By Boris Sorokin, SKA Observatory, United Kingdom, and Masaaki Hiramatsu, National Astronomical Observatory of Japan (NAOJ), National Institutes of Natural Sciences (NINS), Mitaka, Tokyo, Japan

A microwave oven is starting to heat a meal, while a laptop comes alive on a kitchen table. The video call connects and the music starts. Most of this works and exists because some things didn’t go as expected.

Unexpected journeys, everyday gifts

In 1945, radar engineer Percy Spencer noticed a chocolate bar melting in his pocket as he stood near a magnetron. The microwave oven followed: The same physics used to spot incoming aircraft, repurposed to warm last night’s leftovers.

In the 1970s, the United States built a constellation of satellites to give submarines and missiles their precise position; today the same system, the Global Positioning System (GPS), sits in every pocket. Research aimed at one target, landing one field over.

Radio astronomy has its own ledger of such occasions — and it is longer than most people realize.

Wi-Fi: The gift of a failed black-hole hunt

In 1974, Stephen Hawking calculated that very small black holes – if they existed – would evaporate, releasing a final burst of detectable radio signals. The prediction sent radio astronomers searching.

At Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO), Irish-born engineer John O’Sullivan led a team building tools to recover such whispers from background noise: a custom Fast Fourier Transform chip, and a signal-recovery technique designed to undo the smearing introduced by intervening cosmic gas and dust. They missed their initial goal.

But around 1990, O’Sullivan’s team realized that indoor wireless networks face the same problem in microcosm: A transmitted signal arrives at the receiver as a smear of overlapping echoes bouncing off walls and furniture. The same mathematics solved it.

CSIRO patented the technique in 1992 and 1996; it became part of the IEEE 802.11a/g/n standards that run modern Wi-Fi.

More than 21 billion Wi-Fi devices are now in use; one Wi-Fi Alliance study puts Wi-Fi’s global economic value near USD 4.9 trillion in 2025. Each works, in part, because radio astronomers tried to hear a faint cosmic sound; CSIRO’s royalties alone exceeded AUD 430 million (over USD 300 million) – pure curiosity paying for itself.

And not only Wi-Fi

The same lineage runs through other corners of daily life.

Australia’s ASKAP radio telescope uses phased-array multi-beam receivers that let each dish see a wide patch of sky instead of one direction at a time. The Australian start-up Quasar Satellite Technologies is now commercialising the same idea in reverse: a single ground station talking to hundreds of satellites simultaneously.

As mobile networks begin to interconnect with low-Earth-orbit constellations to deliver direct-to-handset coverage, the bottleneck is exactly that ground-side throughput. The mobile signal that finds your phone in a remote valley a few years from now will, in part, travel through hardware whose ancestor was an Australian radio telescope.

A different crossing reaches into hospitals. Radio interferometers and medical scanners face a surprisingly similar problem: each must reconstruct an image from incomplete data – sparse antenna measurements in one case, sparse magnetic-resonance signals in the other.

Algorithms developed in the 1970s for radio astronomy, including Jan Högbom’s CLEAN deconvolution method, have descendants in the MRI (Magnetic Resonance Imaging) and CT (Computed Tomography) pipelines that scan tens of millions of patients yearly. So, when a hospital scanner reconstructs your brain, it owes a quiet debt to people who built tools to reconstruct distant galaxies.

Meanwhile, phased-array beamforming itself, long refined in radio astronomy and radar, is central to the architecture of 5G base stations for today’s advance telecommunications.

Even the Global Positioning System (GPS), part of a global navigation satellite system (GNSS) sector worth forecasted to be about EUR 350 billion (over USD 370 billion) in 2026, owes a quiet debt. Its precision depends on a celestial reference frame maintained by Geodetic Very Long Baseline Interferometry (VLBI), where radio telescopes work as a planet-sized instrument to fix distant quasars. The map beneath the map is, in part, an astronomers’ map.

What we don’t yet know we’ll need

Each new generation of radio telescopes pushes a different frontier.

The Atacama Large Millimeter/submillimeter Array (ALMA), operated through an international partnership among East Asia, Europe, and North America, in cooperation with Chile, drives some of the world’s most sensitive cryogenic detectors.

The SKA Observatory, now coming alive across South Africa and Australia, will produce data at a scale that is forcing genuinely new high-performance computing architectures.

Some technologies, and many specialists trained to build them, will stay inside astronomy. Others will turn up somewhere unexpected – in a hospital, a mobile network, a spectrum agency, or a piece of code written by someone who has never thought about a galaxy.

Why keep the sky quiet?

Radio astronomy, of course, needs a quiet spectrum to function. Harmonizing usage of the radio spectrum and satellite orbits is a global responsibility, carried out by countries worldwide through the International Telecommunication Union (ITU).

ITU’s upcoming World Radiocommunication Conference (WRC-27) in Shanghai will decide how the crucial quiet is preserved against a sky filling with new transmitters.

The case is sometimes made in lofty terms – humanity’s right to ask the oldest questions.

There is also a more practical case. Societies that protect cutting-edge curiosity-driven science have often protected the source of technologies they did not yet know they would need. Wi-Fi was one such gift. The next fifty years will surely produce more.

The microwave oven signals the dish is ready. The call continues. Across the world, countless radio dishes quietly listen for the next signal we don’t yet know we need.

Header image credit: Adobe Stock
Boris Sorokin portrait image credit: SKAO