Solution: Light Switch Logic Puzzle

Light Bulb

Solution to the light switch puzzle:

Flip the first switch and leave it on for a minute, then switch it off.
Ignore the second switch.
Flip the third switch and leave it on.

Hoof your way, painfully gasping, up the many flights of stairs to your apartment.

Examine the lamp.

If the bulb is off, and warm, then the first switch controls the lamp.
If the bulb is off, and cold, then the second switch controls it.
If the bulb is on, do I have to tell you…?

A Box with a Secret – See, Mom, Physics can be Fun!

Puzzle Box-1Beck wanted to build a locking box to keep safe the valuable things 9 year old boys collect (most of them are dead). A quick accounting revealed we had the required stuff:

Old cedar from a recently demolished closet… Check.

Tools… Check.

Can-do spirit… Check.

Twenty fingers… Check (I like to count them before and after. I find if you wait too long, it is harder to clean out the sticky pieces lodged in the machinery).

Instead of a typical box with a padlock, we went minimal. Aesthetically it’s just a box, nothing special, but what makes it cool is its locking mechanism. Everything is flush except for a single, solitary knob on top. The knob doesn’t appear to do anything. It doesn’t turn (much), or lift up, and cannot be pushed in any direction. While you can hear things sliding around inside the box, no matter what you do, opening it appears impossible. Unless you know the secret.

The secret is centrifugal force. You probably guessed that.

Puzzle Box-7

The box’s top is secured in place by six sliding pins (nails, actually). The box remains locked no matter how it is tilted because when some of the pins slide to the open position, others slide closed. In order to open the box, you must place it on a flat surface, knob on top, and spin it. Centrifugal force slides all of the pins to the outer edges of the box allowing the top to be lifted off.

Puzzle Box-3

Yet, even the wonders of physics won’t open the box unless you first orient the seemingly useless knob so a pin can slide through a slot under the knob, all the way out, when the box is spun. Nobody has ever figured out the secret on their own.

Here’s what the inside looks like (dead things not shown for clarity). It’s not elegant, but hey, it was our first try!

Puzzle Box-8

We didn’t build from plans because Beck likes to “Free-build,” or as I call it, “Wing-it and rebuild it ’til mom makes you practice piano.” Thankfully the box was simple and the mechanism easy to “wing.” Someday, though, I’ll chain Beck to his desk for 5 minutes of pre-planning work, just to teach him the “right way” to design. I’m not sure if the chains they use to anchor battleships are strong enough. Might need to add some super-glue and barbed wire, too.

Puzzle Box-9

Bathing in Water and Light – A Contemporary Bathroom

Contemporary Glass Bathroom by Tim Bjella - Arteriors Architects

This contemporary bathroom illustrates a guiding principal behind much of my work: windows should be more than mere holes punched through walls with a bit of glass thrown in to keep the bugs out.

  • Windows make great walls of their own, transparently filling the space between solid masses.
  • When placed on multiple sides of a room, they allow sunlight to bounce off and around the space’s surfaces, eliminating glare and headache inducing extremes of light and dark.
  • They may be used exclusively for natural daylight, omitting the view. These concealed windows wash walls with light and add drama to a space (notice the daylight behind the tile-clad pier below).

Contemporary Glass Bathroom by Tim Bjella - Arteriors Architects

Contemporary Glass Bathroom by Tim Bjella - Arteriors Architects

Contemporary Glass Bathroom by Tim Bjella - Arteriors Architects



What does mom’s night out mean? For me and Beck, it means Dadssert – anything dad can scrounge from the pantry that includes sugar or sugar-like substances. The only things not allowed are those mom wants us to eat.

The best we could do tonight was a mixture of Crispix, marshmallows and chocolate bars (not nearly as good as the candy salad we made before dinner).

It’s finger food!

I Switch Which Switch?

Light Switch

Here’s a logic puzzle for your amusement:

You live on the top floor of a highrise. On your desk sits a lamp which is currently off. The lamp has no integral switch. Instead, it is conveniently controlled by a switch in the sub-basement (the architect of the building won an award for creative, ‘green’ building design by placing all of the light switches in the sub-basement to reduce extravagant and wasteful wiring. You may take comfort that the architect also lives in the building, which curiously maintains a box of rotting tomatoes near his apartment door).

Further complicating your life, the light switch is one of three, with the other two switches not connected to anything (the electrician got a deal on salvaged light switches from Botswana). All of the switches are off.

Your task is simple: determine which of the three switches controls the lamp.

Oh, did I mention you are malnourished and only have enough energy to make the trip down to the sub-basement one time (the contractor ‘forgot’ to build the elevator and is currently living like a king in a cardboard box under a bridge. It’s a single-storey box.)

You may go downstairs one time, flip the switches up and down as much as you like, take a nap, or play fetch with the rats, and when you finally arrive back at your apartment, gasping, you must determine which of the three switches controls your lamp. Easy.

You may not use trickery. No tools, voltage meters, cameras, mirrors, trained seals, telephones to talk with someone in your apartment, etc. Just you, the switches, and the lamp.


Here’s the solution.

210 Days Until Christmas. Just a Reminder, Robyn.

Carved Wood Snowman Christmas Ornament by Tim Bjella

Here’s one of the snowman ornaments I made sometime in year’s past. I can’t remember when. The premise of the design was that this unfortunate, little snowman was built on the top of a hill. Now it’s at the bottom. So sad. Let that be a lesson to you, kids.

For the coming Christmas, I made a very special snowman ornament for my wife, Robyn. It’s all wrapped up in a box waiting to be opened. Only 210 days to go (just thought you’d want a reminder, Robyn).

Carved Wood Snowman Christmas Ornament by Tim BjellaCarved Wood Snowman Christmas Ornament by Tim BjellaCarved Wood Snowman Christmas Ornament by Tim Bjella

Read the story of my snowman ornaments here.

It’s the Little Things

Cross-country flight today, seated next to a young girl, 6 1/2 years old (not 6 or 6 1/4, but 6 1/2. Very important) and her mom. She didn’t have anything to do, so I gave her my sketchbook to color in and we chatted for much of the flight. Kids like Disney World. Who knew? She left me this note.

Sketchbook Note

Sketchbook Coloring

Yet another reason to always carry a sketchbook (and multi-pencil)!

Lego My Haiku!

Legos with Tim and Beck Bjella
Beck, my nine year old son, liked my first attempt at writing Haiku and wanted to write some together. I suggested we eat candy and play video games instead, but he forced me to sit on the floor and write with him. By way of punishment, I’m considering taking away his broccoli at dinner.

This time the theme is ancient Japanese building blocks, sometimes known as Legos (might be ancient Denmarkian. Who really knows).


Click them together,
Can’t get the darn things apart,
Bestest toy ever!

Shiny, red Lego,
Fell out of the brick rainbow.
Now it’s in my soup.

Take the easy route… Naw.

What do you do if your ceiling is high but you want your lights to hang low? Get longer cords, obviously. Unless the word “simple” isn’t in your vocabulary, that is. In which case, you call your friendly local metal fabricator. After a couple of minutes with your phone held away from your ear, answering the question “why do you want to do that?” a couple dozen times, you might get some of these.

Industrial Light Brackets by Arteriors ArchitectsIndustrial Light Brackets by Arteriors Architects Industrial Light Brackets by Arteriors Architects