Popular science manuscript 1 popular science manuscript 2 popular science manuscript 3 popular science knowledge of primary school students:
Why do the stars twinkle?
We see the stars shining, not because the luminosity of the stars has changed, but because of the occlusion of the atmosphere. The atmosphere is between us and the stars. When starlight passes through the atmosphere, it will be affected by the density and thickness of the atmosphere. The atmosphere is not absolutely transparent, and its transparency will change according to its density. So when we look at the stars through it on the ground, we will see that the stars seem to be flashing.
Why do sunflowers always bloom towards the sun?
The stem under the sunflower disk contains a substance called auxin. This substance has the function of accelerating replication, but it is anti-optical, and it will run to the backlight side whenever it encounters light.
So when the sun rises, the stem of the sunflower immediately hides to the side of the backlight, as if the whole plant is bent in the direction of the sun.
Why do fireflies glow?
Fireflies emit light because there is a luminous body at the end of their abdomen, which is filled with a lot of phosphorus-containing luminescent substances and luminescent enzymes, so that fireflies can emit flashing light. The purpose of fireflies is not only lighting, but also courtship, vigilance and trapping. This is also a communication tool for them. Different kinds of fireflies emit light in different ways, frequencies and colors, so they can convey different information.
Why is the squirrel's tail so big?
Don't look at the relaxed mouse tail! When the squirrel jumps around the tree, its tail plays a great role. It can keep balance when the squirrel jumps to the tree to avoid falling and being injured. In addition, this big tail can play a more protective role in winter, tightly surrounding the squirrel's body, which is convenient and practical.
Why is the sea mostly blue and green?
Looking at the sea, it is often found that the sea water is blue-green. However, when you pick up the sea water, you can only see it as transparent and colorless as old water. It turns out that the seawater itself is not much different from the water we touch every day, and it is also transparent. What we see, green, is actually a phenomenon produced by the ability of seawater to absorb light. Only green light can be absorbed and reflected by seawater; When the seawater is deep, the green light is also absorbed, and the seawater looks blue.
Why do leaves change color?
The reason why leaves change color is related to the chemical substance chlorophyll. When autumn comes, the days are shorter and the temperature is lower than that in summer, so the leaves stop producing chlorophyll, and the remaining nutrients are transported to the trunk and roots for storage. Leaves lack green chlorophyll and other chemical pigments appear at the same time, so we often see yellow and brown leaves.
Why does sorbet get angry?
The reason why sorbet bubbles is because there is a lot of invisible water vapor in the outside air. When it comes to cold sorbet, it will liquefy into droplets when it is cold. It seems that the sorbet is bubbling.
Popular science methods to deal with motion sickness and seasickness
Motion sickness (also known as motion sickness) is a general term for motion sickness, seasickness and airsickness. ) can be caused when riding various means of transportation. Sometimes it will suddenly attack you, accompanied by uncomfortable feelings, such as cold sweat, dizziness, vomiting and so on. Once you leave the environment that causes motion sickness, the situation will improve immediately. The more times you travel, the easier it is for you to adapt to this environment.
Before going out, you'd better make some plans in advance to prevent carsickness. If you travel, reserve the seat least likely to cause motion sickness:
When taking a boat, book a cabin in the front or middle of the boat or above the deck.
When flying, reserve a seat above the leading edge of the wing. After boarding the plane, let the air hole in the window face your face directly.
When taking the train, book a window seat facing the front of the train.
When riding, drive or sit in the passenger seat by yourself.
If you have symptoms of carsickness, then:
Keep your eyes on the distant horizon or still life, and don't read.
Keep your head still and lean against the seat back.
Don't smoke or sit next to smokers.
Avoid spicy food and alcohol, and don't be full.
Before feeling unwell, take an over-the-counter cold medicine (such as Maiqimin), an antiemetic medicine (Antivete and Bonin) and a pill (Halotamine).
If you want to sleep, you can take a piece of scopolamine (produced by TransdermScop). You can also use some mucous membranes. Stick these pills behind your ears a few hours before you go out to ensure that you won't get carsick for 72 hours. Patients with asthma, glaucoma or urinary retention should consult a doctor before taking these drugs.
When you feel sick, you can eat some biscuits or drink carbonated drinks to make your stomach feel better.