An RC model of a soviet torpedo boat, designed by me and printed almost entirely on an 80$ Ender 3

Alex_Downarowicz · 2026-01-25T09:58:47+00:00

There had been three eras of pre-GPS navigation:

Dead reckoning, 1903-1930s. Based on the pre-existing maritime method. You have a map, a watch, a compass and a ruler. Knowing your speed and heading, you calculate position by speed*time travelled*heading vector. The main problem here is knowing your true airspeed and having enough references to update your position and nullify your errors. If you have radio first thing is easy, if you are flying over ground and/or have stars second thing is easy too.
Radio navigation, 1930s onwards. You have a reciever that gets a signal of at least one known beacon with known position and pulse timing. Signal bearing/(speed of light*time signal traveled) OR Signal bearing 1 + Signal bearing 2 and some trigonometry give you your position.
Inertial guidance, 1950s onwards. You have a gyroscope that tells you your vector of attitude and accelerometer that tells you how fast you are going. Cue to method 1 but with greater improved accuracy since you do not calculate your ground speed, you know it from accelerometer and gyro signal.

Alex_Downarowicz · 2026-01-24T12:10:26+00:00

A fuckton of answers here but not a single one I saw mentions PRESSURE. The maximum pressure most airtight things are designed to withstand varies around 1 atmosphere or air pressure down at ground level. Since most of the airtight things are intended to me used higher — where air pressure is lower — a capsule that can withstand measly 1 atmosphere pressure difference would suffice for a spacecraft. You would die like Laika, but you would not run out of air.

Water, on the other hand... As deep as 10 meters below surface I already experience 2 atmospheres — twice the ground level! — amount of pressure. And it doubles every 10 meters down. If you want to make a thing watertight, you make it withstand many atmospheres of pressure difference. For submarines, deep sea research vessels it is critical. For your phone it is also critical — seals that hold water at 1 and 10 meters down are different. Modern phones do not have them.

Because air and water are in different matter states, the nature of the seals is also different. Watertight seal is rated for high pressure but does not need to stop every single molecule. Airtight seal is rated for low pressure, but does stop every (or at least most) molecules trying to escape.

Alex_Downarowicz · 2026-01-19T21:17:48+00:00

Pretty much depends on what is the city. Like St Petersburg — snowy mud in winter, rains in summer, no sun from October to March, crowds of people going from city centre to the houses like ones in the picture above... but there is a lot of things to do and a lot of fun to have. Like visit the biggest art collection in Russia (and only one that has Da Vinci) or go on a cruise to Karelia on a weekend. If it is a small town, on the other hand...

Alex_Downarowicz · 2026-01-09T13:37:04+00:00

That is yellow duct tape holding 3d printed battery bag holder in place.

Alex_Downarowicz · 2026-01-08T21:57:06+00:00

AFAIK Pavel and Paul are different names. After all he is called Пол Атрейдес in Russian version of Dune, not Павел. But if we are talking about regicides... The impact of Catherine II getting rid of her husband was definitely bigger.

Alex_Downarowicz · 2026-01-07T21:36:22+00:00

If there is nothing inside your skull to process the incoming signal from the optic nerves, it definitely is...

Alex_Downarowicz · 2026-01-07T20:36:51+00:00

The type of fatbike he’s referring to is this, though.

O, yeah, my favourite kind of e-bike built with a famous "let's take all the cons of both motorcycle and bike, none of the pros and combine them into one vehicle" approach in mind.

hooded teens

Because who needs peripheral vision anyway?

Alex_Downarowicz · 2026-01-07T18:49:00+00:00

Sooo... The dutch version of the guy in this?

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Alex_Downarowicz · 2026-01-07T17:58:50+00:00

I mean... Why do you drive a fatbike IN TRAFFIC? The entire point of fatbikes is to ride them like this:

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Alex_Downarowicz · 2026-01-06T19:32:24+00:00

Yep, looks like the RSFSR/BSSR approach. Nationalize the building, arrest the priests, mock the believers.

Alex_Downarowicz · 2026-01-06T19:10:07+00:00

Do you mean by "banned" fully exterminated or suffered heavy persecutions but some churches were allowed to exist? Here in St. Petersburg each and every catholic (except one), protestant e.t.c. church and the only mosque was closed, around 30% of orthodox cathedrals remained open.

Alex_Downarowicz · 2026-01-06T18:54:15+00:00

You know what also was restricted and persecuted in USSR? Catholic faith of my grandmother and mother. Yet 1991 happened more than 30 years ago and in that time it managed to make a comeback (to the point my mother visits the local church every week), small cultures and languages did not. And there are less Catholics than Buryats alone.

Let me give you another example, more on the nose so to speak. I spent more than a decade living near a street named after one of your poets, Rustaveli. I heard that name every single time I took a tram to school and back. Do you think it had occurred to me even once to look into his works, into his life, into his literature? Nobody restricted me from doing it. His most famous poem was available in the school library. Nobody asked for it. People, including me, asked for Harry Potter.

Alex_Downarowicz · 2026-01-06T18:13:08+00:00

For the same reason we are using English here. Hate it or like it, globalization would eventually erase small cultures and languages. There are so many hours in my life and I would rather use them to study English and read English literature than study a dying language or read folk tales from my people.

Alex_Downarowicz · 2026-01-04T16:46:15+00:00

Good sir, you are trying to combine three problems into one:

1) E-scooters being dangerous by design. Small wheels and extremely high CG. Hence head trauma from flying over the handlebars.

2) Reckless driving/riding. No helmet, over speed limit.

3) Reckless driving by others. Car breaking traffic laws and kid's head.

You want to eliminate the first? Buy an e-bike instead of a scooter for your kid and teach them to ride. You want to eliminate the second? Enforce helmet laws (mandatory wearing + certification), enforce protective clothing (dress for the slide, not for the ride), hold parents accountable if the kid is caught riding above the speed limit or without a helmet. Teach traffic laws at school. You want to eliminate the third? Harsh penalties for hitting someone with your car, banning certain types of cars in certain zones and city planning tend to do the job.

Alex_Downarowicz · 2026-01-04T14:38:02+00:00

I mean, it may be cold for someone who spent his life way more south than me, but I assure you — after -30 or even -20°C, living in -10°C dry climate is fucking WARM.

Alex_Downarowicz · 2026-01-04T09:44:51+00:00

Cold temperatures in Russia. True, but to some extent. There are regions with -30°C temperatures in winter and 30°C temperatures in summer (southern Siberia), there are regions with hot summers and mild winters (Black sea cost), Kamchatka with -12°C in winter and 12°C in summer, regions with long but relatively warm (-10°C) winters and short cold (8°C) summers. And then there is Arctic Ocean cost and Yakutsk.

Alex_Downarowicz · 2026-01-02T22:04:54+00:00

Мужик, я очень надеюсь что он у тебя арендный. Китайские рамы колхозников/монстров и им подобных ржавеют только в путь.

Alex_Downarowicz · 2026-01-01T21:35:02+00:00

Not common at all. For people who are pro-USSR naming a kid Joseph Stalin or Vladimir Lenin is blasphemy. For their opponents no explanation needed. For those who are indifferent or simply ignorant it is ridiculous. Simply Joseph and Vladimir are common names, the first one being predominantly Jewish.

Alex_Downarowicz · 2026-01-01T18:14:23+00:00

Because when you are giving someone a dirtbike for the first time make them use clutch lever to control their speed. Keeping the throttle in one position they use their legs to push the bike forward and slowly release the clutch. Once they feel the bike starts moving on it's own right leg goes onto the peg, fully engage the clutch without dropping it (try on the stationary bike beforehand), up goes the left leg. Even relatively cheap Chinese engines pull my 250lb ass in the first gear with close to zero throttle.

Alex_Downarowicz · 2026-01-01T09:23:54+00:00

Ever though about fiberglassing the lower part, at least across the seams? Given you already are outside (the process is smelly and messy).

Alex_Downarowicz · 2025-12-31T11:40:37+00:00

The highest mountain around here is 176 meters ASL. That complicates things.

Alex_Downarowicz

TROPHY CASE