query: What is the critical mass of Plutonium?

title: Plutonium-239

text: the reactor of a nuclear power plant produces two to three neutrons, and these neutrons can be absorbed by uranium-238 to produce plutonium-239 and other isotopes. Plutonium-239 can also absorb neutrons and fission along with the uranium-235 in a reactor. Of all the common nuclear fuels, Pu-239 has the smallest critical mass. A spherical untamped critical mass is about 11 kg (24.2 lbs), 10.2 cm (4") in diameter. Using appropriate triggers, neutron reflectors, implosion geometry and tampers, this critical mass can be reduced by more than twofold. This optimization usually requires a large nuclear development organization supported by a sovereign

title: Pakistan and weapons of mass destruction

text: Khan, previously second in command at the Strategic Arms Division of Pakistans' Military told a Pakistani newspaper that Pakistan had "about 80 to 120 genuine warheads." Pakistan tested plutonium capability in the sixth nuclear test, codename Chagai-II, on 30 May 1998 at Kharan Desert. The critical mass of a bare mass sphere of 90% enriched uranium-235 is 52 kg. Correspondingly, the critical mass of a bare mass sphere of plutonium-239 is 8–10 kg. The bomb that destroyed Hiroshima used 60 kg of U-235 while the Nagasaki Pu bomb used only 6 kg of Pu-239. Since all Pakistani bomb designs are

title: Critical mass

text: crystal structure (see allotropes of plutonium). An ideal mass will become subcritical if allowed to expand or conversely the same mass will become supercritical if compressed. Changing the temperature may also change the density; however, the effect on critical mass is then complicated by temperature effects (see "Changing the temperature") and by whether the material expands or contracts with increased temperature. Assuming the material expands with temperature (enriched uranium-235 at room temperature for example), at an exactly critical state, it will become subcritical if warmed to lower density or become supercritical if cooled to higher density. Such a material is

title: Plutonium(IV) oxide

text: bomb would have a considerably larger critical mass than one made from plutonium metal (almost three times larger, even with the oxide at maximum crystal density; if the oxide were in powder form, as is often encountered, the critical mass would be much higher still), due both to the lower density of plutonium in PuO compared with plutonium metal and to the added inert mass of the oxygen contained. The behavior of plutonium oxide in the body varies with the way in which it is taken. Since it is insoluble, when ingested, a very large percentage of it will be

title: Plutonium

text: can form a critical mass. During fission, a fraction of the nuclear binding energy, which holds a nucleus together, is released as a large amount of electromagnetic and kinetic energy (much of the latter being quickly converted to thermal energy). Fission of a kilogram of plutonium-239 can produce an explosion equivalent to . It is this energy that makes plutonium-239 useful in nuclear weapons and reactors. The presence of the isotope plutonium-240 in a sample limits its nuclear bomb potential, as plutonium-240 has a relatively high spontaneous fission rate (~440 fissions per second per gram—over 1,000 neutrons per second per

title: Plutonium-239

text: in principle, such reactors make extremely efficient use of natural uranium. In practice, their construction and operation is sufficiently difficult that they are generally only used to produce plutonium. Breeder reactors are generally (but not always) fast reactors, since fast neutrons are somewhat more efficient at plutonium production. Plutonium-239 is more frequently used in nuclear weapons than uranium-235, as it is easier to obtain in a quantity of critical mass. Both Plutonium-239 and Uranium-235 are obtained from Natural uranium, which primarily consists of uranium-238 but contains traces of other isotopes of uranium such as Uranium-235. The process of enriching uranium,

title: Critical mass

text: a strong propensity toward spontaneous fission. Because of this, a reasonably sized gun-type weapon would suffer nuclear reaction (predetonation) before the masses of plutonium would be in a position for a full-fledged explosion to occur. Instead, the plutonium is present as a subcritical sphere (or other shape), which may or may not be hollow. Detonation is produced by exploding a shaped charge surrounding the sphere, increasing the density (and collapsing the cavity, if present) to produce a prompt critical configuration. This is known as an "implosion type weapon". The event of fission must release, on the average, more than one

title: Critical mass

text: a nucleus is proportional to the density. It follows that 1% greater density means that the distance travelled before leaving the system is 1% less. This is something that must be taken into consideration when attempting more precise estimates of critical masses of plutonium isotopes than the approximate values given above, because plutonium metal has a large number of different crystal phases which can have widely varying densities. Note that not all neutrons contribute to the chain reaction. Some escape and others undergo radiative capture. Let "q" denote the probability that a given neutron induces fission in a nucleus. Let

title: Critical Mass (cycling)

text: a "critical mass" of riders dense enough to occupy a piece of road to the exclusion of drivers of motorized vehicles. Authorities in New York, California and Oregon have expressed concern with the difficulty of coordinating with the riders, due to the lack of leadership. Critical Mass rides vary greatly in many respects, including frequency and number of participants. For example, many small cities have monthly Critical Mass rides with fewer than twenty riders which offer safety in numbers to cyclists in those locales, while on the opposite extreme, in what have been the largest events using the name Critical

title: Critical mass

text: Critical mass A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (specifically, the nuclear fission cross-section), its density, its shape, its enrichment, its purity, its temperature, and its surroundings. The concept is important in nuclear weapon design. When a nuclear chain reaction in a mass of fissile material is self-sustaining, the mass is said to be in a "critical" state in which there is no increase or decrease in power, temperature, or neutron population. A numerical measure of a critical

title: Critical mass

text: measurement of the reactivity is that suggested by Louis Slotin: that of the dollar and cents. Critical mass A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (specifically, the nuclear fission cross-section), its density, its shape, its enrichment, its purity, its temperature, and its surroundings. The concept is important in nuclear weapon design. When a nuclear chain reaction in a mass of fissile material is self-sustaining, the mass is said to be in a "critical" state in which there is

title: Critical mass

text: shape with minimal critical mass and the smallest physical dimensions is a sphere. Bare-sphere critical masses at normal density of some actinides are listed in the following table. The critical mass for lower-grade uranium depends strongly on the grade: with 20% U it is over 400 kg; with 15% U, it is well over 600 kg. The critical mass is inversely proportional to the square of the density. If the density is 1% more and the mass 2% less, then the volume is 3% less and the diameter 1% less. The probability for a neutron per cm travelled to hit

title: Critical mass (sociodynamics)

text: loses utility, thus pushing more users to discontinue their use. In M. Lynne Markus' essay in "Communication Research" entitled "Toward a 'Critical Mass' Theory of Interactive Media", several propositions are made that try to predict under what circumstances interactive media is most likely to achieve critical mass and reach universal access, a "common good" using Oliver, "et al".'s terminology. One proposition states that such media's existence is all or nothing, where in if universal access is not achieved, then, eventually, use will discontinue. Another proposition suggests that a media's ease of use and inexpensiveness, as well as its utilization of

title: Plutonium

text: alpha decay. Twenty radioactive isotopes of plutonium have been characterized. The longest-lived are plutonium-244, with a half-life of 80.8 million years, plutonium-242, with a half-life of 373,300 years, and plutonium-239, with a half-life of 24,110 years. All of the remaining radioactive isotopes have half-lives that are less than 7,000 years. This element also has eight metastable states, though all have half-lives less than one second. The known isotopes of plutonium range in mass number from 228 to 247. The primary decay modes of isotopes with mass numbers lower than the most stable isotope, plutonium-244, are spontaneous fission and alpha emission,

title: Critical Mass (cycling)

text: was created as a response to Critical Mass. Critical Manners rides through the city on the second Friday of the month, with riders encouraged to obey all traffic laws such as stopping at red lights and signaling. Tucson, Arizona holds the Tuesday Night Community Bike Ride as their alternative to Critical Mass. The weekly ride encourages bicycle commuting and motor vehicle awareness in a peaceful and friendly way. In 2007 there were conversations about starting Critical Manners in Portland, Oregon. According to the Critical Mass book, a similar project known as Courteous Mass is described as "an alternative to Critical

title: Critical mass (sociodynamics)

text: Critical mass (sociodynamics) In social dynamics, critical mass is a sufficient number of adopters of an innovation in a social system so that the rate of adoption becomes self-sustaining and creates further growth. The term is borrowed from nuclear physics and in that field it refers to the amount of a substance needed to sustain a chain reaction. Social factors influencing critical mass may involve the size, interrelatedness and level of communication in a society or one of its subcultures. Another is social stigma, or the possibility of public advocacy due to such a factor. Critical mass may be closer

title: Reactor-grade plutonium

text: having more than 30% Pu-240. A limitation in the number of recycles exists within thermal reactors, as opposed to the situation in fast reactors, as in the thermal neutron spectrum only the odd-mass isotopes of plutonium are fissile, the even-mass isotopes thus accumulate, in all high thermal-spectrum burnup scenarios. Plutonium-240, an even-mass isotope is, within the thermal neutron spectrum, a fertile material like uranium-238, becoming fissile plutonium-241 on neutron capture; however, the even-mass plutonium-242 not only has a low neutron capture cross section within the thermal spectrum, it also requires 3 neutron captures before becoming a fissile nuclide. While most

title: Plutonium hexafluoride

text: Plutonium hexafluoride Plutonium hexafluoride is the highest fluoride of plutonium, and is of interest for laser enrichment of plutonium, in particular for the production of pure plutonium-239 from irradiated uranium. This pure plutonium is needed to avoid premature ignition of low-mass nuclear weapon designs by neutrons produced by spontaneous fission of plutonium-240. It is a red-brown volatile crystalline solid; the heat of sublimation is 12.1 kcal/mol and the heat of vaporization 7.4 kcal/mol. It is relatively hard to handle, being very corrosive and prone to auto-radiolysis. It is prepared by fluorination of plutonium tetrafluoride (PuF) by powerful fluorinating agents such

title: Critical Mass (cycling)

text: of violence and rudeness, the San Francisco Bicycle Coalition credits Critical Mass with spotlighting bicycle issues and aiding their efforts in advocating for cyclists. Critical Mass (cycling) Critical Mass is a cycling event typically held on the last Friday of every month; its purpose is not usually formalized beyond the direct action of meeting at a set location and time and traveling as a group through city or town streets on bikes. The event originated in 1992 in San Francisco; by the end of 2003, the event was being held in over 300 cities around the world. Critical Mass has

title: Melbourne Critical Mass

text: Melbourne Critical Mass Critical Mass Melbourne is an informal grass roots collection of people who gather to take part in the month's Critical Mass event, which is a cycling event typically held in various cities throughout the world on the last Friday of every month, for traveling as a group through city or town streets on bikes. The rides in Melbourne began in November 1995, and have occurred every month since, with between 100 and 1000 riders involved. Like most Critical Mass events in other cities, the Melbourne rides have fostered the development of a coherent urban cycling community, the

title: Melbourne Critical Mass

text: to a small hardcore group of die-hards. Attempts were made to have a closing ride to celebrate the death of Critical Mass but sufficient attendees could not be mustered. Attendance continued to decline until it reach zero in mid 2015. Since 2016 new ride was promoted via social networking links and was touted to reappear on 29 January 2016. Melbourne Critical Mass Critical Mass Melbourne is an informal grass roots collection of people who gather to take part in the month's Critical Mass event, which is a cycling event typically held in various cities throughout the world on the last

title: Plutonium-239

text: Pu-239 has a higher probability for fission than U-235 and a larger number of neutrons produced per fission event, so it has a smaller critical mass. Pure Pu-239 also has a reasonably low rate of neutron emission due to spontaneous fission (10 fission/s-kg), making it feasible to assemble a mass that is highly supercritical before a detonation chain reaction begins. In practice, however, reactor-bred plutonium will invariably contain a certain amount of Pu-240 due to the tendency of Pu-239 to absorb an additional neutron during production. Pu-240 has a high rate of spontaneous fission events (415,000 fission/s-kg), making it an

title: Critical mass

text: neutron activity. The constant of proportionality increases as increases. A "supercritical" mass is one in which, once fission has started, it will proceed at an increasing rate. The material may settle into equilibrium ("i.e." become critical again) at an elevated temperature/power level or destroy itself. In the case of supercriticality, "k" > 1. Due to spontaneous fission a supercritical mass will undergo a chain reaction. For example, a spherical critical mass of pure uranium-235 will have a mass of 52 kg and will experience around 15 spontaneous fission events per second. The probability that one such event will cause a

title: Critical mass

text: material exhibits an inverse relationship with relative neutron velocity. Hot fuel is always less reactive than cold fuel (over/under moderation in LWR is a different topic). Thermal expansion associated with temperature increase also contributes a negative coefficient of reactivity since fuel atoms are moving farther apart. A mass that is exactly critical at room temperature would be sub-critical in an environment anywhere above room temperature due to thermal expansion alone. The higher the density, the lower the critical mass. The density of a material at a constant temperature can be changed by varying the pressure or tension or by changing

title: Conflicts involving Critical Mass

text: a special Critical Mass is organized in cooperation with the city officials to commemorate the Warsaw Uprising. On March 28, 2013, in Buenos Aires, Argentina, a taxi driver ran over a group of Critical Mass riders, injuring 2 cyclists, before fleeing from the scene. Conflicts involving Critical Mass There have been many conflicts during Critical Mass events since the founding of the worldwide bicycling advocacy event in 1992. The conflicts have resulted in injuries, property damage, and arrests, and both bicyclists and motorized vehicle drivers have been victims. Critics say that Critical Mass, held primarily in large metropolitan cities, is

title: Critical mass

text: chain reaction depends on how much the mass exceeds the critical mass. If there is uranium-238 present, the rate of spontaneous fission will be much higher. Fission can also be initiated by neutrons produced by cosmic rays. The mass where criticality occurs may be changed by modifying certain attributes such as fuel, shape, temperature, density and the installation of a neutron-reflective substance. These attributes have complex interactions and interdependencies. These examples only outline the simplest ideal cases: It is possible for a fuel assembly to be critical at near zero power. If the perfect quantity of fuel were added to

title: Plutonium

text: mostly forming uranium (92 protons) and neptunium (93 protons) isotopes as decay products (neglecting the wide range of daughter nuclei created by fission processes). The primary decay mode for isotopes with mass numbers higher than plutonium-244 is beta emission, mostly forming americium (95 protons) isotopes as decay products. Plutonium-241 is the parent isotope of the neptunium decay series, decaying to americium-241 via beta emission. Plutonium-238 and 239 are the most widely synthesized isotopes. Plutonium-239 is synthesized via the following reaction using uranium (U) and neutrons (n) via beta decay (β) with neptunium (Np) as an intermediate: </chem> Neutrons from the

title: Critical Mass (book)

text: Critical Mass (book) Critical Mass: How One Thing Leads to Another is a non-fiction book by English chemist and physicist Philip Ball, originally published in 2004, discusses the concept of a “physics of society”. Ball examines past thinkers, such as Thomas Hobbes, Lewis Mumford, Emyr Hughes, and Gottfried Achenwall, who have attempted to apply (or argue against) the use of physics, chemistry, or mathematics in the study of mass social phenomena. He also discusses how the concept relates to recent research, including his own. Critical Mass was the winner of the 2005 Aventis Prize for Science Books. The outlines of

title: Critical mass

text: a slightly subcritical mass to create an "exactly critical mass", fission would be self-sustaining for only one neutron generation (fuel consumption then makes the assembly subcritical again). If the perfect quantity of fuel were added to a slightly subcritical mass, to create a barely supercritical mass, the temperature of the assembly would increase to an initial maximum (for example: 1 K above the ambient temperature) and then decrease back to the ambient temperature after a period of time, because fuel consumed during fission brings the assembly back to subcriticality once again. A mass may be exactly critical without being a

title: Critical Mass (cycling)

text: Critical Mass (cycling) Critical Mass is a cycling event typically held on the last Friday of every month; its purpose is not usually formalized beyond the direct action of meeting at a set location and time and traveling as a group through city or town streets on bikes. The event originated in 1992 in San Francisco; by the end of 2003, the event was being held in over 300 cities around the world. Critical Mass has been described as "monthly political-protest rides", and characterized as being part of a social movement. It has been described as a "monthly protest by

title: Critical Mass (Canadian band)

text: Critical Mass (Canadian band) Critical Mass is a Canadian Christian rock music group from Waterloo Region. The band is heavily influenced by its Catholic roots. They have produced and released five albums. Their songs have appeared on albums that have sold more than 60,000 copies, making this band one of Canada's most successful independent artists. The name has a double meaning. It is both a reference to the Liturgy and a reference to critical mass in the physical sense. "Critical mass" is symbolically a reference to there being enough young people enthusiastic about their Catholic faith to cause a spiritual

title: Critical Mass (film)

text: Target" called it "enjoyable action nonsense" and stated: "Recycled footage to this extent is just lazy and kind of insulting but if you can get past this, Critical Mass is an enjoyably amusing low rent shoot-em up." "Moria.co" gave the film only one star out of five, calling it "yet another version on Die Hard (1988) and the basic plot template it created of a lone individualistic hero inside a large building/facility single-handedly fending off a terrorist plot." " Critical Mass (film) Critical Mass is a 2001 low budget action film released direct-to-video. It starred Treat Williams, Lori Loughlin, and

title: Plutonium in the environment

text: into an organism if ingested. Much of this plutonium is absorbed into sediments of lakes, rivers and oceans. However, about 66% of the plutonium from a bomb explosion is formed by the neutron capture of uranium-238; this plutonium is not converted by the bomb into a high fired oxide as it is formed more slowly. This formed plutonium is more soluble and more harmful as fallout. Some plutonium can be deposited close to the point of detonation. The glassy trinitite formed by the Trinity bomb has been examined to determine what actinides and other radioisotopes it contained. A recent paper

title: Critical mass (sociodynamics)

text: Innovations" was that of the fax machine, which had been around for almost 150 years before it became popular and widely used. It had existed in various forms and for various uses, but with more advancements in the technology of faxes, including the use of existing phone lines to transmit information, coupled with falling prices in both machines and cost per fax, the fax machine reached a critical mass in 1987, when "Americans began to assume that 'everybody else' had a fax machine". Critical mass (sociodynamics) In social dynamics, critical mass is a sufficient number of adopters of an innovation

title: Critical mass

text: than the mean free path, such an approximation is only marginally applicable. Finally, note that for some idealized geometries, the critical mass might formally be infinite, and other parameters are used to describe criticality. For example, consider an infinite sheet of fissionable material. For any finite thickness, this corresponds to an infinite mass. However, criticality is only achieved once the thickness of this slab exceeds a critical value. Until detonation is desired, a nuclear weapon must be kept subcritical. In the case of a uranium bomb, this can be achieved by keeping the fuel in a number of separate pieces,

title: Critical Mass (film)

text: Critical Mass (film) Critical Mass is a 2001 low budget action film released direct-to-video. It starred Treat Williams, Lori Loughlin, and Udo Kier and was directed by Fred Olen Ray, credited as Ed Raymond. The film features scenes taken straight from other films such as "" and "Universal Soldier" spliced into newly filmed scenes to make up its action sequences. The film centers around a group of terrorist who take over a nuclear power plant and a security guard at the plant who tries to stop them. On Rotten Tomatoes, "Critical Mass" currently holds 13% of audience score. Website "Cool

title: Critical Mass (cycling)

text: 2015 with slogan "Quake or Shake, Sunny or Rainy, we have to flow with time for next smile..." Critical Mass rides have generated controversy and public opposition. The group has often protested in high-profile events, ranging from major political events to the Olympics. Some critics claim that Critical Mass is a deliberate attempt to obstruct traffic and disrupt normal city functions, asserting that individuals taking part refuse to obey traffic laws. Some bicycling advocacy groups have expressed concern that the nature of Critical Mass and altercations with motorists could weaken public support for cyclists. Though it does not condone incidents

title: Plutonium-242

text: of 5.5 × 10%. Plutonium-242 Plutonium-242 is one of the isotopes of plutonium, the second longest-lived, with a half-life of 373,300 years. Pu's halflife is about 15 times as long as Pu-239's halflife; therefore, it is one-fifteenth as radioactive and not one of the larger contributors to nuclear waste radioactivity. Pu's gamma ray emissions are also weaker than those of the other isotopes. It is not fissile (though it is fissionable by fast neutrons) and its neutron capture cross section is also low. Plutonium-242 is produced by successive neutron capture on Pu, Pu, and Pu. The odd-mass isotopes Pu and

title: Plutonium-242

text: Plutonium-242 Plutonium-242 is one of the isotopes of plutonium, the second longest-lived, with a half-life of 373,300 years. Pu's halflife is about 15 times as long as Pu-239's halflife; therefore, it is one-fifteenth as radioactive and not one of the larger contributors to nuclear waste radioactivity. Pu's gamma ray emissions are also weaker than those of the other isotopes. It is not fissile (though it is fissionable by fast neutrons) and its neutron capture cross section is also low. Plutonium-242 is produced by successive neutron capture on Pu, Pu, and Pu. The odd-mass isotopes Pu and Pu have about a

title: Critical mass

text: mass is dependent on the effective neutron multiplication factor , the average number of neutrons released per fission event that go on to cause another fission event rather than being absorbed or leaving the material. When "k" = 1, the mass is critical, and the chain reaction is self-sustaining. A "subcritical" mass is a mass of fissile material that does not have the ability to sustain a fission chain reaction. A population of neutrons introduced to a subcritical assembly will exponentially decrease. In this case, "k" < 1. A steady rate of spontaneous fissions causes a proportionally steady level of

title: Plutonium-240

text: threatened the design of gun-type nuclear weapons in which the assembly of fissile material into a supercritical mass is slow in comparison with the time-scale of the explosion. The minimization of the amount of present in weapons grade plutonium is achieved by reprocessing the fuel after just 90 days of use. Such rapid fuel cycles are highly impractical for civilian power reactors and are normally only carried out with dedicated weapons plutonium production reactors. Plutonium from spent civilian power reactor fuel typically has under 70% and around 26%, the rest being made up of other plutonium isotopes, making it extremely

title: Plutonium-240

text: mass numbers are both more likely to absorb a neutron, and can undergo fission upon neutron absorption more easily than isotopes of even mass number. Thus, even mass isotopes tend to accumulate, especially in a thermal reactor. For producing weapons grade plutonium, the irradiated fuel needs to be as low in as possible, usually less than 7% of the total plutonium. This is because undergoes spontaneous fission, and the resultant released neutrons from this process can cause the weapon to fizzle. This naturally occurring phenomenon was extensively studied by the scientists of the Manhattan Project during World War II. It

title: Critical Mass (cycling)

text: vintage bike rides) is a well dressed mass which takes place annually in a number of cities across the world. Examples of Critical Mass rides for political movements includes the Free Tibet Rides (May 2008): Free Tibet Critical Mass in Columbia, Missouri, "Tibetan Freedom Bike Rally" in San Francisco (Aug 2008), and in "Bike Ride for Tibet" in London (Aug 2008). San Luis Obispo, California, is the home of the "Bikes are happening..." meetup. Bikes are happening... starts at Mission Plaza at 9:30 pm on the first Thursday of the month. The ride consists of a continuous half mile loop

title: Melbourne Critical Mass

text: onto CityLink eight times. A policy of facilitated tolerance was adopted by Victoria Police based on history of no previous problems with the Critical Mass rides. This section summarises media reports that occurred after CityLink highlighted the rides in the media, ultimately causing the police to change their policy in 2004. Critical Mass first crossed the Bolte Bridge in May 1999 before it was opened to traffic a few weeks later. In June 2003 Critical Mass Melbourne rode through the Burnley Tunnel for the second time. Police Minister Andre Haermeyer said it was up to police to decide how to

title: Duke Nukem: Critical Mass

text: Duke Nukem: Critical Mass Duke Nukem: Critical Mass is a shooter game developed by Frontline Studios and published by Deep Silver for the Nintendo DS. A version for the PlayStation Portable began development, however was never released. The Earth Defense Forces attempts to ensure the Earth's continued security by monitoring the future with the help of their own time machine, but both their agent and a special team sent there have been confirmed MIA. Knowing something is wrong, General Graves sends in the famous Duke Nukem. "Duke Nukem: Critical Mass" is largely a run and gun shooter game, however, several

title: Plutonium-244

text: of Pu, the amount of plutonium-244 left should be very small; Hoffman "et al." estimated its content in the rare-earth mineral bastnasite as =1.0×10 g/g, which corresponded to the content in the Earth crust as low as 3×10 g/g (i.e. the total mass of plutonium-244 in the Earth crust is about 9 g). Since plutonium-244 cannot be easily produced by natural neutron capture in the low neutron activity environment of uranium ores (see below), its presence cannot plausibly be explained by any other means than creation by r-process nucleosynthesis in supernovas. Plutonium-244 thus should be the second shortest-lived and the

title: Critical mass

text: reaction. So long as other loss mechanisms are not significant, then, the radius of a spherical critical mass is rather roughly given by the product of the mean free path formula_2 and the square root of one plus the number of scattering events per fission event (call this "s"), since the net distance travelled in a random walk is proportional to the square root of the number of steps: formula_3 Note again, however, that this is only a rough estimate. In terms of the total mass "M", the nuclear mass "m", the density ρ, and a fudge factor "f" which

title: Critical mass

text: the high energy neutrons generated by the primary explosion. This can greatly increase yield, especially if even more neutrons are generated by fusing hydrogen isotopes, in a so-called boosted configuration. The critical size is the minimum size of a nuclear reactor core or nuclear weapon that can be made for a specific geometrical arrangement and material composition. The critical size must at least include enough fissionable material to reach critical mass. If the size of the reactor core is less than a certain minimum, too many fission neutrons escape through its surface and the chain reaction is not sustained. The

title: Critical Mass (book)

text: Ball's "Critical Mass", the most-popular book of his many noted books, beginning in various circa 2001 lectures, talks, and articles focused on what he calls a ‘physics of society’, similar to the social physics in the Auguste Comte sense, a subject Ball approaches using statistical mechanics viewing people as atoms or molecules that show characteristic behaviours in bulk. The following is an excerpt of his 2003 talk on the physical modeling of society: In his 2004 book, Ball summarizes this to the effect that "to develop a physics of society, we must take a bold step that some might regard

title: Conflicts involving Critical Mass

text: Conflicts involving Critical Mass There have been many conflicts during Critical Mass events since the founding of the worldwide bicycling advocacy event in 1992. The conflicts have resulted in injuries, property damage, and arrests, and both bicyclists and motorized vehicle drivers have been victims. Critics say that Critical Mass, held primarily in large metropolitan cities, is a deliberate attempt to obstruct automotive traffic and disrupt normal city functions, when individuals taking part refuse to obey traffic laws, while participants variously consider it a celebration of cycling, of cyclists' rights, and a practical re-imagining of urban space. On May 11, 2007,

title: Conflicts involving Critical Mass

text: Critical Mass riders police themselves. "It does the bicycle-advocacy community no good to have people that are aggressive and dispirit the entire movement," Newsom said. "I would encourage the bicycle coalition to say, 'Look, we don't put up with this, enough is enough.' " In November 2009, Stanley Roberts of KRON 4 News recorded several Critical Mass confrontations between bicyclists and vehicles at Van Ness and O'Farrell Streets. An old Critical Mass website advised riders not to be confrontational and block traffic, but in footage filmed by Roberts, bicyclists engaged in confrontational arguments with motorists and blocked roads to vehicular

title: Critical Mass Energy Project

text: Critical Mass Energy Project The Critical Mass Energy Project was formed by Ralph Nader in 1974 as a national anti-nuclear umbrella group. It was probably the largest national anti-nuclear group in the United States, with several hundred local affiliates and an estimated 200,000 supporters. Part of Nader's support comes from a Green agenda and the belief that "the most important office in America for anyone to achieve is full-time citizen." The organization's main efforts were directed at lobbying activities and providing local groups with scientific and other resources to campaign against nuclear power. The first national anti-nuclear conference, "Critical Mass

title: Melbourne Critical Mass

text: focus of which is the temporary intentional community of the rides themselves. The biggest rides of the year are always held each November to celebrate the birthday of the first ride in Melbourne. These rides are typically five to ten times larger than a normal Critical Mass in Melbourne. This is also a suitable time of year to encourage cycling as the warmer weather arrives. Rides occur at 6:00pm on the last Friday of every month, with people congregating on the steps of the State Library of Victoria from around 5pm: . Following its opening in 1999, Critical Mass rode

title: Critical mass (sociodynamics)

text: to majority consensus in political circles, where the most effective position is more often that held by the majority of people in society. In this sense, small changes in public consensus can bring about swift changes in political consensus, due to the majority-dependent effectiveness of certain ideas as tools of political debate. Critical mass is a concept used in a variety of contexts, including physics, group dynamics, politics, public opinion, and technology. The concept of critical mass was originally created by game theorist Thomas Schelling and sociologist Mark Granovetter to explain the actions and behaviors of a wide range of

title: Critical Mass (cycling)

text: move through the intersection. This term from the footage of the movie, was applied to the name of the ride, and the name caught on, replacing "Commute Clot" by the time of the second event. Critical Mass has a decentralized (rather than hierarchical) structure. Critical Mass is sometimes called an "organized coincidence", with no leadership or membership. The routes of some rides are decided spontaneously by whoever is currently at the front of the ride, while others are decided prior to the ride by a popular vote of suggested routes often drawn up on photocopied fliers. The term "xerocracy" was

title: Critical Mass (cycling)

text: The practice of corking roads in order to pass through red lights as a group is in contravention of traffic laws in some jurisdictions and is sometimes criticized to be contrary to Critical Mass' claim that "we are traffic", since ordinary traffic does not have the right to go through intersections once the traffic signal has changed to red. Joel Pomerantz, the writer, rider and co-founder of Critical Mass who popularized corking in San Francisco, explained in his 1992 instructional flyer that he sees the ride as a single vehicle for safety purposes, similar to a longer, articulated bus. He

title: Plutonium

text: most common form of radioactive decay for plutonium. A 5 kg mass of Pu contains about atoms. With a half-life of 24,100 years, about of its atoms decay each second by emitting a 5.157 MeV alpha particle. This amounts to 9.68 watts of power. Heat produced by the deceleration of these alpha particles makes it warm to the touch. Resistivity is a measure of how strongly a material opposes the flow of electric current. The resistivity of plutonium at room temperature is very high for a metal, and it gets even higher with lower temperatures, which is unusual for metals.

title: Critical Mass (cycling)

text: other bicycle movements, that range from political movements to the "Critical Tits" ride during the yearly Burning Man festival. In Chicago, a movement has grown out of the Critical Mass community to promote winter cycling via the bikewinter campaign. The extensive news coverage of San Francisco's July 1997 ride spawned an international celebration of bicycling, called Bike Summer. Kidical Mass originated in Oregon, and encourages bicycle riding for children and families. Critical Sass was an all-female version of the ride in Baton Rouge, Louisiana, that took place the second Friday of every month. The Tweed Run (along with various other

title: Critical Mass (cycling)

text: argued that it enhances both traffic flow overall and safety to keep the ride together as in a funeral procession, which he viewed Critical as, metaphorically, for the death of car culture and crash victims. Frustrated car drivers inhibited by the ride have sometimes reacted in hostile ways toward riders, even erupting into violence and arrests of motorists and cyclists alike during Critical Mass rides. Pomerantz's flyers have also proposed that drivers should only be as mad as they are at any traffic jam, most of which they accept as normal. The Critical Mass rides have inspired a number of

title: Critical Mass (cycling)

text: Mass, cyclists in Budapest, Hungary hold only two rides each year on April 22 (Earth Day) and September 22 (International Car Free Day). The "Budapest style" attracts tens of thousands of riders. The April 20, 2008, Budapest ride participation was estimated at 80,000 riders. In Vienna, close to Budapest, a Critical Mass Ride has been held every month since 2006 and attracts up to 1,000 or more riders. Because Critical Mass takes place without an official route or sanction, participants in some cities have sometimes practiced a tactic known as "corking" in order to maintain the cohesion of the group.

title: Critical Mass (book)

text: as a leap of faith and others as preposterous idealization: particles become people." Nearly as soon as he gives this definition, however, Ball falls back on the two biggest hurdles to this perspective: that of the theories of being alive and of free will, both of which seem to contradict the physics viewpoint. Critical Mass (book) Critical Mass: How One Thing Leads to Another is a non-fiction book by English chemist and physicist Philip Ball, originally published in 2004, discusses the concept of a “physics of society”. Ball examines past thinkers, such as Thomas Hobbes, Lewis Mumford, Emyr Hughes, and

title: Critical mass

text: criticality then depends upon a typical neutron "seeing" an amount of nuclei around it such that the areal density of nuclei exceeds a certain threshold. This is applied in implosion-type nuclear weapons where a spherical mass of fissile material that is substantially less than a critical mass is made supercritical by very rapidly increasing ρ (and thus Σ as well) (see below). Indeed, sophisticated nuclear weapons programs can make a functional device from less material than more primitive weapons programs require. Aside from the math, there is a simple physical analog that helps explain this result. Consider diesel fumes belched

title: Critical Mass (cycling)

text: Mass." An alternative ride named RideCivil formed in Seattle in late 2007. Rides are on the second Friday of every month, and focus on encouraging civility between motorists, pedestrians and cyclists. On June 12, 2009, an Indianapolis Critical Manners ride called "Courteous Mass" was launched but is no longer active as of 2016. On August 14, 2009 there was a Critical Manners ride in Vancouver, British Columbia. The ride consisted of between 70–100 cyclists riding through the downtown core, making all attempts to follow the rules of the road (stopping at red lights / stop signs, using hand signals to

title: Melbourne Critical Mass

text: to their report "Some riders wore silly hats, dressed as clowns and animals and decorated their bikes with stuffed toys and teddy bears." While State Opposition Leader Robert Doyle denounced the tunnel's closure as "political correctness gone mad", a Victoria Police spokeswoman was pleased the action was over quickly. Cyclists rode over the Bolte Bridge in February 2004 as part of their Critical Mass ride. One of the complaints of Critical Mass is that the Bolte Bridge makes no provision for cycle access, whilst more broadly it further entrenches car and oil dependency. According to a police spokeswoman about 300

title: History of nuclear weapons

text: Emilio Segrè that the plutonium-239 produced by the Hanford reactors had too high a level of background neutron radiation, and underwent spontaneous fission to a very small extent, due to the unexpected presence of plutonium-240 impurities. If such plutonium were used in a gun-type design, the chain reaction would start in the split second before the critical mass was fully assembled, blowing the weapon apart with a much lower yield than expected, in what is known as a fizzle. As a result, development of Fat Man was given high priority. Chemical explosives were used to implode a sub-critical sphere of

title: Critical mass

text: perfect homogeneous sphere. More closely refining the shape toward a perfect sphere will make the mass supercritical. Conversely changing the shape to a less perfect sphere will decrease its reactivity and make it subcritical. A mass may be exactly critical at a particular temperature. Fission and absorption cross-sections increase as the relative neutron velocity decreases. As fuel temperature increases, neutrons of a given energy appear faster and thus fission/absorption is less likely. This is not unrelated to Doppler broadening of the U resonances but is common to all fuels/absorbers/configurations. Neglecting the very important resonances, the total neutron cross-section of every

title: Critical Mass Energy Project

text: '74" was held in Washington D.C. under the sponsorship of Ralph Nader. Workshops were held and groups throughout the United States learned about forming anti-nuclear organizations. At about the same time, Karen Silkwood, a nuclear plant worker, was killed in a car accident while investigating her nuclear energy company. There was speculation that the accident may have been intended. The second Critical Mass conference was held in November 1975, and this involved a candlelight vigil in front of the White House for Karen Silkwood. Critical Mass Energy Project The Critical Mass Energy Project was formed by Ralph Nader in 1974

title: Critical Mass (Canadian band)

text: influences the direction of the contemporary Catholic music scene as a music columnist for the "Catholic Register", a position he has held since 1995. Critical Mass has had a part to play in a recent return by the youth to more traditional Catholicism When asked if they would ever consider signing with a major record label they stated that they "are an independent band and very proud of it". Critical Mass has been featured in two 1 hour music specials on Salt + Light Television and has been featured on the CBC and Vision TV, among others. Critical Mass (Canadian

title: Conflicts involving Critical Mass

text: Plac Konstytucji (Constitution Square), who demanded their dispersal and detained some of the participants. Other Critical Mass participants responded with a sit-in protest, blocking an important traffic junction, and then tried to evade the blockade by taking different routes to Plac Zamkowy (Castle Square), the Critical Mass rally point. This event was widely reported by the media and, as a result, the Warsaw municipality decided to legalize future events, rather than escalate the conflict. Beginning in September 2002, Critical Mass events in Warsaw are organized in full cooperation with the police force. Once a year in August, beginning in 2007,

title: Critical Mass (Dutch band)

text: Critical Mass scored a hit. That same year Critical Mass were given a face by female singer Ludmilla Odijk and rapper MC Energie. In 1996 the band had a few hits with singles like "Burnin' Love", "Believe In The Future" and "Happy Generation". Later that year ID&T announced that Critical Mass would be combined with 2 Unlimited. In 1997, when happy hardcore became less popular in the Netherlands, the single "Together In Dreams" was produced. This single was a lot less successful then expected. Bout and Van Hasselaar decided to change their career by trying different styles of music. In

title: Duke Nukem: Critical Mass

text: video that contains screenshots from both the DS and PSP versions, as well as a video with gameplay from both versions, were released in March 2009. A PlayStation Portable version entitled "Duke Nukem Trilogy: Critical Mass" was developed but was cancelled. The DS and PSP versions were going to be unique games unified by the same basic story. The games announced to be included in the trilogy are "Duke Nukem: Critical Mass", "Duke Nukem: Chain Reaction", and "Duke Nukem: Proving Grounds". The company announced that the first game in the trilogy "Duke Nukem: Critical Mass" was released for the DS

title: Critical Mass (Dave Holland album)

text: a stellar double-live CD by his quintet. And all the while, the least grateful among us have been hankering for some new music from Holland’s quintet. Well, here it is, and it holds its own against Prime Directive, the group’s most impressive release... The groupthink mentality manifests itself most obviously on the New Orleans tribute “Easy Did It,” for which Holland and Smith create a slithering, swelling rhythm that culminates in a five-way roundtable of near-chaos. Critical Mass will be on everyone’s list of 2006’s best." Critical Mass (Dave Holland album) Critical Mass is a 2006 album release by the

title: Critical mass

text: takes into account geometrical and other effects, criticality corresponds to formula_4 which clearly recovers the aforementioned result that critical mass depends inversely on the square of the density. Alternatively, one may restate this more succinctly in terms of the areal density of mass, Σ: formula_5 where the factor "f" has been rewritten as "f"' to account for the fact that the two values may differ depending upon geometrical effects and how one defines Σ. For example, for a bare solid sphere of Pu criticality is at 320 kg/m, regardless of density, and for U at 550 kg/m. In any case,

title: Critical mass

text: said to have a negative temperature coefficient of reactivity to indicate that its reactivity decreases when its temperature increases. Using such a material as fuel means fission decreases as the fuel temperature increases. Surrounding a spherical critical mass with a neutron reflector further reduces the mass needed for criticality. A common material for a neutron reflector is beryllium metal. This reduces the number of neutrons which escape the fissile material, resulting in increased reactivity. In a bomb, a dense shell of material surrounding the fissile core will contain, via inertia, the expanding fissioning material. This increases the efficiency. A tamper

title: Critical Mass (1985 video game)

text: heavily defended power station and disable it before the reactor reaches critical mass and implodes. The player may control the hovercraft in either a normal joystick operational mode or with vectored movement. When the player pushes forward on the joystick, the hovercraft accelerates, and when pulling back on the joystick, speed decreases. In 1988, "Dragon" reviewed "Power!", and gave the game 4 out of 5 stars. Critical Mass (1985 video game) Critical Mass (known as Power! in North America) is a computer game developed by Simon Francis in 1985 for the Amstrad CPC, Commodore 64 and ZX Spectrum. An anti-matter

title: Melbourne Critical Mass

text: means of transportation needed to gain greater prominence. "It (the ride) has raised the profile of the issue of the under-provision of infrastructure for bicycles and the failings of CityLink." he said. Critical Mass continued to gather each month between 2005 and 2014, with a focus on safer cycling and becoming a party on wheels/example of the freedom and enjoyment of cycling. Large infrastructure and major arteries were avoided in the interests of public safety and promoting cycling (and the event) as inclusive and enjoyable for everyone. After numbers of attendees dropped off during 2015, Critical Mass Melbourne was reduced

title: Critical mass (sociodynamics)

text: "Bandwagon and underdog effects and the possibility of election predictions", published in 1954 in Public Opinion Quarterly, has been cited as a predecessor to the concept we now know as critical mass. Critical mass and the theories behind it help us to understand aspects of humans as they act and interact in a larger social setting. Certain theories, such as Mancur Olson's Logic of Collective Action or Garrett Hardin's Tragedy of the Commons, work to help us understand why humans do or adopt certain things which are beneficial to them, or, more importantly, why they do not. Much of this

title: Critical mass (sociodynamics)

text: less than 15% of the membership, may actually be encouraged to develop legislative agendas that are distinct from those of their male colleagues. Others argue that we should look more closely at parliamentary and electoral systems instead of critical mass. While critical mass can be applied to many different aspects of sociodynamics, it becomes increasingly applicable to innovations in interactive media such as the telephone, fax, or email. With other non-interactive innovations, the dependence on other users was generally sequential, meaning that the early adopters influenced the later adopters to use the innovation. However, with interactive media, the interdependence was

title: Critical Mass (cycling)

text: cyclists reclaiming the streets." Participants have insisted that these events should be viewed as "celebrations" and spontaneous gatherings, and not as protests or organized demonstrations. This stance allows Critical Mass to argue a legal position that its events can occur without advance notification of local police. Critical Mass-like bike tours with hundreds of participants took place in Stockholm, Sweden in the early 1970s. But the first ride within the present wave took place on Friday, September 25, 1992, at 6 pm in San Francisco. At that time, the event was known as "Commute Clot" and was composed of a couple

title: History of nuclear weapons

text: on Earth, but is fissile like uranium-235. After Fermi achieved the world's first sustained and controlled nuclear chain reaction with the creation of the first atomic pile, massive reactors were secretly constructed at what is now known as Hanford Site to transform uranium-238 into plutonium for a bomb. The simplest form of nuclear weapon is a gun-type fission weapon, where a sub-critical mass would be shot at another sub-critical mass. The result would be a super-critical mass and an uncontrolled chain reaction that would create the desired explosion. The weapons envisaged in 1942 were the two gun-type weapons, Little Boy

title: Duke Nukem: Critical Mass

text: game was released to negative reviews. The game received "unfavorable" reviews according to the review aggregation website Metacritic, an overall score of 29. Duke Nukem: Critical Mass Duke Nukem: Critical Mass is a shooter game developed by Frontline Studios and published by Deep Silver for the Nintendo DS. A version for the PlayStation Portable began development, however was never released. The Earth Defense Forces attempts to ensure the Earth's continued security by monitoring the future with the help of their own time machine, but both their agent and a special team sent there have been confirmed MIA. Knowing something is

title: Plutonium-244

text: heaviest primordial isotope yet detected or theoretically predicted. However, the detection of primordial Pu in 1971 is not confirmed by recent, more sensitive measurements using the method of accelerator mass spectrometry. In this study, no traces of plutonium-244 in the samples of bastnasite (taken from the same mine as in the early study) were observed, so only an upper limit on the Pu content was obtained: < 0.15×10 g/g, which is 370 (or less) atoms per gram of the sample, at least 7 times lower than the abundance measured by Hoffman "et al." Live interstellar plutonium-244 has been detected in

title: Conflicts involving Critical Mass

text: 11 of the Public Order Act 1986. The ruling was reversed on appeal. In 2008, Friends of the Earth, who supported the legal action, said the case would be appealed to England's highest legal authority, the House of Lords, on the grounds that, after 11 years, Critical Mass is "commonly or customarily held." In October 2008, the House of Lords ruled in favour of the Critical Mass participant. During the 2012 Summer Olympics, cyclists were arrested on opening day after police claim they ignored regulations in place during the Olympics. Jenny Jones of the Green Party and the Greater London

title: Critical Mass (Canadian band)

text: as some remakes of songs from the album "Completely". This album was nominated for 6 United Catholic Music and Video Association Awards. In 2009, Critical Mass released "Body Language", an album based on Pope John Paul II's Theology of the Body. This is one of the first Christian rock albums to ever deal so explicitly with the topics of sex, love and communion, in a Catholic Christian context. Critical Mass marked 2012 with the release of "15 (1997-2012)", a compilation album with three new songs along with 12 other songs from their catalog. In addition to performing, founder David Wang

title: Conflicts involving Critical Mass

text: $3,000 worth of damage was done to the bicycles. Berkeley police did not make any arrests in the incident. On May 30, 2003, in Buffalo, New York, during an incident known locally as "Critical Massacre," police stopped two cyclists for "failure to yield to an emergency vehicle." Several people were allegedly attacked by police. Nine cyclists were arrested and three were later convicted, including a journalist. Chicago Police Department officers are often seen riding with Critical Mass participants, and squad cars block intersections to provide safe passage to Critical Mass cyclists. However, on August 31, 2007, seven riders were arrested

title: Conflicts involving Critical Mass

text: a gross misdemeanor. On May 27, 2011, in Minsk, Belarus, police forces aided by special units transported 13 cyclists to the police station for violation of traffic rules and for not following orders to disband. Detained participants were fingerprinted and fined, then released. On April 30, 2016 two cyclists were arrested during a Critical Mass action. As of September 2016, one was released and the other is facing trial. Police in New York City have claimed that Critical Mass bicyclists blocking intersections to allow bikes to pass may delay emergency vehicles in the gridlock. During the US 2004 Republican National

title: Plutonium Playhouse

text: popular movie starring Academy Award winners Olympia Dukakis and Brenda Fricker and Ryan Doucette, and won over thirty film festival best picture awards. The company is also known for its popular program The Sex Festival, which presents plays, readings and events on the subjects of sex and sexuality. Plutonium Playhouse Society was involved in producing or presenting the following productions: PRODUCTIONS PUBLIC READINGS Critical response to the works of Plutonium Playhouse Society has been generally positive. Ron Foley MacDonald called the original production of Cloudburst "a knockout" and the company "the most exciting thing to happen on the Halifax Theatre

title: Reactor-grade plutonium

text: to Alexander DeVolpi, the isotopic composition of the plutonium used in the US-UK 1962 test could not have been what we now consider to be reactor-grade, and the DOE now implies, but doesn't assert, that the plutonium was fuel grade. Likewise, the World Nuclear Association suggests that the US-UK 1962 test had at least 85% plutonium-239, a much higher isotopic concentration than what is typically present in the spent fuel from the majority of operating civilian reactors. In 2002 former Deputy Director General of the IAEA, Bruno Pelaud, stated that the DoE statement was misleading and that the test would

title: Critical mass (sociodynamics)

text: reasoning has to do with individual interests trumping that which is best for the collective whole, which may not be obvious at the time. Oliver, Marwell, and Teixeira tackle this subject in relation to critical theory in a 1985 article published in the American Journal of Sociology. In their essay, they define that action in service of a public good as "collective action". "Collective Action" is beneficial to all, regardless of individual contribution. By their definition, then, "critical mass" is the small segment of a societal system that does the work or action required to achieve the common good. The

title: Isotopes of plutonium

text: a source of energy. The other fissile materials are uranium-235 and uranium-233. Plutonium-239 is virtually nonexistent in nature. It is made by bombarding uranium-238 with neutrons in a nuclear reactor. Uranium-238 is present in quantity in most reactor fuel; hence plutonium-239 is continuously made in these reactors. Since plutonium-239 can itself be split by neutrons to release energy, plutonium-239 provides a portion of the energy generation in a nuclear reactor. There are small amounts of Pu-238 in the plutonium of usual plutonium-producing reactors. However, isotopic separation would be quite expensive compared to another method: when a U-235 atom captures a

title: Critical Mass (cycling)

text: coined to describe a process by which the route for a Critical Mass can be decided: anyone who has an opinion makes their own map and distributes it to the cyclists participating in the Mass. Still other rides decide the route by consensus. The disorganized nature of the event allows it to largely escape clampdown by authorities who may view the rides as forms of parades or organized protest. Additionally, the movement is free from the structural costs associated with a centralized, hierarchical organization. In order for the event to function, the only requirement is a sufficient turn-out to create

title: Plutonium

text: gram), raising the background neutron levels and thus increasing the risk of predetonation. Plutonium is identified as either weapons-grade, fuel-grade, or reactor-grade based on the percentage of plutonium-240 that it contains. Weapons-grade plutonium contains less than 7% plutonium-240. Fuel-grade plutonium contains from 7% to less than 19%, and power reactor-grade contains 19% or more plutonium-240. Supergrade plutonium, with less than 4% of plutonium-240, is used in U.S. Navy weapons stored in proximity to ship and submarine crews, due to its lower radioactivity. The isotope plutonium-238 is not fissile but can undergo nuclear fission easily with fast neutrons as well as

title: Critical mass (sociodynamics)

text: certain people stand to gain more, they are willing to give or pay more. Critical mass theory in gender politics and collective political action is defined as the critical number of personnel needed to affect policy and make a change not as the token but as an influential body. This number has been placed at 30%, before women are able to make a substantial difference in politics. However, other research suggests lower numbers of women working together in legislature can also affect political change. Kathleen Bratton goes so far as to say that women, in legislatures where they make up

title: Critical Mass (Matthew Shipp album)

text: album "This is the most accomplished recording of Shipp's career, a breathtaking summary of his complex sense of musical form and lava-like flow of unstoppable imagination." Critical Mass (Matthew Shipp album) Critical Mass is an album by American jazz pianist Matthew Shipp which was recorded in 1994 and released on 2.13, a division of the 2.13.61 label, founded by Henry Rollins. Shipp adds violinist Mat Maneri to his usual trio lineup with bassist William Parker and drummer Whit Dickey. Shipp met Maneri when the violinist was just 17 in Boston, this is their first collaboration on record. "The Penguin Guide

title: Critical Mass (1985 video game)

text: Critical Mass (1985 video game) Critical Mass (known as Power! in North America) is a computer game developed by Simon Francis in 1985 for the Amstrad CPC, Commodore 64 and ZX Spectrum. An anti-matter power station on an orbiting asteroid is used by the local star system for energy. The station has been taken over by hostile aliens who are threatening to overload the power system which will turn the reactor into a massive black hole and destroy not only the planetary system, but several nearby stars as well. The object of the game is to make it to the

title: Critical Mass (Dave Holland album)

text: Critical Mass (Dave Holland album) Critical Mass is a 2006 album release by the Dave Holland Quintet, and the first to feature drummer Nate Smith. This is the first Dave Holland Quintet album to be released outside the ECM label, through which he had released all of his albums since his 1972 debut as leader, "Conference of the Birds". Steve Greenlee of "JazzTimes" stated "It’s been five years since Dave Holland’s quintet released an album of new material. The bassist hasn’t exactly been relaxing in the meantime; he put out two albums of big-band music and toured extensively, and released

title: Conflicts involving Critical Mass

text: police took five participants into custody, including two minors, for not following orders to disband. In Walnut Creek, California, on June 20, 2008, a car bumped into the rear wheel of a Critical Mass rider. An argument ensued among the driver and passenger of the car and the cyclist involved, after which the passenger and driver of the car assaulted the cyclist. The police arrived and arrested the passenger and driver of the automobile involved in the assault. On June 21, 2002, in Warsaw, Poland, the Critical Mass event was stopped by a cordon of fully armed riot police on

title: Critical Mass (Canadian band)

text: cover of the Kansas classic, "Carry On Wayward Son" also was nominated for "Best Rock Song". Over the past two years Critical Mass has extended its reach into the United States with touring and retreats. In October 2006, the band again received "International Group of the Year" honours from the "United Catholic Music and Video Association". About the same time the band was joined by new member Dave Flitton, who substitutes in at keyboard and guitar whenever necessary. In 2007, Critical Mass released a live praise and worship effort called "Celebrate", which includes covers of popular worship songs as well

title: Conflicts involving Critical Mass

text: fell and hit her head on the ground, sustaining injuries requiring hospitalization. While no arrests were made, the police did issue citations and confiscate bicycles. Due to the gradual increase of cyclists participating in Critical Mass, as well as complaints from motorists and concerns for safety, Houston Police Department officers helped direct the October 2013 Critical Mass ride in Houston, Texas by controlling intersections on the bike route. In January 2014, after two months of providing free security and safe passage through heavy intersections, the Houston Police Department began considering options to charge the group for providing security for the

title: Duke Nukem: Critical Mass

text: in Europe on April 8, 2011. On October 29, 2010, developer Frontline Studios released news that "Critical Mass" for both platforms would no longer carry the Duke Nukem license and be renamed "Extraction Point: Alien Shootout". However, on March 23, 2011, Apogee Software announced that they never lost the license and would release "Duke Nukem: Critical Mass" for the Nintendo DS on April 8, 2011 in Europe, June 6, 2011 in North America and July 7, 2011 in Australia. The source code of the unreleased PSP game was discovered in 2014 to be preserved at the Library of Congress. The