As much as I love living in China, taking a break from it feels pretty healthy. I didn’t realise how much I missed the blue sky until I saw it again this weekend. Of course California (or at least parts of it) has bluer skies than anywhere I’ve been so we have been spoiled.
The reason that the sky looks blue comes from this thing called Rayleigh scattering. Some physics coming so skip to pictures down below ….
Here’s how I understand it from this guy. Light travels and on its way can hit stuff (or interact with air molecules) so the light we see in the sky is sunlight that has been scattered off these air molecules. So why does it look blue? White sunlight is made up of all the colors of the rainbow but light from the blue-violet end of the spectrum is apparently more likely to bounce off an air molecule and scatter into our eyes. Reddish light travels through the atmosphere without being bothered by air molecules. Like me being able to wander around China without being bothered much but my rather tall blond cousin constantly being scattered off curious Chinese people. Maybe I’ll start calling her blue light.
Apparently desert air is very pure (not much stuff floating in it) which allows these red guys to get on with their journey. Air in other places however may contain aerosols (tiny particles or droplets). These can be clouds as well as air pollution. The aerosols are so annoying that even the red guys cannot avoid them so all the colors of the spectrum get scattered equally and therefore the blue gets diluted. And there are few aerosols in the desert air is because it is so dry.
So there, blue desert air versus the grey, humid and polluted Chinese air I have been breathing. Physics lesson over (believe it or not, I was really bad at physics in school).
Now here are some blue skies from our short trip to Yosemite which was truly amazing, even the second time. We did an approx. 10km hike from Happy Isles at Yosemite Valley following the Mist Trail to Vernal Fall, onto Nevada Fall and back via the John Muir Trail.
View of the Half Dome from Olmsted Point.
A little swim in Tenaya Lake to make up for the absence of showers all weekend…
Further along the way we made a stop at Mono Lake.
And our final destination was the ghost town of Bodie. Unfortunately the hotel was closed so we camped near Twin Lakes.
Enjoy the rest of your week. I know I will