O‘zbekiston respublikasi sog‘liqni saqlash vazirligi toshkent farmatsevtika instituti fizika, matematika va axborot texnologiyalari kafedrasi fizika fanidan farmatsiya fakulteti farmatsiya va sanoat farmatsiya fakultetlari yo`nalishlari

Special Theory of Relativity:
Albert Einstein’s first major theory, dating from 1905, special relativity builds on Galileo's more simplistic principle of relativity and relates what one person sees when looking at another person moving at constant speed relative to them. “Special” indicates that the theory restricts itself to observers in uniform or constant relative motion, a restriction Einstein addressed later in his General Theory of Relativity. The theory incorporates the principle that the speed of light is the same for allinertial observers, regardless of the state of motion of the source. Among other things, it reveals that the moving person appears to shrink in the direction of their motion (length contraction)and their time slows down (time dilation), effects which are ever more marked as speeds approach the speed of light. The theory also leads to some famous paradoxes like the so-called Time Travel Paradox and the Twin Paradox.

Speed of Light:
In a vacuum, light travels at a speed of exactly 299,792,458 metres per second, or about 300,000 kilometres per second, a speed which remains constant irrespective of the speed of the source of the light or of the observer (one of the cornerstones ofAlbert Einstein’s Special Theory of Relativity). It is the term c in Einstein’s famous equation E = mc².


Spin:

A fundamental property of sub-atomic elementary particles that means that behave as though they are spinning or rotating (although in reality they are not spinning at all). The concept has no direct analogue in the everyday world. Particles of spin Ѕ (e.g. electrons, positrons, neutrinos and quarks) make up all the matter in the universe, while particles with integer spin (0, 1 or 2) give rise to, or mediate, the forces operating between thematter particles (e.g. photons, gluons, W and Z bosons).

Star:
A massive, luminous ball of gas or plasma, held together by its own gravity, that replenishes the heat it loses to space by means of nuclear energy generated in its core. Almost all of theelements heavier than hydrogen and helium were created by thenuclear fusion processes in stars. There are many different types of stars including binary stars, proto-stars, dwarf stars (like our nearest star which we call the Sun), supergiants, supernovas, neutron stars, pulsars,quasars, etc. There are a roughly estimated 10,000 billion billion stars (10²²) in the observableuniverse.