In an expanding universe, the overall energy of the universe is conserved, which means that the total energy remains constant over time. However, this conservation of energy does not prevent localized energy transfers or transformations.
When it comes to magnets, their energization or the presence of a magnetic field can be explained through the behavior of charged particles, particularly electrons. Magnets consist of atoms or materials with aligned electron spins, creating a net magnetic field. The alignment of electron spins can occur through various processes such as thermal agitation or the application of an external magnetic field.
In an expanding universe, the presence and behavior of magnets, as well as their energization, can be understood within the framework of the conservation of energy. The expansion of the universe itself does not directly affect the behavior or properties of magnets. The energy associated with magnets is stored in the arrangement of charges and their motion, and this energy remains conserved as long as the system is isolated from external influences.
However, it's worth noting that the universe's expansion does have implications for the behavior of electromagnetic fields on cosmological scales. The expansion causes a redshift in the wavelengths of electromagnetic waves, which results in a decrease in their energy. This effect is known as cosmological redshift. Nevertheless, this redshift primarily affects the propagation and characteristics of electromagnetic radiation on cosmological scales rather than the properties of individual magnets or their energization.