This article is from WeChat public account: Husk (Guokr42) , author: window knock rain, editor: Li Xiaokui, title figure from: US drama” big Bang “
Some scientific discoveries have expanded human understanding of the world, some have bred practical new technologies, and some have a lot of fun just by looking at the pictures. In the past year, what exciting technology videos / movies have been born? Let’s review them together.
“Emerging from nothing”
Animated animation | Brett E. Kelly et al
This is a new 3D printing technology. The light beam irradiates the rotating cylinder, and the original liquid resin material is partially cured. We will see that a printed part appears as if it emerges out of nowhere. The whole process takes only a few minutes. [1] .
The idea of CT tomography borrowed from this technology no longer requires layers of superimposed printing materials, so the printing speed is increased, and components with smoother surfaces can be obtained.
Magma Eruption
Magma Eruption Experiment | Ingo Sonder et al
This is a genuine magma eruption, but it has been reduced to a meter scale. The square container is filled with steaming fresh magma, and the pipes on the side of the container are filled with cold water. Next, the hot lava, steam, and water droplets rushed towards the camera set up above.
This is a simulation experiment by volcanologists who want to understand the conditions under which water and magma contact can cause dangerous explosive reactions-a condition known as “ejecting magma eruption” (phreatomagmatic eruptions) [2] .
Bee paddling
When bees accidentally fall into a pool of water, they will flap their wings and paddle, creating asymmetric waves on the water surface, using this as a motivation to push themselves to the shore to escape.
Picture is a slow motion | Chris Roha & Morteza Ghariba
This is an accidental discovery by two engineers. They used high-speed photography to record the strokes of bees in detail. They also wrote the analysis results and published them in the Proceedings of the National Academy of Sciences. [ 3] . This interesting behavior has also brought new inspiration to engineers, and the two authors have already begun designing small robots to make them move on the water in the same way.
Bubble snowflake ball
Snowflake freezing of soap bubbles in cold environments | Farzad Ahmadi et al
Blowing a bubble outdoors in very cold winter, it freezes in a very beautiful way: ice crystals float on the bubble film, as if shaking a snow globe. A similar animation has actually been popular on the Internet for several years, but this year scientists finally came forward to explain it and wrote it as a paper and published it in Nature-Communications [4] .
Researchers point out that what drives small ice crystals to move on the surface of soap bubbles is unbalanced surface tension. Ice crystals are first generated at the bottom of the soap bubbles, and the icing phase change is accompanied by exothermic heat, which will cause the soap bubbles to heat up locally, and the temperature change will cause a difference in surface tension. The small ice crystals will move with the liquid film. This beautiful freezing method requires that the surrounding environment and the surface temperature in contact with the soap bubbles are much lower than the freezing point of the soap bubble solution. (in research, -18 ° C ~ -20 ° C) .
black in the black
The world’s darkest material has a new record. In September of this year, researchers at the Massachusetts Institute of Technology developed a new type of ultra-black material. This time it absorbed 99.995% of incident light, which is an order of magnitude darker than the previous ultra-black material Vantablack.
However, what really caught my attention was that the researcher collaborated with an artist (Diemut Strebe) and made it with ultra-black materials. A work of art [5] . This work is called “The Redemption of Vanity” (The Redemption of Vanity) , its content is: a 16.78 carat yellow diamond span class = “text-remarks” label = “Remarks”> (It is said to be worth 2 million US dollars) The surface is completely covered with carbon nanotube material, which makes it change from bright and shiny to dark … >
The following is a comparison chart before and after processing:
Blacker than the background is OK | Diemut Strebe
Little worm takes off
This is a slow motion. To study these bugs in detail, researchers used high-speed photography at 20,000 fps | G. M. Farley et al
You can excel at jumping without legs. The little guy in the picture is a maggot larva. It can bounce its soft little body into the air and jump out of the distance of 36 times its own body length.
How did this happen? Researchers have discovered that larvae use micro-structures like velcro to secure themselves in a loop, and accumulate hydraulic pressure at the tail of the body [6] . But the reason I like this animation is that it looks like a flying shrimp …
Supersonic Champagne
When champagne is opened under high-speed photography, it is at room temperature (20 ° C) | Gérard Liger-Belair et al
At the moment when champagne is opened, the high-pressure gas that is rapidly ejected can also reach supersonic speed. The researchers also observed a type of “Mach plate” (Mach disks) [7] , this phenomenon also occurs when jet planes and rockets emit supersonic exhaust gas.
The white arrows in the figure indicate where the Mach disk appears, and the numbers represent time in microseconds | Gérard Liger-Belair et al
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Unlike fighters, the Mach plate produced by opening champagne is very short. After all, the inside and outside of the bottle are not enough to maintain a sufficiently high pressure difference for a long time. The Mach plate appeared approximately 580 microseconds after the corks were opened, and disappeared within 1 millisecond.
Auto-floating
Metal sheet structure that can float when pressed in water | Matt Mann / University of Rochester
Researchers from the University of Rochester have created an interesting metal structure: it looks like it is just two pieces of metal with a gap in the middle, but it is different from ordinary metal pieces even if it is fully pressed into In the water, it can still float to the surface automatically. Even if you poke a few holes in the middle, it still won’t sink. This characteristic is due to the superhydrophobic properties of the inner surface of the metal sheet and the air trapped between them.
Researchers have used lasers to “etch” metal surfaces, leaving microstructures behind and achieving superior hydrophobic properties. On super-hydrophobic treated metal surfaces, water droplets can bounce up like small balls and look very pleasing:
Water droplets bouncing on a hydrophobic surface | Matt Mann / University of Rochester
Finally, enjoy two of the most memorable tech videos of the year.
Big Voice
This year’s most memorable new discovery: the loudest bird song is currently known.