https://wiki.nivel-teorico.com/index.php?action=history&feed=atom&title=Energia_de_Planck 2026-09-10T22:47:44Z Histórico de edições para esta página nesta wiki MediaWiki 1.40.1 https://wiki.nivel-teorico.com/index.php?title=Energia_de_Planck&diff=5728&oldid=prev 2013-05-03T11:16:16Z

<p>uma edição</p> <p><b>Página nova</b></p><div>Em [[física]], a unidade de [[energia]] no sistema de [[unidades naturais]] conhecida como [[unidades de Planck]] é chamada a &#039;&#039;&#039;energia de Planck&#039;&#039;&#039;, notada por &#039;&#039;E&#039;&#039;&lt;sub&gt;P&lt;/sub&gt;.<br /> <br /> :&lt;math&gt;E_p = \sqrt{\frac{\hbar c^5}{G}} \approx&lt;/math&gt; [[1 E9 J|1.956 &amp;times; 10&lt;sup&gt;9&lt;/sup&gt;]] [[Joule|J]] &lt;math&gt;\approx&lt;/math&gt; [[1 E9 J|1.22 &amp;times; 10&lt;sup&gt;19&lt;/sup&gt;]] [[GeV]] &lt;math&gt;\approx&lt;/math&gt; 0.5433 [[Quilowatt-hora|MWh]]<br /> <br /> onde &#039;&#039;c&#039;&#039; é a [[velocidade da luz]] no vácuo, &lt;math&gt;\hbar&lt;/math&gt; é a [[constante de Planck]] reduzida, e &#039;&#039;G&#039;&#039; é a [[constante gravitacional]]. &#039;&#039;E&#039;&#039;&lt;sub&gt;P&lt;/sub&gt; é a &#039;&#039;derivada&#039;&#039;, como oposta a &#039;&#039;básica&#039;&#039;, unidade de Planck.<br /> <br /> Um definição equivalente é:<br /> <br /> :&lt;math&gt;E_p = {\frac{\hbar} {t_P}},&lt;/math&gt;<br /> <br /> onde &lt;math&gt;\ t_P&lt;/math&gt; é o [[tempo de Planck]].<br /> <br /> &lt;!--<br /> <br /> The [[ultra-high-energy cosmic ray]]s observed in [[1991]] had a measured energy of about 50 [[joule]]s, equivalent to about 2.5&amp;times;10&lt;sup&gt;-8&lt;/sup&gt; &#039;&#039;E&#039;&#039;&lt;sub&gt;p&lt;/sub&gt;. Most Planck units are fantastically small and thus are unrelated to &quot;macroscopic&quot; phenomena. One &#039;&#039;E&#039;&#039;&lt;sub&gt;p&lt;/sub&gt;, on the other hand, is definitely macroscopic, approximately equaling the energy of a bolt of lightning, or two weeks&#039; per capita consumption of electricity in the [[United States]] in 2001.{{Citations missing|date=maio 2008}}<br /> <br /> Even so, &#039;&#039;E&#039;&#039;&lt;sub&gt;p&lt;/sub&gt; is a meaningful quantity in particle physics when [[gravitation]] is taken into account. The Planck energy is not only the energy needed (in principle) to probe the [[Planck length]], but is probably also the maximum possible energy that can fit into a region of that scale. A sphere 1 [[Planck length]] in diameter, containing 1 unit of Planck energy, will result in a tiny (and very hot) [[black hole]].<br /> <br /> Planck units are designed to normalize the [[physical constant]]s &lt;math&gt;\hbar&lt;/math&gt;, &#039;&#039;G&#039;&#039;, and &#039;&#039;c&#039;&#039; to 1. Hence given Planck units, the [[mass-energy equivalence]] &#039;&#039;E&#039;&#039;&amp;nbsp;=&amp;nbsp;&#039;&#039;mc&#039;&#039;² simplifies to &#039;&#039;E&#039;&#039;&amp;nbsp;=&amp;nbsp;&#039;&#039;m&#039;&#039;, so that the Planck energy and mass are numerically identical. In the equations of [[general relativity]], &#039;&#039;G&#039;&#039; is often multiplied by 8π. Hence writings in [[particle physics]] and [[physical cosmology]] often normalize 8π&#039;&#039;G&#039;&#039; to 1. This [[normalization]] results in the &#039;&#039;&#039;reduced Planck energy&#039;&#039;&#039;, defined as:<br /> :&lt;math&gt;\sqrt{\frac{\hbar{}c^5}{8\pi G}}&lt;/math&gt; &lt;math&gt;\approx&lt;/math&gt; 0.390 &amp;times; 10&lt;sup&gt;9&lt;/sup&gt; J &lt;math&gt;\approx&lt;/math&gt; 2.43 &amp;times; 10&lt;sup&gt;18&lt;/sup&gt; GeV.<br /> <br /> --&gt;<br /> <br /> == {{Ver também}} ==<br /> * [[Unidades de Planck]]<br /> * [[Constante de Planck]]<br /> * [[Princípio holográfico]]<br /> <br /> {{esboço-física}}<br /> <br /> {{DEFAULTSORT:Energia Planck}}<br /> [[Categoria:Unidades de medida]]<br /> [[Categoria:Metrologia]]</div>

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