Francisco Lachowski shirtless runway 2017

Reckless Turtle

Reckless Turtle

Kraken
Joined
Jul 29, 2021
Posts
17,143
Reputation
23,783
 
  • +1
  • JFL
  • Ugh..
Reactions: LooksThinker, BrazilianLooksmaxxer, MaxillaMaxing and 3 others
2747943 DNRD
 
  • JFL
  • Love it
  • +1
Reactions: fabi, MaxillaMaxing, ItsOver.com and 7 others
I bet a large portion of this forum would suck prime chico on the spot
 
  • JFL
  • +1
Reactions: Karstossos, Tallooksmaxxer, SAR and 3 others
3.5/10
 
  • +1
Reactions: Deleted member 16834
Ethereal said:
I bet a large portion of this forum would suck prime chico on the spot
Click to expand...
I was looking for women in the show when I stumbled upon this. I swear.
 
  • JFL
Reactions: Deleted member 15099
Ethereal said:
I bet a large portion of this forum would suck prime chico on the spot
Click to expand...
I bet, you would suck prime Lima titties on the spot(y)

sexy adriana lima GIF
 
  • JFL
  • +1
Reactions: Deleted member 8165, Xangsane and Deleted member 15099
Soo sexyyyy yummm
 
Sister 👭 found 🔎 my Chico 👨 folder 📁🤤😰😫
 
  • JFL
Reactions: aesthetic beauty, TsarTsar444 and StrangerDanger
Korea said:
View attachment 1545586
Click to expand...
There's literally no man better looking than Francisco Lachowski
And I'm not talking about 2007 Chico with autistic photos on his Facebook, I'm not talking about 2008 Francisco who won the Ford Men's Supermodel of the World in São Paulo and then won a Ford modelling contract and worked for Dior Homme, Versace, Dolce & Gabbana, DSquared, Gucci, Cavalli, Armani and others, I'm not talking about 2016 post-prime bearded Chico with two kids and married with Jessiann Gravel Beland, hell, I'm talking about 2010 Francisco with perfect facial harmony and universal appeal, 6'5" tall with perfect frame and bideltoid breadth, completely hooded eyes with aegyo sal and neutral canthal tilt with no scleral show and no upper eyelid exposure, flawless skin and perfect facial leanness, 1.88 fwhr, 0 on the NW scale, 7 cm interpupillary distance and 14.2cm of zygo width, forward grown maxilla and jawline with a massive skull.Francisco Lachowski comes very close to perfection. There are virtually no flaws in his facial appearance, the only flaws can be drawn when we go below the neck.. which is irrelevant when you consider his facial aesthetics.He has perfect maxillofacial growth which becomes evident from the zygomatic arches that project wide (adds facial width) and are round in shape in the tipping points. The nose is perfect: straight nasal septum indicates the face hasn't grown vertically more than it should at any point in developmental time so it doesn't appear hooked, it is also devoid of any obscure mal/formations, crookedness or deviation (some of which are typically caused by allergies or force trauma).He has near perfect dentofacial growth. While he has gotten some dental aid with orthodontics (evident from the appearance of his top central and lateral incisors+canines), his bite is perfect. You can tell this by looking at his lip posture, which is affected by the position of the mandible, and anyone will agree that it looks nice and balanced.The mandible is in an ideal position which means there's no malocclusion, and malocclusions have an enormous impact on the aesthetic appearance of the face. This is rare because with modern [western] diet and the rapid increase of allergies, it is extremely hard for most males to develop a nice looking jaw (not to mention that you need the appropriate testosterone levels and genetics to develop one). Lots of males that would normally develop a jaw similar to Lachowski's don't, because of mouth breathing or improper masticatory usage (the diet is too soft). It takes a perfect growing environment on top of good genes and hormone profile to develop a balanced facial structure like Lachowski's, and that's leaving out the individual features like the eye area, which in Lachowski's case is unique in itself.Now combine all this with the fact that he is over 6'2''. A good looking face with pretty features is hard to achieve when given a tall skeletal build. Most guys that you see with really pretty or handsome faces are 5'9'' to 5'11'', i.e. average height. You will very rarely see someone as aesthetic with masculine features as Francisco. You see beautiful women all the time and there's nothing admirable about being a pretty girl because it's so easily achievable and common. Beautiful men are an exception to the rule; something that should be admired, not only because of the beauty itself but the difficulty in achieving such beauty.
U771y23he
 
  • JFL
Reactions: Deleted member 16801 and MaxillaMaxing
Very good body but face looks average
 
  • JFL
Reactions: TsarTsar444
StrangerDanger said:
There's literally no man better looking than Francisco Lachowski
And I'm not talking about 2007 Chico with autistic photos on his Facebook, I'm not talking about 2008 Francisco who won the Ford Men's Supermodel of the World in São Paulo and then won a Ford modelling contract and worked for Dior Homme, Versace, Dolce & Gabbana, DSquared, Gucci, Cavalli, Armani and others, I'm not talking about 2016 post-prime bearded Chico with two kids and married with Jessiann Gravel Beland, hell, I'm talking about 2010 Francisco with perfect facial harmony and universal appeal, 6'5" tall with perfect frame and bideltoid breadth, completely hooded eyes with aegyo sal and neutral canthal tilt with no scleral show and no upper eyelid exposure, flawless skin and perfect facial leanness, 1.88 fwhr, 0 on the NW scale, 7 cm interpupillary distance and 14.2cm of zygo width, forward grown maxilla and jawline with a massive skull.Francisco Lachowski comes very close to perfection. There are virtually no flaws in his facial appearance, the only flaws can be drawn when we go below the neck.. which is irrelevant when you consider his facial aesthetics.He has perfect maxillofacial growth which becomes evident from the zygomatic arches that project wide (adds facial width) and are round in shape in the tipping points. The nose is perfect: straight nasal septum indicates the face hasn't grown vertically more than it should at any point in developmental time so it doesn't appear hooked, it is also devoid of any obscure mal/formations, crookedness or deviation (some of which are typically caused by allergies or force trauma).He has near perfect dentofacial growth. While he has gotten some dental aid with orthodontics (evident from the appearance of his top central and lateral incisors+canines), his bite is perfect. You can tell this by looking at his lip posture, which is affected by the position of the mandible, and anyone will agree that it looks nice and balanced.The mandible is in an ideal position which means there's no malocclusion, and malocclusions have an enormous impact on the aesthetic appearance of the face. This is rare because with modern [western] diet and the rapid increase of allergies, it is extremely hard for most males to develop a nice looking jaw (not to mention that you need the appropriate testosterone levels and genetics to develop one). Lots of males that would normally develop a jaw similar to Lachowski's don't, because of mouth breathing or improper masticatory usage (the diet is too soft). It takes a perfect growing environment on top of good genes and hormone profile to develop a balanced facial structure like Lachowski's, and that's leaving out the individual features like the eye area, which in Lachowski's case is unique in itself.Now combine all this with the fact that he is over 6'2''. A good looking face with pretty features is hard to achieve when given a tall skeletal build. Most guys that you see with really pretty or handsome faces are 5'9'' to 5'11'', i.e. average height. You will very rarely see someone as aesthetic with masculine features as Francisco. You see beautiful women all the time and there's nothing admirable about being a pretty girl because it's so easily achievable and common. Beautiful men are an exception to the rule; something that should be admired, not only because of the beauty itself but the difficulty in achieving such beauty.
View attachment 1545587
Click to expand...

Conservation of energy​

From Wikipedia, the free encyclopedia



Jump to navigationJump to search
This article is about the law of conservation of energy in physics. For sustainable energy resources, see Energy conservation.
Continuum mechanics
Part of a series on
{\displaystyle J=-D{\frac {d\varphi }{dx}}}
{\displaystyle J=-D{\frac {d\varphi }{dx}}}

Fick's laws of diffusion
hide
Laws
Inequalities
Conservations
show
Solid mechanics
show
Fluid mechanics
show
Rheology
show
Scientists
In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time.[1] This law, first proposed and tested by Émilie du Châtelet,[2][3] means that energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another. For instance, chemical energy is converted to kinetic energy when a stick of dynamite explodes. If one adds up all forms of energy that were released in the explosion, such as the kinetic energy and potential energy of the pieces, as well as heat and sound, one will get the exact decrease of chemical energy in the combustion of the dynamite.
Classically, conservation of energy was distinct from conservation of mass. However, special relativity showed that mass is related to energy and vice versa by E = mc2, and science now takes the view that mass-energy as a whole is conserved. Theoretically, this implies that any object with mass can itself be converted to pure energy, and vice versa. However this is believed to be possible only under the most extreme of physical conditions, such as likely existed in the universe very shortly after the Big Bang or when black holes emit Hawking radiation.
Conservation of energy can be rigorously proven by Noether's theorem as a consequence of continuous time translation symmetry; that is, from the fact that the laws of physics do not change over time.
A consequence of the law of conservation of energy is that a perpetual motion machine of the first kind cannot exist, that is to say, no system without an external energy supply can deliver an unlimited amount of energy to its surroundings.[4] For systems which do not have time translation symmetry, it may not be possible to define conservation of energy. Examples include curved spacetimes in general relativity[5] or time crystals in condensed matter physics.[6][7][8][9]

Contents​

History[edit]​

This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (November 2015) (Learn how and when to remove this template message)
Ancient philosophers as far back as Thales of Miletus c. 550 BCE had inklings of the conservation of some underlying substance of which everything is made. However, there is no particular reason to identify their theories with what we know today as "mass-energy" (for example, Thales thought it was water). Empedocles (490–430 BCE) wrote that in his universal system, composed of four roots (earth, air, water, fire), "nothing comes to be or perishes";[10] instead, these elements suffer continual rearrangement. Epicurus (c. 350 BCE) on the other hand believed everything in the universe to be composed of indivisible units of matter—the ancient precursor to 'atoms'—and he too had some idea of the necessity of conservation, stating that "the sum total of things was always such as it is now, and such it will ever remain."[11]
In 1605, Simon Stevinus was able to solve a number of problems in statics based on the principle that perpetual motion was impossible.
In 1639, Galileo published his analysis of several situations—including the celebrated "interrupted pendulum"—which can be described (in modern language) as conservatively converting potential energy to kinetic energy and back again. Essentially, he pointed out that the height a moving body rises is equal to the height from which it falls, and used this observation to infer the idea of inertia. The remarkable aspect of this observation is that the height to which a moving body ascends on a frictionless surface does not depend on the shape of the surface.
In 1669, Christiaan Huygens published his laws of collision. Among the quantities he listed as being invariant before and after the collision of bodies were both the sum of their linear momenta as well as the sum of their kinetic energies. However, the difference between elastic and inelastic collision was not understood at the time. This led to the dispute among later researchers as to which of these conserved quantities was the more fundamental. In his Horologium Oscillatorium, he gave a much clearer statement regarding the height of ascent of a moving body, and connected this idea with the impossibility of perpetual motion. Huygens' study of the dynamics of pendulum motion was based on a single principle: that the center of gravity of a heavy object cannot lift itself.
Gottfried Leibniz
It was Leibniz during 1676–1689 who first attempted a mathematical formulation of the kind of energy that is associated with motion (kinetic energy). Using Huygens' work on collision, Leibniz noticed that in many mechanical systems (of several masses, mi each with velocity vi),
{\displaystyle \sum _{i}m_{i}v_{i}^{2}}
\sum _{i}m_{i}v_{i}^{2}

was conserved so long as the masses did not interact. He called this quantity the vis viva or living force of the system. The principle represents an accurate statement of the approximate conservation of kinetic energy in situations where there is no friction. Many physicists at that time, such as Newton, held that the conservation of momentum, which holds even in systems with friction, as defined by the momentum:
{\displaystyle \sum _{i}m_{i}v_{i}}
{\displaystyle \sum _{i}m_{i}v_{i}}

was the conserved vis viva. It was later shown that both quantities are conserved simultaneously, given the proper conditions such as in an elastic collision.
In 1687, Isaac Newton published his Principia, which was organized around the concept of force and momentum. However, the researchers were quick to recognize that the principles set out in the book, while fine for point masses, were not sufficient to tackle the motions of rigid and fluid bodies. Some other principles were also required.
Daniel Bernoulli
The law of conservation of vis viva was championed by the father and son duo, Johann and Daniel Bernoulli. The former enunciated the principle of virtual work as used in statics in its full generality in 1715, while the latter based his Hydrodynamica, published in 1738, on this single vis viva conservation principle. Daniel's study of loss of vis viva of flowing water led him to formulate the Bernoulli's principle, which asserts the loss to be proportional to the change in hydrodynamic pressure. Daniel also formulated the notion of work and efficiency for hydraulic machines; and he gave a kinetic theory of gases, and linked the kinetic energy of gas molecules with the temperature of the gas.
This focus on the vis viva by the continental physicists eventually led to the discovery of stationarity principles governing mechanics, such as the D'Alembert's principle, Lagrangian, and Hamiltonian formulations of mechanics.
Emilie du Chatelet
Émilie du Châtelet (1706–1749) proposed and tested the hypothesis of the conservation of total energy, as distinct from momentum. Inspired by the theories of Gottfried Leibniz, she repeated and publicized an experiment originally devised by Willem 's Gravesande in 1722 in which balls were dropped from different heights into a sheet of soft clay. Each ball's kinetic energy—as indicated by the quantity of material displaced—was shown to be proportional to the square of the velocity. The deformation of the clay was found to be directly proportional to the height from which the balls were dropped, equal to the initial potential energy. Earlier workers, including Newton and Voltaire, had all believed that "energy" (so far as they understood the concept at all) was not distinct from momentum and therefore proportional to velocity. According to this understanding, the deformation of the clay should have been proportional to the square root of the height from which the balls were dropped. In classical physics the correct formula is {\displaystyle E_{k}={\frac {1}{2}}mv^{2}}
E_{k}={\frac {1}{2}}mv^{2}
, where {\displaystyle E_{k}}
E_{k}
is the kinetic energy of an object, {\displaystyle m}
m
its mass and {\displaystyle v}
v
its speed. On this basis, du Châtelet proposed that energy must always have the same dimensions in any form, which is necessary to be able to consider it in different forms (kinetic, potential, heat, ...).[2][3]
Engineers such as John Smeaton, Peter Ewart, Carl Holtzmann, Gustave-Adolphe Hirn and Marc Seguin recognized that conservation of momentum alone was not adequate for practical calculation and made use of Leibniz's principle. The principle was also championed by some chemists such as William Hyde Wollaston. Academics such as John Playfair were quick to point out that kinetic energy is clearly not conserved. This is obvious to a modern analysis based on the second law of thermodynamics, but in the 18th and 19th centuries, the fate of the lost energy was still unknown.
Gradually it came to be suspected that the heat inevitably generated by motion under friction was another form of vis viva. In 1783, Antoine Lavoisier and Pierre-Simon Laplace reviewed the two competing theories of vis viva and caloric theory.[12] Count Rumford's 1798 observations of heat generation during the boring of cannons added more weight to the view that mechanical motion could be converted into heat and (that it was important) that the conversion was quantitative and could be predicted (allowing for a universal conversion constant between kinetic energy and heat). Vis viva then started to be known as energy, after the term was first used in that sense by Thomas Young in 1807.
Gaspard-Gustave Coriolis
The recalibration of vis viva to
{\displaystyle {\frac {1}{2}}\sum _{i}m_{i}v_{i}^{2}}
{\frac {1}{2}}\sum _{i}m_{i}v_{i}^{2}

which can be understood as converting kinetic energy to work, was largely the result of Gaspard-Gustave Coriolis and Jean-Victor Poncelet over the period 1819–1839. The former called the quantity quantité de travail (quantity of work) and the latter, travail mécanique (mechanical work), and both championed its use in engineering calculations.
In a paper Über die Natur der Wärme (German "On the Nature of Heat/Warmth"), published in the Zeitschrift für Physik in 1837, Karl Friedrich Mohr gave one of the earliest general statements of the doctrine of the conservation of energy: "besides the 54 known chemical elements there is in the physical world one agent only, and this is called Kraft [energy or work]. It may appear, according to circumstances, as motion, chemical affinity, cohesion, electricity, light and magnetism; and from any one of these forms it can be transformed into any of the others."

Mechanical equivalent of heat[edit]​

A key stage in the development of the modern conservation principle was the demonstration of the mechanical equivalent of heat. The caloric theory maintained that heat could neither be created nor destroyed, whereas conservation of energy entails the contrary principle that heat and mechanical work are interchangeable.
In the middle of the eighteenth century, Mikhail Lomonosov, a Russian scientist, postulated his corpusculo-kinetic theory of heat, which rejected the idea of a caloric. Through the results of empirical studies, Lomonosov came to the conclusion that heat was not transferred through the particles of the caloric fluid.
In 1798, Count Rumford (Benjamin Thompson) performed measurements of the frictional heat generated in boring cannons, and developed the idea that heat is a form of kinetic energy; his measurements refuted caloric theory, but were imprecise enough to leave room for doubt.
James Prescott Joule
The mechanical equivalence principle was first stated in its modern form by the German surgeon Julius Robert von Mayer in 1842.[13] Mayer reached his conclusion on a voyage to the Dutch East Indies, where he found that his patients' blood was a deeper red because they were consuming less oxygen, and therefore less energy, to maintain their body temperature in the hotter climate. He discovered that heat and mechanical work were both forms of energy and in 1845, after improving his knowledge of physics, he published a monograph that stated a quantitative relationship between them.[14]
Joule's apparatus for measuring the mechanical equivalent of heat. A descending weight attached to a string causes a paddle immersed in water to rotate.
Meanwhile, in 1843, James Prescott Joule independently discovered the mechanical equivalent in a series of experiments. In the most famous, now called the "Joule apparatus", a descending weight attached to a string caused a paddle immersed in water to rotate. He showed that the gravitational potential energy lost by the weight in descending was equal to the internal energy gained by the water through friction with the paddle.
Over the period 1840–1843, similar work was carried out by engineer Ludwig A. Colding, although it was little known outside his native Denmark.
Both Joule's and Mayer's work suffered from resistance and neglect but it was Joule's that eventually drew the wider recognition.
For the dispute between Joule and Mayer over priority, see Mechanical equivalent of heat: Priority.
In 1844, William Robert Grove postulated a relationship between mechanics, heat, light, electricity and magnetism by treating them all as manifestations of a single "force" (energy in modern terms). In 1846, Grove published his theories in his book The Correlation of Physical Forces.[15] In 1847, drawing on the earlier work of Joule, Sadi Carnot and Émile Clapeyron, Hermann von Helmholtz arrived at conclusions similar to Grove's and published his theories in his book Über die Erhaltung der Kraft (On the Conservation of Force, 1847).[16] The general modern acceptance of the principle stems from this publication.
In 1850, William Rankine first used the phrase the law of the conservation of energy for the principle.[17]
In 1877, Peter Guthrie Tait claimed that the principle originated with Sir Isaac Newton, based on a creative reading of propositions 40 and 41 of the Philosophiae Naturalis Principia Mathematica. This is now regarded as an example of Whig history.[18]

Mass–energy equivalence[edit]​

This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (November 2015) (Learn how and when to remove this template message)
Main article: Mass–energy equivalence
Matter is composed of atoms and what makes up atoms. Matter has intrinsic or rest mass. In the limited range of recognized experience of the nineteenth century it was found that such rest mass is conserved. Einstein's 1905 theory of special relativity showed that rest mass corresponds to an equivalent amount of rest energy. This means that rest mass can be converted to or from equivalent amounts of (non-material) forms of energy, for example kinetic energy, potential energy, and electromagnetic radiant energy. When this happens, as recognized in twentieth century experience, rest mass is not conserved, unlike the total mass or total energy. All forms of energy contribute to the total mass and total energy.
For example, an electron and a positron each have rest mass. They can perish together, converting their combined rest energy into photons which have electromagnetic radiant energy, but no rest mass. If this occurs within an isolated system that does not release the photons or their energy into the external surroundings, then neither the total mass nor the total energy of the system will change. The produced electromagnetic radiant energy contributes just as much to the inertia (and to any weight) of the system as did the rest mass of the electron and positron before their demise. Likewise, non-material forms of energy can perish into matter, which has rest mass.
Thus, conservation of energy (total, including material or rest energy), and conservation of mass (total, not just rest) are one (equivalent) law. In the 18th century these had appeared as two seemingly-distinct laws.

Conservation of energy in beta decay[edit]​

Main article: Beta decay § Neutrinos in beta decay
The discovery in 1911 that electrons emitted in beta decay have a continuous rather than a discrete spectrum appeared to contradict conservation of energy, under the then-current assumption that beta decay is the simple emission of an electron from a nucleus.[19][20] This problem was eventually resolved in 1933 by Enrico Fermi who proposed the correct description of beta-decay as the emission of both an electron and an antineutrino, which carries away the apparently missing energy.[21][22]

First law of thermodynamics[edit]​

Main article: First law of thermodynamics
For a closed thermodynamic system, the first law of thermodynamics may be stated as:
{\displaystyle \delta Q=\mathrm {d} U+\delta W}
\delta Q=\mathrm {d} U+\delta W
, or equivalently, {\displaystyle \mathrm {d} U=\delta Q-\delta W,}
\mathrm {d} U=\delta Q-\delta W,

where {\displaystyle \delta Q}
\delta Q
is the quantity of energy added to the system by a heating process, {\displaystyle \delta W}
\delta W
is the quantity of energy lost by the system due to work done by the system on its surroundings and {\displaystyle \mathrm {d} U}
\mathrm {d} U
is the change in the internal energy of the system.
The δ's before the heat and work terms are used to indicate that they describe an increment of energy which is to be interpreted somewhat differently than the {\displaystyle \mathrm {d} U}
\mathrm {d} U
increment of internal energy (see Inexact differential). Work and heat refer to kinds of process which add or subtract energy to or from a system, while the internal energy {\displaystyle U}
U
is a property of a particular state of the system when it is in unchanging thermodynamic equilibrium. Thus the term "heat energy" for {\displaystyle \delta Q}
\delta Q
means "that amount of energy added as a result of heating" rather than referring to a particular form of energy. Likewise, the term "work energy" for {\displaystyle \delta W}
\delta W
means "that amount of energy lost as a result of work". Thus one can state the amount of internal energy possessed by a thermodynamic system that one knows is presently in a given state, but one cannot tell, just from knowledge of the given present state, how much energy has in the past flowed into or out of the system as a result of its being heated or cooled, nor as a result of work being performed on or by the system.
Entropy is a function of the state of a system which tells of limitations of the possibility of conversion of heat into work.
For a simple compressible system, the work performed by the system may be written:
{\displaystyle \delta W=P\,\mathrm {d} V,}
\delta W=P\,\mathrm {d} V,

where {\displaystyle P}
P
is the pressure and {\displaystyle dV}
dV
is a small change in the volume of the system, each of which are system variables. In the fictive case in which the process is idealized and infinitely slow, so as to be called quasi-static, and regarded as reversible, the heat being transferred from a source with temperature infinitesimally above the system temperature, the heat energy may be written
{\displaystyle \delta Q=T\,\mathrm {d} S,}
\delta Q=T\,\mathrm {d} S,

where {\displaystyle T}
T
is the temperature and {\displaystyle \mathrm {d} S}
\mathrm {d} S
is a small change in the entropy of the system. Temperature and entropy are variables of the state of a system.
If an open system (in which mass may be exchanged with the environment) has several walls such that the mass transfer is through rigid walls separate from the heat and work transfers, then the first law may be written:[23]
{\displaystyle \mathrm {d} U=\delta Q-\delta W+u'\,dM,}
{\displaystyle \mathrm {d} U=\delta Q-\delta W+u'\,dM,}

where {\displaystyle dM}
dM
is the added mass and {\displaystyle u'}
u'
is the internal energy per unit mass of the added mass, measured in the surroundings before the process.

Noether's theorem[edit]​

Main article: Noether's theorem
Emmy Noether (1882-1935) was an influential mathematician known for her groundbreaking contributions to abstract algebra and theoretical physics.
The conservation of energy is a common feature in many physical theories. From a mathematical point of view it is understood as a consequence of Noether's theorem, developed by Emmy Noether in 1915 and first published in 1918. The theorem states that every continuous symmetry of a physical theory has an associated conserved quantity; if the theory's symmetry is time invariance then the conserved quantity is called "energy". The energy conservation law is a consequence of the shift symmetry of time; energy conservation is implied by the empirical fact that the laws of physics do not change with time itself. Philosophically this can be stated as "nothing depends on time per se". In other words, if the physical system is invariant under the continuous symmetry of time translation then its energy (which is the canonical conjugate quantity to time) is conserved. Conversely, systems that are not invariant under shifts in time (e.g. systems with time-dependent potential energy) do not exhibit conservation of energy – unless we consider them to exchange energy with another, an external system so that the theory of the enlarged system becomes time-invariant again. Conservation of energy for finite systems is valid in physical theories such as special relativity and quantum theory (including QED) in the flat space-time.

Relativity[edit]​

With the discovery of special relativity by Henri Poincaré and Albert Einstein, the energy was proposed to be a component of an energy-momentum 4-vector. Each of the four components (one of energy and three of momentum) of this vector is separately conserved across time, in any closed system, as seen from any given inertial reference frame. Also conserved is the vector length (Minkowski norm), which is the rest mass for single particles, and the invariant mass for systems of particles (where momenta and energy are separately summed before the length is calculated).
The relativistic energy of a single massive particle contains a term related to its rest mass in addition to its kinetic energy of motion. In the limit of zero kinetic energy (or equivalently in the rest frame) of a massive particle, or else in the center of momentum frame for objects or systems which retain kinetic energy, the total energy of a particle or object (including internal kinetic energy in systems) is proportional to the rest mass or invariant mass, as described by the famous equation {\displaystyle E=mc^{2}}
E=mc^{2}
.
Thus, the rule of conservation of energy over time in special relativity continues to hold, so long as the reference frame of the observer is unchanged. This applies to the total energy of systems, although different observers disagree as to the energy value. Also conserved, and invariant to all observers, is the invariant mass, which is the minimal system mass and energy that can be seen by any observer, and which is defined by the energy–momentum relation.
In general relativity, energy–momentum conservation is not well-defined except in certain special cases. Energy-momentum is typically expressed with the aid of a stress–energy–momentum pseudotensor. However, since pseudotensors are not tensors, they do not transform cleanly between reference frames. If the metric under consideration is static (that is, does not change with time) or asymptotically flat (that is, at an infinite distance away spacetime looks empty), then energy conservation holds without major pitfalls. In practice, some metrics such as the Friedmann–Lemaître–Robertson–Walker metric do not satisfy these constraints and energy conservation is not well defined.[24] The theory of general relativity leaves open the question of whether there is a conservation of energy for the entire universe.

Quantum theory[edit]​

In quantum mechanics, energy of a quantum system is described by a self-adjoint (or Hermitian) operator called the Hamiltonian, which acts on the Hilbert space (or a space of wave functions) of the system. If the Hamiltonian is a time-independent operator, emergence probability of the measurement result does not change in time over the evolution of the system. Thus the expectation value of energy is also time independent. The local energy conservation in quantum field theory is ensured by the quantum Noether's theorem for energy-momentum tensor operator. Due to the lack of the (universal) time operator in quantum theory, the uncertainty relations for time and energy are not fundamental in contrast to the position-momentum uncertainty principle, and merely holds in specific cases (see Uncertainty principle). Energy at each fixed time can in principle be exactly measured without any trade-off in precision forced by the time-energy uncertainty relations. Thus the conservation of energy in time is a well defined concept even in quantum mechanics.

See also[edit]​


References[edit]​

  1. ^ Richard Feynman (1970). The Feynman Lectures on Physics Vol I. Addison Wesley. ISBN 978-0-201-02115-8.
  2. ^ Jump up to:a b Hagengruber, Ruth, editor (2011) Émilie du Chatelet between Leibniz and Newton. Springer. ISBN 978-94-007-2074-9.
  3. ^ Jump up to:a b Arianrhod, Robyn (2012). Seduced by logic : Émilie du Châtelet, Mary Somerville, and the Newtonian revolution (US ed.). New York: Oxford University Press. ISBN 978-0-19-993161-3.
  4. ^ Planck, M. (1923/1927). Treatise on Thermodynamics, third English edition translated by A. Ogg from the seventh German edition, Longmans, Green & Co., London, page 40.
  5. ^ Witten, Edward (1981). "A new proof of the positive energy theorem" (PDF). Communications in Mathematical Physics. 80 (3): 381–402. Bibcode:1981CMaPh..80..381W. doi:10.1007/BF01208277. ISSN 0010-3616. S2CID 1035111. Archived from the original (PDF) on 25 November 2016. Retrieved 12 December 2017.
  6. ^ Grossman, Lisa (18 January 2012). "Death-defying time crystal could outlast the universe". newscientist.com. New Scientist. Archived from the original on 2 February 2017.
  7. ^ Cowen, Ron (27 February 2012). ""Time Crystals" Could Be a Legitimate Form of Perpetual Motion". scientificamerican.com. Scientific American. Archived from the original on 2 February 2017.
  8. ^ Powell, Devin (2013). "Can matter cycle through shapes eternally?". Nature. doi:10.1038/nature.2013.13657. ISSN 1476-4687. S2CID 181223762. Archived from the original on 3 February 2017.
  9. ^ Gibney, Elizabeth (2017). "The quest to crystallize time". Nature. 543 (7644): 164–166. Bibcode:2017Natur.543..164G. doi:10.1038/543164a. ISSN 0028-0836. PMID 28277535. S2CID 4460265. Archived from the original on 13 March 2017.
  10. ^ Janko, Richard (2004). "Empedocles, "On Nature"" (PDF). Zeitschrift für Papyrologie und Epigraphik. 150: 1–26.
  11. ^ Laertius, Diogenes. Lives of Eminent Philosophers: Epicurus.[permanent dead link]. This passage comes from a letter quoted in full by Diogenes, and purportedly written by Epicurus himself in which he lays out the tenets of his philosophy.
  12. ^ Lavoisier, A.L. & Laplace, P.S. (1780) "Memoir on Heat", Académie Royale des Sciences pp. 4–355
  13. ^ von Mayer, J.R. (1842) "Remarks on the forces of inorganic nature" in Annalen der Chemie und Pharmacie, 43, 233
  14. ^ Mayer, J.R. (1845). Die organische Bewegung in ihrem Zusammenhange mit dem Stoffwechsel. Ein Beitrag zur Naturkunde, Dechsler, Heilbronn.
  15. ^ Grove, W. R. (1874). The Correlation of Physical Forces (6th ed.). London: Longmans, Green.
  16. ^ "On the Conservation of Force". Bartleby. Retrieved 6 April 2014.
  17. ^ William John Macquorn Rankine (1853) "On the General Law of the Transformation of Energy," Proceedings of the Philosophical Society of Glasgow, vol. 3, no. 5, pages 276-280; reprinted in: (1) Philosophical Magazine, series 4, vol. 5, no. 30, pages 106-117 (February 1853); and (2) W. J. Millar, ed., Miscellaneous Scientific Papers: by W. J. Macquorn Rankine, ... (London, England: Charles Griffin and Co., 1881), part II, pages 203-208: "The law of the Conservation of Energy is already known—viz. that the sum of all the energies of the universe, actual and potential, is unchangeable."
  18. ^ Hadden, Richard W. (1994). On the shoulders of merchants: exchange and the mathematical conception of nature in early modern Europe. SUNY Press. p. 13. ISBN 978-0-7914-2011-9., Chapter 1, p. 13
  19. ^ Jensen, Carsten (2000). Controversy and Consensus: Nuclear Beta Decay 1911-1934. Birkhäuser Verlag. ISBN 978-3-7643-5313-1.
  20. ^ Brown, Laurie M. (1978). "The idea of the neutrino". Physics Today. 31 (9): 23–8. Bibcode:1978PhT....31i..23B. doi:10.1063/1.2995181.
  21. ^ Wilson, F. L. (1968). "Fermi's Theory of Beta Decay". American Journal of Physics. 36 (12): 1150–1160. Bibcode:1968AmJPh..36.1150W. doi:10.1119/1.1974382.
  22. ^ Griffiths, D. (2009). Introduction to Elementary Particles (2nd ed.). pp. 314–315. ISBN 978-3-527-40601-2.
  23. ^ Born, M. (1949). Natural Philosophy of Cause and Chance, Oxford University Press, London, pp. 146–147.
  24. ^ Michael Weiss and John Baez. "Is Energy Conserved in General Relativity?". Archived from the original on 5 June 2007. Retrieved 5 January 2017.

Bibliography[edit]​

Modern accounts[edit]​

  • Goldstein, Martin, and Inge F., (1993). The Refrigerator and the Universe. Harvard Univ. Press. A gentle introduction.
  • Kroemer, Herbert; Kittel, Charles (1980). Thermal Physics (2nd ed.). W. H. Freeman Company. ISBN 978-0-7167-1088-2.
  • Nolan, Peter J. (1996). Fundamentals of College Physics, 2nd ed. William C. Brown Publishers.
  • Oxtoby & Nachtrieb (1996). Principles of Modern Chemistry, 3rd ed. Saunders College Publishing.
  • Papineau, D. (2002). Thinking about Consciousness. Oxford: Oxford University Press.
  • Serway, Raymond A.; Jewett, John W. (2004). Physics for Scientists and Engineers (6th ed.). Brooks/Cole. ISBN 978-0-534-40842-8.
  • Stenger, Victor J. (2000). Timeless Reality. Prometheus Books. Especially chpt. 12. Nontechnical.
  • Tipler, Paul (2004). Physics for Scientists and Engineers: Mechanics, Oscillations and Waves, Thermodynamics (5th ed.). W. H. Freeman. ISBN 978-0-7167-0809-4.
  • Lanczos, Cornelius (1970). The Variational Principles of Mechanics. Toronto: University of Toronto Press. ISBN 978-0-8020-1743-7.

History of ideas[edit]​

External links[edit]​


Authority control: National libraries Edit this at Wikidata
Categories:

Navigation menu​

Search​


Contribute​

Tools​

Print/export​

In other projects​

Languages​

Edit links
 
  • JFL
Reactions: MaxillaMaxing and StrangerDanger
Korea said:
.
Click to expand...
[Theory] Let’s kidnap Chico

In the next few days I will try to find his house location and monitor his daily movements and routine using some drones.
And when the moment is right a few of us can smuggle him to a warehouse where we can commence measurements of his skull.

He is however 6’5” with 99.5%ile frame so we definitely need @
2486.jpg

cocainecowboy in on this. Don’t flake, I know that you are not larping as 5’5”. We also need around 10 other birdcels, chinlets, eyelets so that we are motivated to take accurate readings of those areas that we are deficient in.

We must also take care of his skull when smuggling him and not bruise his face. (Could affect measurements)

We would give him snacks so he can keep quiet but make sure it’s low sodium and carbs otherwise he will bloat and that’s no good for our objective.

And after well mix some pills in some water so he can sleep and untie him so we can flee the place with our holy grail psl9 measurements. When he wakes up he can go home or whatever. Imagine him explaining to his wife (who probably thought he was cheating) that he was captured by some subhuman manlets and one giant who took him to a basement where they gave him snack while running measuring tape across his face and muttering ‘its over’, ‘NW2’, ‘collagencel’.

1568288395103-gif.111150



1568288462797-gif.111152


He wouldn’t even last the night!!!!!

1568288594173-gif.111154
 
  • JFL
Reactions: aesthetic beauty, Deleted member 19805, Hikicel69 and 4 others
StrangerDanger said:
[Theory] Let’s kidnap Chico

In the next few days I will try to find his house location and monitor his daily movements and routine using some drones.
And when the moment is right a few of us can smuggle him to a warehouse where we can commence measurements of his skull.

He is however 6’5” with 99.5%ile frame so we definitely need @
2486.jpg

cocainecowboy in on this. Don’t flake, I know that you are not larping as 5’5”. We also need around 10 other birdcels, chinlets, eyelets so that we are motivated to take accurate readings of those areas that we are deficient in.

We must also take care of his skull when smuggling him and not bruise his face. (Could affect measurements)

We would give him snacks so he can keep quiet but make sure it’s low sodium and carbs otherwise he will bloat and that’s no good for our objective.

And after well mix some pills in some water so he can sleep and untie him so we can flee the place with our holy grail psl9 measurements. When he wakes up he can go home or whatever. Imagine him explaining to his wife (who probably thought he was cheating) that he was captured by some subhuman manlets and one giant who took him to a basement where they gave him snack while running measuring tape across his face and muttering ‘its over’, ‘NW2’, ‘collagencel’.

1568288395103-gif.111150



1568288462797-gif.111152


He wouldn’t even last the night!!!!!

1568288594173-gif.111154
Click to expand...
LMAOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
 
  • JFL
Reactions: StrangerDanger
Korea said:
LMAOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
Click to expand...

Chico found my Chico folder​

I went into the shower and left my laptop with my Chico folder open. It's just some random folder I use when posting on this site with Chico pictures and gifs and other PSL pictures and memes inside.

When I came back from the shower I notice Chico using my laptop and I started to rage at him and he told me he borrowed it because he ”needed it to print his photoshoot”. HE PROCEEDED TO ASK ME WHY I HAVE CHICO PICTURES ON MY LAPTOP.
I just grabbed my laptop and walked away in shame.

He probably thinks I'm gay now JFL.
 
  • JFL
Reactions: aesthetic beauty, Deleted member 16801, MaxillaMaxing and 1 other person
StrangerDanger said:

Chico found my Chico folder​

I went into the shower and left my laptop with my Chico folder open. It's just some random folder I use when posting on this site with Chico pictures and gifs and other PSL pictures and memes inside.

When I came back from the shower I notice Chico using my laptop and I started to rage at him and he told me he borrowed it because he ”needed it to print his photoshoot”. HE PROCEEDED TO ASK ME WHY I HAVE CHICO PICTURES ON MY LAPTOP.
I just grabbed my laptop and walked away in shame.

He probably thinks I'm gay now JFL.
Click to expand...
Chico always knew you were gay, he just wanted to hear you say it.
 
  • JFL
Reactions: StrangerDanger
StrangerDanger said:

Chico found my Chico folder​

I went into the shower and left my laptop with my Chico folder open. It's just some random folder I use when posting on this site with Chico pictures and gifs and other PSL pictures and memes inside.

When I came back from the shower I notice Chico using my laptop and I started to rage at him and he told me he borrowed it because he ”needed it to print his photoshoot”. HE PROCEEDED TO ASK ME WHY I HAVE CHICO PICTURES ON MY LAPTOP.
I just grabbed my laptop and walked away in shame.

He probably thinks I'm gay now JFL.
Click to expand...
The fuck are these threads
 
  • JFL
Reactions: StrangerDanger
Gymcels on sudoku watch.

Chico had already hit the wall in 2017 though.

He peaked 21-22. Went downhill from there.
 
You must log in or register to reply here.

Similar threads

HighLtn
Serious 2017
Replies
2
Views
35
PARISIEN
PARISIEN
project chadlite
Not OP Rate my ethnic friend who believes he has become Chico Lachowski
Replies
11
Views
288
20/04/2008
20/04/2008
qazw
Discussion Pre-2017 internet mogs today's internet
Replies
8
Views
121
SoundnVision
SoundnVision
Pau Torres
Francisco Lachowski has a recessed jaw
Replies
1
Views
62
anthony111553
anthony111553
boxface34
  • Poll
Mog Battle (POLL) (Non frauded pics) Chico Lachowski vs Jorge Del Rio Romero
Replies
1
Views
208
boxface34
boxface34

Users who are viewing this thread

Total: 2 (Looksmaxers: 0, Bluepillers: 2)
Back
Top