Urban green spaceIn land-use planning, urban green space is open-space areas reserved for parks and other "green spaces", including plant life, water features - also referred to as blue spaces - and other kinds of natural environment. Most urban open spaces are green spaces, but occasionally include other kinds of open areas. The landscape of urban open spaces can range from playing fields to highly maintained environments to relatively natural landscapes.
Commuter townA commuter town is a populated area that is primarily residential rather than commercial or industrial. Routine travel from home to work and back is called commuting, which is where the term comes from. A commuter town may be called by many other terms: "bedroom community" (Canada and northeastern US), "bedroom town", "bedroom suburb" (US), "dormitory town", or "dormitory suburb" (Britain/Commonwealth/Ireland). In Japan, a commuter town may be referred to by the wasei-eigo coinage "bed town".
Public transportPublic transport (also known as public transportation, public transit, mass transit, or simply transit) is a system of transport for passengers by group travel systems available for use by the general public unlike private transport, typically managed on a schedule, operated on established routes, and that charge a posted fee for each trip. There is no rigid definition of which kinds of transport are included, and air travel is often not thought of when discussing public transport—dictionaries use wording like "buses, trains, etc.
Car dependencyCar dependency is the concept that some city layouts cause cars to be favoured over alternate forms of transportation, such as bicycles, public transit, and walking. In many modern cities, automobiles are convenient and sometimes necessary to move easily. When it comes to automobile use, there is a spiraling effect where traffic congestion produces the 'demand' for more and bigger roads and removal of 'impediments' to traffic flow. For instance, pedestrians, signalized crossings, traffic lights, cyclists, and various forms of street-based public transit, such as trams.
Quantum mechanics of time travelUntil recently, most studies on time travel are based upon classical general relativity. Coming up with a quantum version of time travel requires physicists to figure out the time evolution equations for density states in the presence of closed timelike curves (CTC). Novikov had conjectured that once quantum mechanics is taken into account, self-consistent solutions always exist for all time machine configurations, and initial conditions. However, it has been noted such solutions are not unique in general, in violation of determinism, unitarity and linearity.
Convenience storeA convenience store, bodega, convenience shop, corner store or corner shop is a small retail store that stocks a range of everyday items such as coffee, groceries, fruits, vegetables, snacks, confectionery, soft drinks, ice creams, tobacco products, lottery tickets, over-the-counter drugs, toiletries, newspapers and magazines. In some jurisdictions, convenience stores are licensed to sell alcoholic drinks, although many jurisdictions limit such beverages to those with relatively low alcohol content, like beer and wine.
Greenhouse gas emissionsGreenhouse gas emissions (abbreviated as GHG emissions) from human activities strengthen the greenhouse effect, contributing to climate change. Carbon dioxide (), from burning fossil fuels such as coal, oil, and natural gas, is one of the most important factors in causing climate change. The largest emitters are China followed by the US, although the United States has higher emissions per capita. The main producers fueling the emissions globally are large oil and gas companies.
Climate change mitigationClimate change mitigation is action to limit climate change by reducing emissions of greenhouse gases or removing those gases from the atmosphere. The recent rise in global average temperature is mostly due to emissions from burning fossil fuels such as coal, oil, and natural gas. Mitigation can reduce emissions by transitioning to sustainable energy sources, conserving energy, and increasing efficiency. It is possible to remove carbon dioxide () from the atmosphere by enlarging forests, restoring wetlands and using other natural and technical processes.
Standard ModelThe Standard Model of particle physics is the theory describing three of the four known fundamental forces (electromagnetic, weak and strong interactions – excluding gravity) in the universe and classifying all known elementary particles. It was developed in stages throughout the latter half of the 20th century, through the work of many scientists worldwide, with the current formulation being finalized in the mid-1970s upon experimental confirmation of the existence of quarks.
Energy demand managementEnergy demand management, also known as demand-side management (DSM) or demand-side response (DSR), is the modification of consumer demand for energy through various methods such as financial incentives and behavioral change through education. Usually, the goal of demand-side management is to encourage the consumer to use less energy during peak hours, or to move the time of energy use to off-peak times such as nighttime and weekends.