Is the universe starting to produce "raspberries"? In fact, it is a newly discovered supernova remnant! | Expo Daily

Is the universe starting to produce "raspberries"?

Astronomers have discovered a new supernova remnant (SNR) candidate — nicknamed "Raspberry" — found on the near side of the Scutum-Centaurus Arm of the Milky Way.

Supernova remnants (SNRs) are diffuse, expanding structures resulting from supernova explosions. They contain expanding matter ejected from the explosion, as well as other interstellar matter swept up by the shockwave of the exploded star. It is important to study supernova remnants because they play a key role in the evolution of galaxies: they disperse the heavy elements produced by supernova explosions and provide the energy required to heat the interstellar medium. Supernova remnants are also thought to be responsible for the acceleration of galactic cosmic rays.

The newly discovered Milky Way SNR candidate is named G308.73+1.38, and is nicknamed "Raspberry" because of its shape similar to a raspberry. It is estimated that the diameter of the "Raspberry" is between 32.5 light-years and 98 light-years, and it is between 10,000 and 16,000 light-years away from us. There may be a neutron star or pulsar near the center of the "Raspberry", which was formed by the initial supernova event. In short, although a "Raspberry" has been discovered, a lot of research needs to be done to confirm more information.

"Raspberry" G308.73+1.38. https://scx2.b-cdn.net/gfx/news/2024/raspberry-in-the-sky-a.jpg

They poop in front of you , they are actually saying hello to you

When elephants meet their companions, they often pee and poop in front of them. This seemingly rude behavior is actually a common way for elephants to greet each other!

For humans, such greetings may be a bit beyond the scope, but for elephants, it is a common social etiquette, a way to consolidate the connection between social groups and promote communication between individuals.

In 71% of the recorded greetings, elephants used olfactory behaviors when greeting each other. Olfactory behaviors mainly include sweating, urination and even defecation. These behaviors are extremely unsightly in the eyes of humans, but they are common ways for elephants to greet their companions.

Elephant feces and urine contain many chemicals, which are very important to elephants and reflect many aspects of elephants. By identifying the chemical information in the smell, elephants can understand each other's recent life situation without words when they meet.

So, next time you see elephants "relieving themselves" in a public place, don't feel disgusted, because they are just saying hello to you!

Image source: pixabay

Does not liking broccoli mean you are a picky eater ? Or maybe you are a supertaster!

Green peppers are the natural enemy of Crayon Shin-chan. Is there a food that you avoid eating? Is it possible that we are not picky eaters, but super tasters?

Super taste is an innate ability, and studies have shown that super tasters are related to a gene in humans. Scientists believe that most super tasters have the TAS2R38 gene, which increases people's perception of bitterness, especially the bitterness of PTC, propylthiouracil or related substances in all foods and medicines. A study this year showed that some patients found two antibiotics, chloramphenicol and ofloxacin, so bitter that they were difficult to swallow, which was also related to the TAS2R variant.

In addition to genetic influences, supertasters also have more and denser taste buds on their tongues. Supertasters are defined as having 35 to 60 taste buds in a 6-mm diameter circular portion of the tongue (about the size of a pencil eraser), while average tasters have about 15 to 35. In some cases, a heightened sensitivity to bitter tastes can help humans avoid alkalosis from accidentally ingesting toxic plants.

Supertasters look more like picky eaters, and they also blacklist a series of foods. The reason for not eating these foods is simple, because these foods are bitter and difficult to swallow, such as broccoli, kohlrabi, spinach, Brussels sprouts, radish, watercress, grapefruit juice, green tea, star anise... Especially the chemical 6-n-propylthiouracil (PROP) contained in broccoli is quite bitter for supertasters!

Image source: pixabay

The human brain can store at least 1024TB of files

The brain, a complex biological information system, relies on the connections between neurons - synapses - to form memories and thoughts. The latest research shows that the human brain's ability to store information is almost 10 times the previous estimate. Synapses are the connection points between neurons in the brain, which transmit nerve impulses through electrical and chemical activities to achieve information transmission. The number and strength of synapses in the brain determine its memory storage capacity. The strength of synapses is not static, it can be enhanced during learning and process, which is a manifestation of synaptic plasticity and is also the key to memory formation and cognitive function. Changes in synaptic strength, that is, the "volume" of synapses, can be subtle whispers or loud shouts.

With the help of information theory, the author team of the new study applied the framework originally exclusive to computers to the brain, thereby estimating the number of bits that synapses can accommodate and quantifying the amount of information they store and transmit. By analyzing the synaptic pairs in the rat hippocampus, the author team found that they can respond to the same type and number of brain signals and adjust the strength of synapses. The final analysis results showed that hippocampal synapses can store 4.1 to 4.6 bits of information. This means that the amount of information that the human brain can store is more than 10 times that previously thought, reaching at least 1 PB, or 1024 TB, which is equivalent to 500 billion DVDs, or the space occupied by high-definition versions of all movies to date.

Image source: veer gallery

Building the largest "cornea" for China's "clairvoyance"

If an optical telescope is compared to a human's "clairvoyance", then the primary reflector in the optical telescope is the "cornea". The larger the aperture of the primary reflector, the higher the spatial resolution of the optical telescope.

If a 1-meter-diameter reflector is installed in a space camera, the outline of a car on the ground can be seen from a height of several hundred kilometers. If the reflector diameter is increased to 4 meters, the sunroof and rearview mirror of the car can be clearly seen. The Hubble Space Telescope, with a reflector diameter of 2.4 meters, can detect cosmic signals from the Big Bang 13.4 billion light years away. Among the reflectors of optical telescopes of all sizes around the world, the one with the largest diameter made of silicon carbide comes from China.

For a long time, countries have regarded meter-level and above caliber reflectors as strategic materials. "We cannot buy them but must use them, which forced us to take the path of independent innovation." This "force" actually allowed them to produce the world's largest caliber high-precision silicon carbide optical reflectors.

Silicon carbide was selected as the material for the main reflector due to its excellent comprehensive properties. It has a high hardness, second only to diamond, and is difficult to manufacture, requiring breakthroughs in multiple technical bottlenecks.

After more than ten years of hard work, the team of Changchun Institute of Optics, Fine Mechanics and Physics of the Chinese Academy of Sciences overcame key technical difficulties such as mirror blank preparation, optical processing and testing, modification and coating, and finally realized the full-link manufacturing from basic theory to research, design, manufacturing, assembly, inspection and testing.

The large-aperture silicon carbide mirrors developed have been used in many major national engineering tasks and have incubated a number of high-tech enterprises.

The content is compiled from China Science Popularization Expo Weibo, Global Science, Science Academy, World Science, China Science Daily, and China National Astronomical University.

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