Eric the engineer asks if a real heartbeat sensor can be built, and viewers think of Aliens
Two weeks after it went up, Tech.Explain's Short had its biggest day yet, and its comment section is split between Call of Duty players and fans of a 1986 film.
Why this story? The video is running at 1,344,336 views a day, 13 times its usual pace (103,893).
Can you build a real heartbeat sensor? @Grok #grokbot #spacexaipartner
A typical day for one of Tech.Explain's videos is a few tens of thousands of new views, sometimes a hundred thousand. On its fourteenth day, "Can you build a real heartbeat sensor?" brought in more than 1.3 million, and its total passed 2.3 million.
The channel is Eric the engineer's, out of San Francisco, and its titles are almost all questions: whether an OLED or IPS monitor is the better buy, what a hologram cube is, how an ESP32 proximity sensor works. This one asks whether the heartbeat sensor of video games can exist off the screen. The title tags Grok, xAI's chatbot, and one of the most liked comments argues that other AI coding tools could manage the same build.
The comments suggest the gadget shows people moving nearby rather than reading anyone's pulse. Younger viewers recognize Call of Duty's heartbeat sensor, which reveals enemies on a small screen. Older ones see the motion tracker from Aliens, and several quote the Colonial Marines counting down the meters as the creatures close in. One viewer says that seeing it as an Aliens prop is how they knew they were getting old.
Others have practical plans. One tries to name the exact radar module on the bench, a few ask for a kit, and several picture it finding survivors under rubble after an earthquake or an avalanche. One sees a home security system that needs no cameras, as long as there are no pets in the house.
The proximity sensor video from a week earlier had a good run of its own. Maybe the two Shorts are now pointing viewers toward each other?
Published on Trari
Where next?
What viewers say
Now I know i'm old because I was like, oh, that's from aliens, not cod
@ejabgaming1757See it on YouTubeThat’s the M314 Motion Tracker.
“Five meters, man! Four! What the hell's going on? Three meters! They're right on top of us, man! There's nothing here!"@DWIL2307See it on YouTubeThis should be good for finding survivors of earthquakes and avalanches etc
@decillion-See it on YouTube
7 more comments
I wish I had this in my teenage years.
@Honda_Africa_TwinSee it on YouTubeNow I can see if my parents are coming to my room when I'm playing CoD.
@_GnomeblasterSee it on YouTubeAll I think is the Aliens movie 😎
@KRONOS996See it on YouTubeHonestly, this sounds like the best home security solution if you don’t want to use cameras and have no pets.
@mihailml1905See it on YouTubeThis cool. You should make a kit with this.
@whiteflag2366See it on YouTubeGame over man, GAME OVER
@adamalexander5634See it on YouTubeAliens sensor but sure call of duty. Awesome either way.
@DeeepfistSee it on YouTube
Public comments from the video's page on YouTube
- Channel
- Tech.Explain
- Subscribers
- 321,000 ▲ 7,000 this week
- Channel views, last 7 days
- 3,679,288
- Channel views, pace per day
- 1,040,243 (on a normal day: 693,559)
- Video published
- September 25, 2026
- Video views so far
- 2,368,272 (14 days online)
- Video views, pace per day
- 1,344,336 (on a normal day: 103,893)
The numbers
One Short, two weeks old, set the pace on a channel that already does well over half a million views on an ordinary day.
💡 Test your knowledge
Many viewers see the motion tracker from Aliens in this gadget. Who directed Aliens (1986)?
James Cameron wrote and directed Aliens, the 1986 sequel to Ridley Scott's Alien.



