An air shower in physics refers to a cascade of secondary particles produced when a high-energy cosmic ray, typically a proton or atomic nucleus, interacts with the Earth's atmosphere. When these cosmic rays, which can have energies many orders of magnitude greater than that achievable in human-made particle accelerators, collide with atmospheric molecules, they produce a wide variety of secondary particles, including pions, muons, electrons, and photons.

The term "reverse waterfall" can refer to various concepts depending on the context in which it is used. Here are a couple of interpretations: 1. **Project Management/Software Development**: In some contexts, particularly in agile methodologies, a "reverse waterfall" can refer to a non-linear approach to project development that contrasts with the traditional waterfall model. The waterfall model typically involves a linear, sequential design process where each phase must be completed before the next begins.

"Aurora" can refer to several different things depending on the context. Here are a few common meanings: 1. **Natural Phenomenon**: In the context of natural phenomena, an aurora refers to the auroras, specifically Aurora Borealis (Northern Lights) and Aurora Australis (Southern Lights). These are natural light displays predominantly seen in high-latitude regions around the Arctic and Antarctic.

Auroral chorus is a natural phenomenon associated with the auroras, which are spectacular light displays occurring primarily in polar regions. These visual displays are caused by the interactions between charged particles from the solar wind and Earth's magnetic field and atmosphere. The term "auroral chorus" specifically refers to a type of natural radio wave emissions that occur in the vicinity of the auroras.

Some good insights on the earlier history of the industry at: The Supermen: The Story of Seymour Cray by Charles J. Murray (1997).

Brine rejection refers to the process by which concentrated saltwater (brine) is expelled from certain environments, particularly in relation to the formation of sea ice or during the desalination process in natural bodies of water. This phenomenon has significant ecological and climate implications. 1. **Sea Ice Formation**: When seawater freezes to form sea ice, the salt does not become incorporated into the ice structure.

Sea ice is a type of ice that forms from the freezing of seawater in polar regions and in some subarctic regions. It plays a crucial role in the Earth's climate system and is an essential component of marine ecosystems. Here are some key points about sea ice: 1. **Formation**: Sea ice typically forms during the winter months when air temperatures drop and the surface of the ocean cools. As the water freezes, it creates a layer of ice on the ocean's surface.

"Dusk" can refer to a few different things depending on the context: 1. **Time of Day**: Dusk is the period of time that occurs after sunset and before nightfall. It is characterized by diminishing sunlight and can be further divided into civil, nautical, and astronomical dusk, each defined by differing degrees of the sun's angle below the horizon.

In astronomy, "Earthlight" refers to the illumination of the Moon by sunlight that is reflected off the Earth. When the Earth’s surface, including oceans and land, reflects sunlight, some of that light can reach the Moon, providing a faint glow. This phenomenon is most noticeable when the Moon is in its crescent phase, as the darkened portion of the Moon can be subtly illuminated by this reflected Earth's light, making it visible even in the daytime.

The Equation of Time is a concept in astronomy that describes the difference between solar time (as indicated by a sundial) and mean time (as kept by a clock). It accounts for the irregularities in the Earth's orbit and axial tilt, which cause the solar day (the time it takes for the Earth to rotate so that the sun returns to the same position in the sky) to vary throughout the year.

There aren't any 2020, except in the trivial one-time pad case where the key is as large as the message: crypto.stackexchange.com/questions/10815/how-do-we-prove-that-aes-des-etc-are-secure

A fog bow is a type of optical phenomenon that occurs in foggy conditions, similar to a rainbow but typically fainter and less colorful. It is created when light interacts with tiny water droplets suspended in the air. Unlike rainbows, which are formed by larger raindrops, fog bows form from much smaller droplets that scatter light in a way that creates a whitish or pale arc rather than the vibrant colors seen in rainbows.

The only perfect cryptosystem!

The problem is that you need a shared key as large as the message.

Systems like advanced Encryption Standard allow us to encrypt things larger than the key, but the tradeoff is that they could be possibly broken, as don't have any provably secure symmetric-key algorithms as of 2020.

In photography, the "golden hour" refers to the period of time shortly after sunrise and before sunset when the natural light is particularly soft, warm, and golden in color. This specific lighting condition is highly sought after by photographers because it creates flattering and visually appealing images, with enhanced depth and texture. During the golden hour, the sun is low in the sky, which results in longer shadows and a more diffused light, reducing harsh contrasts.

Robert W. Fuller is an American author, former president of Oberlin College, and activist known for his work on issues related to dignity and the concept of "dignity for all." He has written several books, including "Somebodies and Nobodies: Overcoming the Abuse of Rank," where he explores societal hierarchies and how they impact human interactions and dignity.

A list of natural phenomena encompasses various events and occurrences in the natural world that can be observed and studied. These phenomena can be categorized into several groups based on their nature and causes. Here’s a broad overview of some prominent natural phenomena: ### Atmospheric Phenomena 1. **Auroras** (e.g., Aurora Borealis) 2. **Lightning** 3. **Tornadoes** 4. **Hurricanes** (or Typhoons/Cyclones) 5.

Measurement of sea ice refers to the techniques and methods used to assess the extent, thickness, volume, and other properties of sea ice in polar regions. This measurement is crucial for understanding climate change, marine ecosystems, and global weather patterns. Several approaches are employed to measure sea ice: 1. **Satellite Remote Sensing**: Satellites equipped with sensors can capture images and data about sea ice cover across large areas.