What old technology are you surprised is still in use today?

It is time for the fax machine to die.

It has been time for the fax Machine to die for the last 18 years.

For the love of God somebody, please kill the fax machine.

Need a simple end to end encrypted email solution, and for regular users to understand that solution isn't Gmail for fax to die. The health and financial sectors are keeping fax alive, and it isn't completely their fault.
- Correct me if I’m wrong but fax isn’t end to end encrypted so how is it deemed more secure than email which also isn’t end to end encrypted (by default).
- Email encryption has been a thing since '91. https://en.wikipedia.org/wiki/Pretty_Good_Privacy
Abraham Lincoln sent faxes! Ancient tech.
As someone who provides customer support for software that basically turns a Windows server into a giant fax machine, I 100% agree.

Heating water to set something in motion to generate energy.... For example, a nuclear power plant generates electricity based on this principle.

Someone said steam engines are still in use as NYC infrastructure.

Manhattan has an entire network of steam transmission.
@xia @TheImpressiveX Not a steam engine, but an entire network of pipes carrying steam into buildings for heating.

Microwave because it is an old tech that was so ahead of its time...
If it didn't exist and was invented today it would be such a hit!
Personally I believe it was invented by aliens or a time traveler.

Gas stoves. Yeah, real smart to use a source of pollution inside your home. Electric ranges have been available for decades. Recently available induction stoves are like magic. Yet people cling to cooking with fire.

I live in a country with abhorrently unreliable electricity.

Even now that I have solar and even if I mostly (85%+) cook on a plug-in resistance hob and electric oven, gas is just unbeatable as a backup during the winter. No sun? Grid down? Milk boiled over and got into the hob’s thermostat? Need to cook more than one pot at a time? Israel decided to bomb a fucking residential substation for no reason again? Power company operator decided to accidentally pull an epic prank and route the wrong voltage to everyone’s house, frying a whole town’s fridges, during a year when people couldn’t afford to replace them (I can’t find an English article to link but I promise this happened)? No problemo

I also got a plug-in ~~induction~~ infrared plate and while it is pretty much magical it also makes my inverter shit itself uncontrollably (all my LED lights flicker and it makes an uncomfortable noise) so I really only use it when the ”good” grid is on (the bad one can’t handle it, the good one is the one from the prank above).

You can pry my backup butane from my cold dead hands. I replace the tank less than once a year, it’s fine. Not everyone who wants this option to stay is a regressive cultist.
- Can you get a battery to handle the unstable input and output nicely since there's a buffer?
I like cooking with fire. Temperature changes (especially reduction of heat) are much faster than resistive electric, and when cooking on an unfamiliar stove, it's easy to tell what's going on; I don't have to guess what "6" means on a dial because I can look at the fire and see.

Both the awareness that gas stoves are a significant source of pollution (mostly nitrogen oxides) and availability of induction are fairly recent and not universally distributed. I'd accept the pollution for a better cooking experience than resistive electric, but induction is pretty compelling all things considered.
Agreed, but I really miss the sheer power of gas stoves. Wondering if they make (or if I can make) souped-up versions of electric or induction stoves. Or do I just have a really weak electric stove?
- My induction hob can heat things up faster than gas
  
  It's a combination of high power and high efficiency
- An induction stove with booster can outheat any gas stove.
- Or do I just have a really weak electric stove?
  
  I think you might just have a really weak one, or poor compatibility pots? I've had both, and if anything my gas burners feel a little slower and cooler than my induction stove did.
- Our induction plate rivals the power of the electric range in this apartment. Our previous induction plates were on par with our gas stove. Am hoping for even more power when I upgrade to a built in induction range that’s wired into 240v.

RSS. And very happy that it is!

When I was a child I thought houses would look drastically different in the future. They in fact do not.

George jetson house, what they thought the future would look like in 1960:

COBOL

Well, I was surprised at the time...

IPv4

Imagine the world as we know it is a work of speculative fiction: you're reading a book about a world that has harnessed the power of electricity to achieve all kinds of incredible things. Electric power's not just magic, though, right? This is hard sci-fi, there are technical limitations on how this fantastical technology works. There are ways to generate electricity enough for everyone to use but to actually use it they need the electricity to travel long distances from its source to their location and the route is required to be more or less contiguous.

Now electricity, according to this wild sci-fi premise, is a force that kind of wants to travel; it is possible for it to move, then it will. And I said "more or less contiguous" up there because it can actually cross small gaps as long as the rest of the route remains valid. And one thing it is possible for it to move through is a human body, which can be nightmarishly harmful to the human it travels through. Indeed, there is a history of intentionally placing humans into that route in order to execute them. And living creatures aren't the only thing it can harm: electricity traveling through a flammable medium can start fires and, if misdirected in some way, can even destroy the very technology it's being harnessed to power.

Even setting aside the destruction it can cause should it end up traveling where they don't want it to travel, there is also the fact that if it fails to travel along the desired route then electrical technology that people have built their lives around will simply stop functioning. There are ways to generate one's own limited supply of electricity as a stopgap until the main course is reestablished but most people in the setting don't have that and it's a temporary measure even if they do. And I don't just mean stuff like their business failing to function, I mean that even the basic day to day operations of their lives will fail. They have stores of food kept safely cold by electrical technology that will spoil if the electricity stops, they have kitchens that run on electricity to cook that food even if the ingredients are still good, and most of them never learned how to do these kinds of basic things the old fashioned way and if they want to learn how then their primary source for information is itself a technology that requires electricity to function.

So you're talking to a friend about this book you've been reading about this electrical world. And your friend asks you about these "routes" you told them the electricity travels along:

"How do they move this super dangerous yet super integral substance across such long distances that even people in the middle of nowhere have access to it?"

"For the millionth time, it's not a substance."

"Whatever it is, how do they get it from A to B?"

"Well... mostly they the put wires that conduct it on top of thirty foot tall wooden posts."

"Wouldn't those just fall down whenever there's bad weather?"

"Yeah, 'power outages' as they call them are not entirely infrequent."

"So these wooden posts that if they fall over could start fires or kill bystanders or, like, melt stuff. They keep all that away from where people are at least?"

"Well, okay, I was simplifying. There's these bigger and sturdier metal constructions for carrying wire the longest distances and they build those in the middle of nowhere. These wooden posts that fall down easily are mostly situated around where people are, like roadsides. They were first on my mind because they're more what's present where the story takes place."

"Didn't you say earlier they've all got these individually operated vehicles on the roads that are measured in the strength of dozens of horses, thousands of pounds of metal that move faster than jungle cats? Wouldn't they just hit the poles by accident and, like, demolish them?"

"Yeah that happens sometimes."

"...I guess I'm being uncharitable. If I were in this scenario I'd probably be more excited and not thinking as clearly as I do from this distance. It makes sense that such a radical new technology would have some unforeseen negative consequences."

"Actually it's not new. Electrical power's been commonplace for something like a century as of when the story takes place. The characters don't remember a world without it."

"And they're still just... putting it on sticks?"

"To be fair, some of the characters started running the cables underground in those populated areas."

"Oh, that makes sense. So they probably have those marked and don't have to worry about them?"

"Mostly. They don't actually mark them, and most characters don't know where they are. If they need to dig, they have to find them each time. Sometimes they forget to find them first."

Toilets

Surprised it hasn't been superseded meaningfully? Or surprised people are still using it instead of another better tech?
- I think there have been great advances in comfort and convenience factors. The toilet itself and the valve system, hasn't changed in 80 years. It feels like a technology that should have been eclipsed to something more efficient and easier for the sanitary sewer system to handle.

Radio

Rat traps

Vasectomies (+ birth control pills)
animal testing for human research.
I'm sure that anyone working in a hospital can cough up a few dozen more.

RISUG has been invented in 1978,
is reversable, cheaper, zero side effects,
and with so far 0% failure rate when implemented properly,
Vasalgel, an improvement on RISUG by having a longer shelf-life,
has been invented around 2015.

So this stuff has been invented in the same year as the first Star Wars movie,
had gone through all trials multiple times with flying colors,
and instead we use knives and pills with large side effects.

If any invention could be been ubiquitous in use at a much earlier stage,
then this would be it.
It could and should have been widely used by the 1980's.

For animal testing we have 3D printed human tissue.
So why test on animals if your question is "Does this stuff work on human tissue?"
The answer you'll be getting is whether or not it works on mice.
Mice are not human.

As I was thinking of getting a vasectomy, you got me curious. But it is still in clinical trials according to Wikipedia

https://en.m.wikipedia.org/wiki/Reversible_inhibition_of_sperm_under_guidance

For the animal trials: we could cut them down by a lot, but experimenting on tissue is not the same as on a full body and its complex system.
- Risug is in trials forever.
  
  It's very likely to have been
  deliberately held back for decades now
  by a true conspiracy and for petty reasons.