Symmetry is not enough by itself. In electromagnetism, for example, if you write down all the symmetries we know, such as Lorentz invariance and gauge invariance, you don't get a unique theory that predicts the magnetic moment of the electron. The only way to do that is to add the principle of renormalisability – which dictates a high degree of simplicity in the theory and excludes these additional terms that would have changed the magnetic moment of the electron from the value Schwinger calculated in 1948.
Steven WeinbergRelated topics
add additional degree electron enough example gauge high invariance magnetic moment principle simplicity symmetry theory unique value way write lorentz electromagnetism renormalisabilityRelated quotes
Were I to deduce any system from my feelings on leaving Eton, it might be called The Theory of Permanent Adolescence. It is the theory that the experiences undergone by boys at the great public schools, their glories and disappointments, are so intense as to dominate their lives and to arrest their development. From these it results that the greater part of the ruling class remains adolescent, school-minded, self-conscious, cowardly, sentimental, and in the last analysis homosexual.
Cyril Connolly
On this question of principle, while actual suffering was yet afar off, they the Colonies raised their flag against a power to which, for purposes of foreign conquest and subjugation, Rome in the height of her glory is not to be compared,a power which has dotted over the surface of the whole globe with her possessions and military posts, whose morning drum-beat, following the sun, and keeping company with the hours, circles the earth with one continuous and unbroken strain of the martial airs of England.
Daniel Webster
Parliament is not a congress of ambassadors from different and hostile interests which interests each must maintain, as an agent and advocate, against other agents and advocates but parliament is a deliberative assembly of one nation, with one interest, that of the whole where, not local purposes, not local prejudices ought to guide, but the general good, resulting from the general reason of the whole. You choose a member indeed but when you have chosen him, he is not a member of Bristol, but he is a member of parliament.
Edmund Burke
O God, enlarge within us the sense of fellowship with all living things, even our brothers, the animals, to whom Thou gavest the earth as their home in common with us. We must remember with shame that in the past we have exercised the high dominion of man with ruthless cruelty so that the voice of the earth, which should have gone up to thee in song, has been a groan of pain. May we realize that they live, not for us alone, but for themselves and for Thee and that they love the sweetness of life.
Basil of Caesarea
Unbelievers, those who believe with difficulty, or believe in part, are those who do not show their faith through works. Apart from works the demons also believe (cf. Jms. 2:19) and confess Christ to be God and Master. 'We know Who You are' (Mk. 1:24), they say, 'You are the Son of God' (Mt. 8:29), and elsewhere, 'These men are the servants of the Most High God' (Acts 16:17). Yet such faith will not benefit the demons, nor even humans. This faith is of no use, for it is dead.
Symeon the New Theologian
