I constructed a relatively simple dark matter model a few days ago. After several days of thinking, I found that this dark matter model can also be used to explain some basic problems in modern physics. Among them, how are the gravitational field, electric field and magnetic field generated, and why the masses of electrons and protons are not equal, and so on. Considering that dark matter is an elastic medium, when there is energy, the elastic dark matter will be squeezed. At this time, the strain and stress generated by dark matter correspond to the bending and gravitational force of time and space. For electromagnetic interaction, it can be explained by the microscopic effects of dark matter molecules. If one considers that the "covalent bond" between dark matter molecules exists in both stretch and compression, it can be foreseen that the dark matter molecules are stretched, which means that the space occupied by the entire dark matter will expand. Considering that dark matter fills the universe, this also means that a part of dark matter molecules will be stretched, and another part of dark matter molecules will be compressed. If the stretched dark matter molecules are regarded as a negative electric field effect, the compressed dark matter molecules correspond to a positive electric field effect. Considering the Covalent bond force model inside the molecule, it is necessary to stretch and compress the same distance, and the energy required for compression is greater than the energy required for stretching. We can think of molecules being stretched as a negative electric field, corresponding to electrons. Compression is regarded as a positive electric field, corresponding to protons. This also means that the energy of the electron and the proton, that is, the mass, are not equal. Due to the existence of certain boundary conditions or Dirac charge quantization conditions, the charge and mass of all electrons or protons are equal. This can even provide a theoretical basis for the "multi-world" model: Planck's constant is different in different worlds.