# Tag Info

### What are the earliest inventions to store and release energy (e.g. fly wheels)?

One early invention for storing energy was a basin above the level of the river. It was filled with water when the water in the river was high, and then, when the water in the river was low, it was ...
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### What was the vis viva controversy, including its philosophical aspects?

The controversy was ostensibly over what gets to be the "true quantity of motion", momentum or vis viva (kinetic energy), with Newton and Leibniz on the opposing sides. While there was some ...
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### What are the earliest inventions to store and release energy (e.g. fly wheels)?

This is probably not what you were thinking of but "the earliest invention that allowed energy to be stored and released after a delay even it's just a short time" was a stone. I can store ...
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### What were the early empirical tests of Einstein's mass-energy equivalence $E=mc^2$?

Let me clarify first that there are deep conceptual issues with what $E=mc^2$ means, and what it means to verify it. That energy contributes to inertial mass was known before Einstein. In 1900 ...
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### What are the earliest inventions to store and release energy (e.g. fly wheels)?

Agriculture The purpose of farming is to harness the freely available energy from the sun, and convert it into a form that can fuel the human body. Agriculture enabled significant food surpluses, ...

### Who was the first scientist to suggest that objects can keep moving without applied force?

This depends on which objects you have in mind and who you would call a scientist. There was a broad consensus in the ancient Greek natural philosophy that superlunar objects, like the stars and ...
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### Why is kinetic energy denoted by the letter $T$ in quantum mechanics?

Gaspard-Gustave Coriolis and Jean-Victor Poncelet used the name "quantité de travail" (quantity of work) and "travail mécanique" (mechanical work) to denote the kinetic energy. I guess that this (the ...
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### Why is kinetic energy denoted by the letter $T$ in quantum mechanics?

I’m pretty sure Lagrange started this, in Méchanique analitique (1788, p. 224; 1809, p. 263; 1811, p. 311; 1815, p. 2): his predecessors mostly worked with the vis viva ($=2T$) instead. (As to why he ...
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### When was the energy of the electron first measured?

I suspect what you really are after is the electron's mass, since we can then "easily" get its energy via an obscure :-) equation developed by some fellow named Einstein. The path thru measuring the ...
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### How did Huygens derive the conservation law for of kinetic energy?

There are several themes in Huygens' unpublished paper De motu corporum ex percussione ("On the motion of bodies out of collisions"), but maybe the most significant is that he frequently investigates ...
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### How did Huygens derive the conservation law for of kinetic energy?

("How did Huygens derive the conservation law for of kinetic energy?") Huygens in 'The Motion of Colliding Bodies' (English translation) contributed ingenious reasoning, mathematics and thought-...
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### How did Huygens derive the conservation law for of kinetic energy?

The "mathematics" was a combination of experiments with falling bodies, imaginative thought experiments, common sense, and geometric reasoning. Part of it is explained in the book. Galileo ...
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### Are there any direct comments by Isaac Newton on Leibniz's living force / vis-viva?

The controversy was not so much about the tension between vis viva and mechanics, as about what is the "true" quantity of motion, vis viva or momentum, and what is the "metaphysical&...
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### What are the earliest inventions to store and release energy (e.g. fly wheels)?

According to this page, charcoal was in use circa 3750 BCE. That's an energy storage medium, although perhaps not the class of energy-release you were thinking of.
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### Who discovered the Virial Theorem?

According to the OED, Clausius coined the German word "virial" (from vīs force, strength): a. In Clausius' kinetic theorem of gases: (see quots.). virial theorem, the theorem that for a steady-...
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### References about the the development of the concept of mechanical work

You can see : Agamenon Oliveira, A History of the Work Concept: From Physics to Economics, Springer (2014). Also interesting : Danilo Capecchi, History of Virtual Work Laws: A History of Mechanics ...
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### What was the vis viva controversy, including its philosophical aspects?

I must put up a clarifying answer. They groped towards different concepts and talked past each other, in the modern perspective. Much of what we call Newtonian mechanics is due to Euler, who called ...
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### History of Energy

This is a very interesting and complex topic that is far from closed. Here are some of the sources I have found. Energy the subtle concept, by Jennifer Coopersmith, is probably the book you are ...
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### How did Newton establish the conservation laws in the Principia?

In Principia Newton presents a picture based on forces rather than energy and momentum, and he did not have the concepts of vector and of mechanical energy at his disposal. Moreover, Newton opposed ...
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### Clausius regarding energy

There is a second sentence to the quote:"The energy of the universe is constant. The entropy of the universe is increasing". The conservation of energy law. The second law of thermodynamics. The quote ...
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### What are the earliest inventions to store and release energy (e.g. fly wheels)?

Tree limb. Before humans became ground bound, they used tree limbs to catapult themselves to the next tree. But seriously, probably a stone, then a stone attached to a stick, then a stone attached ...
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### What are the earliest inventions to store and release energy (e.g. fly wheels)?

How about good-old fashioned pit traps? If 'stored energy' is something where you input work ahead of time and then it is expended at a later date for a use, a pit trap is a perfect example. While ...
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### Why did energy-momentum relationship have to wait until 1928 to be established?

It is not that it had to wait to be "established", it is obtainable from what was known by trivial algebra, but rather that it had to wait for a reason to write it that way. In the early ...
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### When was relativistic mass first observed?

In theory, relativistic mass was preceded by the "electromagnetic mass" introduced by J.J. Thomson in 1881, and further developed by Heaviside (1888), Searle (1897), Poincaré (1900), Abraham (1902), ...
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### Why did energy-momentum relationship have to wait until 1928 to be established?

Actually, it wasn't Dirac who first found that relation. It was already used by Planck as early as in 1906 while deriving the Hamiltonian equations of motion Planck: The Principle of Relativity and ...
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### How did people figure out the formula for mechanical work, and related it to energy?

It was a side effect of the vis viva controversy described in What was the vis viva controversy, including its philosophical aspects? about what to call the "quantity of motion", momentum (...
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### Landau doubting conservation of energy---and what followed

In 1932 Landau speculated that the conservation of energy is not valid in neutron stars and appealed to the authority of Niels Bohr[1]: Following a beautiful idea of Professor Niels Bohr’s we are ...
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Let us consider the following info on developments prior to 1905. Before 1905 (The forthcoming of $E = mc^2$) 1881 J. J. Thompson proposed that a charged conductor in motion increases its mass by \$\...