Assertion: photon's energy | /r/CapableOf | take about a million years
Facets:
value: to reach the surface
type: PURPOSE
Source sentences:
text: For example, photons engage in so many collisions on the way from the core of the Sun that radiant energy can take about a million years to reach the surface; however, once in open space, a photon takes only 8.3 minutes to reach Earth.