SherbyNet - /page/wikibook/entry.mu

Micron Document

<!DOCTYPE html>

<title>Preferred frame</title>

</head>

<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Preferred frame</span></span>

</h1>

</header>

<p>In <a href="Theoretical_physics" title="Theoretical physics">theoretical physics</a>, a <b>preferred frame</b> or <b>privileged frame</b> is usually a special <a href="Hypothetical" class="mw-redirect" title="Hypothetical">hypothetical</a> <a href="Frame_of_reference" title="Frame of reference">frame of reference</a> in which the <a href="Laws_of_physics" class="mw-redirect" title="Laws of physics">laws of physics</a> might appear to be identifiably different (simpler) from those in other frames.

</p><p>In theories that apply the <a href="Principle_of_relativity" title="Principle of relativity">principle of relativity</a> to <a href="Inertia" title="Inertia">inertial</a> motion, physics is the same in all <a href="Inertial_frame" class="mw-redirect" title="Inertial frame">inertial frames</a>, and is even the same in all frames under the principle of <a href="General_relativity" title="General relativity">general relativity</a>.

</p>

<div class="mw-heading mw-heading2"><h2 id="Preferred_frame_in_aether_theory">Preferred frame in aether theory</h2></div>

/* start https://en.wikipedia.org/ */

.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}

/* end https://en.wikipedia.org/ */

</style>

<p>In theories that presume that light travels at a fixed speed relative to an unmodifiable and detectable <a href="Luminiferous_aether" title="Luminiferous aether">luminiferous aether</a>, a preferred frame would be a frame in which this aether would be stationary. In 1887, <a href="Michelson%E2%80%93Morley_experiment" title="Michelson–Morley experiment">Michelson and Morley</a> tried to identify the state of motion of the aether. To do so, they assumed Galilean relativity to be satisfied by clocks and rulers; that is, that the length of rulers and periods of clocks are invariant under any Galilean frame change. Under such an hypothesis, the aether should have been observed.

</p><p>By comparing measurements made in different directions and looking for an effect due to the Earth's orbital speed, their experiment famously produced a <a href="Null_result" title="Null result">null result</a>. As a consequence, within <a href="Lorentz_ether_theory" title="Lorentz ether theory">Lorentz ether theory</a> the <a href="Galilean_transformation" title="Galilean transformation">Galilean transformation</a> was replaced by the <a href="Lorentz_transformation" title="Lorentz transformation">Lorentz transformation</a>. However, in Lorentz aether theory the existence of an undetectable aether is assumed and the relativity principle holds. The theory was quickly replaced by <a href="Special_relativity" title="Special relativity">special relativity</a>, which gave similar formulas without the existence of an unobservable aether. All inertial frames are physically equivalent, in both theories. More precisely, provided that no phenomenon violates the principle of relativity of motion, there is no means to measure the velocity of an inertial observer with regard to a possible medium of propagation of quantum waves.

</p>

<div class="mw-heading mw-heading2"><h2 id="Inertial_frames_preferred_above_noninertial_frames">Inertial frames preferred above noninertial frames</h2></div>

/* start https://en.wikipedia.org/ */

.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}

/* end https://en.wikipedia.org/ */

</style><div role="note" class="hatnote navigation-not-searchable">Further information: <a href="Absolute_space_and_time" title="Absolute space and time">Absolute space and time</a></div>

<p>Although all inertial frames are equivalent under <a href="Classical_mechanics" title="Classical mechanics">classical mechanics </a> and <a href="Special_relativity" title="Special relativity">special relativity</a>, the set of all inertial frames is privileged over non-inertial frames in these theories.<sup id="cite_ref-Ferraro_1-0" class="reference"><a href="#cite_note-Ferraro-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 10">: 10 </span></sup> Inertial frames are privileged because they do not have physics whose causes are outside of the system, while non-inertial frames do. Einstein gives the following example: suppose two equally-<a href="Chemical_composition" title="Chemical composition">composed</a> elastic bodies are in space and distant from each other such that the interaction between them can be ignored, and whose only relative motion is a uniform rigid rotation around the line joining the centers of both bodies (like spinning wheels around an <a href="Axle" title="Axle">axle</a>). One of the bodies is a <a href="Sphere" title="Sphere">sphere</a>, and the other is a <a href="Spheroid" title="Spheroid">spheroid</a>, a squashed sphere. The observable <a href="Proper_length" title="Proper length">proper</a> physical shape of the bodies remains the same in all frames. The non-rotating-spheroid frame has physics whose cause lies outside the system, responsible for the oblateness of the spheroid. The non-rotating-sphere frame does not, which makes it privileged in that it doesn't require external causes. This applies to all inertial frames, who are privileged in the same regard.<sup id="cite_ref-Ferraro_1-1" class="reference"><a href="#cite_note-Ferraro-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 209">: 209 </span></sup> Einstein went on to develop <a href="General_relativity" title="General relativity">general relativity</a> and the <a href="Equivalence_principle" title="Equivalence principle">equivalence principle</a>, in which inertial-gravitational frames are no longer privileged,<sup id="cite_ref-Ferraro_1-2" class="reference"><a href="#cite_note-Ferraro-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 215–223">: 215–223 </span></sup> because the <a href="Geodesics_in_general_relativity" title="Geodesics in general relativity">geodesics</a> of <a href="Spacetime" title="Spacetime">spacetime</a> explain these inertial-gravitational effects without an external cause.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup>

</p>

<ul><li><a href="Tests_of_special_relativity" title="Tests of special relativity">Tests of special relativity</a></li>

<li><a href="Modern_searches_for_Lorentz_violation" title="Modern searches for Lorentz violation">Modern searches for Lorentz violation</a></li>

<li><a href="Cosmic_microwave_background" title="Cosmic microwave background">Cosmic microwave background</a></li>

<li><a href="Test_theories_of_special_relativity" title="Test theories of special relativity">Test theories of special relativity</a></li></ul>

<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

/* start https://en.wikipedia.org/ */

.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}

/* end https://en.wikipedia.org/ */

</style><div class="reflist">

/* start https://en.wikipedia.org/ */

.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("./mw/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("./mw/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("./mw/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("./mw/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}

/* end https://en.wikipedia.org/ */

</style><cite id="CITEREFFerraro2007" class="citation cs2">Ferraro, Rafael (2007), <i>Einstein's Space-Time: An Introduction to Special and General Relativity</i>, Springer Science & Business Media, <a href="Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2007esti.book.....F">2007esti.book.....F</a>, <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>9780387699462</bdi></cite></span>

</li>

<li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><cite id="CITEREFGilson2004" class="citation cs2">Gilson, James G. (September 1, 2004), <i>Mach's Principle II</i>, <a href="ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://arxiv.org/abs/physics/0409010">physics/0409010</a></span>, <a href="Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2004physics...9010G">2004physics...9010G</a></cite></span>

</li>

</ol></div></div>

<div class="mw-heading mw-heading2"><h2 id="Further_reading">Further reading</h2></div>

<ul><li>Einstein (1954) <i>Relativity, the special and the general theories</i></li></ul></div><div><div class="zim-footer">

This article is issued from <a class="external text" title="Last edited on 2022-02-16" href="https://en.wikipedia.org/wiki/?title=Preferred_frame&oldid=1072274017">Wikipedia</a>. The text is available under <a class="external text" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en">Creative Commons Attribution-Share Alike 4.0</a> unless otherwise noted. Additional terms may apply for the media files.

</div>

</div></div>

</div>

</main>

</div>

</body></html>