The Remote Control Challenge: How Invisible Infrared Light Travels 15 Meters
I’m Ken Kuwako, your Science Trainer. Every day is an experiment.
“How far can a TV remote actually reach?”
Have you ever tried operating it from a distant corner of the room or intentionally testing its limits from far away? Well, I had the pleasure of lending a hand behind the scenes for a quiz that challenged exactly that limit. I served as the science supervisor for the program “Sokuketsu Nitaku Quiz!! Shirokuro” (Instant Two-Choice Quiz!! Black or White), which aired on Nippon TV on Sunday, October 26, 2025.
Can a Remote Control Work from 15 Meters Away?
The segment I supervised was the two-choice quiz: “Can a TV remote control turn on (or off) the TV from 15 meters away?” The experiment was performed live in the spacious environment of a TV studio, with the remote operator standing 15 meters away.
15 meters is nearly double the length of a standard school classroom (about 8 meters). You might think, “There’s no way it can reach that far…” But when the button was pressed…
…the TV miraculously turned off!
The Power of Invisible Light: Infrared Rays
How did the signal manage to travel that far? The secret lies in the light emitted by the remote, called “infrared rays.”
Infrared is a form of light invisible to our eyes, but it has the property of having a “longer wavelength” than the light we normally see (visible light).
For TV remotes, being invisible is an advantage because it’s not distracting. It’s also safer than ultraviolet rays because it carries less energy. More importantly, its long wavelength means it is less affected by obstacles like dust or water vapor in the air, giving it a strong “straight-line progression” (linearity), which allows it to travel far.
This is likely why the infrared signal from the remote was able to reach the TV receiver directly, even from 15 meters away. However, since infrared is a form of light, it will be blocked by solid obstacles such as walls or a person standing in the way. That’s why your remote sometimes stops working!
During the show, there was a narration and on-screen text explaining the “reason why infrared rays can travel so far.” My job was to check that the content was scientifically accurate and presented in a way that was easy for middle school students and the general public to understand. Though it was a small task, I was credited for the supervision.
Even the remote control you use every day is packed with fascinating scientific secrets. I encourage you all to look for the “whys” in the things around you!
Click here to learn how to see infrared rays with your own eyes:
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