{"id":104,"date":"2025-03-02T22:44:02","date_gmt":"2025-03-02T22:44:02","guid":{"rendered":"https:\/\/sebstack.com\/?page_id=104"},"modified":"2026-04-14T14:57:16","modified_gmt":"2026-04-14T14:57:16","slug":"steinmetzs-theoretical-elements","status":"publish","type":"page","link":"https:\/\/sebstack.com\/index.php\/steinmetzs-theoretical-elements\/","title":{"rendered":"Steinmetz&#8217;s Theoretical Elements"},"content":{"rendered":"\n<p><strong>PART I.<br>GENERAL THEORY.<\/strong><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. MAGNETISM AND ELECTRIC CURRENT.<\/h3>\n\n\n\n<p>A magnet pole attracting (or repelling) another magnet pole of equal strength at unit distance with unit force is called a <strong>unit magnet pole<\/strong>.<\/p>\n\n\n\n<p>The space surrounding a magnet pole is called a <strong>magnetic field of force<\/strong>, or <strong>magnetic field<\/strong>.<\/p>\n\n\n\n<p>The magnetic field at unit distance from a unit magnet pole is called a <strong>unit magnetic field<\/strong>, and is represented by <strong>one line of magnetic force<\/strong> (or shortly &#8220;one line&#8221;) per square centimeter. From a unit magnet pole, a total of [math] 4\\pi [\/math] lines of magnetic force issue.<\/p>\n\n\n\n<p>The <strong>total number of lines of force<\/strong> issuing from a magnet pole is called its <strong>magnetic flux<\/strong>.<\/p>\n\n\n\n<p>The <strong>magnetic flux<\/strong> [math] \\Phi [\/math] of a magnet pole of strength [math] m [\/math] is given by:<\/p>\n\n\n\n<p>[math] \\Phi = 4 \\pi m. [\/math]<\/p>\n\n\n\n<p>At a distance [math] R [\/math] from a magnet pole of strength [math] m [\/math], and therefore of flux [math] \\Phi = 4 \\pi m [\/math], the magnetic field has the intensity:<\/p>\n\n\n\n<p>[math] H = \\frac{4\\pi m}{4\\pi R^2} = \\frac{m}{R^2}, [\/math]<\/p>\n\n\n\n<p>since the [math] \\Phi [\/math] lines issuing from the pole distribute over the area of a sphere of radius [math] R [\/math], that is, the area [math] 4\\pi R^2 [\/math].<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"425\" height=\"321\" src=\"https:\/\/sebstack.com\/wp-content\/uploads\/2025\/08\/image.png\" alt=\"\" class=\"wp-image-356\" srcset=\"https:\/\/sebstack.com\/wp-content\/uploads\/2025\/08\/image.png 425w, https:\/\/sebstack.com\/wp-content\/uploads\/2025\/08\/image-300x227.png 300w\" sizes=\"auto, (max-width: 425px) 100vw, 425px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"418\" height=\"687\" src=\"https:\/\/sebstack.com\/wp-content\/uploads\/2025\/08\/image-1.png\" alt=\"\" class=\"wp-image-357\" srcset=\"https:\/\/sebstack.com\/wp-content\/uploads\/2025\/08\/image-1.png 418w, https:\/\/sebstack.com\/wp-content\/uploads\/2025\/08\/image-1-183x300.png 183w\" sizes=\"auto, (max-width: 418px) 100vw, 418px\" \/><\/figure>\n\n\n\n<p>In historical physics and engineering literature, especially texts grounded in the CGS electrostatic (ESU) system, one often encounters unit conversions involving seemingly peculiar numerical factors. A notable example is the constant [math]1.11 \\times 10^{-6}[\/math], which appears in equations converting CGS-based capacitance formulas into practical SI-based expressions, particularly when computing capacitance per unit length in coaxial or parallel-wire geometries.<\/p>\n\n\n\n<p>To understand this factor, we begin with the fundamental conversion between capacitance units:<\/p>\n\n\n\n<p>From classical sources:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>[math]1 \\ \\text{statfarad} = 1.111\\ldots \\times 10^{-12} \\ \\text{farads}[\/math]<\/li>\n<\/ul>\n\n\n\n<p>This is derived from the identity:<\/p>\n\n\n<p>[math]<br \/>\n1 \\ \\text{statfarad} = \\frac{1}{9 \\times 10^{11}} \\ \\text{farads} = 1.111\\ldots \\times 10^{-12} \\ \\text{F}<br \/>\n[\/math]<\/p>\n\n\n\n<p>Converting farads into millifarads (noting that [math]1 \\ \\text{F} = 1000 \\ \\text{mf}[\/math]):<\/p>\n\n\n<p>[math]<br \/>\n1.111\\ldots \\times 10^{-12} \\ \\text{F} = 1.111\\ldots \\times 10^{-9} \\ \\text{mf}<br \/>\n[\/math]<\/p>\n\n\n\n<p>However, in several historical references, including early electromagnetic texts, the coefficient used in the capacitance per unit length formula is not [math]10^{-9}[\/math], but rather:<\/p>\n\n\n<p>[math]<br \/>\nC = 1.11 \\times 10^{-6} \\cdot \\frac{l}{\\log_e \\left( \\frac{2D}{d} \\right)} \\ \\text{mf}<br \/>\n[\/math]<\/p>\n\n\n\n<p>At first glance, this appears inconsistent. The key lies in understanding the role and meaning of the coefficient [math]1.11 \\times 10^{-6}[\/math]. This constant is not merely a conversion from statfarads to farads; it encapsulates multiple layers of transformation:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Conversion from statfarads per centimeter (CGS-ESU) to millifarads per meter (SI)<\/strong><br>Since geometrical parameters like [math]l[\/math], [math]d[\/math], and [math]D[\/math] are expressed in centimeters in the CGS system, while practical capacitance values are often required in SI-derived units (millifarads), the conversion must also account for a change in length scale (centimeters to meters).<\/li>\n\n\n\n<li><strong>Incorporation of the electrostatic constant [math]4\\pi \\varepsilon_0[\/math]<\/strong><br>SI expressions for capacitance include the vacuum permittivity constant, while ESU units embed it in the definition of the unit itself. Transitioning between systems involves absorbing this factor numerically.<\/li>\n\n\n\n<li><strong>Unit transformation to practical quantities<\/strong><br>Engineers and physicists commonly express small capacitance values in millifarads for ease of calculation and readability. The factor [math]1.11 \\times 10^{-6}[\/math] is scaled accordingly.<\/li>\n<\/ol>\n\n\n\n<p>In sum, the constant:<\/p>\n\n\n<p>[math]<br \/>\n1.11 \\times 10^{-6}<br \/>\n[\/math]<\/p>\n\n\n\n<p>functions as a compact numerical bridge between CGS electrostatic capacitance per centimeter and SI millifarads per meter, while inherently incorporating:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The statfarad-to-farad conversion<\/li>\n\n\n\n<li>The centimeter-to-meter length scaling<\/li>\n\n\n\n<li>The absorption of physical constants specific to each system<\/li>\n\n\n\n<li>A rescaling to practical engineering units<\/li>\n<\/ul>\n\n\n\n<p>It is best interpreted as the <strong>number of millifarads per centimeter per ESU unit of capacitance<\/strong>, appropriately scaled and normalized to fit into modern electrostatics expressions involving logarithmic geometry factors.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"429\" height=\"678\" src=\"https:\/\/sebstack.com\/wp-content\/uploads\/2025\/08\/image-2.png\" alt=\"\" class=\"wp-image-359\" srcset=\"https:\/\/sebstack.com\/wp-content\/uploads\/2025\/08\/image-2.png 429w, https:\/\/sebstack.com\/wp-content\/uploads\/2025\/08\/image-2-190x300.png 190w\" sizes=\"auto, (max-width: 429px) 100vw, 429px\" \/><\/figure>\n\n\n\n<div data-wp-interactive=\"core\/file\" class=\"wp-block-file\"><object data-wp-bind--hidden=\"!state.hasPdfPreview\" hidden class=\"wp-block-file__embed\" data=\"https:\/\/sebstack.com\/wp-content\/uploads\/2026\/04\/steinmetz-trigonometry3.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"Embed of steinmetz-trigonometry3.\"><\/object><a id=\"wp-block-file--media-e0303a7d-6a6c-4886-b711-f124e8a1cbd4\" href=\"https:\/\/sebstack.com\/wp-content\/uploads\/2026\/04\/steinmetz-trigonometry3.pdf\">steinmetz-trigonometry3<\/a><a href=\"https:\/\/sebstack.com\/wp-content\/uploads\/2026\/04\/steinmetz-trigonometry3.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-e0303a7d-6a6c-4886-b711-f124e8a1cbd4\">Download<\/a><\/div>\n\n\n\n<p><a href=\"https:\/\/sebstack.com\/wp-content\/uploads\/2026\/04\/steinmetz-trigonometry3.pdf\">https:\/\/sebstack.com\/wp-content\/uploads\/2026\/04\/steinmetz-trigonometry3.pdf<\/a><\/p>\n\n\n\n<div data-wp-interactive=\"core\/file\" class=\"wp-block-file\"><object data-wp-bind--hidden=\"!state.hasPdfPreview\" hidden class=\"wp-block-file__embed\" data=\"https:\/\/sebstack.com\/wp-content\/uploads\/2026\/04\/Steinmetz-trigs-3-tablet-size.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"Embed of Steinmetz trigs 3 - tablet size.\"><\/object><a id=\"wp-block-file--media-4f613437-2d80-43dd-bb52-b711bb845b4d\" href=\"https:\/\/sebstack.com\/wp-content\/uploads\/2026\/04\/Steinmetz-trigs-3-tablet-size.pdf\">Steinmetz trigs 3 &#8211; tablet size<\/a><a href=\"https:\/\/sebstack.com\/wp-content\/uploads\/2026\/04\/Steinmetz-trigs-3-tablet-size.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-4f613437-2d80-43dd-bb52-b711bb845b4d\">Download<\/a><\/div>\n\n\n\n<p><a href=\"https:\/\/sebstack.com\/wp-content\/uploads\/2026\/04\/Steinmetz-trigs-3-tablet-size.pdf\">https:\/\/sebstack.com\/wp-content\/uploads\/2026\/04\/Steinmetz-trigs-3-tablet-size.pdf<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>PART I.GENERAL THEORY. 1. MAGNETISM AND ELECTRIC CURRENT. A magnet pole attracting (or repelling) another magnet pole of equal strength at unit distance with unit force is called a unit magnet pole. The space surrounding a magnet pole is called a magnetic field of force, or magnetic field. The magnetic field at unit distance from [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-104","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sebstack.com\/index.php\/wp-json\/wp\/v2\/pages\/104","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sebstack.com\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sebstack.com\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sebstack.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sebstack.com\/index.php\/wp-json\/wp\/v2\/comments?post=104"}],"version-history":[{"count":7,"href":"https:\/\/sebstack.com\/index.php\/wp-json\/wp\/v2\/pages\/104\/revisions"}],"predecessor-version":[{"id":410,"href":"https:\/\/sebstack.com\/index.php\/wp-json\/wp\/v2\/pages\/104\/revisions\/410"}],"wp:attachment":[{"href":"https:\/\/sebstack.com\/index.php\/wp-json\/wp\/v2\/media?parent=104"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}