Why are there so many varieties of chrysanthemums? Because they have found their "Bo Le"｜Bo Lan Daily

There are many varieties of chrysanthemums , because they have found their mentor.

In autumn, chrysanthemum exhibitions across the country must have attracted the attention of friends. But do you know that chrysanthemum is a rare flower in the flower kingdom?

In the 1,600-year history of cultivation in China, chrysanthemum has been integrated with rich cultural connotations, and through superb cultivation technology, more than 30,000 varieties have been formed around the world. Its rich variation is called a miracle in the history of horticultural breeding and is the common wealth of all mankind. So who gave chrysanthemum such excellent and precious genes?

After years of research by scientists, chrysanthemums mainly originated from wild plants of the genus Chrysanthemum, such as hairy chrysanthemum, wild chrysanthemum, and chamomile. These plants all come from the mountains and have tiny flowers. They may be the original father or mother of chrysanthemums, or just distant relatives of chrysanthemums; they form complex and extensive natural hybridization through wind or insects, giving chrysanthemums an unpredictable personality.

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When humans intervened in this process, the varieties of chrysanthemums have exploded exponentially. The genes of the chrysanthemums that people see today have been selected and reorganized by generations of people. It can be said that the wild chrysanthemums in China and generations of breeders have jointly achieved the glory of chrysanthemums.

Can π be calculated completely?

From ancient times to the present, mathematicians have expected that π will have some special properties, such as being calculated to the end, repeating after a certain position, or being expressed as some simpler algebraic expressions.

However, this hope was severely shattered by the group theory founded by Galois mentioned in the previous article. This theory shows that π is a transcendental number, that is, it is not the root of any algebraic equation, and it cannot be expressed in the form of an algebraic expression composed of algebraic numbers of finite length. We can only use the infinite series or integrals mentioned above to accurately represent the value of π.

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However, the mathematical community has a new conjecture about π. They believe that π is a "normal number", which means that the probability of each number appearing in π is equal. This conjecture has not been proven.

Currently, the calculation of pi is mainly to test the computing power of supercomputers. Like the search for Mersenne primes and twin primes, the calculation of pi is a "big test" that supercomputers must go through.

However, even the most powerful computers cannot fully calculate it. There are still infinite secrets hidden in π, waiting for humans to explore.

Five times a year ! Why are earthquakes so frequent in Anhui?

According to statistics from the earthquake information broadcasting robot, there have been five earthquakes of magnitude 3 or above in Hefei, Anhui Province this year. Why are there so many earthquakes in Anhui Province?

The Anhui region is affected by the Pacific and Indian plates, and is squeezed in the east-west direction, which can easily lead to faults in the northeast and northwest directions. Liangyuan in Feidong, Hefei is located at the junction of the northeastern Tanlu Fault and the nearly east-west Feidong Fault. Under the joint action of the stress field, it is easy for small and medium-sized earthquakes to occur frequently. The Hefei earthquake is currently in a state of multiple earthquakes, manifested as repeated activities of medium-sized earthquakes. The current situation is more like a swarm earthquake (a situation in which a specific small area frequently experiences small and medium-sized earthquakes in a relatively short period of time is called a swarm activity). What is certain is that when an earthquake occurs, some of the accumulated energy will be released.

Is it toxic to use cassava flour instead of sweet potato flour?

Cassava is an alien species and is now widely planted in tropical and a few subtropical regions. It is only cultivated in southern China. Moreover, cassava is not usually eaten fresh, and there is rarely any fresh cassava available on the market. Therefore, it is not surprising that most of us have never seen cassava and feel unfamiliar with it.

Cassava is very suitable for cultivation in Africa due to its high yield, drought resistance, and resistance to barrenness, as well as good environmental adaptability. Today, cassava has become one of the most important food sources in Africa.

However, cassava cannot be eaten directly because the whole plant contains toxic ingredients, linalool and radix oleifera, which produce free hydrocyanic acid after being hydrolyzed by gastric acid, causing human poisoning. Hydrocyanic acid is also known as hydrogen cyanide, which may be more familiar to everyone. Its potassium salt, potassium cyanide, is a common toxic prop in TV dramas.

But rest assured, as early as the Indian period, humans had already mastered the method of detoxifying cassava roots. Since linseed glycosides and radix sutchuenensis glycosides are easy to decompose, as long as the roots are soaked, peeled, and then steamed or dried and ground into powder, they can be eaten normally.

The edible root of cassava is usually used to make cassava flour (starch). Most of the cassava varieties available in China are cultivated varieties, and after processing, the root can be eaten.

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The content is compiled from China Science Popularization Expo Weibo, Jimu News, Dingdian News,
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