A ray of light leaves the surface of the Sun. How many seconds later does it arrive on Earth?
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Answer
About 500 seconds
The trip out of the Sun is far slower: energy made in the core takes tens of thousands of years or more to work its way up to the surface.
How to estimate it
Two well known numbers are enough. The Sun is about 150 million km from Earth, and light travels at 300,000 km per second. Divide one by the other: 150,000,000 / 300,000 = 500 seconds, a little over 8 minutes. The accepted value is about 500 seconds, varying slightly over the year because Earth's orbit is not a perfect circle.
Source: NASA
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