Our home, this spaceship, this Earth, keeps spinning and spinning ... suspended in space.
And an invisible force keeps it tethered to its home star, the source of all its energy.
And that star too is not really still. It too has a story to tell.
Once upon a time, 5 billion years ago perhaps, it was just a lot of gas. Then that gas got together and gravity compressed it and when compressed enough, nuclei started fusing in the processing converting some matter into energy — in the ultimate sort of alchemy.
And that energy radiates out in the form of photons that have different energies and span the electromagnetic spectrum.
Some of that light we see as our visual apparatus is sensitive and limited only to those wavelengths. Imagine being present at that day of creation when the Sun would have shown for the first time ... ever.
Like a village getting electricity for the first time ... only, a trillion trillion times more fundamental.
A star shining for the first time ... I wonder if that would really happen like an incandescent bulb getting switched on instantly when we flip a switch or how.
Has the shape/size of the Sun remained more or less constant since the last five billion years?
What is a billion years for the Sun? Four trips only around the center of the Milky Way galaxy.
So, thus far, the Sun has completed only 20 revolutions ... 20 years in some ways, one can say.
And in another similar 20 years, 5 billion Earth years would have gone by.
And the Sun would have grown old ... run out of the ingredients to keep the fusion fire burning bright.
And it would become bloated like some decaying corpse ... becoming so big that even the Earth would be gobbled up inside its body.
And then a supernova explosion would blow much of the mass away leaving behind only a small portion that would settle eventually into a white dwarf star or a brown dwarf.
And what then? What would happen to the universe we inhabit? Not in 5 billion years? Not in 10? Think 50 billion years. 100 billion years.
Go back to the past. The Big Bang happened 'only' 13.7 billion years ago ... so says science.
How much longer does the universe have to live?
Will it last forever? Expanding forever? Or, will the matter of the universe start reversing the present expansionist phase some day and the universe will become a contracting universe?
What do you think?