The Moon-tilt illusion

 I think we are all familiar with the illusion of the moon looking much larger than its true angular size when it is near the horizon, but there's a less familiar moon-related illusion that I only really noticed for myself when I was out running a few years ago. It turns out to be well-documented, and well-understood, but no less weird, because even when you "know" the explanation, your brain still won't readily accept it - or at least, mine won't.

Anyway, today was an ideal day to observe the moon-tilt illusion. It was a crisp clear day and the half-illuminated moon was beautifully clear in the eastern sky well into the afternoon. The Sun was also putting on a jolly good show, roughly in the south at the time I made this short video:

The moon is tiny but visible in this clip taken on my phone. It's in the middle and about two thirds of the way up when the video starts, to the left of the tall bare tree. The view then pans around to the Sun. The illumination angle of the moon, dictated by the moon's apparent tilt, strongly suggests that the illuminating source must be way off to the right and higher in the sky than the apparent elevation of the moon:

But that's very much not where the Sun is! The explanation for the moon-tilt illusion is rather involved, but in essence, it arises from the failure of our brains to possess an innate grasp of spherical coordinate systems. Presumably this is because there would have been no survival benefit in such an understanding, and therefore no selection pressure driving our minds to get better at it. You would think that knowing this would make the moon-tilt illusion evaporate but it remains as stubborn to me as when I first encountered it - just as my brain "insists" that the moon is bigger when it's close to the horizon.

You can read more about the moon-tilt illusion here:

https://www.seas.upenn.edu/~amyers/MoonPaperOnline.pdf

Hoping this is of interest.

Al

RED January done

 I completed my last two runs for RED January. I had theatre rehearsals on Thursday night, and since the venue is about half way around my normal 5K route, I decided to split the run into two halves.

I then finished off with a shorter run this afternoon, just as the light was fading. I managed to spot a lovely pair of male and female bullfinches along the canal, which absolutely made my day.

In total in January I ran 163.9 km, or just over 101 miles. I'm feeling fine so will continue with the running streak for a while, but I'll spare you all the documentation. Suffice to say that I'll be setting my alarm nice and early for parkrun tomorrow morning, and looking forward to seeing many friends from the local running and volunteering community.

Thank you all for your support; I'm sure the money raised for Mind over Mountains will make a difference!

RED January

Normal blogging will resume now, until I start gearing up for the Cardiff Half Marathon in October, for which I'm running for cancer research.

Ta,

Al

Day 29 of RED January

 As we near the end of the challenge, I'm not feeling so anxious about pulling a muscle or something, so I was happy to push for a 10K on this day's run. 

This was pretty brisk by my standards. I've never cracked a sub-60 10K but this was by far the closest I've got, so I don't feel that it's impossible. My 10K route is much nicer than my 5K one, with only a couple of road crossings and some nice long straight intervals over 2 - 2.5K. It's also mostly on the flat.

I spent the first bit of the run listening to "Body Blow", the second album by the New Zealand band Headless Chickens. They had a minor hit in NZ and Australia in 1991 with the single "Cruise Control" from the same record. I'd been introduced to them a couple of years earlier, while visiting friends in Sydney during one of my telescope runs at the Anglo-Australian Observatory. I became a firm fan of their music and managed (by a stroke of luck) to catch them playing live in Sydney in 1994. They were great!

Meanwhile, in another hemisphere, there was a different group called Headless Chickens. They would become ... Radiohead.

Thanks for supporting me in my RED January challenge for mental health. If you'd still like to chip in, the link is here:

RED January

Ta, Al

Days 27 and 28 of RED January

 The one thing about running in the valleys is that you're never far from a hill. My Monday run took me up 90 m with around 1.5 km of continuous climbing, but it felt more! The descent is nice, though.

Back onto the nearly-level yesterday. There are some elevation changes around this route but they're mostly short steep bits rather than continuous grinds.

Thanks again for your support so far. Just three more runs to go, then I'll have completed my RED January challenge in aid of Mind over Mountains, for which we have raised 180 pounds. I don't plan to stop the daily runs just yet, though.

Days 25 and 26 of RED January

 It's not often that the worlds of SF and running combine, but they did on Saturday. Our dear friends John and Yvonne Meaney were in the area for a half-marathon Yvonne was doing in the morning. I was Run Director for my local parkrun, so once I'd finished the results processing, we were able to meet the Meaneys for a pleasant few hours of catching-up. Like me, John got his start in Interzone, with a bunch of stylish stories in the early nineties that paved the way for his first novel, TO HOLD INFINITY, and a string of dazzling follow-ups. John has diversified into many different sub-genres of SF&F since then, so check out where he's at right now by visiting his website:

https://www.johnmeaney.com/index.html

John's a really interesting guy, a martial-arts expert, computer trainer and a great natural story-teller with a delicious twinkle in his eye. Yvonne is a running machine who was doing another half-marathon on Sunday. Obviously one half-marathon per weekend isn't enough for some people!

After we'd said goodbye to John and Yvonne I did my Saturday stint on the treadmill:

And followed it up with a 5K road-run on Sunday, during one of the lulls as the storm passed through.

My total for January is now 133 km.

There are still a few days remaining of my RED January challenge in aid of the mental health charity Mind over Mountains. Thank you all who have supported me so far.

RED January

Warm wishes,

Al R

Days 23 and 24 of RED January

 I completed a 5K yesterday:

Just before my wife and I drove down to Cardiff to see Hamilton at the Millennium Centre. We'd seen it a couple of weeks ago and enjoyed it so much we decided to try and get two more tickets before the end of the run. It was well worth it. The majority of the main players were different this time, which meant it was almost like seeing a completely new show. They all handed their roles wonderfully and brought out different nuances in their characters. Seeing it twice, as well, meant that we picked up on details of the story a little more clearly the second time round. It's fast! I can't add anything to the plaudits that have already been heaped on this spectacular piece of theatre, but the hype is more than justified.

After stopping overnight in Cardiff Bay we drove back through the tail-end winds of last night's storm. I got my gear on and did another run:

Was it fun? No!!!

Day 22 of RED January, plus signing.

 A nice run round town and the park today, with some hill work for variety. Back on Ladytron for musical accompaniment. Whatever twinge was in my knee yesterday was not present at all today so I had no qualms about running.

It's not all fun and games, though, because there is work to be done. This week, besides writing, I've been signing a batch of signature sheets for the Subterranean Press edition of ABSOLUTION GAP. Sub Press has been hugely supportive of my work over the years and I'm delighted that they are doing these beautiful new editions of the Revelation Space books.

https://subterraneanpress.com/

And another link to my RED January fundraising page if you'd like to support my running effort for the mental health charity Mind Over Mountains. Much gratitude to those who have already done so:

RED January

Love and best wishes to all,

Al R