Every wireless device you own is built on a discovery that its own inventor thought was pointless. In 1887, the German physicist Heinrich Hertz became the first person to deliberately generate and detect radio waves in a laboratory. When a student asked him what use they might have, he reportedly answered that they were of no use whatsoever, just an experiment that proved the great physicist James Clerk Maxwell was right. He was wrong about the "no use" part in the most spectacular way imaginable. Today the unit of frequency, the hertz, carries his name, and it measures the heartbeat of every Wi-Fi router, Bluetooth earbud, and connected sensor on the planet.
What Hertz actually did
Two decades earlier, in the 1860s, Maxwell had predicted mathematically that electricity and magnetism could travel together through space as waves moving at the speed of light. It was a beautiful theory, but nobody had seen these waves. Hertz set out to test it. Working at the Karlsruhe Polytechnic between 1886 and 1889, he built a transmitter from an induction coil and a spark gap: when a spark jumped the gap, it sent out an invisible pulse of electromagnetic energy. A few metres away he placed a simple loop of wire with a tiny gap of its own. When the transmitter sparked, a matching spark appeared in the receiver loop, with no wire connecting them.
That faint spark was the first radio signal ever sent and received on purpose. Hertz went further, measuring the waves' wavelength and showing they could be reflected, refracted, and polarised exactly like light. He had confirmed Maxwell's theory and, without realising it, invented the entire field of wireless communication.
From a spark gap to the hertz
Hertz died young, in 1894 at just 36, years before Guglielmo Marconi turned those laboratory sparks into transatlantic telegraphy. He never saw radio become a technology. But his name lived on. In 1930 the International Electrotechnical Commission named the unit of frequency the "hertz," and in 1960 it was formally adopted into the International System of Units. One hertz means one cycle per second. When you read that Wi-Fi runs at 2.4 gigahertz, or that an ESP32's processor clocks at 240 megahertz, or that a LoRa module transmits at 868 megahertz, you are counting in units named after the man who found the waves in the first place.
Why this matters for IoT and embedded work
Radio waves are not a niche corner of the Internet of Things; they are the medium the whole field swims in. Every wireless protocol an embedded engineer reaches for is simply a disciplined way of shaping the waves Hertz discovered. Wi-Fi, Bluetooth Low Energy, Zigbee, LoRaWAN, NB-IoT and cellular all modulate radio waves at different frequencies, each trading range, power, and data rate in its own way. Choosing between them is one of the first real decisions in any connected-product design.
Understanding the physics beneath the spec sheet is also what separates a reliable radio design from a flaky one. Antenna length is tied directly to wavelength, which is tied to frequency. Interference, multipath fading, and range limits are all consequences of how these waves behave in the real world. A device that works perfectly on the bench and fails across a warehouse is almost always a radio problem, not a software one. The engineers who ship dependable wireless products are the ones who respect the 140-year-old fundamentals that Hertz uncovered.
The local angle
For builders across the Philippines, wireless is often the difference between an idea and a deployable product. Flood sensors along a river, GPS trackers on delivery fleets, LoRaWAN nodes spread across a farm, and smart-metering devices in a subdivision all depend on picking the right band and designing the radio path properly for local conditions and regulations. Getting that layer right early saves painful redesigns later. It is exactly the kind of work we help students and companies get right, whether it is a thesis prototype or a product headed for the field.
If you are building something that has to talk wirelessly and you want it engineered properly from the silicon up, take a look at our IoT and embedded services, or get in touch to talk through your project. The next time you see "Hz" on a datasheet, remember it started with one spark, one loop of wire, and a physicist who was sure he had discovered nothing useful at all.
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