Sun Joe SPX2598-MAX 2000 PSI Electric Pressure Washer with Foam Cannon

2000 (MM) was a century leap year starting on Saturday of the Gregorian calendar, the 2000th year of the Common Era (CE) and Anno Domini (AD) designations, the 1000th and last year of the 2nd millennium, the 100th and last year of the 20th century, and the 1st year of the 2000s decade.

2000 was designated as the International Year for the Culture of Peace and the World Mathematical Year.

Popular culture holds the year 2000 as the first year of the 21st century and the 3rd millennium, because of a tendency to group the years according to decimal values, as if non-existent year zero was counted. According to the Gregorian calendar, these distinctions fall to the year 2001, because the 1st century was retroactively said to start with the year AD 1. Since the Gregorian calendar does not have year zero, its first millennium spanned from years 1 to 1000 inclusively and its second millennium from years 1001 to 2000. (For further information, see century and millennium.)

The year 2000 is sometimes abbreviated as "Y2K" (the "Y" stands for "year", and the "K" stands for "kilo" which means "thousand"). The year 2000 was the subject of Y2K concerns, which were fears that computers would not shift from 1999 to 2000 correctly. However, by the end of 1999, many companies had already converted to new, or upgraded existing, software. Some even obtained "Y2K certification". As a result of massive effort, relatively few problems occurred.

A cannon is a large-caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder during the late 19th century. Cannons vary in gauge, effective range, mobility, rate of fire, angle of fire and firepower; different forms of cannon combine and balance these attributes in varying degrees, depending on their intended use on the battlefield. A cannon is a type of heavy artillery weapon. The word cannon is derived from several languages, in which the original definition can usually be translated as tube, cane, or reed.

The earliest known depiction of cannons may have appeared in Song dynasty China as early as the 12th century; however, solid archaeological and documentary evidence of cannons do not appear until the 13th century. In 1288, Yuan dynasty troops are recorded to have used hand cannons in combat, and the earliest extant cannon bearing a date of production comes from the same period. By the end of the 14th century, cannons were widespread throughout Eurasia.

Cannons were used primarily as anti-infantry weapons until around 1374, when large cannons were recorded to have breached walls for the first time in Europe. Cannons featured prominently as siege weapons. In 1464 a 16,000 kg (35,000 lb) cannon known as the Great Turkish Bombard was created in the Ottoman Empire. Cannons as field artillery became more important after 1453 when cannons broke down the walls of the Roman Empire's capital, with the introduction of limber, which greatly improved cannon maneuverability and mobility. European cannons reached their longer, lighter, more accurate, and more efficient "classic form" around 1480. This classic European cannon design stayed relatively consistent in form with minor changes until the 1750s.

In the modern era, the term cannon has fallen into decline, replaced by guns or artillery, if not a more specific term such as howitzer or mortar, except for high-caliber automatic weapons firing bigger rounds than machine guns, called autocannons.

Foams are two-phase material systems where a gas is dispersed in a second, non-gaseous material, specifically, in which gas cells are enclosed by a distinct liquid or solid material.^{: 6 : 4} The foam "may contain more or less liquid [or solid] according to circumstances",^: 6 although in the case of gas-liquid foams, the gas occupies most of the volume.^: 4 The word derives from the medieval German and otherwise obsolete veim, in reference to the "frothy head forming in the glass once the beer has been freshly poured" (cf. ausgefeimt).^: 1

Theories regarding foam formation, structure, and properties—in physics and physical chemistry—differ somewhat between liquid and solid foams in that the former are dynamic (e.g., in their being "continuously deformed"), as a result of gas diffusing between cells, liquid draining from the foam into a bulk liquid, etc.^: 1–2 Theories regarding liquid foams have as direct analogs theories regarding emulsions,^: 3 two-phase material systems in which one liquid is enclosed by another.

In most foams, the volume of gas is large, with thin films of liquid or solid separating the regions of gas. A bath sponge and the head on a glass of beer are examples of foams; soap foams are also known as suds.

Solid foams can be closed-cell or open-cell. In closed-cell foam, the gas forms discrete pockets, each completely surrounded by the solid material. In open-cell foam, gas pockets connect to each other. A bath sponge is an example of an open-cell foam: water easily flows through the entire structure, displacing the air. A sleeping mat is an example of a product composed of closed-cell foam.

Foams are examples of dispersed media. In general, gas is present, so it divides into gas bubbles of different sizes (i.e., the material is polydisperse)—separated by liquid regions that may form films, thinner and thinner when the liquid phase drains out of the system films. When the principal scale is small, i.e., for a very fine foam, this dispersed medium can be considered a type of colloid.

Foam can also refer to something that is analogous to foam, such as quantum foam.

Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed.^: 445 Gauge pressure (also spelled gage pressure) is the pressure relative to the ambient pressure.

Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m²); similarly, the pound-force per square inch (psi, symbol lbf/in²) is the traditional unit of pressure in the imperial and US customary systems. Pressure may also be expressed in terms of standard atmospheric pressure; the unit atmosphere (atm) is equal to this pressure, and the torr is defined as 1⁄760 of this. Manometric units such as the centimetre of water, millimetre of mercury, and inch of mercury are used to express pressures in terms of the height of column of a particular fluid in a manometer.

The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light and infrared radiation with 10% at ultraviolet energies. It is by far the most important source of energy for life on Earth. The Sun has been an object of veneration in many cultures. It has been a central subject for astronomical research since antiquity.

The Sun orbits the Galactic Center at a distance of 24,000 to 28,000 light-years. Its distance from Earth defines the astronomical unit, which is about 1.496×10⁸ kilometres or about 8 light-minutes. Its diameter is about 1,391,400 km (864,600 mi), 109 times that of Earth. The Sun's mass is about 330,000 times that of Earth, making up about 99.86% of the total mass of the Solar System. Roughly three-quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron.

The Sun is a G-type main-sequence star (G2V), informally called a yellow dwarf, though its light is actually white. It formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. Most of this matter gathered in the centre; the rest flattened into an orbiting disk that became the Solar System. The central mass became so hot and dense that it eventually initiated nuclear fusion in its core. Every second, the Sun's core fuses about 600 billion kilograms (kg) of hydrogen into helium and converts 4 billion kg of matter into energy.

About 4 to 7 billion years from now, when hydrogen fusion in the Sun's core diminishes to the point where the Sun is no longer in hydrostatic equilibrium, its core will undergo a marked increase in density and temperature which will cause its outer layers to expand, eventually transforming the Sun into a red giant. After the red giant phase, models suggest the Sun will shed its outer layers and become a dense type of cooling star (a white dwarf), and no longer produce energy by fusion, but will still glow and give off heat from its previous fusion for perhaps trillions of years. After that, it is theorised to become a super dense black dwarf, giving off negligible energy.

Washer most commonly refers to:

• Washer (hardware), a thin usually disc-shaped plate with a hole in the middle typically used with a bolt or nut
• Washing machine, for cleaning clothes

Washer may also refer to:

• Dishwasher, a machine for cleaning dishware, cookware and cutlery
• Dishwasher (occupation), a person who cleans dishware, cookware and cutlery
• Washer, a person with obsessive-compulsive disorder who washes her/his hands compulsively
• Washer method, a mathematical formula for finding volume
• Washer pitching, an outdoor game involving tossing discs at a target

With or WITH may refer to:

• With, a preposition in English
• Carl Johannes With (1877–1923), Danish doctor and arachnologist
• With (character), a character in D. N. Angel
• With (novel), a novel by Donald Harrington
• With (album), a 2014 album by TVXQ
• With (EP), a 2021 EP by Nam Woo-hyun