How photos were transmitted by wire in the 1930s
kottke.org
kottke.org
https://en.m.wikipedia.org/wiki/Wirephoto
I really like these old "explaining" films. The pedagogical level is far higher than what seems common today. And the they take their time to convey the message.
I wonder what happened? I have been blown away by some of the older explainer videos from the 40s and 50s, esp. some of the military training videos for vehicle repair, electrical engineering, etc. Very concise and very clear explanations, always with visual examples. Today, we have things like 3brown1blue that are kind of like that, but in general you don't see information transfer like this either online or in school (at least not in my experience).
Today any unemployed bozo can make explainer YouTube videos. That great as a "democratization", but the average quality is obviously lower.
Today, the cheapest Netflix-approved camera is $2k [0]
Lower barrier to entry is a blessing and a curse. Signal v noise, etc.
[0] https://noamkroll.com/the-3-most-affordable-netflix-approved...
(Not that I would consider all those cameras on the Netflix list cinematic. Some are geared more towards documentary.)
https://www.youtube.com/@animagraffs
https://www.youtube.com/@engineerguyvideo
https://www.youtube.com/@Lesics/videos
The problem is more that they are drowned under the volume of content available.
The problem is that libraries Dewey decimals are managed by librarians who want to sort things correctly. YouTube would be managed by uploaders who wants their stuff to be managed _incorrectly_.
YouTube recommendations and search is a super interesting problem not just because of the scale but also because uploaders are an adverse opponent, trying to keyword stuff their spam.
Which videos? The 500 hours of video uploaded every minute?
- Old Royal Navy instruction manuals and documentaries: https://www.youtube.com/@davidbober7035
My favorite is Hands To Flying Stations (1975): https://youtu.be/cALccuPShQc
- Historic films and clips, mostly focused on workplace safety: https://www.youtube.com/@markdcatlin
My favorite is NASA's Toxic Propellant Hazards: https://www.youtube.com/watch?v=ND2TeNfcmKA
Everything you ever wanted to know (and more) about light and lenses, explained in a way that's totally comprehensible if you learned electricity and magnetism physics in college.
I wanted to like it but couldn't.
I would love something of the same caliber of quality but with a blueprint for an entire series that would cover the compete gamut of a subject.
A popular YouTuber mentioned on HN, and deservedly so, is Ben Eater. His series on building a 6502 computer on a breadboard is exactly the kind of blueprint-driven content I would like to see more of. He had a goal of beginning from a clock circuit and ending up with an 8-bit breadboard computer displaying ASCII to an LCD display and he delivered it in a series of chapters.
Try it yourself - read some of the comments here in that manner and observe the difference.
The technical manuals are all available through Army epubs, but even though they're not classified, you still need a common access card to login and use the site. A lot of them get mirrored somewhere the public can find them, but I would definitely not call the sprawl of where you might find them very searchable.
Where should I start looking? If there's enough high quality content, it might be worth it to download entire websites and index everything to classify and surface things.
Maybe they made plenty of trash explainer videos, and those didn't survive.
Though for economic reasons, that's clearly less true than today.
This is a growing pet peeve of mine. I used to think that advancing media formats and productions tools would generally make conveying knowledge faster, better and deeper. Instead, we see most media intentionally engaging in overall 'dumbification'. It's not just more content being shorter or more summarized, as I'm trying to compare 'apples to apples' here in terms of content targeting, length etc.
Right now, we see every piece of crap uploaded to YouTube. No doubt there's awesome video content being created today - Smarter Every Day by Destin Sandlin seems to fit - but it's surrounded by junk.
How Differential Steering Works (1937) https://www.youtube.com/watch?v=yYAw79386WI
Flak (1943) https://www.youtube.com/watch?v=H8zPNMqVi2E
Note how they made a model in the wirephoto video too to show the concept but with painted rope.
Models seems to me to be a very good pedagogical tool.
Some Youtubers should try that style. Neckbeards with headphones are so over.
Attenuation most have been a problem though? I guess you could send some sort of calibration photo to adjust gain? I don't think practical FM signal modulation was a thing yet in the 30s?
I think that is true for some content, but there's certainly a contingent of content creators out there now putting out a lot of good technical explainer videos. They're doing it far better than your typical mass media content producers.
I prefer reading for theoretical concepts most of the time, but something more complex that I don't have the time to properly study is sometimes better served by a good video or series as well.
Practically, most everything I dig into it's using both, although I just now started using phind.com (thanks for the tip HN) to fill in some of the things all my sources seemed to be skipping over or presupposing, and that has helped me get answers to latent questions I had for quite some time. I really need those links out because I can't rely on AI generated information otherwise, of course.
In the past - as in now - media production is driven by the demands of capital.
We can wax nostalgic for commercials all we want but comparing it to a different modern product does a disservice to the past and media workers in the present.
The painted rope on two spools was also remarkable because of its simplicity - and it holds up today on explaining what a "download" is. ;-)
And even cooler - if we wanted to, I would wager a high school student could implement something along these lines using lego today. There's optical sensors, and you could rig up something to hold a pen like this [1] to render the image.
Why even this simple thing seems unthinkable nowadays?
The devices you mention are what makes most movies unwatchable. The over the top and increasingly forced devices used to essentially manipulate the viewer, lest there's any ambiguity as to what they "should" be feeling. No room for subtlety, just shove it down the viewer's throat.
They're a great alternative to fine acting, directing and cinematography that's able to speak for itself.
I ask this because I swear, as a kid, I’ve seen a cameramen open up a telecom/telephone box and connect something to it. I assumed it was for an uplink back to the station to transmit video.
Since most transmitters were located outside of city limits, equalized telephone lines were used to send the sound from master control to the transmitter.
This was the most common and cheapest way to make the connection to the transmitter until the advent of inexpensive microwave equipment. And microwave links have a nasty habit of fading out during tropospheric inversions so they were actually not as reliable, over long distances, as a phone line with a backup phone line that took an alternate path. (first hand experience here. Ya I'm that old) :-)
Most people today have no idea how you transmit analogue audio faithfully and reliably over long distances, via wires. Telephone engineers figured it out over 100 years ago.
by the way the old bell system technical journals are a fun read and are generally available at places like archive.org
The response of a twisted pair was pretty good over 2 to 4 miles as I recall but for a audio grade (50Hz to 5000Hz) various techniques were used that at the simplest involved coils but there were also active equalizers available for long haul circuits and/or "hi-fi" requirements. Remember DSL lines were/are shipping 1..2Mhz carriers over those same old telco lines. :-)
Of course some old trunk lines used paper insulation. Really. Which meant noise went up ... when it rained.
https://en.m.wikipedia.org/wiki/Hellschreiber
Edit: some ham radio operators still use it for fun, and I'd heard that one of the SDR decoders can read it
https://www.youtube.com/watch?v=saac0ZtTeX4 (be sure to switch to 1080p)
We need to burn all computers and limit technology to this level.
Also, that GO/STOP traffic “light”!!!
Incandescent lights produce visible light largely through heat of the filament, whereas neon lights emit by passing current through the gas, meaning that rapidly changing the current is more effective- the had e doesn't need to cool down like a filament to stop producing light.