🧵 Like clouds, #contrails form when water (H2O) condenses... on tiny particles in the air. 💦☁️ Gas turbine (jet) engine exhaust 💨contains particles (carbon/soot)🚬 from the combustion of fuel & oxygen. This exhaust plume is about 400C 🔥 rushing out into -50C❄️ ambient air…..show more

Raw thrust, pure legacy. The General Electric J79 is... a military turbojet built for speed, power, and high-altitude performance. Air is compressed, mixed with fuel, and ignited to produce high-energy exhaust gases that drive the turbine and exit at extreme velocity, generating thrust. With an afterburner system, additional fuel is injected into the exhaust stream, delivering a massive boost in thrust when needed. Designed to power legendary aircraft like the Lockheed F-104 Starfighter, it became known for its high thrust-to-weight ratio and distinctive performance in supersonic flight. Its robust design and ability to operate under extreme conditions made it a cornerstone of early jet combat technology. Built for speed. Proven in the skies.show more

This is a turbine blade from a 571 MW... General Electric gas turbine. It sits inside the hottest part of a machine where combustion gases can reach roughly 1,600°C, while the turbine rotor spins at 3,000+ rpm depending on the grid. At that speed the blade tips are a couple of metres out and the centrifugal load is in the range of something like 10,000+ g or more. And yet this blade isn't bolted to the rotor. It’s root slides into a precision Fir-tree groove machined into the turbine disc, spreading the enormous centrifugal load across multiple contact surfaces instead of concentrating it through a fastener. The hottest first stage buckets are single crystal nickel superalloys like Rene N5 or similar. No grain boundaries, which is what would fail first under the heat and creep The blade is also cooled internally and protected by thermal barrier coatings, allowing the metal itself to remain far below the temperature of the gas flowing around it. At full power you’re looking at 571 MW and about 93 tonnes of natural gas burn rate an hour, that’s roughly a tonne and a half every minute. And the exhaust still contains enormous amounts of usable heat. In a combined cycle plant, that heat is recovered in a heat recovery steam generator, which boils water into steam. The steam then drives a second steam turbine, extracting energy that would otherwise disappear out of the exhaust into the environment. The result is more than 64% thermal efficiency, compared with about 44% for the gas turbine operating alone. For a sense of scale, A single gas turbine installation of this scale can supply electricity equivalent to roughly 600,000+ homes. What’s still odd is that, the blade carrying all of this load can still look like a simple piece of metal being hammered into a slot to the untrained eye. Source, 1989alibekshow more

This man lives in a village, and near his... house he has a dairy farm where he keeps milk-producing animals. He installed two very large exhaust fans in the farm for proper air ventilation and to remove the heat. Because of this, the electricity bill for both his house and the dairy farm was very high every year, running into lakhs of rupees. A large portion of his income was being spent on electricity bills. One day, the man noticed that a very strong stream of air was coming out of the exhaust fans. Since both exhaust fans run all day, he realized he could use this airflow to generate electricity. He then installed two large wind turbines in front of the exhaust fans. The wind turbines spin at high speed all day using the strong air coming from the exhaust fans and generate about 30 units of electricity every day, around 900 units per month, and nearly 11,000 units per year. He uses this electricity to power his house, saving around ₹80,000 every year. Now he has to pay a much lower electricity bill. With his smart thinking, this man turned the waste air coming out of the two large exhaust fans into useful electricity by using two wind turbines, giving himself a significant financial benefit.show more

The moisture question always comes up when I post... pics of my indoor pools on my new builds. Step by step below on how I control it. We create a room where moisture can’t escape into other areas of the home while also having a mechanical system in place to pull the moisture out of the air so mildew/mold don’t ever develop in the pool room itself. In the STR space, investors are trying to stand out. Pools rent. Indoor pools rent even better. You can swim in the winter or summer. 1) Pool is always built on lowest floor inside (generally basement structure) 2) Concrete block wall for basement with very little wood frame 3) Densglass (kind of like a moisture resistant drywall) attached to concrete block 4) Special stucco just like you see on exterior of homes sprayed onto Densglass. The stucco is dyed to color of my choice. 5) Industrial grade dehumidifier (I use Santa Fe or Watchdog Brand). The humidity pulled from air is pumped back into the pool system near the mechanical room or outside. 6) Mini split for the pool room. Main floor HVAC covers the sleeping rooms, bathroom of basement and is always separated from pool room. You don’t want chlorinated air running through a main HVAC system. I look at having to replace the minisplit & dehumidifier about every 4 to 5 yrs because of the chlorinated air that goes through them. 7) Exhaust Fan leading to exterior which also pulls humid air out of the room as a supplemental support for the dehumidifier. When overhead lights are turned on, we have it so the exhaust fan kicks on as well. That’s it. We create a “bubble”, where no moisture gets into the other areas of home and the humid air gets pulled from the pool room.show more

Toxic cloud from Iran is moving towards Central Asia... and China The consequences of the strike on Iranian oil refineries and fuel storage facilities are spreading far beyond the country's borders. The impact of the strike released huge amounts of toxic compounds into the atmosphere, forming a strong polluting cloud. Black snow has fallen in Iran - a phenomenon caused by the deposition of soot particles and other pollutants from the atmosphere. Meteorologists in the country quickly warned the population about the upcoming toxic rain, predicting it will fall in the coming days. The polluted air cloud has already begun moving towards Central Asia and China. Experts point out that Uzbekistan, Kazakhstan, and Kyrgyzstan, which lie along the path of the toxic front, are at the greatest risk of toxic precipitation.show more

We're cold just looking at this video 🥶⁣ This... is rime, which forms when tiny, near-freezing water droplets, usually from thick fog and clouds, attach to the surface of a below-freezing object and turn into ice immediately on contact. Rime builds up in the direction of the wind and is more like accumulated freezing dew rather than thick frost.⁣show more

Ker-PLOEY! The new pool of boiling water that formed... last week in Yellowstone National Park at Biscuit Basin (following a small hydrothermal explosion on June 13) erupted this morning (June 23) at 8:51 a.m. MDT, sending a plume of steam and dirty water tens of feet (several meters) into the air. This is the first observed eruption of the feature since June 18, when it had several pulses of smaller spouting. 🎥: 10-second clip from the Biscuit Basin camera from 8:51 a.m. MDT Yellowstone National Parkshow more

This F-15 fighter jet is hooked up mid-air to... a tanker getting topped off when the pilot decides it’s time to go. The second he disconnects he banks hard and blasts away over the patchwork farmland below while the text pops up saying the Air Force doesn’t do “goodbye” — they just hit you with a “SEEEYUH!” and disappear into the sky. Would you ever ride along in a jet that treats aerial refueling like a quick gas station stop before vanishing like it was never there? Or is this exactly why USAF pilots live in a whole different reality from the rest of us?show more

The Fundamental principles of Mastering high-performance vehicle tuning requires... an in-depth understanding of mechanical engineering, from suspensions to drivetrain optimization. A turbocharger utilizes the power of forced induction, where exhaust energy drives the turbo impeller to increase intake air density for efficient combustion. For every car enthusiast, analyzing the relationship between a turbocharger, torque, and horsepower is vital when optimizing sportscars, super cars, American muscle, or SUVs. The automotive industry showcases the constant evolution of global car culture. Whether focusing on JDM legends, custom vehicle modifications, or modern cars, prioritizing engine durability and reliability remains essential. Mastering these mechanical engineering standards ensures that turbo technology maximizes performance and capability across all cars.show more

In the skies above Britain during the Cold War... a sound existed that many described as the most terrifying and awe-inspiring noise in aviation history. This was the Vulcan Howl. The Avro Vulcan was a massive delta-wing bomber designed to carry nuclear weapons and it was powered by four Bristol Olympus engines. While the engines themselves were incredibly powerful the iconic sound did not actually come from the exhaust or the combustion process. The howl was the result of a strange aerodynamic coincidence. When the pilots pushed the throttles to approximately ninety percent power the massive volume of air rushing into the narrow intake ducts became restricted. This created a physical phenomenon known as resonance which is similar to the sound made when blowing across the top of a glass bottle. Because the intake ducts were so large the resulting vibration produced a haunting low frequency scream that could be felt in the chests of spectators miles away.show more

Many people are unaware of this but Hand Dryers... get disgustingly dirty due to their design and the nasty environment they’re in All you have to do is flip the blower over These units pull air from the room and to blow on your hands. Public restrooms have high humidity, aerosolized particles from toilets like fecal matter and bacteria get airborne when flushing. So does dust, lint, soap scum, skin cells, hair, and mineral deposits from water. Over time, this stuff gets trapped inside But it gets even worse, there are real studies on this. It’s a real, well-documented issue Studies have shown hand dryers can blow out bacteria, sometimes including fecal bacteria, onto clean hands because they’re circulating contaminated air I never use these anymoreshow more

✈️ Boeing 787-8 Dreamliner APU Inlet Door Explained The... small door on the left side of the tail is the APU inlet door. 🔧 🛑 APU OFF: Door stays closed to keep out rain 🌧️, dust 💨, and birds 🐦 while reducing drag. 🚀 APU START: The door opens first, allowing fresh air 🌬️ into the APU. ⚡ APU RUNNING: It stays open so the APU can generate: 🔋 Electrical power ❄️ Air conditioning on the ground ✈️ Engine start support 🔒 APU SHUTDOWN: Once the APU stops, the door closes again. 👀 Fun fact: If you see this little door open while the aircraft is parked, the APU is usually about to start or is already running! With fairportshow more

The War was cold, but accidents happened... May 25... 1968: a Soviet Air Force Tu-16 "Badger" [Reg. Unknown] crashes 150 mi West of Norway, all 6 aboard die. Jet made a low pass near US Navy aircraft carrier USS Essex (CV-9), flying just 50 ft above the sea, when the wingtip hit a wave that sent the bomber into a cartwheel. The accident was captured in camera by a US film crew that was aboard the ship. More info below ⬇️ 🧵 ‘I was there and watched the entire thing while working on the flight deck. I was a helicopter mechanic in HS-9 at the time. When it overflew the flight deck you could feel the heat and smell at jet exhaust. After the flight deck overfly (starboard to port) he continued to fly away from the ship at low level. He gained a little altitude and started to make a left turn, leveled back out, lost altitude and just when it looked like he was going to make a controlled ditching his left wing dipped and hit the water and then he cartwheeled in a ball of flame.. Our helicopters were in the air already and made a beeline for the crash, hovered in the smoke but no one survived.’ Extra info with statements by an eyewitness are from an article from "The Aviation Geek Club" (will add link to their full article latershow more

Millions of Fish. One Insane Moment. I think most... people are familiar with the great Wildebeest migration in Africa but very few people know of the great fish migration that happens each year along the east coast of Florida. It’s simply called, “The Fall Mullet Run,” but there is nothing simple about it. Millions of fish make their way down the coastline and everything, I mean everything wants to eat them. They get attacked by large predatory game fish from below and when they try to escape by hurling themselves into the air, large winged beasts from the sky are waiting to gobble them up in droves! It’s a rare convergence of multiple biomes colliding in a feeding frenzy of explosive, cinematic chaos. The fish in this clip explode like fireworks into the air. Something massive is hunting beneath the surface and as soon as this young brown pelican decides it has found the motherlode, a snook blasts out of the water, forcing the pelican to hit the brakes mid-air and reroute fast. Talk about being in the right place at the right time. I still remember watching it unfold through the tiny viewfinder of my Sony, and not believing my eyes. It’s one of my favorite times of the year, and it’s coming soon!show more

Jet Fuel is a fascinating story. We don’t measure... it in litres, we measure it in weight, because fuel expands/contracts with temperature while weight stays constant. Jet fuel’s specific gravity is ~0.8, so 1 litre ≈ 0.8 kg (lighter than water). It’s also worth noting that jet fuel is essentially a highly refined kerosene, far less volatile than gasoline, which makes it safer to handle in large quantities. On a long-haul, fuel can be close to half the aircraft’s total weight at departure. On the A350-1000, that can be ~129 tonnes. At most major international airports, this much fuel doesn’t turn up in a tanker. It’s stored in a depot and delivered through a network of underground hydrant pipes to each stand. The “tanker” you see is really a pump truck connecting the hydrant to the aircraft and metering the exact uplift. When I moved from the A340-600 to the A350-1000, one of the things that struck me most was just how much simpler and smarter the fuel system became and how much less fuel we required for the same journeys. On the A340-600, we needed a rear trim tank in the tail to keep the aircraft in balance during cruise. It worked beautifully, but it added complexity. The A350 doesn’t need that, instead, it uses tiny fractions of flap in cruise, together with the latest wing aerodynamics, to keep perfectly in trim. London → New York comparison (typical figures): - A340-600: ~80–90 tonnes of trip fuel - A350-1000: ~50–60 tonnes of trip fuel That’s roughly 30–40% less fuel, saving ~25–30 tonnes on a single flight, which also means about 80–95 tonnes less CO₂ (rule of thumb: 1 tonne of jet fuel ≈ 3.16 tonnes CO₂) 📸 by ig/captainchrisshow more

:Scientists Capture the Birth of Water, Atom by AtomFor... the first time ever, researchers have directly observed hydrogen and oxygen atoms combining in real time to form tiny nanoscale bubbles of water—essentially witnessing one of chemistry’s most fundamental reactions at the molecular early 2024, a team from Northwestern University unveiled a groundbreaking imaging technique that traps gas molecules inside tiny, honeycomb-shaped nanoreactors sealed by ultra-thin glassy membranes. This innovation allows scientists to observe chemical processes in real time using high-vacuum transmission electron microscopes, something previously impossible for gaseous reactions.The team, led by Professor Vinayak Dravid and including first author Yukun Liu, turned their attention to a century-old puzzle: how palladium—a rare metallic element—acts as a powerful catalyst to rapidly combine hydrogen and oxygen into water As Yukun Liu explained: “It’s a known phenomenon, but it was never fully understood. You really need both direct visualization of the reaction and atomic-level structural analysis to figure out exactly what’s happening.”What they saw was astonishing.Using their nanoreactor platform, the researchers watched hydrogen atoms diffuse into a palladium nanocube, causing its crystal lattice to expand slightly. Then, when oxygen was introduced, the gases reacted at the surface. Suddenly, tiny water bubbles began to nucleate and grow right before their eyes on the palladium surface.“We think it might be the smallest bubble ever formed that has been directly viewed,” said Liu. “It’s not what we were expecting. Luckily, we were recording it—so we could prove to others that we weren’t crazy.” The bubbles were confirmed to be water using electron energy-loss spectroscopy and heating experiments. Remarkably, the reaction occurs efficiently at room temperature, and palladium itself is recyclable—it doesn’t get consumed in the process. The order in which the gases are introduced also plays a key role in the speed of water formation.This direct, atomic-scale observation not only solves a long-standing mystery in catalysis but could also inspire new technologies: from more efficient ways to generate clean water in remote or arid environments to improved hydrogen fuel cells and even systems for producing water in space.What once seemed like “water from thin air” is now literally visible—captured in stunning detail at the nanoscale. This breakthrough highlights how advanced imaging tools are unlocking secrets of matter that have remained hidden for generations.The study was published in the Proceedings of the National Academy of Sciences (PNAS) in 2024.show more

🚨🇨🇳 Chinese scientists identify previously unknown cause of Alzheimer's... disease A substance formed when particles break down — called 6PPD-quinone — may trigger inflammation and oxidative stress, both hallmarks of dementia, the new study suggests 🔸 The chemical is created when microscopic tire rubber reacts with ozone in the air, washing into water, soil, and even our bodies — it has been found in human blood 🔸 The compound can cross the blood-brain barrier — a filter that normally keeps harmful substances out of the brain 🔸 Scientists used databases to map over 100 potential ways this substance could interact with human biology 🔸They found 92 overlaps — including 23 key genes acting as communication hubs. These genes are most active in brain regions critical for memory and movement, such as the cortex and basal ganglia, which are especially vulnerable to Alzheimer's If experimental validation follows, this discovery could significantly improve the effectiveness of Alzheimer's future therapies.show more

There's a bacteriophage that turns bacteria into “liquid crystals.”... Specifically, Pseudomonas aeruginosa bacteria make Pf phages, which are rod-shaped, negatively-charged, and measure about 2 micrometers in length (roughly the length of an E. coli cell). These phages leave the cells and enter their surroundings. There, they mix with polymers, also secreted by the cells, to form a crystalline matrix. Surprisingly, this is good for the cells. Although the phages kill some of them, it also makes their biofilms stickier and able to withstand certain antibiotics. These bacteria + phages are prevalent in cystic fibrosis patients; they've formed a sort of symbiotic relationship. The Pf phages are made from thousands of repeating copies of a coat protein, called CoaB, which wraps around a single-stranded, circular DNA genome. These genes are integrated directly on the bacterial chromosome. The bacteria “turn on” these phage genes when placed in a viscous environment with low oxygen levels. This is like a trigger to start forming a biofilm. And the cells make a lot of phages; about 100 billion per milliliter. These liquid crystals form because of a physics principle called “depletion attraction.” If you just mix a bunch of loose or flexible polymers together (such as long carbon chains) they will not form a liquid crystal. But if you mix stiff rods (the phages) with loose polymers at a high enough concentration, the polymers will force the phages close together to create a material that flows like a liquid despite being ordered like a crystal. See the video below. These liquid crystal biofilms are hard to get rid of. The negatively-charged phages block many antibiotics (like aminoglycosides, which are positively-charged) from entering cells. Liquid crystals also retain water, so these biofilms can survive on drier surfaces. I first heard about this from Malmesbury’s excellent newsletter, called “Telescopic Turnip.”show more