If I am measuring my age in solar orbits, it should measure its age in galactic orbits.
A single orbit takes 230 million years. Measured against this benchmark, Mr High and Mighty “billions of years old” plasma furnace is still some punk college-kid.
On this scaling:
The sun’s birth (formation from a collapsing cloud of gas and dust) took about 4 hours
It then went through a difficult period of having intense solar winds for 5 days (protostar)
It has stayed in pretty much it’s current form for the following 19 years (main sequence)
But it will start to expand over the next 23 years (red giant)
It will then massively expand for 6 months, followed by a month in which its size changes frequently.
Finally it will exist as a white dwarf. The scaling breaks down here, as white dwarves will likely take trillions of years to fizzle out, so even scaled, we’re talking hundreds of thousands of years.
Why? The only thing that would accomplish is to create an annoying second step by sending people to Google to find out how old the sun is in “real” years. Not only that, it is a totally relativistic system. Two stars of identical mass are born at the same time, but one is half way towards the center of the galaxy, and the other is in the outskirts of the galaxy. In your system, one would be twice as “old” as the other simply because it was circling the galactic core twice as fast.
I was intrigued by the title but not expecting a CT at all, quickly thought it was a neat idea when I read the explanation, and found the breakdown (formation → protostar → main sequence → etc) was well developed. Mijin, you did well in my opinion. Now I wonder whether this thread can give some interesting angles to the original idea apart from the criticism already expressed.
I guess saying that based on my experience the sun should soon run out of spots at this age is not really constructive. I’ll try to think of something better and more relevant. But yeah, I was a punk too at that age and had a lot of fun. I wish the Sun many more happy years!
Galaxies don’t rotate like that, because of the influence of their dark matter halo. Unlike planets orbiting a star, a galaxy rotates almost like a solid object, with the rotation period largely independent of distance from the center. This breaks down somewhat in the central bulge, but out in the disk part, the rotation curve is nearly flat.
Some 5 billion years from now, there will be a last perfect day on Earth… then the sun will begin to die, life will be extinguished, the oceans will boil and evaporate away.
-Carl Sagan
