The reason why chewing gum can break open coconut shells is because the gum base component contained in chewing gum belongs to shear thickening fluid; If you gently press the chewing gum, it will feel sticky and soft to the touch, but if you hit it quickly, the chewing gum will instantly harden, and with the reaction force brought by the impact force when hitting the coconut hard, it is not surprising that the coconut shell will be punctured in minutes.

In daily life, we can also easily make a shear thickening solution, such as water starch formed by mixing corn starch with water. When stirring with a spoon, it will be found that with the increase of stirring speed, the difficulty of stirring is also increasing; Poke the surface of water starch hard and quickly with a spoon, but it can't be poked; But if you put a spoon on it, it will sink slowly.

Shear thickening liquid is widely used in practice. In the field of scientific research, the liquid bulletproof vest made of this fluid property is more comfortable to wear and has better bulletproof effect than the ordinary fiber bulletproof vest.

Main varieties of coconut:

Coconut trees are monocotyledonous plants, which can usually be divided into two types: cross-pollinated high-grade coconuts and self-pollinated low-grade coconuts. Cross-pollinated high-grade coconut: the trunk is as high as 15-25m, which begins to bear fruit in 6-8 years under good conditions and has a life span of more than 80 years. It is the main cultivated variety in China. According to the size and shape of fruit, it can be divided into large round fruit, medium round fruit and pedicled fruit, with pedicled fruit being the best.

Among the above three fruit types, they are divided into green coconut and red coconut according to fruit color, among which green coconut is common. Self-pollinated dwarf coconut: the trunk height is about 5- 12m, it begins to bear fruit in 3-5 years, and its life span is 30-40 years, so it is rarely cultivated in China.

According to the fruit color, it can be divided into three types: Pu Milla, abel Virginia and Regia. The advantages of dwarf coconut are early fruiting, more fruits, early maturity and short growth.