Toshkent farmatsevtika instituti fizika, matematika va axborot texnologiyalari kafedrasi

Gravity (or Gravitational Force):
The force of attraction that exists between any two masses, whether they be stars, microscopic particles or any other bodies with mass. It is by far the weakest of the fourfundamental forces (the others being the electromagnetic force, the strong nuclear force and the weak nuclear force), and yet, because it is a consistent force operating on all bodies withmass, it is instrumental in the formation of galaxies, stars, planets and black holes. It was approximately described by Sir Isaac Newton’s Law of Universal Gravitation in 1687, and more accurately described by Albert Einstein’s General Theory of Relativity in 1916.

H

Half-Life:
A measure of the speed of radioactive decay of unstable, radioactive atoms. It is the time taken for half of the nuclei in a radioactive sample to disintegrate or decay. Half-lives can vary from a split-second to billions of years depending on the substance.
Hawking Radiation:
Random and featureless sub-atomic particles and thermal radiation predicted to be emitted by black holes due to quantum effects. Over long periods of time, as a black hole loses morematter through radiation than it gains through other means, it is therefore expected to dissipate, shrink and ultimately vanish.
Horizon:
The horizon of the universe is much like the horizon on Earth: it is the furthest that can be seen from a particular position. Because light has a finite speed and the universe has a finite age, we can only see objects whose light has had time to reach us since the Big Bang, so that the observable universe can be thought of as a bubble centred on the Earth.
Hubble’s Law:
Formulated by Edwin Hubble in 1929, the law states that the redshift in light coming from distantgalaxies is proportional to their distance, so that every galaxy appears to be rushing away from us (or from any other point in the universe) with a speed that is directly proportionate to its distance from us. It is considered the first observational basis for an expanding universe (or the metric expansion of space), and the most often cited evidence in support of the Big Bang theory, and arguably one of the most important cosmological discoveries ever made.