1001 questions: Why is the soil brown?

From space, the earth is green and blue, but up close, most of the time you will only see brown. Where did this color come from?

As plants wilt and die, their leaves and branches fall, carrying the carbon they’ve stored into the ground. Tiny bacteria on Earth have bitten these plant remains with specialized enzymes. But because the hungry microorganisms process a large amount of carbon in the soil, even taking in some elements into their cells, the bacteria cannot do the full job, so there are pieces of carbon that are not broken down. dishwashing bacteria. Moreover, they also have carbon in their bodies, so when the bacteria die, the carbon goes back to the ground. It’s a cycle, where there’s always carbon left over. These small pieces accumulate over time. Such tiny pieces are the humus material, which accumulates year after year. And bacteria’s carbon storage has given the earth its dirty brown color, because carbon absorbs most of the colors in the solar spectrum, except for the brown light it reflects back. However, not all land around the earth is brown. Some deserts seem to have only white sand. The soil in Hawaii, rich in iron, is reddish in color. Dig deep into the ground in some areas that are dirty brown, you’ll see other colors underneath. If there wasn’t too much carbon in the ground, the ground would be yellow, red, and gray. They depend on the color of the dominant mineral there. The Mysteries of the Earth 1. Does anyone know what the structure of the middle layer of the Earth is? According to research by seismologists, we already know that the internal structure of the Earth includes: The inner core is solid. The outer core layer is molten lava. The intermediate layer, called the mantle or mantle, lies at a depth of 30 to 2,900 km. The rock crust can slide away freely. But what the mantle is made of is still a mystery to researchers because we haven’t been able to dig down to this layer or have any evidence of its composition. Until now, the deepest hole that humans can dig is the Kola Drilling Hole in Russia, only 12.3 km deep. 2. Earth’s two poles are interchangeable Scientists have proven that the two magnetic poles of the Earth can change positions and reverse directions. This phenomenon has happened many times in Earth’s history. The last time the Earth changed poles was 10 million years ago, and it is very likely that this will happen again in the future. Until now, scientists did not know how this phenomenon could happen. 3. Earth used to have two moons Scientists confirm that, 4.6 million years ago, Earth had two natural satellites. The second satellite exists in the same orbit as the Moon and has a diameter of about 1,200 km. After a few million years, these two satellites collided. This may explain why the two halves of the Moon are so different today. 4. The Earth actually rotates very fast The Earth, including the atmosphere and everything on the planet’s surface, rotates at a tremendous speed of more than 1,600 km/h, while the Earth’s rotation speed around the Sun is 108,000 km/h. Humans can live and function normally while standing on the ground because we, everything around and the Earth are rotating at the same speed. We can feel this movement thanks to the wind, but since the entire atmosphere is moving at the same speed as us, we don’t feel anything. If the Earth suddenly stopped rotating, we could feel this movement. But it will not be pleasant at all, everything on Earth will be swept away at more than 1,600km/h. 5. Time on Earth is “getting longer” every day 620 million years ago, a day on Earth lasted only about 21.9 hours. But the Earth is spinning more and more slowly, so in the future, our day will be 25 hours long. Scientists have shown that after every century, the Earth’s rotation slows down by about 1.8 milliseconds, which means that a day will be only 2 milliseconds longer. So we have to wait another 200 million years for a day on Earth to have 25 hours. 6. Gravity on Earth is not the same everywhere The Earth is not a perfect sphere, so Earth’s gravity is not uniform, there will be areas of weak gravity and regions of different strong gravity, even places where there is almost no gravity. Hudson Bay in Canada is known as a place of near zero gravity due to the low density of rock here, caused by the rapid melting of glaciers. 7. In primitive times, the Earth used to be purple In ancient times, plants used retinal instead of chlorophyll to absorb light. This substance causes them to reflect red and blue light. This is the reason why ancient plants were red, not green like today’s plants. This led scientists to hypothesize that the original Earth was once purple because it was covered with ancient plants. 8. The ocean hidden in the ground Scientists believe there is a giant ocean, and the amount of water contained in it is estimated to be three times greater than that of all the oceans on the Earth’s surface. In early 2014, researchers discovered “ringwoodite,” a material located in the transition zone (between 410 km and 660 km deep), as proof that a giant sea of ​​water exists. exist below the surface of the Earth. According to scientists, this underground ocean is about 2.7 million years old, under tremendous pressure.