QCD matter

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/QCD_matter 

Quark matter or QCD matter (quantum chromodynamic) refers to any of a number of phases of matter whose degrees of freedom include quarks and gluons, of which the prominent example is quark-gluon plasma. Several series of conferences in 2019, 2020, and 2021 are devoted to this topic.

Quarks are liberated into quark matter at extremely high temperatures and/or densities, and some of them are still only theoretical as they require conditions so extreme that they can not be produced in any laboratory, especially not at equilibrium conditions. Under these extreme conditions, the familiar structure of matter, where the basic constituents are nuclei (consisting of nucleons which are bound states of quarks) and electrons, is disrupted. In quark matter it is more appropriate to treat the quarks themselves as the basic degrees of freedom.

In the standard model of particle physics, the strong force is described by the theory of QCD. At ordinary temperatures or densities this force just confines the quarks into composite particles (hadrons) of size around 10⁻¹⁵ m = 1 femtometer = 1 fm (corresponding to the QCD energy scale Λ_QCD ≈ 200 MeV) and its effects are not noticeable at longer distances.

However, when the temperature reaches the QCD energy scale (T of order 10¹² kelvins) or the density rises to the point where the average inter-quark separation is less than 1 fm (quark chemical potential μ around 400 MeV), the hadrons are melted into their constituent quarks, and the strong interaction becomes the dominant feature of the physics. Such phases are called quark matter or QCD matter.

The strength of the color force makes the properties of quark matter unlike gas or plasma, instead leading to a state of matter more reminiscent of a liquid. At high densities, quark matter is a Fermi liquid, but is predicted to exhibit color superconductivity at high densities and temperatures below 10¹² K.

Occurrence

Natural occurrence

• According to the Big Bang theory, in the early universe at high temperatures when the universe was only a few tens of microseconds old, the phase of matter took the form of a hot phase of quark matter called the quark–gluon plasma (QGP).
• Compact stars (neutron stars). A neutron star is much cooler than 10¹² K, but gravitational collapse has compressed it to such high densities, that it is reasonable to surmise that quark matter may exist in the core. Compact stars composed mostly or entirely of quark matter are called quark stars or strange stars.

At this time no star with properties expected of these objects has been observed, although some evidence has been provided for quark matter in the cores of large neutron stars.

• Strangelets. These are theoretically postulated (but as yet unobserved) lumps of strange matter comprising nearly equal amounts of up, down and strange quarks. Strangelets are supposed to be present in the galactic flux of high energy particles and should therefore theoretically be detectable in cosmic rays here on Earth, but no strangelet has been detected with certainty.
  
• Cosmic ray impacts. Cosmic rays comprise a lot of different particles, including highly accelerated atomic nuclei, particularly that of iron.

Laboratory experiments suggests that the inevitable interaction with heavy noble gas nuclei in the upper atmosphere would lead to quark–gluon plasma formation.

• Quark matter with baryon number over about 300 may be more stable than nuclear matter. This form of baryonic matter could possibly form a continent of stability.

Laboratory experiments

Particle debris trajectories from one of the first lead-ion collisions with the LHC, as recorded by the ALICE detector. The extremely brief appearance of quark matter in the point of collision is inferred from the statistics of the trajectories.

Even though quark-gluon plasma can only occur under quite extreme conditions of temperature and/or pressure, it is being actively studied at particle colliders, such as the Large Hadron Collider LHC at CERN and the Relativistic Heavy Ion Collider RHIC at Brookhaven National Laboratory.

In these collisions, the plasma only occurs for a very short time before it spontaneously disintegrates. The plasma's physical characteristics are studied by detecting the debris emanating from the collision region with large particle detectors. 

Heavy-ion collisions at very high energies can produce small short-lived regions of space whose energy density is comparable to that of the 20-micro-second-old universe. This has been achieved by colliding heavy nuclei such as lead nuclei at high speeds, and a first time claim of formation of quark–gluon plasma came from the SPS accelerator at CERN in February 2000.

This work has been continued at more powerful accelerators, such as RHIC in the US, and as of 2010 at the European LHC at CERN located in the border area of Switzerland and France. There is good evidence that the quark–gluon plasma has also been produced at RHIC.

Thermodynamics

The context for understanding the thermodynamics of quark matter is the standard model of particle physics, which contains six different flavors of quarks, as well as leptons like electrons and neutrinos. These interact via the strong interaction, electromagnetism, and also the weak interaction which allows one flavor of quark to turn into another. Electromagnetic interactions occur between particles that carry electrical charge; strong interactions occur between particles that carry color charge.

The correct thermodynamic treatment of quark matter depends on the physical context. For large quantities that exist for long periods of time (the "thermodynamic limit"), we must take into account the fact that the only conserved charges in the standard model are quark number (equivalent to baryon number), electric charge, the eight color charges, and lepton number. Each of these can have an associated chemical potential. However, large volumes of matter must be electrically and color-neutral, which determines the electric and color charge chemical potentials. This leaves a three-dimensional phase space, parameterized by quark chemical potential, lepton chemical potential, and temperature.

In compact stars quark matter would occupy cubic kilometers and exist for millions of years, so the thermodynamic limit is appropriate. However, the neutrinos escape, violating lepton number, so the phase space for quark matter in compact stars only has two dimensions, temperature (T) and quark number chemical potential μ. A strangelet is not in the thermodynamic limit of large volume, so it is like an exotic nucleus: it may carry electric charge.

A heavy-ion collision is in neither the thermodynamic limit of large volumes nor long times. Putting aside questions of whether it is sufficiently equilibrated for thermodynamics to be applicable, there is certainly not enough time for weak interactions to occur, so flavor is conserved, and there are independent chemical potentials for all six quark flavors. The initial conditions (the impact parameter of the collision, the number of up and down quarks in the colliding nuclei, and the fact that they contain no quarks of other flavors) determine the chemical potentials.

Phase diagram

Conjectured form of the phase diagram of QCD matter, with temperature on the vertical axis and quark chemical potential on the horizontal axis, both in mega-electron volts.

The phase diagram of quark matter is not well known, either experimentally or theoretically. A commonly conjectured form of the phase diagram is shown in the figure to the right.^[15] It is applicable to matter in a compact star, where the only relevant thermodynamic potentials are quark chemical potential μ and temperature T.

For guidance it also shows the typical values of μ and T in heavy-ion collisions and in the early universe. For readers who are not familiar with the concept of a chemical potential, it is helpful to think of μ as a measure of the imbalance between quarks and antiquarks in the system. Higher μ means a stronger bias favoring quarks over antiquarks. At low temperatures there are no antiquarks, and then higher μ generally means a higher density of quarks.

Ordinary atomic matter as we know it is really a mixed phase, droplets of nuclear matter (nuclei) surrounded by vacuum, which exists at the low-temperature phase boundary between vacuum and nuclear matter, at μ = 310 MeV and T close to zero. If we increase the quark density (i.e. increase μ) keeping the temperature low, we move into a phase of more and more compressed nuclear matter. Following this path corresponds to burrowing more and more deeply into a neutron star.

Eventually, at an unknown critical value of μ, there is a transition to quark matter. At ultra-high densities we expect to find the color-flavor-locked (CFL) phase of color-superconducting quark matter. At intermediate densities we expect some other phases (labelled "non-CFL quark liquid" in the figure) whose nature is presently unknown. They might be other forms of color-superconducting quark matter, or something different.

Now, imagine starting at the bottom left corner of the phase diagram, in the vacuum where μ = T = 0. If we heat up the system without introducing any preference for quarks over antiquarks, this corresponds to moving vertically upwards along the T axis. At first, quarks are still confined and we create a gas of hadrons (pions, mostly). Then around T = 150 MeV there is a crossover to the quark gluon plasma: thermal fluctuations break up the pions, and we find a gas of quarks, antiquarks, and gluons, as well as lighter particles such as photons, electrons, positrons, etc. Following this path corresponds to travelling far back in time (so to say), to the state of the universe shortly after the big bang (where there was a very tiny preference for quarks over antiquarks).

The line that rises up from the nuclear/quark matter transition and then bends back towards the T axis, with its end marked by a star, is the conjectured boundary between confined and unconfined phases. Until recently it was also believed to be a boundary between phases where chiral symmetry is broken (low temperature and density) and phases where it is unbroken (high temperature and density). It is now known that the CFL phase exhibits chiral symmetry breaking, and other quark matter phases may also break chiral symmetry, so it is not clear whether this is really a chiral transition line. The line ends at the "chiral critical point", marked by a star in this figure, which is a special temperature and density at which striking physical phenomena, analogous to critical opalescence, are expected.

For a complete description of phase diagram it is required that one must have complete understanding of dense, strongly interacting hadronic matter and strongly interacting quark matter from some underlying theory e.g. quantum chromodynamics (QCD). However, because such a description requires the proper understanding of QCD in its non-perturbative regime, which is still far from being completely understood, any theoretical advance remains very challenging.

Theoretical challenges: calculation techniques

The phase structure of quark matter remains mostly conjectural because it is difficult to perform calculations predicting the properties of quark matter. The reason is that QCD, the theory describing the dominant interaction between quarks, is strongly coupled at the densities and temperatures of greatest physical interest, and hence it is very hard to obtain any predictions from it. Here are brief descriptions of some of the standard approaches.

Lattice gauge theory

The only first-principles calculational tool currently available is lattice QCD, i.e. brute-force computer calculations. Because of a technical obstacle known as the fermion sign problem, this method can only be used at low density and high temperature (μ < T), and it predicts that the crossover to the quark–gluon plasma will occur around T = 150 MeV  However, it cannot be used to investigate the interesting color-superconducting phase structure at high density and low temperature.

Weak coupling theory

Because QCD is asymptotically free it becomes weakly coupled at unrealistically high densities, and diagrammatic methods can be used. Such methods show that the CFL phase occurs at very high density. At high temperatures, however, diagrammatic methods are still not under full control.

Models

To obtain a rough idea of what phases might occur, one can use a model that has some of the same properties as QCD, but is easier to manipulate. Many physicists use Nambu-Jona-Lasinio models, which contain no gluons, and replace the strong interaction with a four-fermion interaction. Mean-field methods are commonly used to analyse the phases. Another approach is the bag model, in which the effects of confinement are simulated by an additive energy density that penalizes unconfined quark matter.

Effective theories

Many physicists simply give up on a microscopic approach, and make informed guesses of the expected phases (perhaps based on NJL model results). For each phase, they then write down an effective theory for the low-energy excitations, in terms of a small number of parameters, and use it to make predictions that could allow those parameters to be fixed by experimental observations.^[17]

Other approaches

Main article: AdS/QCD

There are other methods that are sometimes used to shed light on QCD, but for various reasons have not yet yielded useful results in studying quark matter.

1/N expansion

Treat the number of colors N, which is actually 3, as a large number, and expand in powers of 1/N. It turns out that at high density the higher-order corrections are large, and the expansion gives misleading results.

Supersymmetry

Adding scalar quarks (squarks) and fermionic gluons (gluinos) to the theory makes it more tractable, but the thermodynamics of quark matter depends crucially on the fact that only fermions can carry quark number, and on the number of degrees of freedom in general.

Experimental challenges

Experimentally, it is hard to map the phase diagram of quark matter because it has been rather difficult to learn how to tune to high enough temperatures and density in the laboratory experiment using collisions of relativistic heavy ions as experimental tools. However, these collisions ultimately will provide information about the crossover from hadronic matter to QGP. It has been suggested that the observations of compact stars may also constrain the information about the high-density low-temperature region. Models of the cooling, spin-down, and precession of these stars offer information about the relevant properties of their interior. As observations become more precise, physicists hope to learn more.

One of the natural subjects for future research is the search for the exact location of the chiral critical point. Some ambitious lattice QCD calculations may have found evidence for it, and future calculations will clarify the situation. Heavy-ion collisions might be able to measure its position experimentally, but this will require scanning across a range of values of μ and T.

Evidence

In 2020, evidence was provided that the cores of neutron stars with mass ~2M_⊙ were likely composed of quark matter. Their result was based on neutron-star tidal deformability during a neutron star merger as measured by gravitational-wave observatories, leading to an estimate of star radius, combined with calculations of the equation of state relating the pressure and energy density of the star's core. The evidence was strongly suggestive but did not conclusively prove the existence of quark matter.

Stellar black hole

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Stellar_black_hole 

 

A stellar black hole (or stellar-mass black hole) is a black hole formed by the gravitational collapse of a star. They have masses ranging from about 5 to several tens of solar masses. The process is observed as a hypernova explosion or as a gamma ray burst. These black holes are also referred to as collapsars.

Properties

By the no-hair theorem, a black hole can only have three fundamental properties: mass, electric charge and angular momentum (spin). It is believed that black holes formed in nature all have some spin. The spin of a stellar black hole is due to the conservation of angular momentum of the star or objects that produced it.

The gravitational collapse of a star is a natural process that can produce a black hole. It is inevitable at the end of the life of a large star, when all stellar energy sources are exhausted. If the mass of the collapsing part of the star is below the Tolman–Oppenheimer–Volkoff (TOV) limit for neutron-degenerate matter, the end product is a compact star — either a white dwarf (for masses below the Chandrasekhar limit) or a neutron star or a (hypothetical) quark star. If the collapsing star has a mass exceeding the TOV limit, the crush will continue until zero volume is achieved and a black hole is formed around that point in space.

The maximum mass that a neutron star can possess (without becoming a black hole) is not fully understood. In 1939, it was estimated at 0.7 solar masses, called the TOV limit. In 1996, a different estimate put this upper mass in a range from 1.5 to 3 solar masses.

In the theory of general relativity, a black hole could exist of any mass. The lower the mass, the higher the density of matter has to be in order to form a black hole. (See, for example, the discussion in Schwarzschild radius, the radius of a black hole.) There are no known processes that can produce black holes with mass less than a few times the mass of the Sun. If black holes that small exist, they are most likely primordial black holes. Until 2016, the largest known stellar black hole was 15.65±1.45 solar masses. In September 2015, a rotating black hole of 62±4 solar masses was discovered by gravitational waves as it formed in a merger event of two smaller black holes. As of June 2020, the binary system 2MASS J05215658+4359220 was reported to host the smallest-mass black hole currently known to science, with a mass 3.3 solar masses and a diameter of only 19.5 kilometers. 

There is observational evidence for two other types of black holes, which are much more massive than stellar black holes. They are intermediate-mass black holes (in the centre of globular clusters) and supermassive black holes in the centre of the Milky Way and other galaxies.

X-ray compact binary systems

Stellar black holes in close binary systems are observable when matter is transferred from a companion star to the black hole; the energy release in the fall toward the compact star is so large that the matter heats up to temperatures of several hundred million degrees and radiates in X-rays. The black hole therefore is observable in X-rays, whereas the companion star can be observed with optical telescopes. The energy release for black holes and neutron stars are of the same order of magnitude. Black holes and neutron stars are therefore often difficult to distinguish.

However, neutron stars may have additional properties. They show differential rotation, and can have a magnetic field and exhibit localized explosions (thermonuclear bursts). Whenever such properties are observed, the compact object in the binary system is revealed as a neutron star. 

The derived masses come from observations of compact X-ray sources (combining X-ray and optical data). All identified neutron stars have a mass below 3.0 solar masses; none of the compact systems with a mass above 3.0 solar masses display the properties of a neutron star. The combination of these facts make it more and more likely that the class of compact stars with a mass above 3.0 solar masses are in fact black holes. 

Note that this proof of existence of stellar black holes is not entirely observational but relies on theory: we can think of no other object for these massive compact systems in stellar binaries besides a black hole. A direct proof of the existence of a black hole would be if one actually observes the orbit of a particle (or a cloud of gas) that falls into the black hole.

Black hole kicks

The large distances above the galactic plane achieved by some binaries are the result of black hole natal kicks. The velocity distribution of black hole natal kicks seems similar to that of neutron star kick velocities. One might have expected that it would be the momenta that were the same with black holes receiving lower velocity than neutron stars due to their higher mass but that doesn't seem to be the case, which may be due to the fall-back of asymmetrically expelled matter increasing the momentum of the resulting black hole.

Mass gaps

It is predicted by some models of stellar evolution that black holes with masses in two ranges cannot be directly formed by the gravitational collapse of a star. These are sometimes distinguished as the "lower" and "upper" mass gaps, roughly representing the ranges of 2 to 5 and 50 to 150 solar masses (M_☉), respectively. Another range given for the upper gap is 52 to 133 M_☉. 150 M_☉ has been regarded as the upper mass limit for stars in the current era of the universe.

Lower mass gap

A lower mass gap is suspected on the basis of a scarcity of observed candidates with masses within a few solar masses above the maximum possible neutron star mass. The existence and theoretical basis for this possible gap are uncertain. The situation may be complicated by the fact that any black holes found in this mass range may have been created via the merging of binary neutron star systems, rather than stellar collapse. The LIGO/Virgo collaboration has reported three candidate events among their gravitational wave observations in run O3 with component masses that fall in this lower mass gap. There has also been reported an observation of a bright, rapidly rotating giant star in a binary system with an unseen companion emitting no light, including x-rays, but having a mass of 3.3+2.8
−0.7 solar masses. This is interpreted to suggest that there may be many such low-mass black holes that are not currently consuming any material and are hence undetectable via the usual x-ray signature.

Upper mass gap

The upper mass gap is predicted by comprehensive models of late-stage stellar evolution. It is expected that with increasing mass, supermassive stars reach a stage where a pair-instability supernova occurs, during which pair production, the production of free electrons and positrons in the collision between atomic nuclei and energetic gamma rays, temporarily reduces the internal pressure supporting the star's core against gravitational collapse. This pressure drop leads to a partial collapse, which in turn causes greatly accelerated burning in a runaway thermonuclear explosion, resulting in the star being blown completely apart without leaving a stellar remnant behind.

Pair-instability supernovae can only happen in stars with a mass range from around 130 to 250 solar masses (M_☉) (and low to moderate metallicity (low abundance of elements other than hydrogen and helium – a situation common in Population III stars). However, this mass gap is expected to be extended down to about 45 solar masses by the process of pair-instability pulsational mass loss, before the occurrence of a "normal" supernova explosion and core collapse. In nonrotating stars the lower bound of the upper mass gap may be as high as 60 M_☉. The possibility of direct collapse into black holes of stars with core mass > 133 M_☉, requiring total stellar mass of > 260 M_☉ has been considered, but there may be little chance of observing such a high-mass supernova remnant; i.e., the lower bound of the upper mass gap may represent a mass cutoff.

Observations of the LB-1 system of a star and unseen companion were initially interpreted in terms of a black hole with a mass of about 70 solar masses, which would be excluded by the upper mass gap. However, further investigations have weakened this claim.

Candidates

Our Milky Way galaxy contains several stellar-mass black hole candidates (BHCs) which are closer to us than the supermassive black hole in the galactic center region. Most of these candidates are members of X-ray binary systems in which the compact object draws matter from its partner via an accretion disk. The probable black holes in these pairs range from three to more than a dozen solar masses.

Name	BHC mass (solar masses)	Companion mass (solar masses )	Orbital period (days)	Distance from Earth (light years)	Location
A0620-00/V616 Mon	11 ± 2	2.6–2.8	0.33	3,500	06:22:44 -00:20:45
GRO J1655-40/V1033 Sco	6.3 ± 0.3	2.6–2.8	2.8	5,000–11,000	16:54:00 -39:50:45
XTE J1118+480/KV UMa	6.8 ± 0.4	6−6.5	0.17	6,200	11:18:11 +48:02:13
Cyg X-1	11 ± 2	≥18	5.6	6,000–8,000	19:58:22 +35:12:06
GRO J0422+32/V518 Per	4 ± 1	1.1	0.21	8,500	04:21:43 +32:54:27
GRO J1719-24	≥4.9	~1.6	possibly 0.6	8,500	17:19:37 -25:01:03
GS 2000+25/QZ Vul	7.5 ± 0.3	4.9–5.1	0.35	8,800	20:02:50 +25:14:11
V404 Cyg	12 ± 2	6.0	6.5	7,800 ± 460	20:24:04 +33:52:03
GX 339-4/V821 Ara	5.8	5–6	1.75	15,000	17:02:50 -48:47:23
GRS 1124-683/GU Mus	7.0 ± 0.6		0.43	17,000	11:26:27 -68:40:32
XTE J1550-564/V381 Nor	9.6 ± 1.2	6.0–7.5	1.5	17,000	15:50:59 -56:28:36
4U 1543-475/IL Lupi	9.4 ± 1.0	0.25	1.1	24,000	15:47:09 -47:40:10
XTE J1819-254/V4641 Sgr	7.1 ± 0.3	5–8	2.82	24,000–40,000	18:19:22 -25:24:25
GRS 1915+105/V1487 Aql	14 ± 4.0	~1	33.5	40,000	19:15:12 +10:56:44
XTE J1650-500	9.7 ± 1.6	.	0.32		16:50:01 -49:57:45

Extragalactic

Candidates outside our galaxy come from gravitational wave detections:

Outside our galaxy

Name	BHC mass (solar masses)	Companion mass (solar masses )	Orbital period (days)	Distance from Earth (light years)	Location
GW150914 (62 ± 4) M☉	36 ± 4	29 ± 4	.	1.3 billion
GW170104 (48.7 ± 5) M☉	31.2 ± 7	19.4 ± 6	.	1.4 billion
GW151226 (21.8 ± 3.5) M☉	14.2 ± 6	7.5 ± 2.3	.	2.9 billion

The disappearance of N6946-BH1 following a failed supernova in NGC 6946 may have resulted in the formation of a black hole.

Deathtrap (plot device)

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Deathtrap_(plot_device) 

 

A deathtrap is a literary and dramatic plot device in which a villain who has captured the hero or another sympathetic character attempts to use an elaborate, improbable, and usually sadistic method of murdering them.

It is often used as a means to create dramatic tension in the story and to have the villain reveal important information to the hero, confident that the hero will shortly not be able to use it. It may also be a means to show the hero's resourcefulness in escaping, or the writer's ingenuity at devising a last-minute rescue or deus ex machina.

History

This plot device is generally believed to have been popularized by movie serials and 19th-century theatrical melodramas. A well-known example is the cliché of the moustache-twirling villain leaving the heroine tied to railroad tracks. Its use in the James Bond film series and superhero stories is well known.

Narrative use

It is a common criticism that it is unbelievable in story plots to have villains try to kill the heroes in such elaborate ways when they could use simple methods like shooting them. Throughout the decades, comic book writers have responded to these complaints by devising ways in which the deathtraps have served other purposes.

For instance, one Legion of Super-Heroes story by Jim Shooter had a team of Legionnaires put into a variety of deathtraps and the villains wanted the heroes to successfully escape. This was because the real purpose of the deathtraps was to have the Legionnaires use a great deal of energy doing so, which the villains then harnessed for their own benefit. Other stories have had villains use deathtraps as a means of testing the heroes or to distract them while the villain attends to other matters. On some occasions, the deathtrap is a machine that "absorbs" the energy from the hero/heroes.

Another rationalization for a deathtrap is when a particular villain simply enjoys leaving his victims some small chance of survival, just for the sake of sport. Such "sporting" villains include the Riddler, who has an uncontrollable compulsion to create intellectual challenges for his enemies. Also included in this list is the Jigsaw Killer, who places his victims in life-or-death situations to prove that they appreciate life. The Joker and Arcade are other villains who simply enjoy the challenge. 

On occasion, the villain may employ a slow deathtrap because they enjoy their victim's suffering prior to death, either due to sadistic tendencies or a desire for painful vengeance.

In a similar vein, the villain, often a megalomaniac, may feel that, as a reflection of his own imagined greatness, it would be "beneath him" to murder his enemy like any common criminal, and that his enemy's death should be the worthy spectacle that a successful deathtrap would provide. In contrast, he may feel that his enemy, having provided him with a worthy challenge in their earlier encounters, himself "deserves" such a grandiose death, or that the enmity between the two is so "epic" that it merits no less than such a conclusion. 

Conversely, the protagonists' act of falling into such a trap may itself be the reason they are written off and left unattended. The villain, disappointed in such a non-threatening opponent, loses interest, and intentionally leaves some chance of escape for the protagonists to "redeem" themselves. However, the disillusioned villain tends to assume that the chance is minuscule. Despite secretly hoping that the opponent survives and proves worthy of interest, the now-bored villain is invariably shocked when that actually occurs. 

If fully serious, the villain may simply be too insane to recognize the impracticality of the situation, although this characterization is rarely seen outside of deliberately parodic characters such as Dr. Evil.

A more recent reason is villains do it simply because it is considered 'tradition' or 'rule' of being a supervillain to place a hero in a deathtrap and then leave them to their fate. This even goes as far as heroes, or other villains, insulting a villain for attempting to avoid using a deathtrap or staying to watch. El Sombrero is one villain who exemplifies this reason.

When a hero's sidekick or loved one is placed in a deathtrap, its purpose is often to distract the hero, occupying time and attention while the villain pursues their evil plan. Less frequently, the villain intends to instill grief and guilt as a means of defeating a hero that cannot be defeated physically. Multiple secondary characters may be placed in deathtraps to offer the hero an agonizing choice, ostensibly forcing the hero to save one victim and leave the other(s) to die.

Famous examples

• The Engineer's Thumb (Sherlock Holmes story): the engineer Victor Hatherley is trapped inside a hydraulic press which would crush him to a pulp
  • Escape method: a woman working for the villains but not sharing their criminal ruthlessness opens a side panel at the last moment, allowing Hatherley to escape
• Raiders of the Lost Ark: Sealing Indiana Jones and Marion in the Well of Souls
  • Escape method: Seeing a possible tunnel entrance, Jones climbed a statue and toppled it towards the wall to create an entrance to a passageway that led to the outside.
• Live and Let Die: Doctor Kananga and a minion tie James Bond and Solitaire to a platform to be lowered into a shark-infested pool to be eaten alive.
  • Escape method: Without the villains seeing, Bond activates his watch's rotary saw function to cut through his restraints to free himself and attack Kananga.
• Goldfinger: James Bond is shackled spreadeagled to a table and a circular saw (a laser in the film) is approaching to cut him in half. Unlike many deathtrap scenarios, Bond remains under constant supervision, and he does not use (or have) a device or outside help to escape.
  • Escape method: Bond bluffs Goldfinger, and persuades him that his replacement "008" also knows about Goldfinger's plans and that Bond's death will immediately summon him to investigate, so Goldfinger elects to not take the chance of another spy coming on the scene to interfere, which he can avoid by holding Bond captive.
• Edgar Allan Poe's "The Pit and the Pendulum": The unnamed character finds himself bound to a large slab, beneath a bladed pendulum that slowly lowers toward him as it swings, with the intention of slicing through his chest.
  • Escape method: The character lures mice to the ropes with a piece of meat. They chew through the ropes, allowing him to escape before the pendulum can slice him open.
• In the Dudley Do-Right cartoon, villain Snidely Whiplash (a parody of the stereotypical "movie-serial" villain) tied up Nell Fenwick on a table-saw conveyor belt. The narrator (Paul Frees) noted that, "Fortunately, the belt was in need of oiling, so the trip was a slow one." In elapsed time, through the course of the story, this actually took several hours.
• The 1960s live action television series Batman usually had two-part episodes use a bizarre deathtrap as a cliffhanger.
  • Example: The Joker traps the Dynamic Duo without their utility belts in the bottom of an industrial smokestack and begins to gradually fill it with a deadly heavier-than-air gas.
    • Escape method: The pair lock elbows and brace their backs against each other to walk up the smokestack to the top opening and slide down a support cable safely to the ground.
• The Venture Brothers: Doctor Venture in Escape to the House of Mummies Part 2. He described the trap he was in as "Slower than haunted house spiked walls, but not quite as slow as evil scientist spiked walls."
  • Escape Method: Magic forcing the walls to stop. A secondary, previously unknown Boiling Oil trap failed when a henchman confused it for "Hot Voile", which was being warmed in a clothes dryer.
• The Perils of Penelope Pitstop always involved improbable deathtraps, usually set by the Hooded Claw.
• Disney's The Great Mouse Detective: Ratigan ties up Basil and Dawson in an intricate mousetrap and tells them about his plot to kill the queen. He then leaves to see his scheme unfold, assuming that they will soon be dead.
  • Escape method: Basil activates the mousetrap he and Dawson are trapped in early, catching the ball that was meant to crush them, and setting off a chain reaction that interferes with every other aspect of the trap.
• Saw: The plot of the series revolves around the Jigsaw Killer, a terminally ill vigilante who kidnaps his victims and places them in deadly traps, both to test them and to give them an opportunity to repent for former lifestyles in which they took their lives for granted and were unappreciative and unconcerned with the well-being of others.
• The Snowman: Rakel, Harry Hole's beloved, is forced to sit on a fast-melting snowman; when it had melted she would fall down and the razor-sharp wire around her neck would decapitate her.
  • Escape Method: Harry arrives on the scene and extricates Rakel in nick of time, at the acceptable price of the wire cutting off one of his fingers.
• Titanic (1997 film): Jack Dawson is chained in a room deep down inside the ship, where he is meant to disappear and be conveniently drowned as the ship sinks, but is rescued by his lover Rose. The entire second half of the film can also be seen as an extended deathtrap situation, where the thousands of people on board find themselves faced with a painful and absurd death, due to their having bought tickets or enlisted as crew on the glamorous ship, the epitome of technical progress and luxury, and now have to either reach the lifeboats and escape or else accept their death. The villain here, in a sense, is the ship and its careless masters.
• Final Destination: The plot of the series revolves around several people surviving a catastrophe because one of them had a premonition of it. In doing this the survivors have cheated Death, a malevolent and unseen force that sets up deathtraps to kill off the survivors in the order in which they had originally died.

A simpler variation on the deathtrap is the villain speech, also known as monologuing. The villain, after having captured the hero or another victim, gives a long speech taunting and sneering at his victim, pontificating on how said victim will soon die, and reminiscing over how he tried for so long to get his kill and is now about to reap the reward. Villains may also give away details of their evil plots, on the rationale that the victim will die immediately and the villain often believes their victim deserves to know. This speech, given when the villain could have just killed the victim in a matter of seconds, is invariably used to give another character time to come in and save the victim, or for the victim to escape. In The Incredibles (which used the term "monologuing"), Mr. Incredible and Frozone attacked villains in the middle of their speeches (Mr. Incredible is seen attacking Syndrome and Frozone is mentioned to have attacked Baron von Ruthless off-camera). In a literary sense, the villain speech is also used as a form of exposition. 

Even in relatively realistic stories, villains will often take a moment to say something pithy before finishing off the victim. The antagonist would often leave the victim to die whilst they commit their evil scheme. This is echoed in the film 2001 - A Space Odyssey when Hal the supercomputer, confident that Dave will soon perish outside the ship, tells him that he is about to take control of the expedition and then sees Dave off with the flat remark: "This conversation can have no meaningful purpose anymore - goodbye!". Dave manages to make his way inside and kill Hal.

Spoofs

The concept of the deathtrap/monologue is featured in many satires.

• Deathtraps were spoofed heavily in the Austin Powers movies, including a replication of James Bond's Shark Infested Water deathtrap. It is first introduced as "an easily escapeable situation involving an overly elaborate and exotic death" with Austin placed on a platform over a pool (which Dr. Evil calls "the unnecessarily slow-moving dipping mechanism"). The trap is escaped by swinging on a grapple of dental floss. As the intended sharks with laserbeams were unavailable due to the complexities of international law regarding endangered species (much to Dr. Evil's disappointment), ill-tempered mutant seabass are used instead. As part of the spoof, Scott Evil, Dr. Evil's son, insists that the deathtrap is pointless and that they could simply shoot them with a pistol, which is nearby, and yells at his father for the further incompetence of leaving them alone. Dr Evil responds that not watching the killing but assuming it went well makes perfect sense.
• In the sitcom Blackadder, Prince Edmund is captured by his nemesis, the Hawk, who straps him into a chair which, in sixty seconds, will mutilate him in a variety of ways. Edmund's friends, Baldrick and Percy, manage to poison the Hawk and his followers, but while celebrating this unlikely victory, the time runs out, and Edmund suffers a terrible fate. In another episode, Lord Flashheart is confronted by a villain who begins an evil villain speech. However, rather than waiting for him to finish, Flashheart merely shoots him without warning.
• Curse of Monkey Island makes fun of this cliché. The villain LeChuck, after capturing Guybrush Threepwood, insists on telling him his plans before executing him. By this dialogue, interesting background story that connect the games together are given to the player. Guybrush does him the favour to listen, but after a while he is so bored that he refuses to listen any more, even if LeChuck pleads to continue.
• The famous line from Watchmen wherein the character Ozymandias takes his time and explains in detail how he will set his plan irrevocably in motion and then, in a deliberate skewering of the monologuing tendencies of supervillains, explains that "Dan, I'm not a Republic serial villain. I did it thirty-five minutes ago."
• In The Simpsons episode "You Only Move Twice", which generally spoofs Bond villain clichés, supervillain/great boss Hank Scorpio has "Mr. Bont" strapped to a table with a laser à la Goldfinger. Bont manages to escape, only to be tackled by Homer. Scorpio's henchmen promptly shoot Bont.
• Some incarnations of the Evil Overlord List point out the impracticality of deathtraps. Some examples include making sure the deathtrap has a VERY small estimated time of death or such lines as "Shooting is NOT too good for my enemies."
• Season 5 Episode 8 of the animated classic series The Flintstones entitled "Dr. Sinister" spoofed the James Bond series ("James Bondrock") and featured, among other deathtraps, Fred and Barney being tied to a slab with a slowly descending pendulum with blade, a la Poe's "The Pit and the Pendulum". The duo escape when Barney holds his tied hands up and the blade slices through his bonds. He then unties himself and frees Fred before the final swing slices the slab in half.

PythagoraSwitch

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/PythagoraSwitch 

 

PythagoraSwitch
Genre	Educational
Country of origin	Japan
Production
Running time	15 minutes
Production company(s)	NHK
Release
Original network	NHK
Audio format	Stereo
Original release	April 9, 2002 – present
External links
Website

PythagoraSwitch (ピタゴラスイッチ, Pitagora Suitchi) is a 15-minute Japanese educational television program that has been aired by NHK since April 9, 2002. It encourages augmenting children's "way of thinking" under the supervision of Masahiko Satō (佐藤雅彦) and Masumi Uchino (内野真澄). A five-minute format called PythagoraSwitch Mini is also available.

During the beginning and ending of each episode, and between each corner (segment), there are Pythagorean Devices (ピタゴラ装置, Pitagora Sōchi). "Pythagorean device" is the equivalent Japanese colloquialism for the American "Rube Goldberg machine" and British "Heath Robinson" contraption. The main focus of the program is a puppet show, but the subject is mainly advanced by small corners. World phenomena, principles, characteristics, and the like are introduced in an entertaining way. At the end of each segment, the show's title is sung as a kind of punchline.

Segments

In the show, segments are called "corners".

Today's Topic

A puppet show in which Grandpa Encyclopedia (百科おじさん, Hyakka Oji-san) explains the structure of the world to young penguins Pita and Gora. A recurring situation is that, while discussing each topic, Encyclopedia would often say "The details are on my Nth page", to what the Penguins, after looking at said page, respond "We're children, so we can't read..." After that, the three call upon Televi-John (テレビのジョン, Terebi no Jon) an anthropomorphic dog-like TV, who shows them a video about the topic. A mouse called Suu is also featured.

Pythagora Devices

Pythagora Devices (ピタゴラ装置, Pitagora Souchi) are frequently featured.

Algorithm Exercise

A corner broadcast since 2002. It stars the duo Itsumo Kokokara. It is algorithm themed, so that the movements that are done side by side are related ("crouching motion" combines with "shaking arms", so that the arms avoid the action, etc.). Usually, the duo does the exercise with special guests, such as NHK announcers, baseball players, sumo wrestlers, etc.

There are also individual versions for each member: the "Yamada version" and the "Kikuchi version".

Algorithm March

Otou-san Switch

A segment in which a father and his child act out sequences and play games based on any of the Japanese letter sounds.

Other Corners

• Bend the Stick Anime (ポキポキアニメ, Pokipoki Anime)
• The Black Box Person Question (ブラックボックス人問題, Burakku Bokkusu Jin Mondai)
• Botejin (ぼてじん, Botejin): A potato shaped like a dice (voiced by Iwao Nozomi) moves forward and backward and to the left and right in the tiles drawn on the ground, with words written on each side of him. He can move even if he is out of the tiles.
• The Circles and Triangles (○と△のしゅうだん, Maru to Sankaku no Shūdan)
• Do Your Best!! Product Test (がんばれ!製品テスト, Ganbare! Seihin Tesuto): This segment introduces the stages of product testing before the shipment of industrial products.
  1. Office chairs
  2. Ballpoint pens
• Framy (フレーミー, Furēmī): Animated shorts about a dog named Framy, who is made out of clear squares. Other characters that are composed of simple figures, but they are not transparent.
• How the Trick Works! By Ms. Hammer Critic! aka Ms. Hammer Critic's Time (トンカッチのそこのしくみがしりタイム, Tonkachi no Soko no Shikumi ga Shiri Taimu): a critique of Pythagorean Devices by Ms. Hammer Critic (voiced by Mio Ueda), in some segments a dissection of the Pythagora Devices are demonstrated to “how the trick works”.
  1. Equipment No. 147: 3 Cups
  2. Equipment No. 175: The Come Back Car
  3. Equipment No. 144: The Toothpick
• If You Don't Believe it! Just Try it! (ウソだと思うなら、やってみな。, Uso Da to Omou Nara, Yattemina.)
  1. Pine cone dipped in water then sit in the cold
  2. Egg and glass of water mixed with salt
  3. Seaweed and glass of water
• The Invisible Man X (とうめい人間X, Tōmei Ningen Ekkusu)
• It Can't Be Done (こんなことできません, Konna Koto Dekimasen): Tsutomu Sekine and Jonio Iwai perform what seems to be physically impossible feats using stop-motion photography. At the end of each segment, the title of the corner changes to "It Can't Can Be Done" (こんなことできませんした, Konna Koto Dekimasenshita).
• Nendore Nandore Mr. Clay, What's Got Stuck on You Today? (ねんどれナンドレラッツの跡じまん, Nendore Nandorerattsu no Atojiman)
  1. TV remote and peanuts
  2. Colored pencils and a piece of cheese
  3. Bottle opener and clothespin
  4. Acorns and dice
• A New Creature (新しい生物, Atarashii Seibutsu): A stop-motion animation segment featuring ordinary objects being brought to life.
  1. Erasersaurus (ケシゴムザウルス, Keshigomuzaurusu), eraser
  2. Strawceraps (ストロケラプス, Sutorokerapusu), drinking straw
  3. Rubberbandnus (ワゴムヌス, Wagomunus), rubber band
  4. Boltnodon (ボルトノドン, Borutonodon), bolt
  5. Sugarcubeton (カクザザトン, Kakuzazaton), sugar cube
  6. Stickynus (フセンヌス, Fusennusu), sticky note
  7. Chopsticknodon (ハシノドン, Hashinodon), chopsticks
  8. Brushnodon (ブラシノドン, Burashinodon), shoe brush
  9. Matchboxnus (マッチバコヌス, Matchibakonus), matchbox
  10. Aluminumfoilps (アルミホイルプス, Arumihoirupusu), aluminum foil

  Also includes Afterwards (そのあと, Sono Ato) and Evolution (進化, Shinka) segments for some of the above creatures.

• Pythagora Equipment Academy (ピタゴラ装置アカデミア, Pitagora Sōchi Akademia): This segment teaches how to make gadgets and gimmicks included in Pythagora Devices.
• PythagoraSwitch Folding Handkerchief Theater (ピタゴラスイッチおりたたみハンカチ劇場, Pitagora Suitchi Oritatami Hankachi Gekijō)
• See the Wiggle Men! What's Different? (くねくね人まちがいさがし, Kunekune Hito Machigaisagashi)
• Tape Measure Jackie (まきじゃくのジャック, Makijaku no Jakku)
• 10-Stick Anime (10本アニメ, 10-Pon Anime): Ten small sticks join together and transform into various things.
• Then the Bridge Thought of What to Do (そこで橋は考えた, Soko de Hashi wa Kangaeta)
  1. Swing bridge (Amanohashidate, Kyoto)
  2. Bascule bridge (Tei Port Moveable Bridge in Kōnan, Kōchi)
  3. Lift bridge (Kagasunobashi in Tokushima)
  4. Transporter bridge (Vizcaya Bridge in Biscay, Spain)
  5. Submersible bridge (on Corinth Canal in Isthmia, Greece)
  6. Rolling bascule bridge (Te Matau ā Pohe in Whangarei, New Zealand)
• Today's Counting Numbers (かぞえてみよう, Kaozetemiyou)
• Today's Switch (今日のスイッチ, Kyō no Suitchi): In a certain place, a start switch is pressed in a machine, which introduces something happening.
• Today's Just Barely (きょうのスレスレ, Kyō no Suresure)
• Today's Robot (今日のロボット, Kyō no Robotto): A segment which introduces various robots (mainly work robots).
  1. Sentry robot
  2. Bicycle parking
• Understand in 5 Seconds (5秒でわかる, 5-Byō de Wakaru)
• What Animal is This? (なんのどうぶつ?, Nan no Dōbutsu?)
• What Numbers are They? (何の数字?, Nan no Sūji?)
• What on Earth is This? (なんだこれ?, Nanda Kore?)
  1. A horse
  2. Fish bones
  3. Walking the dog
• Which One is Real? (どっちが本物？, Dotchi ga Honmono?)
  1. Tangerines
  2. Pencils
  3. Teacups

Actors

Dankichi Kuruma (車だん吉), Jun Inoue (井上順), and Tsuyoshi Kusanagi (草彅剛), are some of the voice actors who perform and call out the topics.

Broadcast

Outside Japan, NHK World Premium broadcasts PythagoraSwitch Mini. Starting April 2015, an English version of PythagoraSwitch Mini has been broadcast on NHK World TV. In Brazil, TV Cultura is broadcasting it with the title Viva Pitágoras. In addition, some PythagoraSwitch videos are also available on Google Video, YouTube and DailyMotion.

Awards

At the 30th Japan Prize International Educational Program Contest, in 2003, episode 25 "Let's Look at It Another Way" won top prize, the Prime Minister's award, of the Early Education category. At Prix Jeunesse 2004 in Munich it won top prize in the age 6 and below non-fiction category.