poopfeast6969's recent activity
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Comment on Startups want to geoengineer a cooler planet. With few rules, experts see big risks. in ~enviro
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Comment on Startups want to geoengineer a cooler planet. With few rules, experts see big risks. in ~enviro
poopfeast6969 Link ParentThe most reasonable idea I have heard for geoengineering was release of volcanic materials into the upper atmosphere. Because we understand the impacts very well, at least compared to...The most reasonable idea I have heard for geoengineering was release of volcanic materials into the upper atmosphere. Because we understand the impacts very well, at least compared to alternatives.
I think I'm parroting this omega tau episode:
https://omegataupodcast.net/385-solar-geoengineering/
(Fantastic podcast btw, if anyone is looking for something deeply technical that covers anything that meets my personal definition of "cool".) -
Comment on NASA's 3D-printed detonation engine revs up for four minutes in breakthrough test in ~space
poopfeast6969 Link ParentThis engine is missing a big axial compressor because this is a rocket engine. An air-breathing RDE (eg for use on an aircraft) would require the intake air to be compressed somehow.This engine is missing a big axial compressor because this is a rocket engine.
An air-breathing RDE (eg for use on an aircraft) would require the intake air to be compressed somehow. -
Comment on NASA's 3D-printed detonation engine revs up for four minutes in breakthrough test in ~space
poopfeast6969 (edited )Link ParentNo I don't have a good source for the mechanism that allows detonation to have a higher efficiency. After looking for papers I'm not even sure a thermodynamic cycle has been agreed upon. My...No I don't have a good source for the mechanism that allows detonation to have a higher efficiency. After looking for papers I'm not even sure a thermodynamic cycle has been agreed upon.
My intuition says there isn't enough time for the reactants to move away from the combustion, maybe this increases the pressure ratio?
Also the way in which the reaction spins around the RDE would allow the peak temperature to be higher before the engine starts to melt.The exhaust speed wouldn't necessarily be increased under detonation, from my understanding. Detonation occurs when combustion moves across an area faster than the speed of sound, but the actual reactants may not move at all.
Like a trail of gunpowder burning across the ground, the gunpowder itself is not moving, but the reaction has a speed. -
Comment on NASA's 3D-printed detonation engine revs up for four minutes in breakthrough test in ~space
poopfeast6969 (edited )Link ParentDetonation is the supersonic version of combustion. Detonation is more efficient than subsonic combustion, but the conditions it reliably occurs in are specific and still under research. In...Detonation is the supersonic version of combustion. Detonation is more efficient than subsonic combustion, but the conditions it reliably occurs in are specific and still under research.
In current rocket and jet engines, the "flame front" advances along a suitable flow of oxidiser and fuel at subsonic speeds. Proportional to the rate at which new fuel and oxidiser are being injected.
Assuming you can create the conditions for a detonation reaction, you could imagine for the reaction to be continuous, the propellants would need to be injected at supersonic speeds. Or the flame front would reach the injector and no longer be "supersonic".
A rotating detonation engine solves this problem by advancing the flame front around a closed loop. By the time the supersonic combustion reaction is back to where it started, fresh propellants have been injected.
The loop is visible in the video as the glowing ring. The side of the loop is cut away to make the engines exhaust.
Injecting propellants at supersonic speeds is done in scramjets. I'm interested to hear if someone knows why there are no rocket engines that work like that.
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Comment on This transparent engine is fascinating (How internal combustion engines work) in ~engineering
poopfeast6969 Link ParentOh, sorry for jumping the gun. What's confusing me is that "throttle body" is just a general term for the air metering system of butterfly valve and the surrounding pipe. A carburettor still has...Oh, sorry for jumping the gun.
What's confusing me is that "throttle body" is just a general term for the air metering system of butterfly valve and the surrounding pipe.
A carburettor still has one, it's just all in one unit.(from my understanding).
I've never heard that term, could it be another word for "single point fuel injection"?
Which I think of as one big fuel injector, and some (probably analogue) computer to control the flow rate.
It doesn't pulse like multi point fuel injection, it's more like an electronic carburettor.Car lingo can be confusing because it's mixed in with all the marketing names they used in period.
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Comment on This transparent engine is fascinating (How internal combustion engines work) in ~engineering
poopfeast6969 Link ParentA way of restricting (or throttling) the airflow into the engine is also required for a carburettor. It's just not shown in the video. Butterfly valves have been used for this since time...A way of restricting (or throttling) the airflow into the engine is also required for a carburettor. It's just not shown in the video.
Butterfly valves have been used for this since time immemorial as far as I'm aware. If you look hard enough they'll probably be one somewhere on every engine made in the last 70 years.
Carburettors dispense the correct amount of fuel for a given airflow, and have been superseded by electrically driven fuel injectors.
The airflow is set by the throttle. -
Comment on Tyre Extinguishers – deflating SUV tyres as a form of climate action in ~enviro
poopfeast6969 Link ParentIt might at least partly be due to the fact that European fuel is a higher octane. And cars sold in Europe can be optimised for this. Higher octane fuel can give you better distance per volume,...It might at least partly be due to the fact that European fuel is a higher octane. And cars sold in Europe can be optimised for this.
Higher octane fuel can give you better distance per volume, and most likely worse distance per dollar. -
Comment on What are your failed hobbies? in ~hobbies
poopfeast6969 Link ParentSailplane gliding is ~1/3rd of the price of powered flying. At least where I live. Outside of cost, it's better for aerobatics (most gliders are aerobatics capable to some extent) but much less...Sailplane gliding is ~1/3rd of the price of powered flying. At least where I live.
Outside of cost, it's better for aerobatics (most gliders are aerobatics capable to some extent) but much less practical if you want to travel between airports.
The reduced cost comes mainly from simpler machines and less regulation. -
Comment on Steam Deck launch day megathread in ~games
poopfeast6969 Link ParentThat is a good question. I haven't measured the latency. I'm simply trusting that it's using the buffer size I've set. I can hear a reduction in latency over the default 1024 sample buffer (21.3...That is a good question. I haven't measured the latency. I'm simply trusting that it's using the buffer size I've set. I can hear a reduction in latency over the default 1024 sample buffer (21.3 ms) and 256 samples (5.3 ms).
Because pipewire uses JACK interfaces, you set the pipewire buffer size using any program that can set the JACK buffer size.
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Comment on Steam Deck launch day megathread in ~games
poopfeast6969 Link ParentI was able to get 5.3ms with zero effort on fedora 35. Probably something to do with pipewire.I was able to get 5.3ms with zero effort on fedora 35. Probably something to do with pipewire.
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Comment on <deleted topic> in ~comp
poopfeast6969 Link ParentIt's probably down to Intel offering to design custom variants of their processors for cheap rather than a low cost per unit. Even for a large company developing custom silicon would be a big expense.It's probably down to Intel offering to design custom variants of their processors for cheap rather than a low cost per unit. Even for a large company developing custom silicon would be a big expense.
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Comment on <deleted topic> in ~comp
poopfeast6969 (edited )Link ParentEspecially in that era, ECUs were custom silicon as general purpose microcontrollers weren't capable enough. My mid 2000s ford has an Intel chip that ford commissioned called the Intel 8065, it...Especially in that era, ECUs were custom silicon as general purpose microcontrollers weren't capable enough.
My mid 2000s ford has an Intel chip that ford commissioned called the Intel 8065, it has different hardware to allow them to optimise it for the code they intended to run. (How crazy is that?).Because creating large application specific silicon is extremely expensive (only very large companies could afford it), the entire chip and it's code have been reverse engineered. Because there was no cheaper way for the public to get ahold of computers capable of running engines.
Nowadays there is something of a revolution happening because general purpose microcontrollers have become very fast and easy to program. Open source engine management software running on extremely cheap microcontrollers is on the horizon.
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Comment on Berserk Manga Creator Kentarou Miura Passes Away at 54 in ~anime
poopfeast6969 Link ParentBerserk is one of my favourite pieces of media ever, I'm a sucker for a tragedy. At what point should you give up? Berserk poses so many interesting questions dreams, and what you would give up in...Berserk is one of my favourite pieces of media ever, I'm a sucker for a tragedy.
At what point should you give up?
Berserk poses so many interesting questions dreams, and what you would give up in exchange for them. Not a unique talking point but the best execution of that kind of theme I've ever seen. And one that really connected with me.It's also generally amazingly well crafted.
It's a shame Miura didn't get to finish what was clearly his life's work.
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Comment on Plasticenta: First evidence of microplastics in human placenta in ~science
poopfeast6969 Link ParentI couldn't find much info on how severe these health effects will be. I know many kinds of plastic have toxic additives, but given the current lack of evidence maybe they have already leached out,...I couldn't find much info on how severe these health effects will be.
I know many kinds of plastic have toxic additives, but given the current lack of evidence maybe they have already leached out, or just aren't present in great enough concentrations yet? -
Comment on Share a link to a song that tells a story in ~music
poopfeast6969 Link ParentI heard he didn't set out to make The Party a concept album (all based around a party). But whether he meant it or not I'll agree the storytelling is a little more minimal than the others here.I heard he didn't set out to make The Party a concept album (all based around a party). But whether he meant it or not I'll agree the storytelling is a little more minimal than the others here.
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Comment on Share a link to a song that tells a story in ~music
poopfeast6969 LinkAndy Shauf - Quite Like You Most (all those I remember) of Andy's songs could fit in this thread. I just like this one.Andy Shauf - Quite Like You
Most (all those I remember) of Andy's songs could fit in this thread. I just like this one. -
Comment on Looking for albums/artists with a rough, imperfect production style in ~music
poopfeast6969 (edited )LinkI love the Voidz! They were my favourite sound a few years ago. I was thinking about making a similar thread. Because unfortunately they're pretty unique. I'm going to try for things that sound a...I love the Voidz! They were my favourite sound a few years ago. I was thinking about making a similar thread.
Because unfortunately they're pretty unique.I'm going to try for things that sound a little bit like the Voidz:
The I.L.Y's
Street Sects
Bent Knee (from tildes, thank you so much whoever that was!) -
Comment on Vintage bicycle repair in ~transport
poopfeast6969 LinkI haven't restored a bicycle, but I know with a lot of Japanese products (including motorcycles), many of the Phillips looking fasteners are actually something called JIS fasteners. The...I haven't restored a bicycle, but I know with a lot of Japanese products (including motorcycles), many of the Phillips looking fasteners are actually something called JIS fasteners. The differences are not really visible to the naked eye, aside from a mark that is sometimes cast into the head:
http://www.agcoauto.com/content/images/fastener/screws_JIS_phillips_pozidriv.jpgIf you find yourself stripping star fasteners then maybe you could try a JIS screwdriver. (And some penetrating oil and heat of course).
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Comment on The future of Risk of Rain 2 - Hopoo Games Dev Thoughts #18 in ~games
poopfeast6969 (edited )Link ParentI wasn't even aware OSP existed in this game. Most of my runs end with me being what I would describe as "one-shot". With enough old war stealthkits and medkits you might do pretty well then huh?...I wasn't even aware OSP existed in this game. Most of my runs end with me being what I would describe as "one-shot". With enough old war stealthkits and medkits you might do pretty well then huh?
My pet peeve is the sprint toggle. The way it deactivates when you start strafing is really non intuitive, and it took me 10 hours or so to remember to toggle it on again consistently.Also, they really nerfed the happiest mask into oblivion.
I'm sorry. Maybe it was naive of me to assume that what I said could be taken in good faith.
I did not post that with the intention of persuading people that climate change doesn't require them to personally take action. Or in any other way indicate that geoengineering isn't by far the worse outcome.
I thought I had some information to add to the conversation that personally was interesting to me.
Even if I did have such an opinion, my odds of snaring an innocent bystander on tildes with misinformation of that kind are (I hope) very low.
I think the podcast won't be what you're expecting, it's not at all a positive spin on any of this.
Maybe I should have defused this preemptively by providing a summary of what I thought was relevant, but I didn't have much time.