{"id":68962,"date":"2026-10-28T05:06:18","date_gmt":"2026-10-27T20:06:18","guid":{"rendered":"https:\/\/phys-edu.net\/wp\/?p=68962"},"modified":"2026-10-28T05:06:18","modified_gmt":"2026-10-27T20:06:18","slug":"can-you-turn-on-the-tv-downstairs-from-the-second-floor-the-science-of-the-3-mirror-remote-control-experiment-on-tbss-nature-teacher","status":"publish","type":"post","link":"https:\/\/phys-edu.net\/wp\/?p=68962&lang=en","title":{"rendered":"Can You Turn On the TV Downstairs from the Second Floor? The Science of the 3-Mirror Remote Control Experiment on TBS\u2019s \u201cNature Teacher\u201d"},"content":{"rendered":"

I’m Ken Kuwako, Science Trainer. Every day is an experiment!<\/strong><\/span><\/p>\n

Imagine you’re upstairs, you press the TV remote, and the TV downstairs turns on. Sounds impossible, right? But what if you could build an invisible path of light through a house full of walls and floors and send your signal right to the TV?<\/p>\n

A while back, I appeared on and supervised the science segment “The Science of Pulling a Tablecloth Out from Under Dishes” (here<\/a>) for the TBS science show “Nature Teacher,” and the show came back to me with another challenge. This time I worked as both supervisor and guest. It aired on Tuesday, October 27<\/strong>, and I was thrilled to team up with Chocolate Planet again. The question this time: “Can you turn on the TV downstairs from the second floor?”<\/p>\n

You can watch it on TVer!<\/a><\/p>\n

\"\"<\/p>\n

Chikyu Marugoto Daijikken: Nature Teacher (The Great Whole-Earth Experiment)<\/p>\n

New segment! Chocolate Planet and timelesz take on the “Can they or can’t they?” prediction quiz. Now streaming on TVer<\/a><\/p>\n

Can we turn on a downstairs TV from the second floor? Let’s try it with science!<\/h3>\n

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The show served up two quiz questions. I handled the first one, “Can you use mirrors to turn on a downstairs TV from the second floor of a house?”<\/p>\n

    \n
  • Can you use mirrors to turn on a downstairs TV from the second floor of a house? Yes or no?<\/li>\n
  • Can you use a sauna heat blast to make a sweet potato soft and fluffy? Yes or no?<\/li>\n<\/ul>\n

    The cast included the hosts from Chocolate Planet (Shohei Nagata and Shun Matsuo), plus Yoshitaka Hara and Daiki Shinozuka from timelesz. I appeared as the resident Nature Teacher.<\/p>\n

    \"\"<\/p>\n

    In the second segment, Genki Ichioka<\/a> took the Nature Teacher role, joined by Sota Amaya<\/a>, a sauna “heat wave master” and roasted sweet potato ambassador.<\/p>\n

    \"\"<\/p>\n

    What comes out of your remote is invisible light<\/h3>\n

    The tip of a TV remote gives off a kind of light called “infrared.” Its wavelength is longer than red light, which makes it invisible to the human eye. The name literally means “below red,” or just beyond the red end of the spectrum. Your remote blinks this light on and off in a special pattern, and that pattern is how it tells the TV things like “turn on” or “volume up.”<\/p>\n

    You can’t see it directly, but if you press a button on the remote and look at its tip through your smartphone camera, it may show up as a white or purple glow. Some phones can’t pick it up, but give it a try!<\/p>\n

    Infrared light from a remote bounces off mirrors just like the light we can see. That’s the trick we used to carry the signal from the second floor to the first. The catch is that every time light bounces, the mirror absorbs a bit of it, so the signal gets weaker. To keep that loss down, we limited ourselves to just three mirrors.<\/p>\n

    How far can a remote reach with three mirrors?<\/h3>\n

    Let’s do a little math.<\/p>\n

    A typical remote works from about 13 meters away. Let’s call the infrared light’s starting strength I. Light spreads out as it travels, and its strength is inversely proportional to the square of the distance. So the strength of the light after traveling 13 meters can be written like this:<\/p>\n

    \"\"<\/p>\n

    Next, let’s factor in the mirrors. Say an ordinary mirror reflects light at 0.8 times its original strength with each bounce. Three mirrors gives us 0.8 \u00d7 0.8 \u00d7 0.8, which is about 0.51. In other words, the light loses nearly half its strength. So the strength of the light after traveling a distance d looks like this:<\/p>\n

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    The minimum strength the TV needs to react is the same as it was at 13 meters. So we set up this equation:<\/p>\n

    \"\"<\/p>\n

    Solving it gives d = 9.3 meters. In other words, a signal that could normally fly 13 meters will only stay strong enough to switch on the TV for about 9.3 meters once it’s been through three mirrors. Here, d is the total distance the light travels, from the remote, off the mirrors, and all the way to the TV’s receiver.<\/p>\n

    Of course, this is the ideal case. In real life, dirty mirrors, slightly crooked angles, and light spreading out make things even tougher.<\/p>\n

    Gathering spreading light with a magnifying glass<\/h3>\n

    Light also spreads out the farther it travels. So we came up with a plan to gather it back together: fix a magnifying glass (a convex lens) in front of the TV’s receiver. You know how a magnifying glass can focus sunlight into a point so bright and hot it can scorch paper? Same idea. We focus the spread-out infrared light onto one spot on the receiver to make up for at least some of the lost strength.<\/p>\n

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    So, did it work? Or not? Find out by watching on TVer!<\/a><\/p>\n

    What is Nature Teacher?<\/h3>\n

    Here’s the description from the official TBS website<\/a> for “Nature Teacher”:<\/p>\n

    Episode Summary
    \n[New segment! A thorough investigation of everyday questions: the “Can they or can’t they?” prediction quiz]
    \nChocolate Planet, Hara, and Shinozuka split into two teams and take on a quiz where they predict whether something can or can’t be done!<\/p>\n

    \u30fbCan you make a sweet potato soft and fluffy with a sauna heat blast? Can or can’t they?
    \n\u30fbCan you use mirrors to turn on a downstairs TV from the second floor of a house? Can or can’t they?<\/p>\n

    The losing team faces a forfeit, and an incredible discovery that will shake up the world of variety TV awaits!<\/p><\/blockquote>\n

    A trailer is also available.<\/p>\n