The AI “Master” bested the world’s top Go players

But now even Ke, the reigning top-ranked Go player, has acknowledged that human beings are no match for robots in the complex board game, after he lost three games to an AI that mysteriously popped up online in recent days.

The AI turned out to be AlphaGo in disguise.

Source: The AI “Master” bested the world’s top Go players—and then revealed itself as Google’s AlphaGo in disguise — Quartz

The Ken Thompson Hack

Ken describes how he injected a virus into a compiler. Not only did his compiler know it was compiling the login function and inject a backdoor, but it also knew when it was compiling itself and injected the backdoor generator into the compiler it was creating. The source code for the compiler thereafter contains no evidence of either virus.

Ken wrote, In demonstrating the possibility of this kind of attack, I picked on the C compiler. I could have picked on any program-handling program such as an assembler, a loader, or even hardware microcode. As the level of program gets lower, these bugs will be harder and harder to detect. A well installed microcode bug will be almost impossible to detect.

Source: The Ken Thompson Hack

Gravitational Waves Detected, Confirming Einstein’s Theory

That faint rising tone, physicists say, is the first direct evidence of gravitational waves, the ripples in the fabric of space-time that Einstein predicted a century ago (Listen to it here.). And it is a ringing (pun intended) confirmation of the nature of black holes, the bottomless gravitational pits from which not even light can escape, which were the most foreboding (and unwelcome) part of his theory..

Source: Gravitational Waves Detected, Confirming Einstein’s Theory – The New York Times

“Everything else in astronomy is like the eye,” he said, referring to the panoply of telescopes that have given stargazers access to more and more of the electromagnetic spectrum and the ability to peer deeper and deeper into space and time. “Finally, astronomy grew ears. We never had ears before.”

Math whizzes of ancient Babylon figured out forerunner of calculus

During that interval, Jupiter’s motion across the sky appears to slow. (Such erratic apparent motion stems from the complex combination of Earth’s own orbit around the sun with that of Jupiter.) A graph of Jupiter’s apparent velocity against time slopes downward, so that the area under the curve forms a trapezoid. The area of the trapezoid in turn gives the distance that Jupiter has moved along the ecliptic during the 
60 days. Calculating the area under a curve to determine a numerical value is a basic operation, known as the integral between two points, in calculus. Discovering that the Babylonians understood this “was the real ‘aha!’ moment,” Ossendrijver says.

Source: Math whizzes of ancient Babylon figured out forerunner of calculus | Science | AAAS

After cuneiform died out around 100 C.E., Babylonian astronomy was thought to have been virtually forgotten, he notes. It was left to French and English philosophers and mathematicians in the late Middle Ages to reinvent what the Babylonians had developed.

How a Massachusetts man invented the global ice market

To this day, Europeans rarely put ice in their drinks, but Americans do. Thanks to the low price of ice in the United States, Rees said, people here “developed a taste for cold drinks faster and stronger than anyone else.” This required active involvement from Tudor, who sent operatives to go from bar to bar trying to convince owners to incorporate his product into drinks. To make the sale, Tudor committed to giving some bartenders free ice for a year, figuring that customers would so enjoy the clink in their glasses that other local bars would feel pressure to put in orders. “The object is to make the whole population use cold drinks instead of warm or tepid,” Tudor wrote in his diary. “A single conspicuous bar keeper…selling steadily his liquors all cold without an increase in price, render it absolutely necessary that the others come to it or lose their customers.” According to Gavin Weightman, who wrote a 2003 book about the New England ice trade, Tudor was celebrated for half a century after his death by scholars at the Harvard Business School, who “admired him for creating a demand where it didn’t exist before.”

via How a Massachusetts man invented the global ice market – Ideas – The Boston Globe.

Rosetta to deploy lander on 12 November

Two robust landing scenarios have been identified, one for the primary site and one for the backup. Both anticipate separation and landing on 12 November.

For the primary landing scenario, targeting Site J, Rosetta will release Philae at 08:35 GMT/09:35 CET at a distance of 22.5 km from the centre of the comet, landing about seven hours later. The one-way signal travel time between Rosetta and Earth on 12 November is 28 minutes 20 seconds, meaning that confirmation of the landing will arrive at Earth ground stations at around 16:00 GMT/17:00 CET.

via Rosetta to deploy lander on 12 November / Rosetta / Space Science / Our Activities / ESA.

The Plane Crash That Gave Americans GPS

The U.S. had already launched into orbit almost a dozen satellites that could help locate its military craft, on land, in the air, or on the sea. But the use of the system was restricted. (It was meant, for instance, to help powerful weapons hit their targets—it wasn’t the sort of tool governments usually want to make publicly available.) Now, Reagan said, as soon as the next iteration of the GPS system was working, it would be available for free.

It took more than $10 billion and until over 10 years for the second version of the U.S.’s GPS system to come fully online. But in 1995, as promised, it was available to private companies for consumer applications. Sort of. The government had built in some protection for itself—”selective availability,” which reserved access to the best, most precise signals for the U.S. military (and anyone it chose to share that power with).

via The Plane Crash That Gave Americans GPS – The Atlantic.

Why the Z-80’s data pins are scrambled

I have been reverse-engineering the Z-80 processor using images and data from the Visual 6502 team. The image below is a photograph of the Z-80 die. Around the outside of the chip are the pads that connect to the external pins. (The die photo is rotated 180° compared to the datasheet pinout, if you try to match up the pins.) At the right are the 8 data pins for the Z-80’s 8-bit data bus in a strange order.

via Ken Shirriff’s blog: Why the Z-80’s data pins are scrambled.

The motivation behind splitting the data bus is to allow the chip to perform activities in parallel. For instance an instruction can be read from the data pins into the instruction logic at the same time that data is being copied between the ALU and registers. The partitioned data bus is described briefly in the Z-80 oral history[3], but doesn’t appear in architecture diagrams.

The complex structure of the data buses is closely connected to the ordering of the data pins.