Sunlight is older than you think
Transcript
Deep inside the Sun, fusion in the core forges energy, and those photons begin a long random walk through a radiative zone so dense that they can take about 170,000 years to leave it.<sup class="text_citation" source_id="12"></sup><sup class="text_citation" source_id="4"></sup>
NASA describes this as a random walk problem, because photons are scattered again and again before they ever reach the surface.<sup class="text_citation" source_id="1"></sup><sup class="text_citation" source_id="2"></sup>
Once sunlight escapes the photosphere, it races the distance to Earth in about eight minutes and twenty seconds.<sup class="text_citation" source_id="17"></sup><sup class="text_citation" source_id="19"></sup>
So the warmth on your skin is not just sunlight, but ancient light, born deep within the Sun long before human history.<sup class="text_citation" source_id="9"></sup><sup class="text_citation" source_id="18"></sup>
Sources
- HBY & Math #9: The Random Walk Problem
- I heard that the light from nuclear fusion reactions in the Sun's core takes about 200,000 years to reach its surface. I thought the speed of light is constant. Why does it take so long? | Astronomy.com
- Radiative zone - Wikipedia
- How Long Does It Take a Photon to Leave the Sun?
- Solar core - Wikipedia
- How long it takes light from the Sun to reach Earth
- Seeing in the Dark . Astronomy Topics . Light as a Cosmic Time Machine | PBS
- Light Travel Time
Let's look at alternatives:
- Modify the query.
- Start a new thread.
- Remove sources (if manually added).