So how long can these fossil fuels support human beings? There is no exact answer to this question at present, but according to the known situation, researchers generally believe that fossil fuels on the earth will last for about two or three hundred years, which is worrying. In the not-too-distant future, when all the coal, oil and natural gas on the earth are used up, what should mankind do? Let's discuss it below.
Scientists tell us that coal, oil and natural gas are formed by ancient creatures, and the energy needed for their growth comes from the sun. In other words, the energy contained in the fossil fuels we use now is actually the solar energy stored by these ancient creatures.
The nuclear fusion reaction has been going on in the core of the sun. We can simply understand that in the environment of high temperature and high pressure, hydrogen nuclei are continuously polymerized into helium nuclei, and in this process, huge energy is released because of the loss of mass.
Scientists believe that if humans learn this skill of the sun, they will not worry about energy in the future. Why do you say that? This is because hydrogen is the most abundant element in the universe and can be found everywhere on the earth. A simple example is that each water molecule contains two hydrogen atoms.
What is important is that the energy released by nuclear fusion is incomparable with fossil fuels such as coal, oil and natural gas. According to calculation, if 1 kg hydrogen is used for nuclear fusion, 630 trillion (6.3x10/4) joules of energy will be released, which is equivalent to the energy generated by burning 20,000 tons of standard coal.
Because of this, many scientists all over the world are devoted to the study of controlled nuclear fusion. However, because controlled nuclear fusion needs to maintain extremely high temperature and pressure for a long time, it will take a long time for human beings to achieve controlled nuclear fusion perfectly.
Therefore, before realizing the "controlled nuclear fusion", human beings should consider other methods. The data show that every second, the amount of solar radiation received by the earth is1.73x1017w, which is roughly equivalent to the energy generated by burning 5 million tons of standard coal. Therefore, the most important way for human beings is to directly use the energy radiated by the sun to the earth.
In fact, humans have been trying to do this for a long time. At present, we use solar energy to generate electricity mainly in two ways. The first way is that we first convert solar energy into heat energy, and then convert heat energy into electric energy in various ways, such as semiconductor (or metal material) thermoelectric power generation, alkali metal thermoelectric conversion, magnetic fluid power generation and so on. Of course, we can also use "boiling water" to generate electricity.
1887, physicist heinrich rudolf hertz discovered a strange phenomenon, that is, under certain circumstances, when light strikes a metal, electrons inside the metal will escape, thus forming a current, which is later called "photoelectric effect".
At present, another way adopted by mankind is to use the principle of "photoelectric effect". When people put uneven semiconductor or semiconductor-metal assembly in the sun, potential difference will occur between different parts, thus forming voltage.
At present, mankind still faces many problems in this field, such as high cost, low energy conversion rate, lack of suitable supporting technology for storing electric energy, short life of solar panels, etc., but these problems are completely different from those faced by controlled nuclear fusion. I believe that with the progress of human science and technology, it will be solved one by one in the near future.
It is gratifying that in the past days, mankind has made continuous progress in the field of solar power generation. In 2004, the electricity generated by human using solar energy only accounted for about 0.0 1% of the global electricity generation, but today, this proportion has exceeded 3%. Scientists optimistically estimate that by 2040, this proportion can reach 20%, and by 2050. If this is the case, then even if the fossil fuel on the earth can last for about two or three hundred years, there will be alternative energy sources for future human beings.
In short, we don't have to worry about what human beings will do when all the fossil fuels such as coal, oil and natural gas on the earth are used up. Theoretically, as long as the sun does not go out, human beings can always use this inexhaustible energy source. However, a problem that cannot be ignored is that the scientific community generally believes that when human beings use fossil fuels, they will release a lot of greenhouse gases into the earth's atmosphere, which is the main reason for global warming at present, so we should use fossil fuels as little as possible.