Day: July 8, 2020

Bridge Over Trebled Water: How The Golden Gate Bridge Started To Sing

July 8, 2020 by 28 Comments

Throughout the spring, some Bay Area residents from Marin County to the Presidio noticed a sustained, unplaceable high-pitched tone. In early June, the sound reached a new peak volume, and recordings of the eerie noise spread across Twitter and Facebook. Soon after, The Golden Gate Bridge, Highway, & Transportation District, the agency responsible for the iconic suspension bridge’s maintenance, solved the mystery: The sound was due to high winds blowing through the slats of the bridge’s newly-installed sidewalk railing. Though a more specific explanation was not provided, the sound is most likely an Aeolian tone, a noise produced when wind blows over a sharp edge, resulting in tiny harmonic vortices in the air.

The modification of the Golden Gate Bridge railing is the most recent and most audible element of a multi-phase retrofit that has been underway since 1997. Following the magnitude 6.9 Loma Prieta Earthquake in 1989, The Golden Gate Bridge, Highway, & Transportation District (The District) began to prepare the iconic bridge for the wind and earthquake loads that it may encounter in its hopefully long life. Though the bridge had already withstood the beating of the Bay’s strong easterly winds and had been rattled by minor earthquakes, new analysis technology and construction methods could help the span hold strong against any future lateral loading. The first and second phases of the retrofit targeted the Marin Viaduct (the bridge’s north approach) and the Fort Point Arch respectively. The third and current phase addresses the main span.

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Animatronic Nikola Tesla Sets The Record Straight

July 8, 2020 by 18 Comments

While the Hackaday reader likely knows all about Nikola Tesla and his incredible body of work, the same can’t necessarily be said for the average passerby. Even a child can be counted on to know the names of Thomas Edison and Alexander Graham Bell, but as [Daniel Springwald] laments, the name Tesla is more often associated with the line of sleek electric cars than the brilliant Serbian inventor they were named for.

Hoping to level the playing field a bit, [Daniel] has come up with a way for the great man to plead his case. This custom designed robotic facsimile of the alternating current aficionado is able to speak about Tesla’s life and accomplishments in an interactive, if rather creepy, format.

There isn’t a lot of technical detail on this one yet, but what we can glean from the image gallery and video below is that there are an incredible number of OpenSCAD-designed 3D printed parts knocking around inside Mr. Tesla’s head. Add into the mix a healthy dose of springs, linkages, and servos, and you’re just a mustache short of a museum exhibit.

Most of the animatronic projects we’ve covered in the past have been based on animals, so it’s certainly interesting to see what goes into approximating human mannerisms mechanically. We’re not sure if this talking Tesla head will help educate the masses, but it’s certainly an impressive technical achievement.

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The Latest Linux – On A Floppy In A 486!

July 8, 2020 by 97 Comments

If you have ever studied the early history  of the GNU/Linux operating system in its many forms, you’ll have read that [Linus Torvalds] developed his first kernel for his Intel 386-based computer. Though the 386 architecture is now ancient, the current Linux kernel can still be compiled for it and many distributions still maintain an i386 branch to provide broad compatibility for later machines able to run i386 code. But what if you were to take a current Linux kernel and stick it on a floppy in a machine from the early 1990s, with meagre RAM? [Fozztex] did just that, with not a 386 but a 486, sporting what would have been an impressive for the time 36MB of RAM. You can watch it in action in the video below the break.

A recent Linux kernel is rarely if ever compiled for something as small as a floppy disk, so getting one to boot from such ancient media appeared to be a challenge. It was possible though with the tinyconfig make option, and after finding a small enough root filesystem courtesy of Aboriginal Linux, a bootable floppy was created. It’s not entirely useful and its sole purpose was to see whether Linux could see a large hard drive on the 486, but it’s still a version 5.6 Linux kernel booting from floppy on an ancient computer. Never complain that your Raspberry Pi Zero is slow again, we’ve come a long way!

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