Scientific knowledge is all around us, see if there's anything you don't know

Scientific knowledge is all around us, see if there's anything you don't know

@what you see is very scientific

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Why is sky dark at night?

This is a well-known problem in classical cosmology. Since ancient times, people have been building various conjectures about universe. People in ancient times thought that stars were laid out on a transparent sphere. The ancient theory of structure of universe in China The main idea of ​​the theory of Haiti is that sky is round and earth is round. The geocentric system of Ptole universe and system of heliocentric universe of Copernicus include contents of stars and celestial spheres. The medieval thinker Nicholas believed that universe is infinite, and Newton Taking infinity of space and time as basic principles of his theory, he also came to conclusion that number of stars must be infinite and distributed fairly evenly in space. Observations showed that famous British astronomers William Herschel and John Herschel and his sons announced that at least some observable nebulae are systems of discrete stars with same scale and structure as Milky Way. These galaxies live throughout universe. Astronomers in 19th century generally believed that observable universe should be static, infinite and uniform.

A well-known objection to a static, infinite, and uniform universe is nighttime problem, also known as Olbers paradox.

This paradox lies in fact that if light emitted by stars is constant and same, and space is Euclidean (flat), then brightness of entire sky in such a universe will appear same and bright, like sun. .

Because no matter which direction you look at sky, there will be a star in your field of vision.

This can be illustrated with a simple geometric argument: Consider a thin cone of light entering human eye. Although apparent brightness of a star's surface is inversely proportional to square of distance, cross-sectional area of ​​the cone (or number of stars) increases with square of distance, light concentrated in cone has nothing to do with where it comes from, so entire sky will be as bright as sun, but in fact night sky is black, how can we eliminate observation and what about conflicts between theories?

Olbers' conclusion is based on following cosmological point of view:

1. The universe is infinite.

2. Matter in Universe is evenly distributed.

3. The universe is static.

4. The universe exists for an infinite time.

To avoid conclusion that night sky is as bright as sun, we must reconsider above point of view. A hierarchical model of universe, whose average density decreases with observation distance and takes zero as limit, can eliminate paradox. But you have to pay a price for loss of uniformity, but results of observations so far are as follows: distribution of cosmic matter in large-scale space is uniform and isotropic. This view is called cosmological principle, which underlies modern cosmologeic theories. The axiom of first point mentioned above corresponds to principle of cosmology and should be preserved, so that hierarchical model of Universe should be abandoned. Since Olbers believes that luminosity of stars is constant, this point seems to be most problematic by far.

If we assume that stars are not always so bright, but only began to shine in finite past, since light of distant stars has not yet reached us, then this also avoids conclusion that entire sky is bright as sun, which leads us to this: Since question of what made stars shine, a universe with a finite past seems to escape Olbers' fallacy.

At this point, universe has a beginning in time, and another universe with a sufficiently fast expansion rate can avoid Olbers' paradox, even if it has an infinite past.

Since, according to quantum theory, energy of a photon is proportional to its frequency, and light of a distant high-speed light source will produce a very large redshift, so its energy will be reduced accordingly, so that amount will remain limited or even possible, it can be ignored.

Since there are no grounds for rejecting cosmological principle, first point of view should be accepted, while second and fourth should be reconsidered.

In early 20th century, Einstein created general theory of relativity, which served as a theoretical basis for studying general structure of universe.

The general nature of Universe is determined by gravitational field equation. The Dutch physicist de Sitter first obtained a cosmic solution to gravitational field equation, but it is dynamic and cannot be static: Universe either expands or contracts.

During observations, Hubble found that radial receding velocity of extragalactic galaxies is proportional to distance, that is, farther distance, greater radial velocity, which shows that distance between any two galaxies in universe increases, and universe expands.

If expanding universe goes back in time, it will reach its original superdense state, i.e. universe was created at some point in past as a result of a big explosion of primordial matter.

This is cosmological model of Big Bang.

In order not to contradict theoretical predictions and experimental observations, Universe experienced a stage of inflation at very beginning.

Obviously, an expanding model of Big Bang Universe with a finite past can avoid Olbers paradox, and a stationary model of Universe with an infinite past can eliminate paradox, but violate law of conservation of energy. It cannot explain cosmic microwave background radiation, etc., which is no longer accepted by humans. Thus, observed expansion of universe is scientific.

It is generally accepted in academic circles that big bang cosmological model, which is experiencing an inflationary phase, is a successful model, and its theoretical predictions are in good agreement with experimental observations.

Obviously, this is a dynamical cosmological model, and Universe can have a beginning in time. From this point of view, for a homogeneous, static and infinite classical cosmological model, second and fourth points of view are invalid.

If you discard those two, you naturally won't come to absurd conclusion that night sky is as bright as sun.

Do you see end of world?

When an outside observer sees me slowly falling into (a black hole), they might think it's reasonable to conclude that I'll see universe gradually accelerating - I see that this is end of universe.

This is not true, however.

What an outside observer sees about me depends on light I emit, and what I see depends on light that enters my field of vision.

Light from things far in future doesn't reach my vision at all.

An event in an arbitrary distant future never stops at my "historical light cone" (the edge of which consists of rays that can reach me within a certain amount of time).

The above may be true for an uncharged spinless black hole, but not for a charged or spinning black hole.

In ideal case, such a black hole could contain a "time wormhole".

The hole can serve as a portal to other isolated areas (which could be another universe).

Instead of going into a singularity, I'm going through a wormhole.

But entering a wormhole that is inside a kind of event horizon creates an infinite acceleration phenomenon.

If I were to fall into a wormhole, I would see entire history of universe playing out before my eyes from beginning to end. Moreover, as "movie" plays faster, light starts shifting to blue and energy starts to increase. The moment I pass through wormhole, there is an "infinite blueshift" and its strong radiation will send me to Freeda.

Apparently there is reason to believe that this infinite blueshift will mean demise of wormhole itself, which will be replaced by a singularity that, in my opinion, is not much better.

But either way, it casts doubt on journey through wormhole.

Topics raised by planets

The definition of planet has been questioned lately, perhaps because in past we have been too casual in naming it. With increase in number of new scientific discoveries, scientists began to rethink: what celestial body can be called a planet?

Since discovery of first planet orbiting another star in 1995, scientists have discovered more than 50 planets outside our solar system.

They differ from planets we know in that they are huge - often many times size of Jupiter - and more like another class of stars, brown dwarfs.

Brown dwarfs, whose existence was confirmed in 1995, are massive, but not large enough to form stars as a result of thermonuclear reactions.

These brown dwarfs don't glow like planets and can also orbit their stars, but they don't have many planetary characteristics. They are 5 to 15 times size of Jupiter and have same size range as planets.

With this collection of previously undiscovered objects, our understanding of planetary composition and stellar masses is changing.

Currently, under leadership of Alan Boss, a group of experts of International Astronomical Union, consisting of 13 people, is working on definition of concept of "planet".

Astronomers believe there are still three questions between planets and brown dwarfs: their origin, orbit, and size.

If definition of a planet is based on textbooks, then general statement is that after formation of a star, a vortex consisting of gas and solid dust emitted from it gradually forms a planet.

This is how we explain formation of nine planets in our solar system.

However, Tarter, who once proposed concept of a "brown dwarf" in 1975, believes that planets cannot be determined solely by process of formation.

A planet orbiting a star should also be taken into account when determining a planet, she suggests.

The problem is that brown dwarfs meet both of above "planet" criteria.

They often orbit their stars, which means that brown dwarfs are formed from gas and solid dust.

At center of current debate is size of star.

If a brown dwarf were 13 times size of Jupiter, pressure inside it would be enough to burn deuterium.

But planets can't burn deuterium. Therefore, people usually divide boundary between stars and planets by whether deuterium burns.

What about brown dwarfs, which are smaller than planets?

A star is a star because it is capable of emitting light by converting hydrogen into ammonia through fusion reactions.

Brown dwarfs, although they can burn to carry out "core melt" reaction, cannot provide fusion process required for thermonuclear reaction that occurs in stars.

But brown dwarfs can, like stars, form when another disordered cloud of gas or dust collapses under gravity.

Many scientists believe that Pluto should not have been called a planet at all.

It is much smaller than other planets and is located under a significantth angle to plane of orbits of other planets around Sun.

Pluto is also far from Neptune's orbit, and researchers believe it is likely part of Kuiper Belt, a remote region of frozen rock that was confirmed to exist in 1992.

In early 1999, International Astronomical Union attempted to give Pluto dual status as a planet and an object orbiting Neptune, but proposal was shelved due to objections.

Smaller objects in solar system, including comets, are also known as asteroids.

And there is a strong possibility that other objects larger than Pluto are also orbiting Sun.

Even definition of a star can be ambiguous.

Some experts believe that stars, like planets, are also formed by vortices.

This often happens in binary star systems, where one star is formed and another is formed from its remnants.

Look again at definition of a planet.

Recently, astronomers have proposed two hypotheses for formation of free-floating planets.

First, these planets formed in a planetary system around a star, and then separated from that system after it formed.

On other hand, stars formed alone or were not attached to any stars early in their formation process.

Astronomers believe that no matter how it is formed, existing explanations and definitions are not enough.

New explanations and new definitions are needed to help people more clearly and accurately distinguish planets from other bodies.

Perhaps we can define a planet as follows: "A planet is a spherical star, core of which cannot melt, forming and revolving around another star, core of which sometimes undergoes melting."

Asteroids really are. is it dangerous

In September of this year, two astronomers in Hawaii discovered that asteroid 2000SG344, about 0.6 km in diameter, was orbiting Earth.

November 3, some research scientists announced to media that an asteroid could collide with Earth in 2030 without conducting an in-depth analysis of planet.

But just a day later, some other scientists said that above news was suspected of exaggeration. After further research into orbit of this asteroid, they believed that closest distance when it "passed by" Earth was also as much as 5 million kilometers, it was impossible to collide with earth.

However, asteroid 2000SG344 is first asteroid ever to have an impact level greater than 0.

The Turin scale from 0 to 10 is used to measure danger of a celestial body colliding with Earth.

The International Astronomical Union has warned that there is a 1/500 chance of an asteroid hitting Earth on September 21, 2030. No other celestial body has ever been found to have such a high probability of colliding with Earth. .

Back in 1991, astronomers announced that nine celestial bodies were in space near Earth and could pose a threat to humans.

Since then, number of objects declared dangerous has continued to increase.

Scott Stewart, a researcher at Massachusetts Institute of Technology in United States, believes that we have grossly underestimated number of near-Earth asteroids.

According to previous assumptions, there are between 750 and 900 asteroids that orbit Earth and can collide with it.

The result of his calculations was that there are more than 1100 asteroids in solar system that could pose a threat to Earth.

The late astronomer Eugene Shoemaker came to a similar conclusion by studying number of craters left by asteroid impacts on Moon.

With help of radio telescopes, astronomers map celestial bodies and track trajectories of asteroids.

Using a fixed star as a reference object, you can find moving celestial bodies.

By observing an asteroid's trajectory for several months, you can calculate its orbit and determine if it poses a threat to Earth.

Usually, list of dangerous objects that can cause serious global catastrophes includes only those asteroids whose diameter exceeds 1 kilometer.

The problem is that no one knows how many undiscovered asteroids there are.

Stuart recalculated tilt of asteroid using data from LINEAR telescope.

The so-called tilt refers to angle between asteroid's orbit and plane of Earth's orbit around Sun.

The number of asteroids has been underestimated in past because objects in low inclination orbits are easier to observe.

Over past two years, more than 400 near-Earth asteroids have been discovered under golden sky of LINEAR telescope.

Thankswith its clairvoyant abilities, astronomers can more accurately map distribution of asteroids in high and low inclination orbits.

UK Science Minister Sainsbury said that however remote this danger may be, we cannot ignore it, but must monitor situation through international cooperation.

Scientists at UK's Institute for Nuclear Weapons Research and their European partners are studying how nuclear weapons can be used to deflect an asteroid's orbit.

Scientists plan to develop a system in which a series of nuclear warheads explode on one side of an asteroid, using intense neutron radiation generated by explosions to knock out part of asteroid's surface, thereby altering its orbit, providing According to Consulting Senior Weapons Expert Nigel Holloway, it would take a nuclear warhead equivalent to 100,000 bombs dropped on Hiroshima to deflect an asteroid 1-2 kilometers in diameter.

However, Chinese scientists believe that there is no danger from asteroids.

Astronomers at Purple Mountain Observatory of Chinese Academy of Sciences have noted that an asteroid larger than 2,000 meters in diameter is only likely to hit Earth once every 500,000 years.

The International Near-Earth Object Research Institute has accurately calculated orbits of more than 200 out of 900 asteroids, none of which will hit Earth.

They also specifically told public that there will be asteroids in 21st century that will "approach" Earth three times, but second and third times were asteroid 2340, which flew over 1 million kilometers from Earth. earth in 2069 and 2086 respectively, and they did not pose a threat to earth.

Of course, this does not mean that our monitoring of asteroids will be reduced.

Wang Qi, a researcher at Purple Mountain Observatory, said that asteroid 2000QW7, which recently passed Earth, shocked astronomical community.

Scientists only noticed it 5 days before it "slid" across ground.

After false alarm, astronomers once again pointed out that there are still many gaps in international network for observing near-Earth space asteroids, and in many countries, including China, sufficient monitoring equipment is still lacking.

The first near-Earth object detection telescope built by Ministry of Science and Technology and Chinese Academy of Sciences with an investment of nearly 20 million yuan is expected to be assembled at Purple Mountain Observatory in 2002. still inactive international space warning network.

British astronomers have discovered that second moon revolves around Earth every 800 years.

In 1999, British astronomers discovered that a second moon was orbiting Earth. Although this "moon" makes one revolution around Earth in almost 800 years, it is very helpful in studying stars of solar system.

The moon is heavena body that revolves around earth.

British astronomers have pointed out that second satellite is a star named "Kratni", which has become another satellite of Earth.

Krutni has a diameter of only 3 km and an eccentric orbit. It orbits Earth in 770 years and is expected to last at least 5,000 years. Astronomers have pointed out that Clutney is in such an orbit that it is almost impossible to crash into earth.

He said, "We don't need to worry about every asteroid impact with Earth, because they can all be in eccentric orbit of Earth."

Eight mysteries of solar system

The first riddle: how Mercury was born.

There are two versions:

1. Since Mercury is closest to Sun, scientists believe that Mercury is located in high-temperature region of solar system's primordial nebula, which is formed by an accumulation of solidified metallic iron and other material-rich materials.

2. Mercury was formed when giant protoplanets collided and fused each other's metallic iron.

Riddle 2: Why is Venus so hot?

According to observations, Venus is a hot world with a surface temperature of about 450 °C.

Riddle 3: Is moon moving further and further away from Earth?

The moon is slowly moving away from Earth at a speed of about 3 centimeters per year.

On other hand, speed of Earth's rotation is gradually slowing down.

Riddle 4. Do Martians really exist?

In August 1996, a NASA research team published research findings suggesting that there is life on Mars, as evidenced by a Martian meteorite that fell on Antarctic continent.

The fifth riddle: why does Jupiter have a Great Red Spot?

The Great Red Spot, located in Jupiter's southern hemisphere, has been observed for over 300 years.

A large red spot size of two Earths.

Riddle 6. Why do gas satellites have rings?

Jupiter, Saturn, Uranus and Neptune have rings, and they are different.

The reason for ring, one of which is that a satellite or comet that existed in past was destroyed by planet's tidal force and broke into small fragments. Some of fragments went into orbit around planet, thus forming a ring.

Riddle 7: What is beyond Pluto?

It was previously thought that there might be a tenth planet beyond Pluto.

Riddle 8: Where is end of solar system?

Scientists say Sun is spewing high-energy charged particles known as "solar wind".

The range of solar wind extends beyond Pluto's orbit, forming a huge magnetosphere called "heliosphere".

The final state of solar circle is called "top of solar circle. layer", which is farthest point dominated by sun, and which can be considered astowards end of solar system.

Earth will eventually dry up like Mars

Earth's oceans are drying up, and there's nothing we humans can do about it.

This is latest warning from a group of Japanese geologists.

Each year, as a result of movement of earth's crust, more than 1 billion tons of sea water is ejected into mantle, almost all of which is absorbed by rocks.

As a result, one day Earth will dry up like Mars.

Geologists from Tokyo Institute of Technology in Japan have compiled a detailed assessment of flows and cycles of matter between earth's crust and earth's crust. The above pessimistic conclusions were made.

About 46 billion years ago.

Shortly after formation of our Earth, there were minerals and inorganic substances directly under earth's crust, and they were too hot.

Water cannot be held.

Later, about 750 million years ago, minerals cooled down enough to be able to carry water, carry it deep into earth and bury it there permanently.

Sea levels are estimated to have dropped by about 2,000 feet since then.

Like this, a billion years later.

Oceans on Earth will disappear.

They think a similar process happened on Mars.

Because Mars is smaller than Earth, it gets colder and dries out faster.

About 2-3 billion years ago, it completely dried up.

These ideas could inspire biologists who study evolution of life.

For example, environmental changes that followed initial loss of seawater likely caused Cambrian explosion of species.

And eventually led to appearance of people.

(Fang Cunzheng) There may be eight new planets in solar system European astronomers have released a research report saying there are indications that there may be eight planets orbiting a star outside known solar system, some of which may be more than Jupiter even more.

These latest discoveries bring number of potential planets outside our solar system to over forty.

Since last year, astronomers have begun a massive study of sun-like stars in universe and possible planets around them.

The last signs of planets were discovered by a team of Swiss astronomers at La Silla Observatory in Chile, South America.

While all possible planets are still out of human sight, scientists said in a statement that they have discovered possible planets that scientists believe do exist.

Of eight existing planets, two may not be planets, but black dwarfs. Three of these eight stars are similar in size to Saturn, three are one to three times size of Jupiter, and two are ten times size of Jupiter, or even better.

Scientific facts Why does sherbet float?

Sorbet smokes because there is a lot of invisible water vapor in outside air. When it encounters a very cold sherbet, it turns into mist and surroundst sherbet when it's cold. It seems that sorbet "gassing" "The same.

Why do sunflowers always face sun?

Sunflower stems contain wonderful auxin. This auxin is very sensitive to light.

Once light starts to shine, it goes to backlight side, and at same time, it stimulates cells on backlight side to multiply rapidly, so backlight side grows faster than light side, which makes sunflowers phototropic bends.

Why do cicadas shed their skin?

The shell (exoskeleton) of cicada is hard and cannot expand as cicada grows. When cicada grows to a certain stage, cicada's exoskeleton restricts cicada's growth, and cicada removes original exoskeleton, this is cicada's swamp.

How do bees make honey?

The bees first spit sweet juice from plucked flowers into empty hive. At night, they suck sweet juice into their honey stomach to cook it, then spit it out and swallow it again. It takes 100 to 240 times before it turns into sweet honey.

How Wu sleeps

During day, birds flutter and sing on branches and fly freely in blue sky, and at night they have to rest, sleep and recuperate just like us, but their sleeping positions are different!

Beautiful mallards and swans hunt and play in water during day, and at night they cannot do without their favorite water surface during their rest.

They bend their beautiful long necks, hide their heads in their wings and let themselves float on water, dreaming of sweet dreams, floating with flow, so leisurely.

Long-legged birds, such as cranes, storks and herons, always sleep on one leg independently of each other, and when tired they switch to other leg, which is an example of combining work and rest.

When partridges are resting, they like to form a large circle in groups, head out and tail in.

Thus, no matter which side enemy comes from, he will be able to detect him in time and hide.

Thrushes, larks, and other melodious birds usually bend their legs while they sleep, and their claws bend to hold branches tightly, so you don't have to worry about them falling out of tree.

As for owl, predator of "night shift", you can always see it with one open and one closed eye, standing on a thick branch during day, but in fact it sleeps at this time.

Isn't sleeping position of an owl very different? It is like observing environment and defending against enemy attacks!

Do fish drown too?

Fish have gills and can breathe in water, and fish have a swim bladder and can swim freely in water.

However, some people say that fish that live in water can also drown. This is true?

While this may sound funny, it's true. The swim bladder is "lifeline" for fish swimming, and it can regulate specific gravity of fish's body by inflating and deflating.

Thus, fish require only minimal muscle activity when swimming, and it can maintainbe stable and will not sink or float in water.

However, when a fish dives to a certain depth ("critical depth"), enormous external pressure prevents it from reducing volume of its swim bladder.

At this time, buoyant force he receives is less than his own gravity, so he involuntarily sinks to bottom of water, can no longer float, and finally sinks because he can't breathe.

While fish can still float by wagging its fins and tail, it won't help if it sinks too deep.

On other hand, deep sea fish can live freely in deep water because their bones can withstand a lot of pressure.

If we quickly raise a deep-sea fish above "critical depth" because pressure inside its body cannot be balanced by less pressure outside, it will continue to "expand" until it floats to surface above .

Sometimes it will even spit out its internal organs and "explode" to its death.

Gluttony children become stupid Gluttony reduces blood flow to brain

If you eat too much at one time or eat without stopping, a large amount of blood in human body, including blood from brain, will be mobilized into gastrointestinal tract.

Adequate blood supply is a prerequisite for development. If he is often in a state of ischemia, this will inevitably affect his development.

Greedy eating will lead to "fat brain" overeating, especially if you eat too many highly nutritious foods, calories you eat will greatly exceed calories you consume, and heat energy will be converted to fat and stored in body.

If there is too much fat in brain tissue, it will result in a "fat brain".

Studies have confirmed that human intelligence is related to number of furrows and folds in brain. The more obvious furrows and folds of brain, higher level of intelligence.

In an obese brain, grooves converge, wrinkles disappear, cerebral cortex is smooth, and neural network development is also poor, so level of intelligence is reduced.

Greed can inhibit physiological function of intelligent area of ​​the brain. The mode of activity of human brain is mutual induction of excitation and inhibition, that is, when certain parts of brain are excited, some parts of parts adjacent to it are in a state. The greater excitation, more inhibition deepens in surrounding parts, and vice versa.

Therefore, if autonomic nerve center responsible for digestion in gastrointestinal tract is excited for a long time due to gluttony, this inevitably causes inhibition of adjacent intellectual areas of brain, such as language, thinking, memory and imagination.

If these areas are often suppressed, intelligence will get worse and worse.

Greedy food can damagebrainwash due to constipation. Children's snacks mainly consist of high-quality, high-nutrient foods that are prone to constipation.

With constipation, metabolites accumulate in digestive tract for a long time, and after action of intestinal bacteria, a large amount of harmful substances are produced that are easily absorbed through intestines, enter bloodstream, and stimulate gastrointestinal tract. brain, cause chronic poisoning of brain nerve cells and affect normal development of brain.

Gluttony also contributes to premature aging of brain.

Scientists in a study found that a substance that can contribute to premature brain aging, fibroblast growth factor, will increase tens of thousands of times after eating due to overeating, which is a substance that can promote atherosclerosis. Therefore, in long run, overeating will cause brain to age prematurely.

Easy-to-learn scientific knowledge The secret of automatic rotation

I think: why does water box turn over?

Materials: empty milk bag, nails, 60 cm of rope, sink, water.


1. Poke five holes in an empty milk carton with a nail

2. One hole is in middle of top of box, and other four holes are in bottom left corner of four sides of box

3. Tie a rope about 60 cm long to top hole

4. Put box on a plate, open mouth of box and quickly fill box with water.

5. Lift rope at top of box with your hand and box will rotate clockwise

Explanation: The flow of water creates a force of equal magnitude and opposite direction, and all four corners of box are subject to this thrust.

Because this force acts on bottom left corner of each side, box rotates clockwise, creating:

1. If you make a hole in center of each side, how will box rotate?

2. If holes are located in lower right corner of each side, in which direction will box

of boat and oars rotate

Thinking: Have you seen boat ride? Rowing boat yourself? Do you know why boat moves forward on water?

Materials: 1 scissors, 1 piece of cardboard, 1 piece of rubber band, 1 washbasin and 1 basin of water.


1. Cut out cardboard to approximately 12 x 8 cm in length

2. Trim one end into a pointed shape like a bow and cut a gap of about 5 cm in center of other end like a stern.

3. Cut a piece of cardboard about 3 x 5 cm to fit paddle

4. Wrap a rubber band around stern and tie oars

5. Turn cardboard paddle counterclockwise to tighten elastic and boat will move forward

6. If cardboard spatula is turned clockwise to tighten elastic, boat will move backward. Description:

1. Resinks are twisted in different directions, and boat goes in opposite direction.

2. The power of paper boat comes from torsion energy of rubber band.

When buying a dead chicken, first look at chicken's eyes. If eyes are half closed, it is not a live chicken to be slaughtered; if eyes are closed, it is a sick and dead chicken.

If skin, meat, fat, and innards of a diseased pork have bloodstains or blood stains, it is usually a diseased pig.

Water injection beef, if color of meat is light red and white, looks very tender, water droplets slowly flow out of it, it is not sticky to touch, it has white paper pasted on it, and it will be soaked in water soon, i.e. beef with water injection.

Fake honey can be added with a little cold boiled water and a few drops of iodine or alcohol. If it's purple, green, or reddish brown, it's fake honey.

Fake milk powder that is white or otherwise unnatural in color, with little or no milky taste, and large powder particles.

The central government put forward a strategic deployment to accelerate construction of a conservation-oriented society, to which whole country responded unanimously.

But in real life, people often lack scientific common sense and "tricks" to save money, resulting in massive unnecessary spending.

For example: after TV, air conditioner and other electrical appliances are used up, people are accustomed to using remote control to turn them off, but remote control signal receiving board on electrical appliance is still working, which wastes electricity.

Experts have noted that a 25-inch color TV consumes about 7 watts of power in standby mode, while a computer consumes 4.8 watts. The standby power consumption of household appliances is 10% of energy consumption of urban households in my country. .

Others, such as when burning gas, keep distance between bottom of pot and stove at 20-30mm, which can save gas; and other everyday tips are scientifically good ways to save energy.

Moreover, we must end bad deeds with good intentions and self-defeating "economy".

In order to save water, energy and time, some people are accustomed to re-boiling leftover warm water in a thermos before drinking it, which greatly increases nitrite content of water. Drinking such water can often lead to cause poisoning.

We want to build a civilized and energy efficient society. If we actively research and develop new energy-saving and energy-saving products, we can organize experts from various industries to write a brochure, such as "Tips for Saving Daily Life". ", which will be shown on TVniyu. Newspapers, papers, and other media are widely publicized making it a household name that is bound to play role of getting twice result for half effort.

The theme for this year's National Energy Savings Advertising Week is "Energy Saving and Eliminating Bottlenecks".

In fact, in process of daily electricity consumption, if we are a little more aware of energy saving and use some energy saving tips, we can save a lot of electricity. Here are some tips for saving electricity.

Rice Cooker Energy Saving Tips

There are two types of rice cookers on market: mechanical rice cooker and computerized rice cooker.

When using a mechanical rice cooker, cover rice cooker with a towel and be careful not to block air outlet, which can reduce heat loss.

When rice soup boils, raise button to use residual heat of electric hot plate to steam rice soup, then press button and simmer for 15 minutes before eating.

After rice cooker is used up, be sure to unplug power plug, otherwise, when temperature inside rice cooker falls below 70 degrees, it will automatically turn on power, which will waste electricity and shorten service life. .

Try to choose a high power rice cooker because it takes less time to cook same amount of rice in a 700W rice cooker than in a 500W rice cooker.

Computer rice cookers usually have a higher power, about 800W, to save energy, but price is slightly higher, usually 500 to 800 yuan.

TV Energy Saving Tips

There are several ways to save energy for TVs. First, have good control over contrast and brightness.

Typically, a color TV's power consumption can range from 30W to 50W when it's brightest and darkest. Indoors, it is recommended to turn on a low-power fluorescent lamp and adjust contrast and brightness of TV. towards middle for best.

Second, control volume: louder volume, higher power consumption.

A third way to save energy is to watch DVDs, preferably in AV mode.

Because in AV state, signal is connected directly, which reduces performance of TV tuner, and power consumption is naturally reduced.

Fourthly, after watching TV, you cannot use remote control to turn off TV, but turn off power on TV.

Because after remote control is turned off, TV is still in standby mode of whole machine and is still using electricity.

Under normal conditions, 10 hours of standby time is equivalent to consuming half a degree of electricity.

The last thing to add a dust cover to TV.

This prevents dust from being sucked into TV, which increases power consumption.

Tips for energy saving air conditioner

1. Do not set temperature of air conditioner too low during use.

Because lower temperature controlled by air conditioner, more energy it consumes, it is usually sufficient to lower room temperature by 6-7 degrees.

2. Setting room temperature 1 degree higher in cooling and 2 degrees lower in heating can save more than 10% of electricity, and human body barely perceives this small difference.

3. When starting machine, set strong cooling/high heating to achieve control goal as quickly as possible; when temperature is suitable, switch to medium and light wind to reduce power consumption and noise.

4. The "ventilation" switch cannot be in normally open state, otherwise power consumption will increase.

5. By opening doors and windows less, you can reduce amount of heat entering room, which is good for saving energy.

6. For air-conditioned rooms, it is best to use blackout curtains to reduce loss of cold air.

7. The connecting pipes of indoor and outdoor units should not exceed recommended length, which may enhance cooling effect.

8. To install air conditioner, try to choose shaded side of room to avoid direct sunlight on fuselage.

If this condition is not available, air conditioner should be covered with a sun visor.

9. Dust external cooling fins regularly and keep them clean. Too much dust on heatsink can significantly increase power consumption.

Refrigerator Energy Saving Tips

Energy-saving A++ class refrigerators currently on market save energy compared to conventional refrigerators.

Household energy-saving refrigerators typically use 0.5 to 0.8 kilowatt-hours of electricity per day, while conventional refrigerators typically consume 1 to 1.5 kilowatt-hours of electricity per day, which can save about half electricity .

In addition, when using refrigerator, you should pay attention to following points:

1. Do not place food to be refrigerated too tightly, leaving gaps to facilitate circulation of cold air, so that food cools faster, reduces number of compressor starts and saves energy.

2. When placing fresh fruits and vegetables in refrigerator, be sure to separate them.

Putting fruits and vegetables together will cause external cold and internal heat, resulting in increased energy consumption.

3. For larger products, they can be packaged separately according to amount of food eaten by family.each time, and take out only amount eaten at one time, instead of taking a large piece of food from package. refrigerator, and then reuse it if it is not used up.

Repeated freezing not only consumes energy, but also easily spoils food.

4. There are several methods of thawing, such as rinsing with water and natural thawing.

A few hours before eating, you can transfer food from refrigerator (about 4 degrees) to micro-freezer (about 1 degree), because cold air of frozen food can help maintain temperature and reduce operation of refrigerator. compressor to achieve goal of saving electricity.

The placement of refrigerator is also of particular importance. As a rule, you should pay attention to following two points:

1. When placing a refrigerator, it is usually necessary to leave 5 to 10 cm of free space on both sides, 10 cm at top and 10 cm at back, so that refrigerator can dissipate heat.

2. Do not install refrigerator together with electrical appliances such as stereos, televisions and microwave ovens. The heat generated by these appliances increases power consumption of refrigerator.

There is not much ice at poles of Moon

Scientists have published a study report in an issue of British journal Nature stating that there is not much ice at Moon's poles, which is different from previous assumptions.

This discovery casts a shadow over human plans to colonize moon and build space supply stations there.

Researchers at Smithsonian Institution have used radio telescopes at Arecibo Observatory in Puerto Rico to observe Moon's poles without sunlight and scan craters with 70-centimeter radio beams.

But only very weak signals appeared on ground radar.

The researchers stated in observation report that this shows that there is not much ice at poles of Moon, and even if there is ice, it is only scattered scattered ice particles or thin layers.

Well, this issue has a complete collection of scientific knowledge around us, see if there is any interesting content that you do not know about, I will tell you all about it. In next issue, I will tell you about exciting science content, so stay tuned, don't miss it. Follow me, every time you will see new interesting content.