Fizika u medicini primijenjena je na nekoliko razina. Bazična biofizikalna istraživanja strukture bioloških makromolekula pomažu u rješavanju povezanosti strukture i funkcije jedne molekule.
If we want to measure any physical quantity we have to use an appropriate measuring instrument. If we assume that it is accurate and if we repeat the measurement very carefully for several times we will notice that results differ. Every measurement has some uncertainty. These uncertainties are called errors.