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September 1, 2021 Archives
Wednesday, September 1, 2021
CONTINUITY: HP 9825 Repair Part 11—Debugging the Keyboard, Display, and Printer Board
The repairs of earlier episodes got the Hewlett-Packard 9825 laboratory computer working, but only with a keyboard, display, and printer module borrowed from a working 9825. Now the focus moves on to repairing the module from the unit fried when its power supply blew up. This is a worrisome task, since this module's circuit board includes a custom Hewlett-Packard application-specific integrated circuit (ASIC) which, all these years later, might as well be made of gold-pressed unobtainium.
THE HAPPENING WORLD: Finally—Computer Engineering for Babies
Libro sencillo, pero a la vez brillante: Ingeniería informática para los más pequeños pic.twitter.com/K3tvtV4J7Q
— Mauricio Zapata (@mezvan) August 31, 2021
TRACKING WITH CLOSEUPS: Using Galactic Supernovæ as SETI Signal Beacons
Search for Galactic Civilizations Using Historical Supernovae [IMA] https://t.co/ayhwYIPqKC pic.twitter.com/jYVXgGBYUI
— arXiver (@arXiver) August 4, 2021
The research paper is “Search for Galactic Civilizations Using Historical Supernovae”.
Abstract
We study an interstellar signaling scheme which was originally proposed by Seto (2019) and efficiently links intentional transmitters to ETI searchers through a conspicuous astronomical burst, without prior communication. Based on the geometrical and game theoretic viewpoints, the scheme can be refined so that intentional signals can be sent and received after observing a reference burst, in contrast to the original proposal (before observing a burst). Given this inverted temporal structure, Galactic supernovae recorded in the past 2000 years can be regarded as interesting guideposts for an ETI search. While the best use period of SN 393 has presumably passed ∼100 years ago, some of the historical supernovae might allow us to compactify the ETI survey regions down to less than one percent of 4π, around two rings in the sky.
CONTEXT: Giant Viruses and Their Predators
CONTINUITY: World Energy Production from 1860 to 2019
Amazing timeline of energy production by source. pic.twitter.com/nw9h38pSiT
— Kevin Stevens 🔋⚡️ (@kevindstevens) August 31, 2021