In order to be able to reproduce experiments, standard conditions for temperature and pressure have been defined in different fields of science. Very often these are also called standard temperature and pressure. The table below gives some examples:
STP
STP usually refers to:
STP may also refer to:
Jungle
The jungle is a place in a rain forest where the forest floor is crowded with plants. Like other rainy places, they have many rivers or streams. Scientists think that more types of animals and plants live in the jungles than everywhere else. When people talk about jungles, they sometimes mean the whole rainforest.
The crowding in a jungle leaves little room to walk. This may make it dangerous to people.
Light
Light is a form of electromagnetic radiation with a wavelength which can be detected by the human eye. It is a small part of the electromagnetic spectrum and radiation given off by stars like the sun. Animals can also see light. The study of light, known as optics, is an important research area in modern physics. When light hits an opaque object it forms a shadow but when the light hits a transparent object, it passes through it almost completely without producing a shadow
Light is electromagnetic radiation that shows properties of both waves and particles. Light is a form of energy.Light also keeps the Earth warm. Light exists in tiny energy packets called photons. Each wave has a wavelength or frequency. The human eye sees each wavelength as a different colour. Rainbows show the entire spectrum of visible light. The separate colors, moving in from the outer edges, are usually listed as red, orange, yellow, green, blue, indigo and violet. Other colors can be seen only with special cameras or instruments: Wavelengths below the frequency of red are called infrared, and higher than of violet are called ultraviolet.
The other main properties of light are intensity, polarization, phase and orbital angular momentum.
In physics, the term "light" sometimes refers to electromagnetic radiation of any wavelength, whether visible or not. This article is about visible light. Read the electromagnetic radiation article for the general concept.
The law of reflection is what allows us to see an object reflected in a mirror.
In a vacuum, light moves at the speed of light, which is 299,792,458 meters per second (or about 186,282 miles per second). This means it takes about 8 minutes for light to reach Earth from the Sun. In glass it travels at about two-thirds as fast.
Light moves in a straight line, creating shadows when the path of light is blocked. More solid things will have a darker shadow, things that are more clear have a lighter shadow, and transparent things will have none or very little shadow. Light can pass through transparent things the most easily. When light is not in a vacuum, it travels more slowly than its maximum speed of light. The slowest light ever recorded moved at 39 miles per hour.
Our eyes react to light; when we see something we see the light it reflects, or the light it emits. For example, a lamp gives off light, and everything else in the same room as the lamp reflects its light.
Every color of light has a different wavelength. The shorter the wavelength, the more energy the light has. The speed at which light moves does not depend on its energy. Going through partly clear objects can slow light down by a very small amount.
White light is made up of many different colors of light added together. When white light shines through a prism, it splits up into different colors, becoming a spectrum. The spectrum contains all of the wavelengths of light that we can see. Red light has the longest wavelength, and violet (purple) light has the shortest.
Light with a wavelength shorter than violet is called ultraviolet light. X-rays and gamma rays are also forms of light with even shorter wavelengths than ultraviolet. Light with a wavelength longer than red is called infrared light. Radio waves are a form of electromagnetic radiation with a wavelength even longer than infrared light. The microwaves that are used to heat food in a microwave oven are also a form of electromagnetic radiation. Our eyes cannot see those kinds of energy, but there are some cameras that can see them. The various forms of light, both visible and invisible are the electromagnetic spectrum.
When light is refracted in raindrops, a rainbow is made. The raindrop acts like a prism and refracts the light until we can see the colors of the spectrum.
Light and color are forms of analog information. However, electronic cameras and computer displays work with digital information. Electronic cameras or document scanners make a digital version of a color image by separating out the full color image into separate red, green, and blue images. Later, a digital display uses pixels of just those three colors. Computer screens use only these three colors in different brightness levels. The brain combines them to see all of the other colors in the image.
People think of objects as having color. This is because the molecules that make up the object absorb certain light waves, leaving the other light waves to bounce off. The human eye sees the wavelengths of all of the light that was not absorbed, and the combination of those leaves the brain with the impression of a color.
Stockholm
Stockholm is the capital city of Sweden. It is also the biggest city in Sweden. It is on the east coast of the country. The city is built on islands, with canals and open water in the inner city. Stockholm is found between Sweden's third largest lake, Mälaren, and the Baltic Sea.
Tyresta National Park is near Stockholm.
Central Stockholm has four different parts - Kungsholmen, Södermalm, Norrmalm and Östermalm. Kungsholmen and Södermalm are islands, while Norrmalm and Östermalm are parts of the mainland. Also, there are several smaller islands in the inner city - Gamla Stan, Riddarholmen, Djurgården and Skeppsholmen. Since Stockholm has so many islands, it is sometimes referred to as the "Venice of the North".
Gamla Stan is the oldest part of the city - the name means "Old Town", and is usually called that in English. Djurgården is mostly a large park, but there are buildings on the island. Most of these are museums that commemorate Sweden's and Stockholm's past - like Skansen, a zoo with a Swedish theme. Skeppsholmen is an island that used to be a training ground and military school, but most of the buildings are now used for museums and art galleries, such as the Modern Museum, or the East Asian museum. Riddarholmen is a part of Gamla Stan, but actually a different island.
All of the islands in Stockholm are connected by several bridges. The biggest one is Västerbron, going from Kungsholmen to Södermalm.
Birger Jarl is considered the founder of Stockholm. It is believed that he rebuilt a defense building in the 13th century on what is today the island of the Old town. Around the fortification, a town grew. The town grew mainly because of its sea and land trading.
The last Wikimania conference is hosted in this city in 2019.
Rain
Rain is a kind of precipitation. Precipitation is any kind of water that falls from clouds in the sky, like rain, hail, sleet and snow. It is measured by a rain gauge. Rain is part of the water cycle.
Clouds will often absorb smoke to create rain, commonly referred to as "nature's laundry" due to this process.
Some places have frequent rain. This makes rainforests. Some have little rain. This makes deserts.
A rainstorm is a sudden heavy fall of rain. It may cause flash floods in valleys. Heavy rain for a long time may make floods that destroy houses and drown people. Also, landslides may happen.
When the Sun heats the Earth's surface, the ground heats the air above it. Convection makes the air rise and cool. When it cools to the dew point, clouds form and rain follows.This usually occurs on flat land. This type of rainfall often causes summer showers and thunderstorms.