Helium-4, when cooled below approximately -271 °C (the lambda... point of 2.17 K), becomes a superfluid liquid with zero viscosity in its superfluid component, allowing it to climb container walls and flow through tiny pores or capillaries that viscous liquids cannot penetrate.show more

Timeless Martian
86,932 次观看 • 9 个月前
This is an old Soviet compass inside a homemade... Wilson chamber. At the bottom of the chamber, there is a radiator that is placed in liquid nitrogen. At the top, there is a sponge with alcohol; I used isopropyl alcohol, which, when strongly cooled, becomes supersaturated or supercooled vapor. This is a metastable substance that, when a charged particle passes through it, promotes the formation of a liquid — in this case, traces of fog, which you can see in this video. Perhaps it is also possible to detect uncharged particles in the form of high‑energy gamma quanta or secondary cosmic radiation. I have sometimes seen tracks of particles that are unknown to me. But in this video, it’s more likely to be radium undergoing alpha decay. That’s what compasses were like many years ago. Be careful with them.show more

@jurij0001
144,014 次观看 • 6 天前
Vorflux has opened its new cloud platform, allowing users... to run tasks from a plan to a merged PR on a dedicated machine. It can plan, build, test, and review on its own. > Diff reviews are done by a different model family than the one that wrote it by default. > First boot is saved as a snapshot, with all subsequent sessions waking up from that same starting point. > A browser agent walks through the real user flow, and the recording is included in the pull request. Video proof in the PR 👀show more

🚨 AI News | TestingCatalog
11,894 次观看 • 17 天前
d’Alembert’s Paradox: The 1752 Paradox That Stood in the... Way of Real Aerodynamics In 1752, d’Alembert found a result that still feels wrong at first sight: An ideal fluid can flow around a body and produce no drag at all. In the first animation, viscosity is set to zero. The fluid bends around the object, accelerates, slows down, and stitches itself back together downstream. You get no wake, no loss and no scar in the flow. The equations have removed the very thing that would let the body leave a trace. That is Euler flow: ρ(∂u/∂t + (u · ∇)u) = −∇p ∇ · u = 0 For steady irrotational flow, u = ∇φ and ∇²φ = 0. The pressure field stays perfectly symmetric front to back, so when you integrate pressure over the body, the drag cancels: D = 0 The second animation changes one thing: viscosity is allowed back in. ρ(∂u/∂t + (u · ∇)u) = −∇p + μ∇²u ∇ · u = 0 Now, the surface can grip the fluid. A boundary layer forms. It can separate, vorticity rolls off the body and wake appears. Drag is now built by the flow. Therefore, making viscosity tiny is not the same as deleting it. ν → 0 still has a boundary layer. ν = 0 has no memory.show more

Mathelirium
43,784 次观看 • 4 个月前
The fascinating concept of Non-Newtonian fluids, which transition from... a liquid state to a solid-like state when pressure is applied, has a rich history that spans several centuries. The study and understanding of these peculiar fluids have evolved over time, leading to a wide range of practical applications and scientific insights. One of the earliest references to Non-Newtonian behavior in fluids dates back to the 17th century when Sir Isaac Newton formulated the basic principles of fluid mechanics. Newton's laws of fluid motion primarily applied to Newtonian fluids, which exhibit constant viscosity and flow behavior regardless of the applied force or pressure. However, it soon became apparent that not all fluids behaved in this predictable manner. In the mid-19th century, a scientist named Thomas Andrews made significant contributions to the understanding of Non-Newtonian fluids. Andrews conducted groundbreaking experiments with carbon dioxide, revealing that under high pressure, this gas could transform into a liquid. This observation marked one of the earliest instances of pressure-induced phase changes in fluids. The term "Non-Newtonian" itself was coined in the 20th century to describe fluids that did not adhere to Newton's classical laws of fluid dynamics. These fluids exhibited a variety of behaviors, but one of the most intriguing was their ability to solidify or increase in viscosity when subjected to stress or pressure. One of the most famous examples of such behavior is cornstarch mixed with water, which forms a substance known as "oobleck" that becomes more solid when pressure is applied. In the modern era, Non-Newtonian fluids have found applications in various fields, including food science, engineering, and material science. They are used in products like quicksand, body armor, and even in the development of impact-resistant materials. One of the key insights that emerged from the study of Non-Newtonian fluids is the importance of understanding the relationship between stress and strain, as well as the influence of time-dependent properties on their behavior. This knowledge has led to advancements in rheology, the study of flow and deformation in materials, and has practical implications in areas such as industrial processing, medicine, and the design of everyday products.show more

Historic Vids
2,632,800 次观看 • 2 年前
d’Alembert’s Paradox: ν → 0 Is Not ν =... 0 In 1752, Jean-le-Rond d’Alembert proved a result that still trips people up: An inviscid, incompressible, steady flow exerts zero drag on a body. No wake. No resistance. The equations let the fluid slip past as if the object weren’t there. The first animation shows exactly that world. The flow is ideal Euler flow. Streamlines bend around the body, accelerate, slow down, then recombine perfectly downstream. Nothing is left behind. The motion you see comes from pathlines moving through a steady velocity field, not from any evolving structure in the flow itself. The setup is the ideal fluid model: Euler (ν = 0) ρ(∂u/∂t + (u·∇)u) = −∇p ∇·u = 0 Assume steady flow and zero viscosity and the picture locks in. If the flow is also irrotational, ∇×u = 0, you can write u = ∇φ and the problem collapses to potential flow: ∇²φ = 0 u = ∇φ The force on the body comes entirely from pressure: F = −∮ p n dS D = F·eₓ Under these assumptions the pressure field is perfectly front–back symmetric, so the integral gives D = 0 That’s the paradox. Not a small correction. Zero. Now look at the second animation. This is the same geometry and the same inflow, but with viscosity turned on, even if it’s only a small amount. Navier–Stokes (ν > 0) ρ(∂u/∂t + (u·∇)u) = −∇p + μ∇²u ∇·u = 0 That extra term changes everything. A thin boundary layer forms near the surface. Separation becomes possible. Vorticity is generated and shed. A wake appears. Drag is no longer optional. The contrast is the point. Letting viscosity go to zero is not the same thing as setting it to zero. The inviscid limit deletes the mechanism that breaks time-reversal symmetry and allows energy dissipation. Once that mechanism is gone, wakes can’t exist, and drag vanishes by construction. #FluidDynamics #NavierStokes #EulerEquations #DAlembertParadox #BoundaryLayer #Physicsshow more

Mathelirium
27,053 次观看 • 6 个月前
This one CSS property will fix your z-index headache.... In CSS, a child element with z-index will overlap with any fixed or floating elements outside its container. Instead of stacking higher and higher values to fix it. Use this instead: .card-container { isolation: isolate; } With that, any elements with z-index inside the container will be contained. If you found this useful, follow for more. ❤️show more

Ali
16,738 次观看 • 4 个月前
When you see the little girl dressed as a... fairy running to the entrance of the Court of the Universe with it's grand arch looming in the distance, you can see tiny people in the court - and you didn't realise it was that vast, or that old.show more

DystopiaNow!
53,009 次观看 • 11 个月前
Water usage has been a hot topic in the... AI data center world, but the numbers may surprise you. According to the Manhattan Institute, data centers use 0.2 percent of daily water usage in the U.S. and that number has dramatically decreased in the past few years due to a new method: liquid cooling. By moving to 45°C liquid cooling, AI factories in favorable climates can use dry coolers instead of conventional cooling-tower-based systems, cutting facility cooling water use from roughly 2.6M gallons per MW per year to near zero. Liquid cooling enables AI factories to be both water and energy efficient, while creating opportunities for heat reuse and dispersal to local communities, allowing these factories to become energy grid assets. Learn more below ⬇️show more

NVIDIA
33,842,181 次观看 • 2 个月前
Enjoy this journey while you can. There will be... a day when you don’t have anyone to throw with or lift with or play pickup racquetball and then hit the sauna after with. There will be a day when you can’t immediately roll from your workout into breakfast/lunch/dinner with 8 of your best friends. There will be a day when disputes cannot be settled with a game of madden, 2K or the show. You will realize that showing up late for work pales in comparison to the fear you had about showing up late to the field or the weight room. You can say that you’ll still train hard, keep yourself in shape, hold YOURSELF accountable. It’s easy to say when you have a goal you’re working towards with a collective group. But when you don’t have that, damn it gets hard. So enjoy it. Take advantage of the time and the energy. For some guys it happens after 6 years of pro ball. For others it happens after 4 years of college. But it will leave you. Let me repeat that: IT WILL LEAVE YOU AND IT SUCKS WHEN IT DOES.show more

Jack Barry
63,098 次观看 • 1 年前
This video shows a static fire test of the... Archimedes rocket engine, developed by Rocket Lab. Archimedes uses liquid methane (LCH.) as fuel and liquid oxygen (LOX) as the oxidizer, a combination known as methalox. During combustion, these cryogenic propellants produce extremely high temperatures (over 3,000°C), hotter than lava. To survive this, the engine circulates cold fuel through its walls before burning it, a technique called regenerative cooling. Multiple Archimedes engines will power Rocket Lab's upcoming Neutron rocket, which is being built to launch satellites and cargo to orbit with lower cost and higher reliability. Rocket Lab is best known for its Electron rocket and is now expanding into larger, reusable launch vehicles with Neutron.show more

Mechanical Knowledge
19,463 次观看 • 3 个月前
🇲🇾🇨🇳 Hormuz gets all the attention, but the Strait... of Malacca is the one that keeps Beijing up at night. It's the world's busiest maritime chokepoint, narrowing to just 1.7 miles at its tightest point. In the first half of 2025 alone, 23.2 million barrels of oil per day passed through it. That's more than Hormuz. Around 75% of China's seaborne crude imports flow through it from the Middle East and Africa. The Iran war has forced governments across Asia to think seriously about what happens if Malacca faces the same fate as Hormuz. Indonesia's finance minister floated the idea of tolls this week before walking it back. Singapore has already assured both the U.S. and China that passage is guaranteed and it won't participate in any effort to block it. The difference between Hormuz and Malacca is that 4 countries share the strait and all of them have a strategic interest in keeping it open. That makes it harder to close, but also harder to control. China is watching what the U.S. did to Iran's economy through a single chokepoint. It has one of its own that it can't protect alone. Source: Reutersshow more

Mario Nawfal
278,556 次观看 • 4 个月前
This looks like a simple transparent shock absorber filled... with oil. But what you are seeing is one of the most destructive phenomena in fluid engineering. This is cavitation in its true form. The white cloud forming beneath the piston is not foam and it is not air. The oil is literally changing from liquid to vapour at room temperature. When the piston moves rapidly, the oil is forced through tiny passages inside the damper. The fluid velocity increases, the local pressure drops, and if it falls below the oil's vapour pressure, the liquid begins to boil without any increase in temperature. The moment the pressure recovers, those microscopic vapour bubbles collapse almost instantly. And that is where the real damage begins. The destructive forces of cavitation is really not understood well by most. A collapsing cavitation bubble creates shockwaves and high-speed microjets that strike nearby surfaces with enormous local forces. Repeated millions of times, these tiny implosions can slowly eat away hardened metals, destroy precision components and reduce the lifespan of expensive machinery across industries. This same invisible phenomenon is one of the biggest challenges in naval engineering. Ship propellers operating under enormous loads can suffer cavitation erosion, losing efficiency while creating underwater noise. For advanced stealth submarines, that noise can become a major problem because cavitation can reveal their position. Decades of research have gone into specialised propeller designs, pump-jets, surface finishes and hydrodynamic optimisation to delay its formation. The same issues affects hydroelectric turbines that convert the energy of entire rivers into electricity, and industrial pumps that move oil, chemicals and water through critical infrastructure around the world. Perhaps the most remarkable part is that after 4-5 decades of advances in metallurgy, coatings and manufacturing, engineers still cannot simply build a material that is immune to cavitation. The solution is not to make stronger metals forever. It is to understand the fluid dynamics so precisely that cavitation is prevented before in those destructive bubbles ever form.show more

Ammanichanda
1,188,577 次观看 • 1 个月前
WOW v14.3.2 is very decisive and is able to... execute with great confidence. Big fan. That said, in my first drive it messed up *spectacularly* twice in <15 miles of suburban driving. In one instance, it swerved out of its through lane of traffic into a lane that was ending, right as it was ending. It was not trying to overtake any vehicles, it just swerved over violently. ugh The other, in the video below, it did not consider that the left lane was turn-only, and tried to use it overtake other vehicles while their light was red. (this intersection begins with left turn green and through-lanes red) It is still very slow to merge into the proper lane in time for a turn, and ended up cutting off a large truck to make its turn. Could it have completed its maneuvers and continued without intervention? Yes. Would it be safe or legal to do so? No. Plenty of work left to do on FSD.show more

The Cybertruck Guy
11,016 次观看 • 4 个月前
Have you ever heard of the "Stairway to Heaven"... hidden in Texas Hill Country? Tucked away in Wimberley sits Old Baldy, a limestone hill with 218 stone steps carved into the side of it. Step by step you climb through the trees, and when you finally reach the top, you're greeted with a breathtaking panoramic view stretching for miles. For years people have nicknamed it the "Stairway to Heaven," not because of the climb itself, but because of that moment at the top when everything opens up and you suddenly feel like you've found a place you never knew was there. Where's a place you've visited that you had no idea existed?show more

fOx
134,258 次观看 • 3 个月前
Strait of Hormuz over the last 24 hours: too... deep into the escalation trap or the cycle of stupid. The events over the past week should start to dissuade anyone from contemplating that the Strait of Hormuz is going back to normal anytime soon. The video from MarineTraffic illustrates that clearly with Iran's lane being the only active one. Today, IRGC said that 4 vessels were halted, while the US is saying that's fake. No one knows what's real anymore, but what is real is that shipowners will be reluctant to take the risk. He said, she said isn't good enough anymore when lives are at risk. We are now firmly in Robert A. Pape's escalation trap and Malcolm Nance's cycle of stupid. It is clear and obvious the US cannot give Iran the control of the Strait of Hormuz because it will make it the most powerful oil producer in the world. And since this conflict is all or nothing, we will either have to topple the regime, or Iran will come out victorious. There's no in-between. Let's see how this weekend goes, but from a flow perspective, nothing is going through. Zero barrels went through on July 17 and the last two days have not been revised higher by Kpler.show more

HFI Research
135,721 次观看 • 1 个月前
⚡️Truth is the moment consciousness refuses to be captured... by comfort. That is why it matters. Anyone can “tell the truth” when it costs nothing. That is just description. The real test comes when lying would protect your image, preserve your status, avoid conflict, keep money flowing, satisfy the audience, defend the tribe, protect the ego, or maintain the illusion that your old map still works. That is where truth becomes moral force. A lie is not just a false statement. A lie is reality being bent to serve fear. It lets the person avoid contact with what is real. It keeps the dead pattern alive. It says: the truth is too dangerous, so the self will substitute a more convenient world. Do that enough times and the soul becomes unreal. Not in a mystical decorative sense. In a structural sense. The person loses contact with reality. Their words stop pointing outward. Their identity becomes a defense system. Their relationships become performances. Their work becomes propaganda. Their mind becomes a lawyer for its own comfort. Truth matters because it keeps consciousness aligned with reality. And reality is the only place creation can actually happen. You cannot build a real life on falsehood. You can build status. You can build money. You can build an image. You can build an audience. You can build a career. But the structure will rot because it is no longer in contact with the thing it claims to represent. That is why “telling the truth when lying would be easier” is sacred. It proves that something in you serves reality more than self-preservation. That is the beginning of freedom. Because the person who cannot tell the truth when it costs something is owned by whatever the lie protects.show more

SightBringer
56,009 次观看 • 3 个月前
Double-Slit Experiment ✍️ It shows that tiny things like... electrons act like ripples in water instead of solid marbles. When a particle is fired at two slits, it doesn't just go through one or the other; it travels as a wave of probability that passes through both at the same time. These two waves then overlap and interfere with each other, creating a pattern of light and dark stripes on a back wall. This shows that at the quantum level, reality isn't "set" until we actually measure it. It behaves as a spread-out wave of possibilities until the moment it hits a target. Video 📸 : umtiquinhodefisicashow more

ScieVision
60,696 次观看 • 5 个月前
Jeff Bezos just told you exactly how to price... AI. Nobody listened. Bezos: “AI is real and it is going to change every industry. In fact it’s a very unusual technology in that regard in that it’s a horizontal enabling layer.” Horizontal enabling layer. Three words that reprice the entire technology sector. The iPhone was a vertical. One product. One new market. Electricity was a horizontal. One substrate that rewired every market on Earth. Wall Street is pricing AI like it is the next iPhone. Bezos is telling you it is the next electrical grid. Right now, thousands of companies are trying to sell AI as a product. A feature. A tool. A subscription tier. Every single one of them will be priced to zero. You do not sell a horizontal layer. You do not compete with it. You build on top of it or you disappear beneath it. For a century, entire industries survived on one thing. Complexity. The friction of navigating law, medicine, logistics, finance. That was the moat. If you could not memorize the maze, you could not compete. A horizontal layer does not navigate the maze. It dissolves the walls. Electricity did not compete with the candle industry. It erased the need for one. The most dangerous part of a horizontal shift is how quiet it is. It moves underneath the economy. The surface looks normal. Revenue still holds. Every day you operate on the old substrate, you accumulate a debt you cannot see and cannot repay. The internet repriced distribution. AI is repricing cognition itself. When intelligence becomes a utility that runs through the walls of every company on Earth, the premium on human expertise does not erode. It evaporates. This is not a disruption. Disruptions replace products. This replaces the ground you are standing on.show more

Dustin
541,979 次观看 • 4 个月前
I came across a great persistence mechanism and created... a Sigma rule for it. Just drop your batch script or add a line that points to your payload inside C:\Windows\Setup\Scripts\ErrorHandler.cmd, and upon execution of C:\Windows\System32\oobe\Setup.exe, the payload will run. In the clip below, I have cmd.exe /c calc.exe as the payload. If ErrorHandler doesn't exist, you can create it along with the directory. Thanks to hexing for posting about it 🙏 In regards to the rest binaries under the C:\Windows\System32\oobe\ directory, most of them will not work, whereas others will force a restart (i.e. audit.exe) 🔗:show more

Kostas
17,508 次观看 • 2 年前