Ask Lemmy

About anything to do with computers. Anything.

MRIs

Far too many movies and TV shows use the magnet to cover for their lazy writing by treating it like something that can be turned on and off like a light.

The magnet in an MRI is one of the coolest things in medicine, and writers get it wrong all the time. In the vast majority of cases, it's always on.

In simple terms, an electromagnet works by running a current in a circle and creating a magnetic field. In an MRI, the current is flowing in what is essentially a closed loop of wire. However, in this case the wire is cooled with liquid helium so it becomes a superconductor.

They induce a current in the wire which creates the magnetic field ("ramp up" the magnet). Because it is superconducting, the current doesn't stop. Once it's ramped up, it no longer requires any external power. As long as the current is flowing the magnetic field remains.

There are only two ways to "turn off" the magnet.

One way is to "ramp down". Essentially the opposite process that is used to get it running in the first place. That's what they do if they need to stop it for service.

The other way is to quench the magnet. You hit the emergency stop and vent off the liquid helium. Without the helium, the wire warms and resists the current and the flow stops.

Quenching a magnet is a magnificently dramatic process. Someone hits the panic button, and there is a loud roar as the helium escapes. Clouds of condensation form around the exterior of the building as the cold gas escapes. In the event some construction crew screwed up and accidentally sealed the vents, there could be an explosion from the rapidly expanding gas.

If writers want to use an MRI as a plot device, have an accident and require someone to quench the magnet to save a life. You'd have the immediate drama from the accident and the quench, and then you'd have the long term drama of the hospital trying to figure out where the money to fix the MRI would come from.

https://youtu.be/9SOUJP5dFEg

You don't need a huge wrench when working with the p-trap under the sink and water wont start spraying everywhere either as drains aren't pressurized.

Sprinklers react to heat, not smoke.

Not all spriklers go off at the same time in most systems. Only the sprinkler heads affected by heat.

The water coming out of sprinklers initially isn't clear but dark, rusty sludge. Sometimes even black as ink.

Retail workers spending the day doing shenanigans while barely doing any work, I'd kill for time to do some stupid time wasting shit.

Sorry I can't join your impromptu wedding for two workers whose name I forgot.

TL:DR: Everything? Like, literally everything.

If it's about driving? They're looking everywhere except the road in front of them

Computers? It's cringe, all I will say

Flying? Not even close

Brushing teeth? Put some tooth paste FFS!

Sex, perhaps? As bad as porn videos are at showing realistic sex situations, movies and especially TV shows are typically way worse with all the requirements to not accidentally show a nipple, omg!

Martial arts and fighting? The worst offenders. After twenty punches to the chest that will have broken half of the ribs, the protagonists now suddenly finds the strength in thinking about keeping his little girl safe and now he beats up 20 guys with those broken ribs

Being punched unconscious or getting some chloroform and they wake up the next day? Lolololollll. Humans are notoriously hard to keep them "out" without killing them, it's why anesthetists are paid so well, it's a very complicated job. When you're out from an impact to the head, you need medical attention, you likely have a minor amount of brain damage. If you're out for more than ten seconds, it's brain damage for sure. If you're out for over a minute, you're likely not waking up with full abilities, you're likely going to be a vegetable at best

Okay, doctors then? Saving a patient's life with the buzzer? Yeah no. When the heart stops, that defibrillator won't make it "go" again, the defib actually stops it in case of heart rithm problems. Also, CPR outside a hospital will result in death for about 90% of the cases, give or take, and Har % goes up by another 2 after 3 weeks later. The tiny % that does survive likely will have issues ranging from benign to being a benign vegetable.

I work in IT so appearently i can just type override to get into any computer system. Cool..

I have not unlocked a single chasity belt, it doesnt even come up as a service they might need.

One thing that bothers me, and what everyone should know, is proper placement for defibrillator pads if you're using an AED.

It's not 2 pads on the chest, it's one pad on the upper chest (almost shoulder) on one side, and the other pad goes lower on their side. You're trying to have the current go through their heart (not skip over the top of their skin).

The AEDs found in public locations are all very easy to use and all have pictures for the proper placement. Just open it up and it will tell you everything you need to do. Have someone nearby look for one at the same time you're asking someone else to call emergency services.

They should all have razors if you need to get a little hair off (in case the person is especially hairy for one of the pad placements).

using a red-tailed hawk call whenever a bald eagle is shown

also I like to try and figure out where they filmed based on the birds I hear in the background

If you broaden it a little from job/hobby to living in the real setting of a movie, you'll notice characters going places that make no sense at all. Like if it's Seattle they might start a boating scene on Lake Union and ends up at Mercer Island, swinging by Alki beach on the way.

I almost never see accurate sword fights. If they last more than two or three swings, they’re likely wrong. And Achilles jumping at the beginning of Troy was just comical. Footwork is so vital to sword play that leaving the ground is insane. But realistic sword play would be boring as fuck. It would be over in half a second and you would barely see any movement.

I was led to believe that shipping crates open up easily with one quick pry of a crowbar. In reality, those things are built with so many nails and screws that it takes more work to tear it down than to build it.

The number of people who are "knitting" in a movie or on TV...maybe 40% of them are actually doing it, and that's a high estimate (shout out to Miss Marple!). The rest appear to be wrapping yarn around one of the needles and then moving it vigorously, lol.

3d printing - it prints flawlessly and the first time.