Evolution of entropy perturbation

Here I stand, hidden out from one to see, Between the devil and the deep blue sea.

[dictionaryofobscuresorrows]

sonder

n. the realization that each random passerby is living a life as vivid and complex as your own—populated with their own ambitions, friends, routines, worries and inherited craziness—an epic story that continues invisibly around you like an anthill sprawling deep underground, with elaborate passageways to thousands of other lives that you’ll never know existed, in which you might appear only once, as an extra sipping coffee in the background, as a blur of traffic passing on the highway, as a lighted window at dusk.

video: sonder: everyone has a story

[entropy-perturbation]

Charles’ wedding: Leaving the church

[fuckyeahfluiddynamics]

Scientists have long wondered whether the schooling of fish is driven by hydrodynamic benefits, but the complexity of their environment makes unraveling this complex motion difficult. A recent study uses a different tactic, combining direct numerical simulation of the fluid dynamics with techniques from artificial intelligence and machine learning to build and train autonomous, smart swimmers.

The authors use a technique called deep reinforcement learning to train the swimmers. Essentially, the swimmer being trained is able to observe a few variables, like its relative position to the lead swimmer and what its own last several actions have been – similar to the observations a real fish could make. During training, the lead swimmer keeps a steady pace and position, and the follower, through trial and error, learns how to follow the leader in such a way that it maximizes its reward. That reward is set by the researchers; in this case, one set of fish was rewarded for keeping a set distance from their leader, one intended to keep them in a position that was usually beneficial hydrodynamically. Another set of fish was rewarded for finding the most energy-efficient method for following.

Once trained, the smart swimmers were set loose behind a leader able to make random decisions. Above you can see the efficiency-seeker chasing this leader. Impressively, even though this smart swimmer had the option to go it alone (and had never followed such a dynamic leader), it does an excellent job of keeping to the leader’s wake. Compare it with real swimmers and there’s a definite similarity in their behavior, which suggests the technique may be capturing some of an actual fish’s intuition. (Image and research credit: S. Verma et al., source; thanks to Mark W. for assistance)

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Charles’ wedding, part VI: the vows exchange

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Charles’ wedding, part V: the Ceremony

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Charles’ wedding, part IV: arriving at the church.

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Charles’ wedding, part III: the Bride’s Bouquet.

[srsfunny]

This Has To Be The Greatest Idea Ever

[pearwaldorf]

#can we get a donation box on the house floor? #I want CNN to train one camera on it at all times #I want John Lewis dropping quarters really loudly into it while Paul Ryan speaks #just ‘ping’ ’-and the affordable care act costs taxpayers-’ 'ping’ ’-funding abortions at planned parenthood-’ 'ping’ ’-balance the budget- #'ping’ ’-will you stop that?!?’ 'sure - whenever you’re ready’ #'i got all day mr. speaker - taxpayers pay me to show up here and do my job’ #'and tell the truth’ (wrangletangle)

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Charles’ wedding, part II: dressing the boys up

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Charles’ wedding, part I: dressing the boys up

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Vimy, WWI Canadian memorial and museum.

Nikon F6, Cinestill 50.

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[officialnoire-deactivated202411]

Photographer Desiree Mattsson

[ditavonteese]

Pleased to say #dragrace superstar and #burlesque legend in the making @violetchachki is joining the cast of #artoftheteese for our last stops on the tour in #Houston and #Dallas! Ticket links: artoftheteese.com ・・・ @violetchachki #reglam Photo by @darren_black Styled by @acstudio_ 🚨I don’t smoke kids, this is just a prop🚨 (at House of Blues Houston)

[entropy-perturbation]

Bitch resting face for everyone.

[fuckyeahfluiddynamics]

Pascal’s Law tells us that pressure in a fluid depends on the height and density of the fluid. This is something that you’ve experienced firsthand if you’ve ever tried to dive in deep water. The deeper into the water you swim, the greater the pressure you feel, especially in your ears. Go deep enough and the pressure difference between your inner ear and the water becomes outright painful. 

In the video demonstration above, you’ll see how a tall, thin tube containing only 1 liter of water is able to shatter a 50-liter container of water. Not only does this show just how powerful height is in creating pressure in a fluid, but it shows how a fluid can be used to transmit pressure over a distance – one of the fundamental principles of hydraulics! (Video credit: K. Visnjic et al.; submitted by Frederik B.)

[fuckyeahfluiddynamics]

Reader @hoosierfordman77 writes:

“They’re pressurizing the line by using a syringe sealed to the tube.  Of course, the volume of water in the tube added to this.  But it was not the only source of pressure.  Also explaining that pressure only has one vector as in the illustration using Hoover Dam is preposterous.  Sir [sic] later stated correctly that pressure is evenly distributed through the inside of a container.  If her demonstration was correct then the pressure of the water in lake Meade is not proportional to the volume of the lake…only proportional to its depth.  Now I’ve not done testing but I do not believe a 100,000 acre lake that’s 1 foot deep would be held back by the walls of a kiddie pool that routinely handle that depth.” (emphasis added)

Hi, hoosierfordman77, thanks for your comment! It does seem counter-intuitive that pressure in a reservoir is proportional to depth, not volume, but it is correct. If you go swimming 1 meter below the water surface, the pressure you experience is the same whether you’re in a backyard pool or the Gulf of Mexico. And, yes, a 100,000 acre lake that’s 1 foot deep has a static pressure that could be withstood by a kiddie pool. 

Now engineers don’t build it that way for a couple of reasons. 1) Pascal’s Law only describes hydrostatic forces – that is, the force experienced when the water is motionless. In reality, a dam would need to withstand not only the hydrostatic forces caused by the water’s depth but also any forces exerted when the water moves due to wind action, temperature differences, etc. And 2) after evaluating all of the expected forces a structure will endure, engineers add a factor of safety to make the structure strong enough to withstand forces above and beyond what is expected in ordinary or extraordinary operation.

As for the syringe, it only adds additional pressure to the line if they do not allow a gap for air in the line to escape. That can be a bit of a challenge, as they acknowledge in the video when they discuss the effects of air bubbles in the line. However, there is every indication that they were aware of this potential in their demonstration and did everything they could to ensure that it was not affecting the result. The fact remains, however, that extra pressure in the line is unnecessary – the 1 liter of water’s depth alone will shatter that container.

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Breakfast cereal from miniestudio on Vimeo.

[fuckyeahfluiddynamics]

Photographer Dave Sandford braved the cold and turbulent waters of Lake Erie in late fall to capture some remarkable wave action. Like on the ocean, waves in the Great Lakes are largely driven by winds, but lakes don’t develop the constant set of rolling waves that oceans do. Instead their waves are more erratic and unpredictable. Sandford focused on capturing the moment when wind-driven waves coming into shore collided with waves rebounding from piers or rocks along the shore. The results are waves that, through Sandford’s lens, look like exploding mountainsides. Such energetic waves mix sediment and nutrients in the lake, and the spray of droplets can even loft aerosols and pollutants from the water into the atmosphere.   (Photo credit: D. Sandford; via Flow Vis)