Beijing Youth Daily has an article in May, 20065438+0/8 entitled "Is gravity out of order? After reading the report (see the "Foreign News" section of the website "Contemporary Physics-Physics Essays"), I felt this discussion. I think, on the surface, both American scientists and China scientists are right. In fact, scientists in the United States and China regard the law of gravity as the "basic law". If it is not regarded as the "basic law", American scientists will not question it; Since it is a definite "basic law", scientists in China certainly think that there is no doubt that they should look for other explanations. People's thinking has a shortcoming. Once the phenomenon and fact conflict with the original theory (abnormal), in order to protect the original theory called "paradigm or scientific research programmes" by philosophy of science, we need to find other reasons to explain it. The question is whether the law of universal gravitation is a basic law. If not, why should we take it as a basic law?
The basic law is the "axiom" law of the theoretical system, the starting point of thinking and the original starting point of logic-the original premise, not the law derived from other laws. I don't think the law of gravity is the basic law for two reasons:
First, the basic laws of Newton's theoretical system of mechanics are its three laws. However, the three laws do not contain the content of gravity. As a supplement to the content of "gravity", we have to apply the basic law of gravity. In fact, the law of gravity is a (conceptual) "derivative" law of Newton's three laws, because free fall is an accelerated motion, starting from its first and second laws (the real "paradigm or scientific research programmes" of Newton's mechanical theory). It must be pointed out that Newton's second law is the mathematical expression of his first law. ), so that the cause of free fall is also caused by external forces, so gravity is "discovered". So the law of gravity is not the basic law.
Secondly, only from the process of the formula of the law of gravitation, before Newton's time and at the same time, many other people have obtained the distribution law that the centripetal acceleration of the "solar system" (only in this range) is inversely proportional to the square of the distance from the sun (the real empirical formula, not the basic law). Because Newton discovered that the gravity on the ground (acceleration of gravity) and the centripetal force of satellites and planets in the solar system (or the paradigm of Newton's three laws) are of the same nature (a great discovery), (however, the same nature is regarded as the same force)-the wrong transformation began. Next, according to gravity, it is also related to the mass of the object (on the ground) that represents gravity. At the same time, inverse square law is artificially added to the mass (the central mass is actually the mass of the sun). ), the law of gravity came into being. Then the question changed again. After throwing away the difference between "central mass" and "mass" on the ground, gravity began to "have everything". Therefore, when I eat, the "roast chicken" on my dining table has a kind of "attraction" for me (not because I am hungry, but because the roast chicken is attractive to me). The "inverse square law" in the law of universal gravitation was originally a phenomenon range in the "universe" (solar system), but it was artificially and invisibly expanded to the range of "everything", which is a mistake in human thinking. Only from this point of view, it shows that the "law of gravity" is still an empirical formula, not a basic law. Expanding a certain range of empirical laws artificially indefinitely can sometimes produce "great" discoveries, but at the same time it is a "discovery" with great risks, which is very easy to cause huge cognitive errors. This is where the falsificationism of the scientific philosopher Popper can be established and applied. Because, the inductive (empirical) language of our human thinking (not only language, but also cognition. ) generally use "possessive case".
American scientists say that Newton's "law of gravity" is no longer effective at the cosmic scale level, which means that the "law of gravity" has limitations and is only established under certain conditions. Actually, it's the other way around. The law of gravity is valid on the cosmic scale (solar system scale). There is no "effect" between us and the "roast chicken" at the dinner table. Effective does not mean accurate, because "the law of universal gravitation" is an empirical formula. The law of universal gravitation is "accurate" (not absolute) only in the range of "nine planets", because "inverse square law" is derived from it. Outside the orbit of Pluto or inside the orbit of Mercury, the inverse square law is not necessarily absolute. Therefore, it is normal for Pioneer 1 1, Galileo, Ulysses and other detectors to deviate from the orbit calculated according to the law of universal gravitation. If we regard this "deviation" phenomenon as another inexplicable "force" at work, it is abnormal, and this is the "abnormality" of our thinking.
The empirical formula is not necessarily accurate. Are the basic laws of the theory necessarily accurate? It depends on the angle The Basic Law is "man-made" and of course it is accurate within the theoretical scope. However, if we want to apply the basic law to practice, generally speaking, we must go through the intermediate link of "empirical proposition" to establish a "connection" with the phenomenon world, so it will not be "accurate". Newton's law of inertia is a basic law, and its "empirical proposition" is "an object with the same mass and the same initial velocity has a short moving distance when the resistance is large, and a long moving distance when the resistance is small." Therefore, when we apply Newton's law of inertia to practice, we have to establish a relationship with the phenomenon through this "empirical proposition". Because we can't see that "an object will move in a straight line at a constant speed forever without external force".
It is said that the root of these tangled problems is the defect of Newton's mechanical system itself. In the absence of gravity field, Newton's mechanical system (Newton's first and second laws; Note: Newton's third law is the law of mechanical system, which is not limited by the condition of gravity field or not. ) established. Under the premise of gravity field, Newton's mechanical system does not hold water. Gravity is a misunderstanding of the nature of gravity. Einstein realized the essence of gravity, but he took a detour in space, "just like his light took a detour in the gravitational field", which turned the same understanding of the inertia and gravity of the object into a problem of giving up the transformation of the object reference system. We must take the space without gravity field and the space with gravity field as the premise of understanding, so as to clarify our thinking. The reference frame with gravity field space is certain, because there is a celestial body with "special mass (non-gravitational mass)" in the center of gravity field, and this "celestial body" is the certain reference frame. Without an understanding of this premise, our thinking will always be in the strange circle of "logical cycle". For example, without an understanding of the difference between "special objects" (the whole celestial body) and general objects, the gravitational field will be generated because of its central "mass", which is the root of the gravitational field. Therefore, mass is the source of gravitational field, and gravity is still "the action of force", and the existence of "field" is meaningless. At present, many disputes and discussions in this field are meaningless, but are leading some people to consume their life's energy or many people's energy. Relativity is confusing. When we ask a kindergarten child to count the number of people in the room, the child says there are six, but there are actually seven. You will laugh at him because he doesn't count himself. However, on the issue of "relativity", we are making the same mistake. The assumption that the speed of light is constant (independent of the movement of the light source) in special relativity itself means that there is an absolute frame of reference background. How else can we judge the speed of light itself? When you describe the theory of relativity, don't forget that you are a frame of reference and you are an object. In this respect, it is not as simple as judging children's mistakes, because each of us is not a "bystander" when reading other people's descriptions, and we are also there. Don't worry that there is no absolute frame of reference, because we can always find the frame of reference we need in the objective world.
Why do we regard "the law of gravity" as the basic law is because Newton's mechanical system (the three laws) has no correct understanding of "the law of gravity", so we have to plug it in and treat it as the basic law by deceiving ourselves. What we lack at present is a unified understanding of Newtonian mechanics and "gravity". Otherwise, there wouldn't be so many people discussing "gravity and space" in books and online today. Newton, Newton, you have made great discoveries and made great contributions to mankind. At the same time, your "gravity" has also brought a lot of trouble to many people behind you. It's been 300 years now, and how many people's energy has been spent on how your "gravity" becomes a direct effect. Up to now, people are still discussing the problem of "shielding gravity" (treating gravity as an independent "thing"). This is really a sin. The cause of free fall is neither the result of external force nor the result of force. Does "action" necessarily mean "force"? In this world, if there is no "force", there is nothing to move. Isn't DNA replicating itself? Our understanding of the world is mainly due to our understanding of the world in the process of transforming the world, so we objectify our role in the world and regard it as the role of the objective world. "Force" comes from the function of our human limbs in the world, so we externalize the function of "limbs". Today's human beings have changed our understanding of the objective world, and we have regarded ourselves as a part of it. Then why do we focus on "self" on the issue of "gravity"?