<p>In early modern physics, the luminiferous aether (or ether) was believed to be an invisible space-filling substance or field that was a transmission medium for electromagnetic or gravitational forces.</p>
<h2>Tait's Tabulature of Knots</h2>
<p>Peter Guthrie Tait (1837-1901) was a Scottish mathematical physicist, whose investigations in knot theory contributed to the field of topology as a mathematical discipline. His tabulations of knots with ten crossings, which became known as the <em>Tait conjectures</em>, arose out of experiements he conducted with William Thomspon (Lord Kelvin) in 1867 at the University of Edinburgh.</p>
<p>Peter Guthrie Tait (1837-1901) was a Scottish mathematical physicist, whose investigations in knot theory contributed to the field of topology as a mathematical discipline. His tabulations of knots with ten crossings, which became known as the <em>Tait conjectures</em>, arose out of experiments he conducted with William Thomspon (Lord Kelvin) in 1867 at the University of Edinburgh.</p>
<aid="knot"name="knot"><h2>Knots</h2>
<p>A knot is an entanglement, an intentional complication in cordage.</p>