tech.explain

tech.explain Explaining tech
Hosted by Eric the engineer
đź“ŤSan Francisco, CA
[email protected]

08/21/2026

Will the new AirPods have cameras in them?

08/20/2026

Can you transfer a file using light?

An app called Decimal Optical Transfer claims to use light to transfer files, but what does that even mean? While it does use a fairly complex mechanism called fountain code for file transfer, it's still reliant on QR codes and phone cameras to split up and catch the files.

08/17/2026

Can you make an ad blocker with an ESP32?

08/10/2026

Can you trick Al with a font?

A new font supposedly tricks Al models into reading the wrong message. To humans, the text looks like a strange optical illusion but remains mostly readable. Give the same image to an Al model, however, and it can consistently transcribe something completely different. It's not really a hack or exploit bur rather a clever demonstration of the differences between human vision and the way Al vision systems interpret text in images.

Special thanks to Jack Dwyer for coming on as co-host to help explain this one!

08/05/2026

Can you get a computer chip for $5?

It's called an ESP32, and it's the same microcontroller found inside countless smart devices and loT products. For just a few dollars, you can buy one mounted to a development board, giving you easy access to power programming, and all of its input/output pins. Despite their tiny size, these boards can interface with sensors, motors, relays, displays, and countless other electronic components. Think of it as a tiny programmable brain that you can teach to monitor, control, or automate a specific task. They're incredibly popular for hobby projects, but they're also found in commercial products and industrial applications. If you've ever wanted to start building your own electronics, an ESP32 is one of the best places to begin.

08/03/2026

Why are street lights switching from orange to white?

Cities across the U.S. have been quietly ripping out their sodium-vapor streetlights and replacing them with LEDs, and the internet is not happy about it. In this episode of Tech.Explain, engineer Eric breaks down the engineering reason cities decided to make the switch and why the "upgrade" hasn't landed the way anyone hoped.

The sodium streetlights we're losing are one of the oldest lighting technologies still in wide use, dating back to the 1930s, and they hung around for so long because they were absurdly efficient, a single sodium bulb could light a full city block for decades on almost nothing. The reason cities kept them isn't nostalgia; it's that sodium was, for a long time, the cheapest streetlight per watt on the planet. LEDs finally beat that number in the mid-2010s, which is why the swap happened when it did. The color change was a side effect. And the color of light you're standing under is way more of a design choice than most people realize. Every bulb sold today, from streetlights to your bedroom lamp, has a Kelvin rating and a color temperature that the manufacturer picked on purpose. That's why the orange-to-white shift feels so jarring: it's not just a bulb change, it's a temperature change, and your brain notices even when you don't.

If you've ever wondered why streetlights look different than they did ten years ago, or why your kitchen bulbs and your living room bulbs feel completely different even though they're the same brightness, this one's for you.

07/31/2026

Can you trick a self driving car into thinking you're paying attention?

We stumbled upon a viral post of people mounting 3D-printed heads inside their Teslas to trick the interior camera into thinking they're paying attention to the road. So we LiDAR-scanned Eric's head, printed it in resin, and drove a Tesla with it. In this episode of Tech.Explain, engineer Eric breaks down what's actually inside that little camera above the rear-view mirror, how it's basically a 1.2-megapixel we**am with no depth sensing, how the driver-monitoring neural network really works, and why a piece of paper, a doll head, and a potato with googly eyes all pass the "attentive" test. If you've ever wondered how good Tesla's driver monitoring actually is, this teardown answers the question with the actual engineering. Educational content only. Do not attempt.

07/29/2026

Is it possible to record your voice with no sound?

We took a Plaud Note Pro to the middle of the Golden Gate Bridge and tried to record a sentence you could barely hear over the noise. In this episode of Tech.Explain, engineer Eric breaks down the vibration conduction sensor hiding inside the Note Pro, why it doesn't listen to sound the way a normal microphone does, how your vocal cords and your phone's aluminum body do the same job in different ways, and why this specific sensor is what makes it work in environments where a regular mic would give you nothing. If you've ever wondered how modern recorders survive noisy rooms, loud phone calls, or environments where you can't hear yourself think, this one answers it with the actual engineering.

Checkout Plaud:
Note Pro: https://bit.ly/4fiGKL5
10% off code: EXPLAIN

07/24/2026

Are there microphones inside disposable v**es?

A viral claim has been going around that disposable v**es have a tiny microphone inside its circuit board. So we tore one apart on camera to find out. In this episode of Tech Explain, engineer Eric breaks down the actual hardware inside a disposable v**e, what an electret condenser microphone (ECM) really is, how it works at the component level, and why manufacturers chose this specific part over every other sensor available. If you've ever wondered whether your v**e is listening to you, recording audio, or sending data anywhere this teardown answers the question with the actual engineering. Educational content only. Do not v**e.

07/22/2026

Why does system data use so much space on your iPhone?

iPhone storage is divided into categories like Apps, Photos, Messages, and System Data. Unlike user files, System Data is made up of operating system resources, caches, logs, and other files that aren’t directly exposed through iOS. Although they’re grouped together in Settings, many of these files serve completely different purposes within the operating system.

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