We're dealing with the sum total of everything, if the true nature of things is that there are a finite number of supernovas I'd be surprised. The real shock is how small the number of supernovas is and how young everything seems to be in the known universe (the age of the observed universe is estimated at maybe double digit billion years).
These are tiny numbers given that we're quite possibly dealing with infinity in both time and space. I judge it one of the stronger arguments in favour of the universe being constructed (or, more likely, there is a lot out there we can't see). If god built a universe numbers like 1 supernova a century make some sense for artistic value.
Isn't the observable universe finite? There can't be a infinite number of anything in a space of radius R, even if R is very big.
Anything moving beyond the Cosmological Horizon can no longer be seen.
As I understand it, a frozen image will remain for a time and fade, growing increasingly red shifted.
You can't compare a number of years or events with infinity. Saying it's tiny or huge makes no sense whatsoever.
What amazes me is how young the universe is compared to life. The universe is only about 4 times as old as life on Earth.
The comparison can be made; almost all positive integers can't practically be represented in hindu-arabic because they are too large. If we're dealing with numbers that can be scribed in a few seconds they are small in a meaningful way.
We'd expect that the mathematicians would need to come up with a new notation to represent the age of the universe.
Or to flip that around, life has existed on Earth for about 25% of the lifetime of the universe.
The fact that we are part of that life introduces some nasty sampling biases, but if we find even one more planet that shows a similar ratio, the implications will be that life is ubiquitous.
its 1 supernova per century per galaxy. there are many galaxies: more than 10 stars go supernova every second across the universe. tens of thousands have gone supernova since the article was posted to HN. tiny percentages in a large sample are huge numbers, you might even say 'astronomical'.
There is a really good intuitive analogy hiding here for the scale of the universe:
Our galaxy is to the observable universe as a tenth of a second is to your entire lifetime.
> 1 supernova a century
A century being the amount of time it takes earth, one specific planet to orbit its star 100 times? What about all the other planets and stars?
A century is approximately three billion seconds, the second being variously defined across history as a multiple we find convenient of whatever universal natural constant we can most precisely measure -- most recently 10 billion or so of a specific type of vibration of cesium atoms.
All the other stars and planets would have the same experience, though their local orbital periods might result in different units of expression being more convenient.
Of course, as we leave our galaxy they would also be in significantly different reference frames and perhaps experience the rate differently as a result. We are assuming that, statistically, our relative velocity is not special and they see roughly the same relationship between red shift and distance that we do.