A visualisation of different velocity factors in a PCB.... Both simulations use the same excitation and port parameters. Only the permittivity is different, showing how the signal travels much faster in low Dk dielectrics. This simulation shows an embedded trace. A signal on an outer layer also travels faster because part of the EM field propagates through air, which has a Dk very close to 1show more

A mongoose can react to a cobra's strike in... just 0.06 seconds, which is faster than the blink of an eyeshow more

A mongoose can react to a cobra's strike in... just 0.06 seconds, which is faster than the blink of an eyeshow more

System identification (sysid) is the process of finding the... physical parameters that make a simulation match reality. If you're training an RL locomotion policy in simulation, the accuracy of your motor model directly affects how well the policy transfers to the real robot. A recent git commit by Kevin Zakka added a sysid toolbox to MuJoCo which automates this process: you provide recorded motor data and a MuJoCo model, and it optimizes the model parameters to minimize the difference between simulated and real trajectories. For my RobStride Dynamics RS02 QDD motors (17 Nm peak, 7.75:1 gear), I built a Rust tool that sends multi-sine torque excitation at 1 kHz and records position/velocity feedback. I then feed this data into MuJoCo's sysid optimizer.show more

A simplified summary of my simulations of how drone... detector antenna placement affects signal reception, expressed as a conditional drone detection range for different frequencies - obtained roughly by normalizing the square root of total gain to a typical drone detection range. Red line - detection distance for antenna on the roof, blue line - for antenna under the windshield. Considering that the main sector from which drones can approach the vehicle is elevation from 0 to 30 degrees, and also that in reality the glass will attenuate the signal more strongly than in my simulations - mounting the drone detector antennas inside the vehicle significantly reduces its practical drone detection range, especially in the rear hemisphere.show more

Does glass break faster than a bullet? Since the... vibration transmitted through the glass is much faster than the speed of sound in the atmosphere, the breaking speed of the glass is much faster than the bullet. [📹 Slow Mo Guys]show more

This is a device I use in my office:... it draws outdoor air from outside the window into the room, passes it through a filter, and then vents it indoors. The excess air pressure pushes indoor air out through the gaps around the door. This way, indoor carbon dioxide, particulate matter, and VOCs can be reduced to very low levels. Even an air purifier with activated carbon cannot achieve this effect, because air purifiers cannot lower CO2 concentration. This device is modified from an AirFanta 3Pro. I reversed the fan installation and connected two reducing adapters so that the final diameter matches that of this plastic expandable duct. Finally, I sealed the window with a sealing fabric, leaving only an opening the same size as the duct. Its only drawback is the lack of heat exchange, so it requires some additional air conditioning load. It would be unsuitable in very cold or very hot places.show more

Historic Vids This shows why sound travels faster in... solids, slower in liquids, and slowest in gasesshow more

Gemini (left) vs ChatGPT vs Claude (right) Prompt: Create... an interactive HTML, CSS, and JavaScript simulation of a satellite system that transmits signals to ground receivers. The simulation should show a satellite orbiting the Earth and periodically sending signals that are received by multiple ground stations. Include realistic factors such as signal delay based on distance, occasional signal loss due to obstructions or interference, and visualization of the signal path as lines or waves. The satellites’ position should be updated using simplified orbital mechanics, and the ground receivers should display received signal strength and timestamps.show more

The blade of a saw carries a small electrical... signal. When skin contacts the blade, the signal changes because the human body is conductive and the change to the signal activates the safety system. [📹 SawStop]show more

This is one of the benefits of having a... 6th offensive lineman in. Look at how much time Tua has on this one, and he delivers an absolute dime to Waddle. Opposite hash, 35 yards in the air. One of his best throws of the season.show more

Notice the patterns Ange has already embedded in the... #NFFC attack? Different players in different positions making it very tough for defences to pick players up - plenty of options in the box for crosses or shots. A sign of things to come? #AngeBallshow more

Dagknight technical progress As would be mentioned in a... still unshared post by Michael Sutton, the dagknight effort is split into v0 devnet, v1 testnet and v2 mainnet candidate. I’ve been testing the current v0-based implementation in a small devnet with the help of some testers who run nodes and miners with me. The DK work can be thought of as split into two parts: (1) implementing the actual protocol and (2) wiring it up and using it. The testing and development over the last month has been focused on (2). Obviously, DK is a consensus change for selecting parents. What’s not so obvious is that such a change affects DAA, coinbase, IBD, pruning and a lot more. Each of these areas is very sensitive and requires proper understanding to wire correctly. An important consideration and difference from GD is that DK does not focus on maximizing a property like blue work. So to maintain topological properties of blue work, an independent (free) GD implementation is kept running specifically for maintaining blue work. This allows us to keep using the property for topology. Coloring and blue score use the megachain induced by DK. The wiring around DK as of this posting is in a working state, but still needs to be reviewed. Next efforts will be focused on protocol specific components, particularly Tie-Breaking and incremental UMC. Attached are some captures from the internal devnet. The dense DAG image is what happens when things related to DAA or other similar consensus parameter causes a node to insist on their POV. The video is a recent snippet of the KGI running on the devnet showing (perhaps not obviously) DK at work. The current “dagknight” branch is now posted on the main repo. A topic in the Public R&D has been opened for Dagknight development.show more

This is how a train travels through deep snow... in wintershow more

RONIN (1998) A sneaky 'hidden cut' occurs when an... extra walks past the camera to wipe the frame. The first shot is one location and the second shot is in a completely different part of the French town. A cool way to seamlessly connect different real-world locations.show more

Iran is burning. It is presumed that the video... shows a military garrison on fire Air defense is active in different parts of the country.show more

Added an obstacle in the room and simulated three... different scenarios. This makes any kind of airflow simulation inside a room much more accessible. You can optimize the ventilation of your living room with just 10 lines of Python.show more

The Pirates haven’t won a Paul Skenes start in... over a month and are currently trailing the Marlins 2-1… Skenes has seen a dip in his fastball velocity this season and nobody in Pittsburgh seems to notice he’s holding the baseball with a different set of muscles this year…. Here he is last June holding the baseball with his interossei muscles (left video) compared to his flexor digitorum superficialis today (right video)…. The interossei originate on the hand, the FDS originate on the humerus…. This is why his hand & wrist orientation is so different at the top of his motion as well as at his follow through….show more

Here’s a video simulation that shows the Raymond James... Stadium field design for the #GoBolts outdoor game. The #NHL going all in on a Gasparilla theme with a pirate map layout with #TBLightning-related different points of interest. My favorite: Brayden’s Point of No Return.show more