Is it true that "a dragon gave birth to nine sons"? There is fossil "evidence" | Bolan Daily

Is it true that “a dragon gives birth to nine sons”?

The "Hanjiang Lizard" or "Hanjiang Dragon" has a head and neck, a slender body and short limbs. Doesn't this image look a bit like the legendary Chinese "dragon"?

This dragon has a very pointed head and a slender body. It has nearly 30 dorsal vertebrae, and its limbs are very thin and short. What are the benefits of such a body shape? It can twist its body freely in the sea and swim flexibly like an eel. This is what the first batch of dragons that returned from land to the sea looked like.

In scientific research, the Hanjiang lizard has a certain significance because it is the oldest member of the fin-like marine reptiles and can be said to be the ancestor of all later fin-like reptiles.

The Hanjiang lizard evolved into a variety of marine reptiles, such as the turtle-like placodon, and the Bixi dragon. Bixi is one of the sons of the dragon. You may have seen it. There are stone tablets in many royal gardens. The one under the stone tablet that looks like a turtle but is not a turtle is Bixi, also called Baxia.

Restoration of the Han River Lizard (Image source: video screenshot)

Is it true that if you don't step on cockroaches , the more you step on them, the more they will appear?

During the breeding season, some species of female cockroaches carry with them a special structure that looks like a small brown wallet or a small red bean. This is their egg case.

The egg case usually contains about 8 to 40 cockroach eggs. The specific number of eggs varies depending on the species. For example, the German cockroach usually carries 37 to 44 eggs.

This special structure is formed by the secretion of liquid protein by female cockroaches after laying eggs. It can harden after drying, thus protecting the eggs from threats from microorganisms, weather and predators. This special structure is also the secret weapon that cockroaches have been able to reproduce from ancient times to the present.

Some cockroaches will hide the egg sheaths in dark crevices and hatch them quietly, while some cockroaches prefer to stick the egg sheaths to their tails and carry them with them. Coincidentally, the German cockroach is the type that likes to carry eggs.

The egg case will gradually hatch during the process of being carried. If we slap the female cockroach to death when it happens to be carrying an egg case, and the cockroaches in the egg case are almost hatched, then as we slap it, the egg case may fly out, or simply stick to the soles of our feet and spread to the whole house as we walk.

If we don't clean it in time, there may be more and more cockroaches. But generally speaking, the probability of this happening is still too low.

Can the pilot still hear the sound when the plane exceeds the speed of sound ?

The speed of a supersonic aircraft is expressed by the speed of the aircraft relative to the air.

Inside the plane, the air moves together with the plane at the same speed; the air and the pilot are relatively stationary, so we won't see the pilot flying the plane against strong winds (unless it's an open plane or an accident occurs).

In this case, whether the aircraft's speed is supersonic or not does not affect the pilot's ability to hear the sounds coming from the aircraft's interior space normally.

Airplanes are made of solids, and the speed of sound propagation in solids can reach 5000 meters per second, which is much greater than the speed of sound of 340 meters per second. Therefore, when sound propagates through the fuselage, the pilot can also hear the sound of the aircraft engine and the vibration of the fuselage.

Of course, the supersonic condition can also help shield some sounds. When the sound source is in the atmosphere and cannot be transmitted by solids or liquids, the pilot cannot hear these sounds.

Image source: pixabay

Scientists observe the heaviest antimatter hypernucleus yet

Researchers from the Institute of Modern Physics of the Chinese Academy of Sciences and other institutions participated in the RHIC-STAR international collaborative experimental research and observed for the first time a new antimatter hypernucleus, antihyperhydrogen-4, in relativistic heavy ion gold-gold collisions. This is the heaviest antimatter hypernucleus discovered experimentally so far.

Antimatter is extremely rare, and antimatter nuclei and antimatter hypernuclei (nuclei containing hyperons such as Lambda) formed by further combining several antibaryons are even more difficult to produce. Since the "negative energy solution" of the Dirac equation in 1928 predicted the existence of antimatter, scientists have only discovered six antimatter (hyper) nuclei in the past century.

The anti-hyperhydrogen-4 discovered this time was produced in a relativistic heavy ion collision experiment. Anti-hyperhydrogen-4 consists of an antiproton, two antineutrons and an antihyperon. Because it contains unstable anti-Lambda hyperons, anti-hyperhydrogen-4 will decay after flying only a few centimeters.

The study analyzed experimental data from approximately 6.6 billion heavy ion collision events, and reconstructed anti-superhydrogen-4 through the antihelium-4 and π+ mesons produced by decay, obtaining signals of approximately 16 anti-superhydrogen-4.

The work was led by the team of Qiu Hao, a researcher at the Institute of Modern Physics. The research team of the University of Science and Technology of China made contributions in decay particle reconstruction technology and efficiency calculation. The relevant research results were published in Nature.

Why do we still need to dig canals when railways are so developed?

The Pinglu Canal is the first canal connecting the river and the sea since the founding of New China. The construction period is 52 months, and the estimated cost of the project is 72.7 billion yuan. The total amount of earthwork is equivalent to the excavation of three Three Gorges ship locks. It has created eight world firsts. Why did they spend more than 70 billion yuan to dig the Pinglu Canal? Is the current canal still useful?

The content is compiled from China Science Popularization Expo Weibo, Science Rumors, Institute of Physics, Chinese Academy of Sciences, Gezhi Lundao Forum, Institute of Modern Physics, Chinese Academy of Sciences, Science Popularization China

This article was first published on China Science Expo (kepubolan). Please indicate the source of the public account for reprinting