I was listening to the song What a Wonderful World sung by Louis Armstrong the other day and was really touched by the truth of these lines:
And how true this is! Especially in cosmology. (And physics in general for that matter.) When I was just being born, physicists didn't know things that these days are considered common knowledge by many even layman: that the universe is flat, that it is accelerating, that it is dominated by dark matter and dark energy, (didn't even know about dark energy at all for that matter!), that there were initial perturbations left over after the big bang that seeded the large scale structure like stars and galaxies we see today, etc...I hear babies cry and I watch them grow,They'll learn much more than I'll know,And I think to myself, what a wonderful world
And forget going all the way back to my birth, many of these things were even unknown in the graduate school days of my thesis advisor who obtained his PhD just 11 years ago! While he was a grad student they discovered the universe was flat for the first time. While he was a grad student confirmations started coming in that it was accelerating and dominated by dark energy. And this is evident in his papers which are full of very different cosmology models that today graduate students like me get a kick out of reading knowing how wrong those models fit current data and yet are only 10-15 years old!
And so it continues to be the case. By the time I am a thesis advisor (a big *if* that that will ever happen mind you) we may know what kind of particles make up dark matter... and it may be common knowledge. What dark energy is may be common knowledge. Heck, it was just reported today we may have found a habitable planet other then our own! By the time I am a thesis advisor, who knows what we will know about life in the universe!
And finally, what is great about this song it that it concludes: what a wonderful world. How easy is it for us to have a hard time with someone being "better" or "smarter" then we ever will be? And yet Louis feels perfectly happy marveling that the little children of his day may learn so much more they he'll ever know.
And so it is, and I agree. And I think to myself, what a wonderful world!