Adytonian Tablets
Year 2222: Oracle of Delphi Returns
Building Fiction
The backstory
The Oracle of Delphi was famed throughout history and an indelible part of ancient Greek civilization. Pythia was the priestess who undertook the task of divination. During an assigned period every year, all sections of society would go on pilgrimage to seek advice at the Temple of Apollo. Within the temple premises is a small restricted room called adyton where Pythia would deliver her divinations. For these consultations, the Pythia would enter the adyton and then sit on a tripod chair, possibly behind a curtain. After Apollo’s priests relayed questions posted by petitioners, the Pythia would inhale light hydrocarbon gasses that escaped from a chasm in the ground, falling into a type of trance. While in this trance, the Pythia would mutter incomprehensible words, which the Apollo priests would translate (sometimes conflicting with one another) for petitioners (source).
As the gods may have it, in the year 548 B.C. the temple was destroyed in fire and never recovered in the following millennia. The family of Alcmaeonids tried to revive it but failed to prevent the onslaught of time and wars…until now.
The story 2222 A.D.
Through the centuries the family of Alcmaeonids survived and nursed their desire to resurrect the glory of the Old Gods. They blamed the corrupt priest for the downfall of Delphi. The corrupt priests freely interpreted the sacred ramblings of Pythia to suit their needs or for gold. Now the Alcmaeonidian decedents have finally cracked the code. No need for priests any more. This time around Pythia would write her invisible words on tablets at the adyton. Only the pure of heart could see them when they blow off sacred candle. The sacred tablets would hence be known all over the world as Adytonian tablets.
I’m aware the video could have been better, please excuse me 😔
Prototyping Fiction
The idea
In order the make this project interesting, mystical and a believable scenario, it was important to incorporate a ‘ritual’-like action to trigger the revelation of the message. Hence I settled on blowing off LED light in lieu of blowing off candles.
The blow sensor
I always wanted to implement this really cool paper that showed the sensing possibilities with LEDs. Not only would it be a demonstration of intelligent analog sensing, it would also be something really unusual. This was my chance!
You can see the change in voltage in the serial plotter when I blow on the LED and it goes off.
The heating element
I tried out two heating elements:
- Heating pad with NPN transistor
- Peltier device using L298N motor driver with built-in transistor. This is so that I can switch the direction of current to change the direction of heat on peltier surface in contact with paper.
I prefer the peltier device because it gives better control over heat actuation.
The message
The idea was to unveil an normally unseen message on cue. Within the context of thermochromic pigments, I could have done it in two ways:
- Using lemon juice: NOT thermochromic, also the message is permanent once revealed. But definitely a good editable backup😐.
- An reversible invisible ink: Likely by using a thermochromic ink, the problem is I could not find any ink at my lab that could do this. Solar inks only work in sunlight, not heat activated. On the other hand the available thermal inks were all colored (“color” →yellow when heated).
So I had this juicy idea → instead of heating the ink lets see if cooling works :)
Using two kinds of thermal ink M-Y(magenta to yellow) and G-Y(green to yellow), I can create a message but keeping the paint at higher temperature initially then slowly cooling them down. Definitely cannot use heating pad because its cooling time is too long, hence chose peltier units to do the job.
Few issues with thermal inks:
- Regardless of layers of paint it is difficult to get the right shade of yellow in both colors.
- So I assumed painting in dots might work. Well it didn’t as can be seen in the lower left section of the paper. The right dilution of colors may need more experimentation.
What the message should look like (but currently doesn’t):
Project Status
Ran out of time, components and patience for experimentation with another looming deadline. I had an elaborate skit planned but could only accomplish this. The above is my current update, I am hoping to make it more polished in the following weeks🤞