Your doctor may need to change the doses of your medications or monitor you carefully for side effects. ... Metformin side effects can also affect other parts of the body. It can leave a metallic taste in the mouth, cause heartburn or headache, flushing of the skin, nail changes or muscle pain. More serious metformin side effects include chest pain or rash. ...
Early String Theory. The first attempt to construct a physical model of an atom was made by William Thomson (later elevated to Lord Kelvin) in 1867. The most striking property of the atom was its permanence.
According to the theory, the fundamental constituents of reality are strings of the Planck length (about 10 â33 cm) which vibrate at resonant frequencies. Every string, in theory, has a unique resonance, or harmonic. Different harmonics determine different fundamental particles. The tension in a string is on the order of the Planck force (10 44 newtons). The graviton (the proposed messenger particle of the gravitational force), for example, is predicted by the theory to be a string with wave amplitude zero.