Beta Decay is when a neutron in its nucleus splits into an electron and a proton. The electron is emitted from the nucleus as a beta ray. The new proton increases the element’s atomic number by one, forming a new element with the same atomic mass as the parent isotope. For example, 234Th is unstable and undergoes beta decay to form protactinium-234 (234Pa), which also undergoes beta decay to form uranium-234 (234U). Notice these are all isotopes of different elements but they have the same atomic mass of 234.

Detrital sedimentary rocks contain clasts from separate parent rocks from unknown locations and derived ages are thus meaningless. However, sedimentary rocks with precipitated minerals, such as evaporites, may contain elements suitable for radioisotopic dating. Igneous pyroclastic layers and lava flows within a sedimentary sequence can be used to date the sequence. Cross-cutting igneous rocks and sills can be used to bracket the ages of affected, older sedimentary rocks.

he radioactive decay of any individual atom is a completely unpredictable and random event. However, some rock specimens have an enormous number of radioactive isotopes, perhaps trillions of atoms and this large group of radioactive isotopes do have a predictable pattern of radioactive decay. The radioactive decay of half of the radioactive isotopes in this group takes a specific amount of time.

The giant phase in a star’s life occurs when the star runs out of hydrogen for fusion. If a star is large enough, it has sufficient heat and pressure to start fusing helium into heavier elements.

An element such as hydrogen combines or fuses with other hydrogen atoms in the core of a star to become a new element, in this case, helium.

The Doppler effect is the same process that changes the pitch of the sound of an approaching car or ambulance from high to low as it passes. When an object emits waves, such as light or sound, while moving toward an observer, the wavelengths get compressed. In sound, this results in a shift to a higher pitch. When an object moves away from an observer, the wavelengths are extended, producing a lower-pitched sound.

An early example of how Renaissance scientists began to apply a modern empirical approach is their study of the solar system

Western scientific thought began in the ancient city of Athens, Greece [8]. Athens was governed as a democracy, which encouraged individuals to think independently, at a time when most civilizations were ruled by monarchies or military conquerors.

Once the problem or question is well defined, the scientist proposes a possible answer, a hypothesis, before conducting an experiment or fieldwork. This hypothesis must be specific, falsifiable, and should be based on other scientific work. Geologists often develop multiple working hypotheses because they usually cannot impose strict experimental controls or have limited opportunities to visit a field location [5; 6; 7].