The surface temperature of the sun is above 5500 ° C, like a large stove, and the temperature of the corona is as high as several million degrees Celsius. Imagine that you are sitting next to a large stove now. Does it feel hotter as you get closer to the stove? But at the solar corona, the situation is just the opposite. When you cross the corona, the closer you are to the sun, the colder it becomes. Why is that?
In daily life, we often confuse temperature with heat, thinking that the greater the heat, the higher the temperature. But in fact, these are two different concepts. Temperature represents the degree of hot and cold of an object, and is related to the random movement of molecules inside the object. The more intense the molecular movement, the higher the temperature. Heat is the total energy transferred by the moving molecules. At the solar corona, the atmosphere is very thin and the number of molecules is very small, so although they move violently and the temperature is high, they do not transfer much energy. When you pass through the corona, it is difficult to obtain atmospheric molecules The transferred energy, naturally, will not feel the heat.
NASA used this feature of the corona, launching the Parker Solar Probe in 2018. This probe will penetrate the solar corona of millions of degrees Celsius to explore the mysteries of the sun.
There are many magical and fragile creatures living in the sea. It is a difficult task to study them without harming them. It is almost difficult to bring fish, molluscs, etc. in the deep ocean to the sea surface for research without any damage. Now inspired by the art of origami, scientists have invented a special robot that can safely capture the most vulnerable marine life.
This mechanical catcher is a rotating dodecahedron, each of which is a 3D printed white polymer, 5 of which are connected to a mechanical tentacle to control the opening and closing of the entire structure. It can also adjust the size according to the target’s body size . Scientists put the mechanical catcher into the waters with a depth of 500 to 700 meters and performed several tests. After putting the catcher into the water, they controlled it to open gently, wait for the target to enter, and then silently close it. In this experiment, scientists successfully captured jellyfish and octopus several times and released them intact.
Scientists also plan to add sensors and cameras inside the mechanical catcher. The sensors can help the catcher accurately locate the marine life, and the camera can directly capture the status of the marine life.
Seaweeds are rafts, often carrying microorganisms attached to them for an ocean rafting, so it is not surprising to see a large piece of seaweed floating on the vast sea, but it is worthwhile to find drifting seaweed on the islands of Antarctica. Called a miracle.
Antarctica can be regarded as a paradise on earth, it is isolated from the world, and it is a little bit safe. The polar east wind blows the Antarctic circumpolar circulation, rotating from west to east, tightly embracing the entire Antarctica. It is a natural barrier for Antarctica, and together with the westerly ocean current that flows from Antarctica to low latitudes, it resists the invasion of species from the ocean.
Recently, however, scientists have found drifting seaweeds from other regions in Antarctica. These seaweeds are from South Georgia Island. South Georgia Island is located in the southern Atlantic Ocean, close to the Antarctic Peninsula, but seaweeds drift from there to the Antarctica. Instead of heading up against the current, it is necessary to orbit the earth for a 20,000-kilometer long-distance global drift, which is almost impossible. So how did these seaweeds reach Antarctica?
Scientists believe that this is most likely caused by an Antarctic polar storm. When the polar storm is raging, the circumpolar circulation and westerly drifting can’t compete with it. Seaweed is likely to enter the South Pole on the “high-speed train” of the polar storm. Scientists predict that with global climate change, Antarctic polar storms will become more frequent, and more alien species are likely to enter Antarctica through this channel, and it will no longer be isolated from the world.
An increasing number of studies have proven that human intestinal bacteria are vital to health. Gut bacteria can affect our response to negative stimuli such as fear; affect our body’s immune response; affect our mental health, and so on. Recently, scientists have discovered that intestinal bacteria also affect our nervous system development and are closely related to autism, but it is not the intestinal bacteria that carry autism, but the mother’s intestinal bacteria.
In the human body, there is a molecule called “interleukin-17a”, which is produced by the immune system and plays an important role in the body’s fight against fungal infections. Importantly, it can also affect the development of the brain in the womb. If a pregnant woman becomes infected, her gut bacteria can induce immune cells to produce a large amount of interleukin-17a, which enters the fetus through the placenta and affects fetal brain development.
Scientists have successfully demonstrated in mice experiments a chain reaction from gut bacteria to interleukin-17a to the cerebral nervous system that affects autism. Next, scientists need to further confirm whether the same reaction chain exists in the human body.
There are only two mammals in the world who love spicy food, one is human and the other is tree shrew.
Tree shrews are active in East and Southeast Asia. They look like mice and look like gray squirrels without big tails. They have gray hair on their bodies except for a little white hair on the belly. Tree shrews are small in size and generally only 19-20 cm long. Although their tails are not large, they are very long, almost as long as the body.
Tree shrews actively look for spicy food. Generally speaking, with the exception of human beings, mammals have always kept aloof for spicy flavors. Mammalian tongues and throats have ion channels that act as receptors. When exposed to spicy flavors, ion channels are activated and tell the brain to stay away from foods with this pungent taste. The tree shrews are different. Although their tongues and throats also have ion channels, scientists have found that the species’ ion channel receptors have been mutated, making them less sensitive to spicy taste. Due to the genetic mutation, the pungent spicy taste will not cause pain to the tree shrews, and they will be able to enjoy spicy food happily.