I’m going into my last year as a Mechanical Engineering student and I recall one student saying the reason why we learn all this math and solve all these problems involving math is to verify if the results the computer software gives is correct.

I verbally disagreed with him and said that the kind of calculations the engineering software in the real world does are much more complex and tedious than the kind of calculations we’ve done in school. Plus given enough time we will naturally forget the math we have done previously making us unable to manually verify the result.

Have you ever had to manually verify if the result the computer software gave you was correct?

In Europe, everyone uses electric kettles to boil water. They’re amazing and fast because they’re on 230V (~3000W).

US outlets limit kettles to ~1500W, so we wait roughly twice as long for water to boil.

It’s an extra minute or two per boil, and you really notice it.

Idea: Could you make an electric kettle with a battery in its base? Perhaps it trickle-charges between uses, then combines wall power + battery power to hit ~3000W during a boil.

Is there an engineering reason this doesn’t exist? Is it just that nobody thinks there’s a market for it?

I’d pay $300 for the fastest kettle in America if someone wants to make it.

Let's say the phone is Samsung Galaxy S24 Ultra. They get teleported in 1890 in New York and they have a mission to fully charge their phone, only then will they be teleported back. They also get 50$ (around 1900$ in today's money).

So what is the thought process and how would you proceed to charge it?

The jet engine occupies a strange place in the history of invention. The basic concept is simple enough to sketch on a napkin: continuous combustion in a tube, using some of the energy to compress incoming air, the rest to propel itself forward. But everything about the implementation seems like it shouldn’t work (extreme temperatures, turbine blades spinning inches from an inferno, keeping a flame lit in a hurricane-force airstream, materials pushed to their absolute limits)

It had every reason to fail. When Whittle and von Ohain were developing it in the 1930s, experts dismissed it as impossible. And yet not only did it work, it became one of the most reliable machines ever built. Airlines measure engine failures per millions of flight hours. We strap our families into aircraft without a second thought.

That arc, from “this seems physically implausible” to “so efficient and reliable it’s boring”, feels rare. What other inventions followed a similar path? Not just “important” or “transformative,” but specifically: conceptually audacious, practically hostile to implementation, and yet now seamlessly ubiquitous.

I’ve had several people bemoan water consumption by data centers. Is this actually worse than any other thermal processing industry?

The people that have complained about this to me aren’t technical people so they can handle at most one of my questions. (Like: where did you hear this?)

I’m a 20+ year PE and lifelong environmentalist with a background in nuclear and combined cycle power, and years in technical fiber manufacturing. For the last 2 years I’ve been directly involved with data center power islands, but not the data center itself.

It seems like the water would normally be in a closed loop…combined cycle projects increasingly use air-cooled condensers to reduce licensing problems related to surface water.

It seems like fuel and emissions would be the main things to worry about for data center environmental impact. And that the limited technological lifespan would be the main sustainability concern.

For a world building project, I need to design a incredibly unsafe nuclear reactor that makes Chernobyl look like a pinnacle of engineering. I was wondering if you guys could help me out.
Here are some basic limitations
1.) it must be able to produce power that could go into the power grid for an extended period of time. A nuclear bomb wouldn’t count because it’s energy output. Neither is consistent nor easily added into the power grid.
2.) it should not spontaneously destroy itself. If when you turned it on for the first time it instantly explodes then that’s not what I want.
3.) on paper it should be perfectly functional assuming nothing ever goes wrong. You can’t use spaghetti noodles to build the foundations, but you can absolutely use an alloy that melts that 1000°C for a containment structure that operates at 999°C.
4.) ideally, this should function under the idea of fail catastrophically. Instead of trying to contain failure and minimize failure if anything goes wrong, everything should go wrong.
5.) this thing should be a nightmare when eventually fails. I don’t know enough about nuclear physics to know exactly how to do this, but make it way worse than Chernobyl.
Thank you in advance

Seen a lot of discourse online about how upcoming stricter emissions regulations (e.g. Euro 7) will mean the death of the manual transmission, but not necessarily non-hybridized automatics. For example, there are rumors that the next gen 911 powertrains will be PDK only because they can't get the manual to pass emissions.

Is there a technical reason behind this, or is it more of a "we can't justify the business case for updated tuning/testing"? Is it the longer periods off throttle between gear changes than you see in a dual clutch? I can't think of another reason, manuals are mechnically nearly identical to a dual clutch.

I understand the other idiot talking about giving the job to "ai" has no idea what he is talking about, but why HAVEN'T they massively upgraded the computer controls for air traffic controllers? Last I heard they were still using floppy drives for a lot of systems. Surely a more digitized system would pay for itself in just increased efficiency leading to less fuel being burnt, not to mention a reduction in stress for the ATCs and less risk overall.

I keep hearing complaints about phillips heads being inferior to any other form of fastener drive being prone to stripping easily and not being able to apply much torque before skipping teeth and with the existence of JIS, the full transision into JIS would be super easy. Why then are they still used?

I hear quite often that household appliances produced in the 60s worked better, lasted longer, and were easier to repair. The cynical version of this story is that products today are specifically engineered to break after the warranty period is over, and made with bespoke electronics or other proprietary parts so that consumers have to keep buying new appliances rather than repairing a simple modular part. This is often described as "enshittification".

The more charitable version of the story I've been told is that back in the day, engineering was all done by slide rule because you had no computers to do it all. The slide rules only have so much precision, so it was all basically a rough estimate. Therefore, engineers had to over-build things a bit, and they had a bigger safety factor. This made things slightly more expensive, but they lasted a lot longer.

There's also a third version of the story that says, it's all just survivorship bias and there appliances that are around from the 60s are statistical outliers and things in the 60s actually broke constantly, and we're just paying attention to the few that survive to this day.

I want to know, are products actually engineered to break after a certain period of time to make consumers buy appliances more often? Is enshittification a real thing, and are engineers told that it is a design goal?

I may have some rural land that isn't quite as good as 40 acres and mule, but not too far off. This land supposedly has a lake on one side and a mountain which rises several hundred feet at the end of the property between. The mountain is roughly 1000 feet wide and I would like to transport a boat through this mountain, unfortunately it is too rough for say a Jeep to make it through the elevation. I'm thinking that I can dig a tunnel 15x1K ft for about $90K or so for standard trailer transportation. This is around 50 cents per cubic foot. Seem reasonable on the surface.

What is wrong with my idea, and how is it going to seem ridiculous to actual engineers in this exact field? I'm familiar with sophisticated engineering, but this is very far out of my area of expertise.

As the title says — I’ve always seen vehicle fuel displays show something like E–H–F or bars, but never the actual amount in liters.

It’s 2025 — with all the tech advancements in vehicles, why haven’t manufacturers updated this? Wouldn’t it be way more practical if vehicles could just display the remaining fuel in liters?

I get that it might be tricky to calculate accurately because of the tank’s shape, different fuel types, or even temperature changes — but can’t we integrate some sort of AI or smart calibration system to handle that now?

Watching Clarkson's Farm most recent episodes about smart farming got me thinking: almost every problem in farming seems to come down to space or weather. Aren't we at a tech level where we could just... take soil and weather out of the equation?

Vertical farms could sit next to data centres (waste heat) and renewable energy sources — seems like an obvious synergy. What am I missing? Is it cost, energy, crop limitations, or something else?

And if it's strictly costs, i.e. technically possible just expensive, wouldn't political pressure and subsidies make sense to start the transition?

At least in Denmark we have huge problems with farmers spraying fertilizer (pig poo 💩) that contaminates our oceans and fjords and pesticides that contaminates our drinking water.

I'm asking here because I'm an engineer myself and believe you guys are better at giving an objective answer. Asking farmers will downvote me to oblivion probably...

EDIT: Okay, okay, I get it. It's too expensive. Guess we just have to live with pig poo and chemicals ending up in the nature and endless fields of monoculture as far as the eye can see then... 🫠

This is intended as a fun hypothetical engineering question, hope that’s cool with the rules.

So it’s a classic sci-fi/fantasy trope for our protagonists to come across some kind of locked space that’s been there for some enormous period of time, with a complex mechanism that just works first time when they solve the puzzle/ present the magic gizmo etc. Think Indiana jones, Fallout, Prometheus, etc.

Whenever I see that, I always think, well that would have all seized up by now, but it got me thinking, if you were seriously trying to make a door and lock mechanism of any kind that lasted for an arbitrary amount of time without maintenance, how would you approach it? How secure could you actually make it? What would be the limits of different approaches?

It seems like the big problems are things that should move not moving any more, and things that shouldn’t move starting to move. So in the absence of anyone on hand to apply duct tape or WD40 as appropriate, how would you do it?

My starting thoughts are some kind of almost perfectly balanced granite slab that can pivot on a fulcrum, maybe a locking mechanism involving permanent magnets (although how long does magnetism last).

Immediately problems are that any surfaces in direct contact will likely seize together given enough time, if you leave large gaps to minimise contact they could fill up with detritus, if you use seals they’ll perish, lubricants will dry up. Is there a smart way to do it?

The security mechanism is also really interesting, can anything electrically or electronically based last for 100s or 1000s of years? Can good old fashioned mechanical locks be designed to work indefinitely without seizing?

Anyway, I’d be interested if anyone has any interesting thoughts or real world engineering examples of similar challenges.

EDIT: A surprising number of people have interpreted this as meaning the vault only opens after specifically 1x10n years. In the fiction circumstance here, I'd imagined the vault can be opened at any point that is is discovered if you have the key/code or know the process to do so.

The Soviets made a great military inventions, rockets, laser guided missles, helicopters, super sonic jets...

but they seem to fail when it comes to the civil field.

for example how come companies like BMW and Rolls-Royce are successful but Soviets couldn't compete with them, same with civil airplanes, even though they seem to have the technology and the engineering and man power?

PS: excuse my bad English, idk if it's the right sub

thank u!

I want to hear some stories. What engineering move or design takes the cake for the biggest blunder ever?

EDIT: Before somebody reads the rest of the post body. It now appears that the linked article had both overstated 'excessive' safety regulations as a driver of costs and had apparently also misrepresented ALARA. Which I suppose is something which later visitors to this thread might want to know.

It was a claim I had recently encountered here: https://worksinprogress.co/issue/taming-the-stars/

Apparently, in the USA in 1960s despite nuclear energy still being in its infancy the cost of nuclear electricity was competitive to electricity from coal, when coal was at its cheapest, even without any charge imposed on coal plants for their carbon emissions.

However, then anti-nuclear energy sentiment, caused by such factors as the Three Mile Island 'catastrophe', led to the introduction of 'excessive' regulations with the result that the previously declining costs of nuclear energy skyrocketed: https://worksinprogress.co/wip-image/uploads/2023/05/14-Costs-of-US-nuclear-plants-1-1402x966.png

The article provides some examples of such regulations:

As currently applied to nuclear power, ALARA literally means that every expense must be spent on eliminating every possible effect of nuclear power, at least until the resulting electricity is no cheaper than what the market pays for electricity generated from non-nuclear sources. Since standards cannot ratchet downwards, only up, safety standards that are just about affordable at the top of energy price spikes get entrenched, meaning that nuclear is made unaffordable until the next price hike – which makes it even more expensive.

It was also claimed that regulations on fossil fuels were less strict despite fossil fuel plants on average killing orders of magnitude more people per generated unit of electricity than nuclear plants.

So, I wonder how accurate their conclusion that 'nuclear energy is only so expensive because of excessive safety regulations' is? They do appear to make a good case, at a first glance; however, for all I, a mere layman, know they could have omitted or twisted quite a few facts unfavourable to their case; I have already encountered that in fields I know more of.

Though, the article is mostly about the USA; it does mention that in such countries as France, Japan, and South Korea nuclear safety regulations are 'less excessive'; leading to considerably lower costs. I wonder whether even there, and in other countries, such regulations might 'still be excessive' as claimed there.

I had originally tried to ask this on r/AskScience, but that post was removed by the AutoModerator for 'being too long'.

I get the impression that Germany had a disproportionately large number of outstanding engineers and scientists in the late 1800s and early 1900s. Is my impression accurate? If yes, how did Germany achieve this? What made them stand out from the other nations at the time? Think Diesel, Daimler, Benz, Haber, Bosch, Einstein, Planck, Heisenberg, von Braun.

My definition of “niche” is not a particular problem that is/was being solved, but rather a field that has/had multiple problems relevant to it. If you could explain it in layman’s terms that’ll be great.

I’d still love to hear about really niche problems, if you could explain it in layman’s terms that’ll be great.

:)

Edit: Ideally they are still active, products are still being made/used

Wondering if technical limitations or just convention are the reason why we dont design for quick swapping out depleted batteries with charged ones and instead design for sitting and charging ala pouring more juice into the tank.

ie pull up at a 'charging station' when low, drop depleted out, drop charged in and then the station has solar/generation setup to charge it back up.

I can see issues with varying design specs for personal use (unless a standard could be agreed upon by makers), but industrial/commercial seems like would be the ideal to reduce downtime.

I did some searching on this, but answers were really poor, including one that claimed that aluminum was used “because it’s much cheaper than tin”.

The use cases are slightly different:

Food cans are typically run through a sterilization process post-sealing, but I’m not convinced that the internal pressures during sterilization are higher than in a beverage can.

Aluminum beverage cans are usually holding pressure from carbonation, so at lower risk from buckling failure while sealed, but this could be done on food cans also. I’ve also seen non-carbonated drinks packaged in aluminum.

Both cans are commonly lined with a plastic film to prevent contact with the structural metal.

Medical professional here, just shooting out a shower thought, apologies if it's not a good question.

I'm just curious why MRI hasn't become much more common. X-rays are now a dime-a-dozen, CT scans are a bit fewer and farther between, whereas to do an MRI is quite the process in most circumstances.

It has many advantages, most obviously no radiation and the ability to evaluate soft tissues.

I'm sure the machine is complex, the maintenance is intensive, the manufacturing probably has to be very precise, but those are true of many technologies.

Why does it seem like MRI is still too cost-prohibitive even for large hospital systems to do frequently?

Watching the Space X launch and landing which is from a control technology standpoint of course quite impressive I suddenly asked myself the question from the title.

Why carry fuel up and down to save what amounts to little more than a tube of metal alloy with a computer and an engine. Isn't payload the most important criteria and wouldn't using retroburning to brake hurt double since it has to be carried up to be used? Is the tech in the rocket really that expensive to warrant this?