I have read mostly from pdfs about quantum mechanics, quantum field theory and general relativity. Perhaps the writers told about it in the beginning of the pdfs? I did not read something about it.Vanadium 50 said:This question is threefold - "Why do you need QM?" "Why do you need GR?" and "How does SR" work. These all require chapters of textbooks, if not entire textbooks.
What research have you done to answer this question?
Also, A-level means you want a graduate-level answer. That means you've already seen these textbooks. Which ones and what didn't you understand?
infinitely small said:I have read mostly from pdfs
Very brief answer: because classical Newtonian mechanics is not in accordance with several observations and experiments. For detailed answers you would really need to study few textbooks involving all the topics you asked about, as suggested by @Vanadium 50infinitely small said:Hello. The questions are: Why Newtonian mechanics is not applicable to quantum mechanics and more natural phenomena in gravity? So, we needed general relativity which offers a metric theory about gravity and applies to more phenomena in nature, but how is this explained that special and general relativity where needed? About the Lorentz transformations in special relativity, how did they occur? Thank you.
infinitely small said:Ok, i should better read the pdfs.
infinitely small said:So what kind of questions should i ask?
Where we can help is while you are carefully reading the textbooks and you come on specific small questions that confuse you. This question was far too broad and general. Remember, this is an Internet forum, so answers are going to be a few hundred words at most. We can answer specific questions in that amount, but not write you a textbook.infinitely small said:So what kind of questions should i ask?
Newtonian mechanics is a branch of classical mechanics that describes the motion of objects based on Newton's laws of motion. It is a fundamental theory in physics that has been used to explain the motion of objects in our everyday lives.
Newtonian mechanics is based on the assumption that objects move in a straight line at a constant speed unless acted upon by an external force. However, in certain situations, such as at very high speeds or in the presence of strong gravitational fields, this assumption breaks down and the predictions of Newtonian mechanics do not match with experimental observations.
Some examples include the motion of objects at speeds close to the speed of light, the behavior of subatomic particles, and the motion of objects in strong gravitational fields such as near black holes.
In these situations, scientists use other theories such as Einstein's theory of relativity or quantum mechanics to accurately describe and predict the behavior of objects. These theories have been extensively tested and have been shown to better explain the observed phenomena.
Yes, Newtonian mechanics is still relevant and widely used in many fields of science and engineering. It provides a good approximation for the motion of objects in most everyday situations and is still taught as a fundamental theory in physics. However, it is important to recognize its limitations and use more advanced theories when necessary.