Sun is 4.6 billion years old? Let’s see.
Light takes 8 minutes to reach us from the surface of the sun, So It would oddly take thousands of years for light to travel from the sun’s core to its surface.
We know that earth orbits around the sun at an average of 150 million km away approximately, and the light travels at a speed there around 300,000km/s divide by the distance to the earth gives 500 seconds which gives us those 8 minutes.
Why is sunlight so old?
Light travels in straight lines from the sun to us but a photon’s journey out of the sun is not direct. Photons are byproducts of nuclear reaction in the sun’s core, as hydrogen nuclei are fused to make helium nuclei. The core of the sun is basically billions of hydrogen bombs exploding every second making the outward pressure get held by the enormous mass of hot gas under gravity. all these fusion reactions happening in the sun’s core releases energy in form of gamma rays. So to get to space each photon has to ricochet its way which is a long journey like a Random walk!
A random walk is a distance traveled, on avg, equal to the step size times the square root of steps, eg to walk 1km using 4 sided die method and 1 step every second takes 11 days, so the path of the protons out of the sun is a random walk very small and big scale. Deducing to a random walk, the 690,000,000m from the solar core to the surface would require 10^37 steps which for a proton at light speed is a journey of 100 billion years. but protons of sunlight can’t be that old
The actual random walk a photon takes out of the sun is more complicated because the sun is very dense in the core, less dense in the middle, and even less dense on the outside and changing the energy of the photon. With all this information Scientists hunched the time it takes a photon to random walk from the suns’ core to space is 170,000 years.
The peculiar thing about traveling at the speed of light is that time does not matter. So whenever a photon is created it experiences no time.
Age is something to put numbers on, but it always depends on perspective.