries of the universe's past. This process not only aids in understanding cosmic history but also sheds light on our own origins, offering a glimpse into the fundamental nature of our existence.
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Recent questions
How is the distance of stars measured?
Using trigonometric parallax for nearby objects and standard candles for farther ones.
What aids in determining the luminosity of stars?
Brightness variation of cepheid variables and characteristics of type 1a supernovae.
How does observing distant objects help in understanding the universe's history?
By looking back in time due to light's travel duration.
What is the significance of a light year?
It measures distance based on light's travel time.
How does the Moon's distance from Earth compare to light travel time?
The Moon is only one light-second away.
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