- What signal did Marconi hear on Signal Hill, and how far had it traveled?
Telecommunications History
The development of long-distance communication technology.
- What did ships' radio operators normally expect to hear over wireless before Fessenden's Christmas Eve broadcast?
- Why was the ability to amplify a signal such a significant advance over merely detecting one?
- What role did Kelvin play in laying the first successful transatlantic telegraph cable?
- How did Marconi's transatlantic wireless signal of 1901 depend on innovations he didn't personally develop?
- Why would GPS satellite navigation drift by kilometres a day without correcting for general relativistic effects?
- What everyday technologies today rely on stimulated emission, from barcode scanners to fiber-optic internet?
- What engineering problems had to be solved to enable two-way voice communication across the Atlantic, beyond simply sending a one-way signal?
- How did the ionosphere's behavior at night versus day complicate early long-distance radio transmission?
- How did the 1920 transatlantic radio test lay groundwork for commercial broadcasting?
- What would global radio communication have required without a reflecting layer in the upper atmosphere?
- What limitations did meteorologists face when they could only observe weather from ground-based stations?
- How many cloud-cover photographs did TIROS-1 transmit during its 78-day operational life?
- Why did early meteorologists need to learn a new way of reading weather patterns from satellite images?
- How did TIROS-1 change the ability to track a hurricane from formation to landfall?
- Which ground stations relayed the first live transatlantic television signal via Telstar 1?
- Why did the transatlantic TV signal take about a quarter of a second to cross the ocean?
- What caused Telstar 1 to go silent just seven months after launch?
- How did Telstar 1 prove that intercontinental communication no longer needed undersea cables?
- What everyday technologies today depend on lasers that a Bell Labs administrator once dismissed as a waste of money?
- What is a semaphore, and what problem in process synchronisation did Dijkstra invent it to solve?
- How did TAT-8 encode telephone calls differently from the copper coaxial cables it replaced?
- How much telephone call capacity did TAT-8 have compared to the last copper transatlantic cable?
- What role do undersea fiber-optic cables descended from TAT-8 play in today's internet traffic?
- Who sent the first SMS text message, and what did it say?
- What signalling protocol and infrastructure made the first SMS message possible?
- Why couldn't the recipient of the first SMS message reply to it?
- Why did efficient laser diodes make fibre-optic telephone calls possible?
- How did the ceremony reach roughly 360,000 people blessed in a single day?
- What modern technologies depend on the ultra-precise clocks built from frequency combs?
- Why did early glass fibres lose their signal within twenty metres, and what changed to let light travel kilometres instead?
- What made Kao's purity requirements for glass seem impossible to the engineers of his time?