Summer Solstice 2020

Summer Solstice 2020

In 2020 the Summer Solstice is at 9:44pm UTC on June 20.

We get solstice from the Latin sol (sun) and sistere (to cause to stand) - the moment when the Sun stands still in its journey from north to south and back again.

Summer Solstice is the instant when the Sun is at its highest point in the sky, on the longest day of the year for the Northern hemisphere. This happens because the Earth is tilted by a little over 23 degrees (our planet rotates once a day, but relative to our orbit around the Sun the axis of rotation is at an angle). As we orbit the Sun this tilt means that different latitudes experience more or less sunlight over the course of a year. This pattern is most extreme near the poles. In the Arctic Circle the Sun never sets at the height of summer and never rises in the depth of winter. We mark two solstices each year, summer and winter. At the Summer Solstice the Sun is directly over the Tropic of Cancer (a little over 23 degrees north). We also observe two equinoxes, spring and fall (vernal and autumnal), halfway through the cycle when the Sun is directly over the Equator and a day is the same length everywhere.

The video below shows how the pattern of day and night changes over one year. You can see when the poles are completely dark or light, and the moment when the Sun 'stands still' before days start to get longer or shorter again.

Here's another perspective. This video shows a view from San Francisco made from pictures that each show a complete day (each vertical line on the picture was shot at a different time with noon at the center). You can see the length of day changing throughout the year. On less foggy days you can also see the position of sunset moving, especially with the days getting longer towards the end when San Francisco experiences less fog.

Summer Solstice isn't always on June 20th - sometimes it's June 21st or June 22nd. Irritatingly a day on your clock is not the same as a solar day and a calendar year is not the same thing as one trip around the Sun. This is why we have leap years and leap seconds to stay roughly in sync with celestial mechanics.

It's also interesting to note that Summer Solstice isn't when we're closest to the Sun or when temperatures are the highest. The Earth's orbit is elliptical and we're actually furthest away around the Summer Solstice (for now - this changes over time). Our Northern hemisphere summer is driven by sunlight hitting us directly rather than at an angle (seasons are driven by the 23 degree tilt and the position of the orbit more than our distance from the Sun). Temperatures continue to rise after the Summer Solstice mainly because it takes a while to heat up water, and so warmer weather lags the increase in direct sunlight (and vice versa as we head into colder weather after the Winter Solstice).

The exact moment of Summer Solstice pictured at the start of the post and the video of day/night over a year were created using Catfood Earth. Catfood Earth generates wallpaper from NASA Blue and Black Marble images to show the current extent of day and night combined with near real time cloud cover. Catfood Earth is totally free and available for Windows and Android.

(Previously)

ISS Lunar Transit (4K Video)

ISS Lunar Transit (4K Video)

I tried this with a solar transit last year and discovered that my expensive phone can't keep time. Learned my lesson - for this lunar transit I shot video a few minutes before and after. The video is 4K and has the unedited 1 second transit and a zoomed in slow version where you can actually see the thing. Unfortunately this means the composite at the top is made from frames extracted using ffmpeg. Next time, two cameras, so I can attempt a burst as well as a video.

Shot on a Sony RX10 IV from San Francisco.

(Previously)

Google search-for-your-own-verified-sites Console

Google Search Console

I don't know about you, but when it comes to Google Search Console I spend about 0.01% of the time adding sites and 99.99% analyzing existing ones. And yet when signing into Search Console with many verified sites the interface is ALL about adding a new one. Maybe 10% of the UX would be reasonable but it looks for all the world like I have nothing added.

To get to my sites I need to click the hamburger. Come on Google, being mobile first doesn't have to mean being desktop hostile.

Clicking the hamburger isn't even enough. This just brings up a practically blank sidebar. I then need to expand the 'Search property' drop down. Finally I get a needlessly scrolling list of my sites.

Coronavirus Hikes: April 2020

April 2020 Coronavirus Hikes

On the way back from Grand View park

36.4 unique miles in April (I'm not using the GPS for repeat hikes). Bagged Twin Peaks, wider paths than Mount Davidson.

Book reviews for April 2020

Updated on Saturday, May 16, 2020
Code of Conduct (Scot Harvath #15) by Brad Thor

Code of Conduct (Scot Harvath #15) by Brad Thor

3/5

For some reason I have set myself the task of completing the Scot Harvath series. They are OK thrillers lessened by reading back to back as fundamentally they're very similar. This one is about a deliberate pandemic so it's a good time to read it. Nearly there...

 

The Last Day by Andrew Hunter Murray

The Last Day by Andrew Hunter Murray

4/5

I picked this up because I listen to the no such thing as a fish podcast, co-hosted by the author. I wasn't expecting much but it's really quite good (and not at all funny, more tense and melancholy). I want to find out what happens next.

 

ITHCWY Newsletter for April 2020

Equirectangular clouds for Catfood Earth

A 4K one year global cloud cover timelapse.

Social Undistancing

Niche topic maybe, but if you want to monitor Azure app services via Google Sheets then I've got you covered.

Redesign.

Previously:

Red-Tailed Hawk

Updated on Friday, May 22, 2020

Red-tailed hawk in Stern Grove

Red-tailed hawk in Stern Grove, San Francisco.

Updated 2020-05-22 08:32:

Red-Tailed Hawk at Fort Funston, San Francisco

At Fort Funstion.

ITHCWY Redesign

I've just launched a redesign of I Thought He Came With You. The main thrust is to make the site more usable on desktops. Which seems nuts, but the data doesn't lie. The site has low mobile traffic and for a while I thought this was some kind of technical issue. I optimized the design heavily for mobile and spent a lot of time on speed and some AMP. I guess it's the content. Google loves it when I write documentation for them and doesn't think I have anything useful to say on politics. They're probably right. So I've gone back to having an old school sidebar and I've taken the performance hit of using Bootstrap to get some better looking forms and navigation without spending a lot of time on it. I hope you enjoy it, and if you find anything broken please email or leave a comment.

4K One Year Global Cloud Timelapse

Hurricane Dorian in Catfood Earth

Six 4K images a day at 24 frames per second (so each second is four days) from April 18, 2019 to April 17, 2020:

I made a version of this video a couple of years ago using xplanet clouds. That was lower resolution and only had one frame per day so it's pretty quick. This version uses the new 4K cloud image I developed for Catfood Earth just over a year ago. I've been patiently saving the image six times a day (well, patiently waiting as a script does this for me). It's pretty amazing to see storms developing and careening around the planet. The still frame at the top of the post shows Dorian hitting Florida back in September.

Starlink Train

Updated on Sunday, April 26, 2020

Starlink Train

Caught the end of a SpaceX Starlink Train last night - image above is three stacked six second exposures.