Search results
Results from the WOW.Com Content Network
The following is a list of notable unsolved problems grouped into broad areas of physics. [1]Some of the major unsolved problems in physics are theoretical, meaning that existing theories seem incapable of explaining a certain observed phenomenon or experimental result.
A Fermi problem (or Fermi question, Fermi quiz), also known as an order-of-magnitude problem, is an estimation problem in physics or engineering education, designed to teach dimensional analysis or approximation of extreme scientific calculations. Fermi problems are usually back-of-the-envelope calculations.
Extreme value theory or extreme value analysis (EVA) is the study of extremes in statistical distributions. It is widely used in many disciplines, such as structural engineering , finance , economics , earth sciences , traffic prediction, and geological engineering .
The physics of the earth's atmosphere includes dramatic events like lightning and the effects of volcanic eruptions, with discontinuities of motion such as noted by Helmholtz (1868). [26] Turbulence is prominent in atmospheric convection. Other discontinuities include the formation of raindrops, hailstones, and snowflakes.
In astroparticle physics, an ultra-high-energy cosmic ray (UHECR) is a cosmic ray with an energy greater than 1 EeV (10 18 electronvolts, approximately 0.16 joules), [1] far beyond both the rest mass and energies typical of other cosmic ray particles. The origin of these highest energy cosmic ray is not known.
Since nuclear chain reactions may only require natural materials (such as water and uranium, if the uranium has sufficient amounts of 235 U), it was possible to have these chain reactions occur in the distant past when uranium-235 concentrations were higher than today, and where there was the right combination of materials within the Earth's crust.
The Extreme-ultraviolet Stellar Characterization for Atmospheric Physics and Evolution (ESCAPE) mission aims to find environments beyond Earth's solar system that might host planets with thick atmospheres to support life. [1] The long-term stability of exoplanetary atmospheres depends critically on the extreme-ultraviolet (EUV) flux from the ...
In some fields of physics, they are distinguished by their origin: gamma rays are created by nuclear decay while X-rays originate outside the nucleus. In astrophysics , gamma rays are conventionally defined as having photon energies above 100 keV and are the subject of gamma-ray astronomy , while radiation below 100 keV is classified as X-rays ...