The number of pulsars discovered by the "China Sky Eye" exceeds 1,000! ｜ Expo Daily

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China's Sky Eye has discovered more than 1,000 pulsars

Since its official opening and operation four years ago, China's Sky Eye FAST has achieved a number of important original results in the fields of pulsars, fast radio bursts, neutral hydrogen, and nanohertz gravitational waves. Among them, the breakthrough progress such as the discovery of the shortest orbit pulsar binary in the pulsar field and the capture of preliminary evidence of nanohertz gravitational wave signals has undoubtedly provided strong support for FAST to catch up with the world's advanced level. Since the discovery of the first pulsar in 1967, more than half a century has passed; foreign telescopes have discovered more than 3,000 pulsars so far. In 2016, the team led by Nan Rendong built the world's largest and most sensitive single-aperture radio telescope FAST, opening the FAST era of radio astronomy research!

Since the observation and commissioning, FAST has discovered more than 1,000 pulsars in seven years, accounting for about a quarter of the total number of pulsars. This number exceeds the total number of pulsars discovered by other international telescopes in the same period, including a large number of millisecond pulsars and pulsar binaries, enriching the types and numbers of pulsars, which is of great significance for understanding the formation and evolution of pulsars.

By observing pulsars, we can test the general theory of relativity, detect low-frequency gravitational waves, and provide important data support for theoretical research on pulsar physics and time measurement.

In addition, scientific research teams from Guizhou Normal University, Xinjiang Astronomical Observatory, Nanjing University, Beijing Normal University, Qilu Normal University and other institutions have also made positive contributions to the discovery of pulsars using FAST.

Image source: China Science Expo

Why do you run sometimes?

Will it feel like being drunk?

Running and drinking produce similar "high" feelings, mainly because both can trigger the release of certain neurotransmitters in the brain. When running, the secretion of endorphins increases, which is a natural analgesic produced by the pituitary gland that can relieve pain, increase pleasure, and make people feel less tired.

However, what really makes people addicted are endocannabinoids, substances produced naturally in the body that, despite not being related to the cannabis plant, produce similar effects to smoking marijuana.

Unlike endorphins, which mainly act on the cerebral cortex, endocannabinoids can cross the blood-brain barrier and directly affect the brain areas that control appetite, mood and pain, so they are called "endocannabinoids."

In addition, running promotes the secretion of dopamine and adrenaline, bringing a sense of accomplishment and excitement, which is similar to the relaxation after drinking. With the increase in heart rate and the increase in blood circulation and oxygen supply throughout the body, running helps improve the vitality level of the brain and body, further enhancing the feeling of being "awake" or "high".

Image source: pixabay

It's not easy for an octopus to stay at home.

Hide in a cave and rest to save energy!

Octopuses are known for their amazing camouflage and ability to communicate with their rapidly changing skin colors. But the process by which an octopus changes hue or maintains color requires considerable effort, according to a study published Nov. 18 in the Proceedings of the National Academy of Sciences.

According to the study, which is the first to quantify how much work it takes to fire up chromatophores, the octopus expends the same amount of energy activating its color-changing system as it does maintaining all other aspects of its resting metabolic rate, including digestion, respiration, organ function and circulation.

To quantify the amount of energy required to change color, the scientists took small skin samples from 17 living ruby ​​octopuses. They temporarily anesthetized the octopuses with alcohol to allow small biopsies to be performed with minimal discomfort.

In repeated experiments, the scientists exposed each piece of skin to both darkness and light conditions, while the skin was still fresh and the cells were still alive and responsive, alternately deactivating and expanding the pigment cells. When the pigment cells expanded, the skin samples' oxygen consumption spiked.

The scientists estimate that the total energy required to activate the chromatophores is roughly equivalent to the energy required to maintain all other physiological processes in the animal at rest. The researchers believe that the energetic cost of color change could explain why octopuses spend so much time hiding in burrows.

Coconut Oil for Weight Loss Myth?

Don’t get too excited before the research is finalized!

After buying a coconut and drinking coconut milk, you can see a thick, chewy, white coconut meat on the inner wall of the coconut. This layer of coconut meat has a high fat content, and the oil extracted from it is what we call coconut oil.

The reason why coconut oil helps you lose weight is that it is rich in "medium-chain fatty acids (MCTs). This type of fatty acid has a relatively short carbon chain (8 to 12 carbons) and is believed to be able to be quickly decomposed and absorbed, so it can quickly provide energy without storing fat. Other commonly used vegetable oils are mainly "long-chain fatty acids" and are prone to fat accumulation.

Whether medium-chain fatty acids can really help lose weight, the current research results are inconsistent. Although some experiments have found that they can increase satiety and reduce food intake, and some studies have found that medium-chain fatty acids may help reduce waist circumference and weight, other studies have not found a significant weight loss effect.

Therefore, although medium-chain fatty acids have a good prospect for weight loss, more high-quality research is needed to verify it. Even if medium-chain fatty acids are proven to be beneficial for weight loss in the future, it does not mean that coconut oil can help lose weight. Because coconut oil is not pure medium-chain fatty acids.

Although coconut oil contains 54% medium-chain fatty acids, the majority of them are lauric acid (C12), while C8 and C10, which can help lose weight, only account for 12%. Coconut oil itself is 99% fat, which is very high in calories! Therefore, if you rely on coconut oil to lose weight, you may not lose weight, but gain a lot of fat.

Image source: pixabay

I have seen too many tunnel boring machines moving sideways.

Come and see it walking vertically!

The "Dream Chaser" shaft boring machine is a highly efficient construction equipment that integrates mechanical, electronic and hydraulic technologies and is designed specifically for shaft construction. The excavation diameter of the equipment ranges from 6.5 meters to 8.0 meters, the main machine weighs 270 tons and is 27 meters high.

The content is compiled from China Science Popularization Expo Weibo, National Astronomical Observatory of the Chinese Academy of Sciences, Institute of Physics of the Chinese Academy of Sciences, Science Academy, Science Rumor Refutation, Science Popularization China

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