<?xml version="1.0"?>
<oembed><version>1.0</version><provider_name>book&#x2777;net book scanners</provider_name><provider_url>https://book2net.net/en/</provider_url><author_name>Karin</author_name><author_url>https://book2net.net/en/author/karin/</author_url><title>Light spectrum - book&#x2777;net book scanners</title><type>rich</type><width>600</width><height>338</height><html>&lt;blockquote class="wp-embedded-content" data-secret="7FGf4XRzjD"&gt;&lt;a href="https://book2net.net/en/2022/06/20/light-spectrum/"&gt;Light spectrum&lt;/a&gt;&lt;/blockquote&gt;&lt;iframe sandbox="allow-scripts" security="restricted" src="https://book2net.net/en/2022/06/20/light-spectrum/embed/#?secret=7FGf4XRzjD" width="600" height="338" title="&#x201C;Light spectrum&#x201D; &#x2014; book&#x2777;net book scanners" data-secret="7FGf4XRzjD" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"&gt;&lt;/iframe&gt;&lt;script type="text/javascript"&gt;
/* &lt;![CDATA[ */
/*! This file is auto-generated */
!function(d,l){"use strict";l.querySelector&amp;&amp;d.addEventListener&amp;&amp;"undefined"!=typeof URL&amp;&amp;(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&amp;&amp;!/[^a-zA-Z0-9]/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret="'+t.secret+'"]'),o=l.querySelectorAll('blockquote[data-secret="'+t.secret+'"]'),c=new RegExp("^https?:$","i"),i=0;i&lt;o.length;i++)o[i].style.display="none";for(i=0;i&lt;a.length;i++)s=a[i],e.source===s.contentWindow&amp;&amp;(s.removeAttribute("style"),"height"===t.message?(1e3&lt;(r=parseInt(t.value,10))?r=1e3:~~r&lt;200&amp;&amp;(r=200),s.height=r):"link"===t.message&amp;&amp;(r=new URL(s.getAttribute("src")),n=new URL(t.value),c.test(n.protocol))&amp;&amp;n.host===r.host&amp;&amp;l.activeElement===s&amp;&amp;(d.top.location.href=t.value))}},d.addEventListener("message",d.wp.receiveEmbedMessage,!1),l.addEventListener("DOMContentLoaded",function(){for(var e,t,s=l.querySelectorAll("iframe.wp-embedded-content"),r=0;r&lt;s.length;r++)(t=(e=s[r]).getAttribute("data-secret"))||(t=Math.random().toString(36).substring(2,12),e.src+="#?secret="+t,e.setAttribute("data-secret",t)),e.contentWindow.postMessage({message:"ready",secret:t},"*")},!1)))}(window,document);
/* ]]&gt; */
&lt;/script&gt;
</html><description>The light spectrum is the visible range of the electromagnetic spectrum that can be perceived by the eye. The spectral range visible to humans is between 380 and 780 nanometers, corresponding to a frequency range of about 4-1014 to 7.5-1014 Hz.</description></oembed>
