Monday, October 4, 2021

Comment: You've gotta love a tough Challenge!

 I have to admit to loving difficult Challenges... 

... and this one was (I admit) harder than I expected... and much more fun!

A sundial at 7:30AM in Southern California, as seen on one of my runs near Bolsa Chica.

A Cautionary Tale for Teachers and Authors: 

When I wrote last week's Challenge, I actually had found a great resource to answer the "from a shadow figure out the time and date?" I had actually done the work to compute it, and--for once!--I was ahead of the curve.  

But as I was writing up my Answer last week, I did what I always advise people to do:  I looked for a separate source to validate my answer. 

Good news / Bad news:  I found a couple of other ways to figure the answer!  Hurrah!  

BUT... they all gave somewhat different answers!  

I love problems like this. (And I freely admit that this drives most people crazy.  But insight lives in the difficult questions--anyone can solve the easy Challenges!)  

And so... I'm still working away on the Answer to the Challenge SearchResearch Challenge (9/22/21): Time and date from a shadow?

No, Remmij, I don't have the blahs.  I'm actually working on a good answer to a simple problem... and one that I am sure is correct.  

So, if you're a teacher or a writer, here's a maxim:  Check your work... including the cross-checks that you would normally do.  And, when you find multiple different answers, make sure you understand why they differ.  It will make your explanations plausible to your students and readers.  

Still searching! 


  1. I will admit I didn’t get very far on this challenge, but - It seemed to me that the building was being used as a sundial so I learned more about how those work and took a field trip to a friendly sundial I know.

    Isn’t the year a factor?

    My sundial had year-specific correction factors for various dates. I stumbled on this NOAA site which might be helpful:

  2. waymarking
    Huntington Beach
    sundials & fossil leakage
    has video
    …thought you might still have a Goo birthday party hangover… 23 is long in the tooth for a garage tech start-up ;^]

  3. …the dial goes digital — makes it easier… also solar
    …maybe 7:37?

  4. why does Goo/Chrome keep telling me my clock is wrong?!? - only on some websites & not showing them
    - when it isn't… something about synching certificates/privacy…
    meanwhile, using firefox/swisscows… the shadow — 'sundial skytree tower' (btw, a similar alert, but has a way to over-ride)
    20 alt engines
    thought the interglob was suppose to bring clarity, simplicity & elevated reflection… must search on…

    now I go all conspiratorial… it's a Friday
    "Ultimately, the manifesto extols the autonomy of individuals and small groups from the control of technology and large organizations"
    was Ted on to something, while being contorted?
    the future past

    1. The Swisscows link is really interesting! Thanks for posting. Just curious: What made you think of searching for "skytree as a sundial"? (Was it the pic in my post?)