What is a theory

 the nature of a scientific theory

 in order to talk about the nature of the universe and to discuss such questions as whether it has a beginning or an end

 you have to be clear about what a scientific theory is

 we shall take the simple minded view that a theory is just a model of the universe or a restricted part of it and a set of rules that relate quantities in the model

 to observations that we make it

 exists only in our minds and does not have any other reality whatever that might mean

 a theory is a good theory if it satisfies two requirements

 

it must accurately describe a large class of observations on the basis of a model that contains only a few arbitrary elements

 and it must make definite predictions about their results of future observations

 for example Aristotle believed empedocles's theory that everything was made out of four elements earth air fire and water

 

 this was simple enough but did not make any definite predictions

 

 on the other hand Newton's theory of gravity was based on an even simpler model in which bodies attracted each other with a force that was proportional to a quantity called their mass and inversely proportional to the square of the distance between them

 

 yet it predicts the motions of the sun the moon and the planets to a high degree of accuracy

 

 any physical theory is always provisional in the sense that it is only a hypothesis you can never prove it no matter how many times the results of experiments agree with some theory you can never be sure that the next time a result will not contradict the theory

 

 on the other hand you can disprove the theory by finding even a single observation that disagrees with the predictions of the theory

 

a good theory is characterized by the fact that it makes a number of predictions that could in principle be disproved or falsified by observation

 each time new experiments are observed to agree with the predictions the theory survives and our confidence in it is increased

 

 but if ever a new observation is found to disagree we have to abandon or modify the theory at least that is what is supposed to happen but you can always question the competence of the person who carried out the observation in practice what often happens is that a new theory is devised that is really an extension of the previous theory for example very accurate observations of the planet Mercury revealed a small difference between its motion and the predictions of Newton's theory of gravity Einstein's general theory of relativity predicted a slightly different motion than Newton's theory did the fact that Einstein's predictions matched what was seen while Newton's did not was one of the crucial confirmations of the new theory however we still use Newton's theory for most practical purposes because the difference between its predictions and those of general relativity is very small in the situations that we normally deal with Newton's theory also has the great advantage that it is much simpler to work with than Einstein's the eventual goal of science is to provide a single theory that describes the whole universe

 

Was it that I just didn't like this process was it not fast enough what was the deal with this particular segment that I decided to not go with