Hackaday Links: May 14, 2023

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It’s been a while since we heard from Dmitry Rogozin, the always-entertaining former director of Roscosmos, the Russian space agency. Not content with sending mixed messages about the future of the ISS amid the ongoing war in Ukraine, or attempting to hack a mothballed German space telescope back into action, Rogozin is now spouting off that the Apollo moon landings never happened. His doubts about NASA’s seminal accomplishment apparently started while he was still head of Roscosmos when he tasked a group with looking into the Apollo landings. Rogozin’s conclusion from the data his team came back with isn’t especially creative; whereas some Apollo deniers go to great lengths to find “scientific proof” that we were never there, Rogozin just concluded that because NASA hasn’t ever repeated the feat, it must never have happened.

Can your chair crash your computer? You’d think not, at least under normal use — I mean, hit a computer with a chair and it’ll probably crash eventually — but that’s not Felix Häcker’s experience. He noticed a pesky problem with his monitor, which turns off briefly when he gets in or out of his chair. His first instinct was to look for loose connections, thinking his movements were wiggling the power or data cables loose. But then he discovered similar reports from other users of the Ikea “MARKUS” chair, which apparently builds up enough electrostatic charge that the discharge created by getting in or out of it zaps the monitor. It’s one of the weirdest failure modes we’ve ever heard of. And note to self: Don’t use this chair at the workbench.

Does a USB drive change weight as you add and remove data? It seems like a silly question, but apparently, it does — just not the way you might think. Since electrons have mass — all of 9.109×10−31 kg each — and flash memory works by storing charge, adding and removing data from a USB stick must change its weight. But interestingly, since flash memory removes the charge from the floating gate of the MOSFET to store a logical 1, that means that an empty flash drive (i.e., one storing nothing but zeros) must weigh more than a drive with nothing but ones. But by how much? Knowing that each bit in a flash memory cell holds somewhere around 100 to 1,000 electrons, a little back-of-the-envelope math shows us that a half-terabyte USB drive can vary by as much as 373 femtograms on the low end to 3.73 picograms at the upper limit. Actually measuring the weight change is left as an exercise for the reader.

If you manage to accomplish that task, you’re probably the kind of person who’d enjoy Teardown 2023. Billed as “a conference for hacking, discovering, and sharing hardware,” it sounds right up our collective alley. It’ll be held June 23 through 25 on the campus of Portland State University in Portland, Oregon. Early-bird tickets are available now, and there’s a call for proposals too. It looks like this is the first in-person Teardown since 2019, the “before-times,” so don’t miss the chance to mix and mingle again.

And finally, a few months back we gave everyone the heads up that Bill Hammack would be coming back to YouTube with more of his “The Engineer Guy” videos. It was exciting news at the time, and now that the videos have dropped, we can say that they were well worth the wait. They cover everything from the neolithic engineering of Göbekli Tepe to the invention of the magnetron, and he manages to tie them all together with insights into the engineering mindset. The key takeaway for me was the difference between the scientific method and the engineering method. The videos are fantastic, and I can’t wait to get the accompanying book, The Things We Make. In the meantime, enjoy the videos.



13 thoughts on “Hackaday Links: May 14, 2023

    1. Flash cells are floating-gate designs, where the gate is electrically isolated – so yes, the total electrostatic charge on them *does* change, but obviously it’s trivial.

      However, I’m pretty sure the linked article makes one mistake: empty flash is not all zeros. It’s all ones. Charge is injected into them via hot-electron injection (and taken away during the erase procedure via tunneling).

      1. No !

        The electrons at the dipole layer in any semiconductor always come from somewhere else *inside that semi-conductor*. Otherwise your transistors, fets, IC’s would get electrostatically charged when disconnected from the circuit. :)

      1. Thanks for the link! I was doing some unrelated EMI testing and eventually traced some “intermittent” interference back to my office chair. I ended up writing a test procedure that involved sitting down on the chair, then getting up again to generate a very reliable spike on my oscilloscope. It cost zero dollars and allowed me to keep testing that very day :-)

        I eventually worked around the EMI problem with Schmitt triggers on the logic gates in the circuit, ferrites on the output, and an isolated DC-DC power supply.

  1. War is never entertaining. Rogozin might be a clown and Putin’s stooge but this peter-measuring contest of some middle-aged men (on both sides!) destroys lives of an entire generation. About 400,000 men (both Ukrainian and Russian) have been injured or perished, and for what? Some muddy trenches? Bunch of rubble where cities used to be? Ruined steelworks? Coal mines, which have been economically unviable since 1990s?

    This is also a disaster for science and technology. There are scientific institutes in Russia, which closely cooperated with our universities, doing basic research. Now it’s all gone and it might take decade or more before relations normalize, at least somewhat.

    Can you imagine Polish, British or American troops taking part in Moscow Victory Parade on May 9th? Unthinkable, after all this is “our enemy”, right? But it happened in 2010.

    World really was a brighter place back then. Sometimes I wonder how it would look, if during 2010s we didn’t provide every person in the world with 24/7 access to (anti-)social media, (dis-)information and quick shots of dopamine from all the (un-)important notifications.

    1. “and for what?”

      -To cement strategic access to Black Sea, Baltic Sea, with NATO expansion for US interest, before clash on South China Sea.
      -New market for FED empty papers after war, and wide drip during war to US defense corporations.
      -To deter anyone from ideas to sell oil for any currency other than US.

      You have to admit, Uncle Sam knows how to play the world, and I’m glad to be on his team.

      1. ” -To deter anyone from ideas to sell oil for any currency other than US. -To deter anyone from ideas to sell oil for any currency other than US.”

        Failure to raise debt ceiling. Empowers alternatives.

  2. I’ve got a similar ESD issue with my desk chair. I expected it was because of the lack of grounding. As the setup is complicated, with multiple machines and video sources, I didn’t want to change it much. Getting up slowly, or touching the computer case before getting up, seems to solve the majority of the issues.

  3. I’ve had the chair issue with a previous computer. I was running active speakers connected directly to my sound card.
    Everytime i’d get up from my chair, i’d hear a couple of staticky clicks and the sound card driver would glitch and throw the volume to maximum. Holding the metal parts of my chair while getting up solved it. A newer PC (same sound card) didn’t have the issue.

  4. I had a similarly mysterious monitor problem at work some years ago, jogging my desk would cause one of my monitors to blank and reset. I eventually tracked it down to a dodgy USB cable that was plugged into the monitor’s USB hub, I can’t remember what it was plugged into but when I found it I could simply poke the micro-USB connector and it would briefly short the power pins and cause the monitor to reset. Probably the connector had been leaned on by someone at some point.

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