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AnotherLee

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Published 8 years ago so maybe you've seen it but worth seeing again - power line maintenance via helicopter

 

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Joe Frickin' Friday

Pi (3.14159...) shows up in the weirdest places:

 

 

Two questions:

 

#1: why does pi make an appearance there?

 

#2: who the hell thought they should look there for pi, and why???

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Pi (3.14159...) shows up in the weirdest places:

 

 

Two questions:

 

#1: why does pi make an appearance there?

 

#2: who the hell thought they should look there for pi, and why???

 

ARRRGH Mitch you suck!

 

Now I am going to have to figure it out. Before the 20th.

 

Found paper describing the process - https://www.maths.tcd.ie/~lebed/Galperin.%20Playing%20pool%20with%20pi.pdf

 

Don't have time to read in detail now, quick overview the math does not look terrible.

Edited by BrianM
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  • 2 weeks later...
Joe Frickin' Friday

 

Photoshopping still images is nothing new; we've learned to be skeptical about "photographic evidence" these days.  Video, however, is another matter.  For a long time, it's been difficult, expensive, and time-consuming to manually alter video footage.

 

That's about to change.  If you haven't heard of "deepfake" videos yet, you will soon.  Deepfake tech is getting good enough to realistically superimpose the facial features of person A onto a full-motion video of person B.  Pay person B to engage in whatever activity you ask, and you can then produce video "evidence" of person A engaging in that activity.   It still takes a fair bit of computing power and processing time to make high-quality renderings, but that kind of computing power will, before long, exist in a basic desktop PC.  

 

Here's an amusing but disturbing example of what's possible:

 

 

This is obviously surreal...but imagine instead that someone has made a video of you in bed with someone other than your spouse, and they're using it to blackmail you.  What are you going to do?  They've got high-quality video "evidence" that clearly shows your face.

 

Now imagine that government officials in charge of national security are being similarly blackmailed.  The possibilities are kind of unsettling.   The government is working on ways to identify deepfake videos, but as the tech gets better and better, the cues that give away the fakes become more and more subtle.  

 

In the past, clear video evidence could easily result in a conviction "beyond a reasonable doubt," but deepfake tech is threatening to make video evidence no more reliable than eyewitness testimony.

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The workings of a sequential gearbox are fascinating. They are used in both motorcycles and in F1 racecars. This video has a good explanation and demonstration of an older F1 gearbox internals.

 

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Cool video.

 

Motorcycle gearboxes (at least the ones I have had apart) work very similar, but not quite the same as the F1 box in the video. In a motorcycle, the shift forks slide gears (on both shafts)  back and forth, some gears on each shaft are connected to the shaft, some free. The gear pairs are in constant mesh.

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Joe Frickin' Friday

An impressive FPV drone flight montage here.  Take some Dramamine, find the biggest monitor you can, and run the video in full screen mode:

 

 

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Wow, fantastic footage.  The quality of the video is really amazing.  Some of the aerial scenes remind me of the 70mm movie To Fly, which was funded by and has been airing at the Smithsonian Air and Space Museum since the mid-1970s.  I also wonder if any of the scenes from the US violated the FAA rules on drones.

 

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On 12/29/2017 at 4:57 AM, John Ranalletta said:

NSFW but not porn. Ave is likely a genius w/ deep background fixing industrial machinery & systems. His language is very rough. He buys and tests tools and appliances to their breaking points and isn't a shill for any company or product.

 

Will take the time to explain the metallurgy, electrosity (his term) and hydraulic processes.

 

https://www.youtube.com/channel/UChWv6Pn_zP0rI6lgGt3MyfA

 

LOL, the Mofo just makes up words.  Good info though!

 

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Joe Frickin' Friday

A couple of years ago I bought a SawStop table saw.  It's been reassuring to have that little extra margin of safety, but the downside is that if/when that saw blade brake deploys, it's a one-time-use device and costs $70 for a new brake module.  The device is supposed to sense when the blade contacts meat (i.e. your fingers) but it will react to any material that is conductive enough.  So if you're sawing wet wood, or you hit a nail, you're gonna be out $70 for no good reason (unless you remember to override the mechanism before you begin your cut).

 

So along comes Destin, the "SmarterEveryDay" guy.  In this video, he and a friend demonstrate a patent-pending scheme for preventing kickback in handheld circular saws, as shown in the below video.  It uses accelerometers to identify the beginning of a kickback event, and activates the saw's built-in dynamic braking to slow the blade down before the whole circular saw gets flung up into your face.  So it doesn't care what you're cutting, whether it's wet, dry, or a frozen side of beef, and activation doesn't waste a one-time-use brake mechanism.  Check out the video:

 

 

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Joe Frickin' Friday

Hong Kong's Kai Tak International Airport opened in 1925; by the time it closed in 1998, dense urban development had brought towering apartment blocks right up to the edge of the airfield.   The proximity of mountains required a hard turn late in the landing pattern, at unsettlingly low altitude; together with the nearby buildings, this has resulted in some spectacular aviation footage showing heavy long-haul aircraft behaving more like fighter planes as their crews work their asses off to get them safely down on the ground.    

 

Here then is a montage of footage showing planes landing at Kai Tak Airport, set to the perfect music: the main theme from 633 Squadron.  The final words in the video at 3:37 - "Goodbye Kai Tak, and thank you" - were from a speech given in the control tower after the final flight had departed on July 6, 1998.  

 

For some weird reason, YouTube doesn't allow embedding of this particular video, so no preview image here: you'll just have to click on this link.

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Joe Frickin' Friday

Being married to a Japanese woman (but not speaking more than a few basic words and phrases of Japanese myself), she and I have a lot of conversations about language.  So I found this to be interesting.  If you speak only one English, you take its features for granted, so much so that you don't even consciously think about them.  That is, until you start looking at the features of other languages, and realize that maybe there are some things that might give your language more flexibility (but then of course you wouldn't be speaking English anymore).

 

 

 

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Normally I wouldn't suggest a video almost 43 minutes long, but if this grabs you, you'll wish it was even more detailed!

 

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John Ranalletta

Watching the ash fallout reminds of my childhood.  The railroad tracks were less than 150' from our back door. 

 

Mom would hang the wash outside to dry.  When we heard the steam locomotive's whistle, my sister and I would run outside to take down the wash to keep it from being ash covered.  Yes, I am that old!:classic_blush:

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Then you can never, ever forget the sound of a steam whistle! I have heard my Grand Parents talk about "setting their watch" by the timing of the steam whistles of the locomotives coming to the lumber mills for their loads. 

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Joe Frickin' Friday

Just about everyone has heard of the weird visual effects caused by traveling at nearly the speed of light.  But these effects can be hard to understand and hard to visualize, so MIT has created a "game" that helps people understand these effects.  It's called "A Slower Speed of Light."  You can download it for free here.    Here's their official trailer for it:

 

 

It's kind of a sad setup:  A child has died, and its spirit must "become one" with the light.  Unfortunately the kid's spirit is...well...a little slow.  Since it can't catch up to the light, it has to work on making light slow down.

 

When the game starts, the speed of light is high relative to your walking speed.  As you collect objects in the game, the speed of light gradually slows down until it's almost equal to your walking speed  Several interesting effects occur with increasing intensity because of this:

 

Doppler shift: As you move toward objects, their apparent color shifts toward the blue end of the electromagnetic spectrum; as you move away, their color shifts toward the red end of the spectrum.  Note that the EM spectrum doesn't start/end at red and blue: if you move away from a red object, its color shifts to infrared, at which point you can't see it, and if you move toward a blue object, its color shifts to ultraviolet, meaning you can't see it anymore either.

 

Searchlight effect: as you move toward objects, the photon flux increases, and those objects appear brighter.  As you move away, the photon flux decreases, and those objects appear dimmer.

 

Relativistic aberration:  objects traveling across one's field of view appear shifted from their actual location, resulting in distorted shapes.

 

Note that these effects only occur while you're in motion; objects revert to their normal appearance when you stand still.  These effects are all very subtle when the game starts, but near the end, when the speed of light has slowed to barely above your walking speed, they are severe enough to make navigation challenging.  In the following video, this guy narrates as he plays through the game.  This video 41 minutes long, but I found it instructive to click through and see how the player's view of changes as the speed of light drops.  Pay attention to the meter at bottom-right, which shows the speed of light (the thick white needle) and the player's current speed (the thin black needle):

 

 

 

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RandyShields

Still not sure I understand what they are trying to show, but next, perhaps they can address how to illustrate why nothing contains the vastness of space.

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Joe Frickin' Friday

The TWERP (Twin-Engine Research Project) was a prototype plane powered by a couple of very small jet engines.  During an aborted crosswind landing attempt at the Mojave Air and Space Port, one engine failed and the pilot somehow managed to avoid crashing into a bunch of parked 747s and instead crashed into the softest thing he could find there (which wasn't very soft).   You can read the details here, or watch this oh-my-god video (yeah, he walks away, but dayum)

 

 

 

 

 

As long as we're watching plane crash videos, here's a plane that never should have taken off.  Too much weight, too high a density altitude, and he struggles to get airborne in the first place, struggles to climb, and then eventually just sinks into the trees:

 

 

 

 

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RandyShields

Wow, pretty amazing crash videos.  Those jet engines on the test plane did look pretty tiny.  Years ago after I observed on the steep climb angle of a 757 after they were introduced, a friend who is a former Naval aviator and now a commercial pilot commented that, when that jet was being designed, it was to be the first twin engine jet capable of overseas international flights.  So, Boeing included engines that were way more than the jet needed to make sure it could fly on just one, and to get the various approvals they needed.  In hindsight, the designers of the TWERP probably wished they had included more powerful engines that could fly the plane in the event one went out. 

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Listening to the damage incurred at takeoff it’s pretty amazing this 747 made it around and landed.  There’s some internal Boeing footage that makes this more dramatic but don’t believe it’s ever been released for public consumption. And yes, Randy; the 757 is a Hot Rod!!

 

 

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Joe Frickin' Friday
3 hours ago, RandyShields said:

Years ago after I observed on the steep climb angle of a 757 after they were introduced, a friend who is a former Naval aviator and now a commercial pilot commented that, when that jet was being designed, it was to be the first twin engine jet capable of overseas international flights.  So, Boeing included engines that were way more than the jet needed to make sure it could fly on just one, and to get the various approvals they needed.

 

They do indeed appear to have plenty of spunk:

 

 

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Introduction to "Squatch", expert diesel mechanic & restorer. *link*

By the way, on the subject of a new motorcycle this spring, have you checked with your departments of Free Time, Budget and Ambition?

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