💡 SCIENCE BEHIND THE ILLUSION:
Turn on Switch 1 for 10 minutes. Then turn it off and turn on Switch 2. Immediately walk upstairs! If the bulb is ON, it's Switch 2. If it is OFF, touch the glass: if it is WARM, it's Switch 1! If it is OFF and COLD, it's Switch 3! You used temperature as a second data dimension.