{"id":347,"date":"2020-03-04T08:43:25","date_gmt":"2020-03-04T08:43:25","guid":{"rendered":"https:\/\/blog.praxilabs.com\/?p=347"},"modified":"2025-09-06T21:00:05","modified_gmt":"2025-09-06T21:00:05","slug":"the-most-important-physics-discoveries-in-history-part-one","status":"publish","type":"post","link":"https:\/\/praxilabs.com\/en\/blog\/2020\/03\/04\/the-most-important-physics-discoveries-in-history-part-one\/","title":{"rendered":"The Most Important Physics Discoveries in History (Part One)"},"content":{"rendered":"<p><span style=\"font-weight: 400; font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\">Physics is our tool to perceive the universe and understand the various natural phenomena that surround us. Through our study of natural sciences and physics discoveries that had been made, we were able to harness science for making renaissance and the progress that we have reached now.<\/span><\/p>\n<p><span style=\"font-weight: 400; font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\">Therefore, physics is known as the science that is considered with studying the basic concepts such as energy, strength, and time and everything that follows these, such as mass, matter, and its movement. <\/span><\/p>\n<p><span style=\"font-weight: 400; font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\">More broadly, physics is the general analysis of nature, which aims to understand the structure of our universe and the way it functions. In this series of articles presented by PraxiLabs blog, we will highlight some of the most important discoveries in the history of physics.<\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-4627 size-full\" src=\"https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/07\/Image-Compressor.org_95KB_Important-Physics-Discoveries-2.webp\" alt=\"Important Physics Discoveries\" width=\"1562\" height=\"819\" srcset=\"https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/07\/Image-Compressor.org_95KB_Important-Physics-Discoveries-2.webp 1562w, https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/07\/Image-Compressor.org_95KB_Important-Physics-Discoveries-2-300x157.webp 300w, https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/07\/Image-Compressor.org_95KB_Important-Physics-Discoveries-2-1024x537.webp 1024w, https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/07\/Image-Compressor.org_95KB_Important-Physics-Discoveries-2-768x403.webp 768w, https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/07\/Image-Compressor.org_95KB_Important-Physics-Discoveries-2-1536x805.webp 1536w\" sizes=\"auto, (max-width: 1562px) 100vw, 1562px\" \/><\/span><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_81 counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\r\n<div class=\"ez-toc-title-container\">\r\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\r\n<span class=\"ez-toc-title-toggle\"><\/span><\/div>\r\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/praxilabs.com\/en\/blog\/2020\/03\/04\/the-most-important-physics-discoveries-in-history-part-one\/#1-_Lights_Particle_Nature\" >1-\u00a0 Light&#8217;s Particle Nature:<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/praxilabs.com\/en\/blog\/2020\/03\/04\/the-most-important-physics-discoveries-in-history-part-one\/#2-_Lights_Wave_Nature\" >2- Light&#8217;s Wave Nature:<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/praxilabs.com\/en\/blog\/2020\/03\/04\/the-most-important-physics-discoveries-in-history-part-one\/#3-_Constancy_of_light_speed_Aether\" >3- Constancy of light speed (Aether):<\/a><\/li><\/ul><\/nav><\/div>\r\n<h2><span class=\"ez-toc-section\" id=\"1-_Lights_Particle_Nature\"><\/span><span style=\"font-size: 14pt; font-family: tahoma, arial, helvetica, sans-serif;\"><strong>1-\u00a0 Light&#8217;s Particle Nature:<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><span style=\"font-weight: 400;\">One of the most common questions throughout the history of physics was \u201cwhat is <\/span><span style=\"font-weight: 400;\">light? Is<\/span><span style=\"font-weight: 400;\"> it particles or waves?\u201d In the seventeenth century, Newton came and conducted the famous prism experiment as an attempt to answer this question. <\/span><span style=\"font-weight: 400;\">At that time the belief prevailing was that white light is pure and basic, and the colors appear due to the smearing of white light during its reflectance on the surfaces.<\/span><\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><span style=\"font-weight: 400;\">Newton put a prism in a dark room and brought down a beam of white light on it. The prism caused the white light to decompose into primary colors of the visible spectrum (rainbows). <\/span><span style=\"font-weight: 400;\">Thus he concluded that white light is not pure and basic, but rather a mixture of the colors of the visible spectrum. This conclusion opposed the previous view of light&#8217;s nature.\u00a0<\/span><span style=\"font-weight: 400;\">He also thought that the decomposition of light into those colors can only be explained in terms of particle <\/span><span style=\"font-weight: 400;\">theory, as the waves<\/span><span style=\"font-weight: 400;\"> cannot behave in the same way.<\/span><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><strong>PraxiLabs is a <a href=\"https:\/\/praxilabs.com\/\">3D virtual lab<\/a> now available to all educational institutions<\/strong><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"font-family: tahoma, arial, helvetica, sans-serif; font-size: 12pt;\"><strong><a class=\"maxbutton-3 maxbutton\" href=\"https:\/\/praxilabs.com\/en\/sign-up\"><span class='mb-text'>Try 3D Virtual Labs Now for Free<\/span><\/a><\/strong><\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-5117 size-full\" src=\"https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/08\/Important-Physics-Discoveries-3.webp\" alt=\"Important Physics Discoveries\" width=\"1280\" height=\"649\" srcset=\"https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/08\/Important-Physics-Discoveries-3.webp 1280w, https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/08\/Important-Physics-Discoveries-3-300x152.webp 300w, https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/08\/Important-Physics-Discoveries-3-1024x519.webp 1024w, https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/08\/Important-Physics-Discoveries-3-768x389.webp 768w\" sizes=\"auto, (max-width: 1280px) 100vw, 1280px\" \/><\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><span style=\"font-weight: 400;\">Of course, supporters of the wave theory did not accept Newton&#8217;s results and began to question them. They said that there are defects in the prism that caused the white light to decompose into the spectrum colors.\u00a0 <\/span><span style=\"font-weight: 400;\">But Newton&#8217;s response was prompt. He placed another prism on the opposite side of the seven colors that came out of the first prism, which caused the decomposed colors to combine into one ray of the white light <\/span><span style=\"font-weight: 400;\">again!<\/span><span style=\"font-weight: 400;\"> He reversed the process.<\/span><\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><span style=\"font-weight: 400;\">Thus, Newton confirms his conclusion that the white light is composed of colored particles, which combine to form it. According to the prevalent in the scientific community at the time, light must be either waves or particles. So, Newton&#8217;s experiment was considered a victory for the particle theory of light<\/span><span style=\"font-weight: 400;\"> temporarily!<\/span><\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"2-_Lights_Wave_Nature\"><\/span><span style=\"font-size: 14pt; font-family: tahoma, arial, helvetica, sans-serif;\"><strong>2- Light&#8217;s Wave Nature:<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><span style=\"font-weight: 400;\">Newton&#8217;s particle theory of light was having an important weakness, which was the susceptibility of light to diffraction.\u00a0<\/span><span style=\"font-weight: 400;\">Francesco Grimaldian<\/span><span style=\"font-weight: 400;\">\u2014<\/span><span style=\"font-weight: 400;\">Italian physicist<\/span><span style=\"font-weight: 400;\">\u2014<\/span><span style=\"font-weight: 400;\">directed a light beam towards a barrier that contains a slit. As a result, the light beams passed through the slit and fell on the back-barrier. He observed that the light covered an area on the back-barrier larger than the area of \u200b\u200bthe slit in the first barrier.\u00a0<\/span><span style=\"font-weight: 400;\">Here he noticed that if the light is particles, it is assumed that it goes out in a straight line starting from the light source, passes through the slit, and then falls on the back-barrier making a light spot with similar size of the slit.\u00a0<\/span><span style=\"font-weight: 400;\">But what happened in this experiment is that the light beams diffracted in all directions during its passing through the slit, causing a spot of light on the back-barrier larger than the size of the slit.<\/span><\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-350\" src=\"https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2020\/03\/unnamed-1.gif\" alt=\"\" width=\"512\" height=\"125\" \/><\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><span style=\"font-weight: 400;\">Newton tried to explain the light diffraction in terms of particle theory but he was not convincing to many in his explanation<\/span><span style=\"font-weight: 400;\">, as he<\/span><span style=\"font-weight: 400;\"> said that the diffraction of light is just a new type of refraction. <\/span><span style=\"font-weight: 400;\">But the Christian Huygens<\/span><span style=\"font-weight: 400;\">\u2014<\/span><span style=\"font-weight: 400;\">Dutch physicist<\/span><span style=\"font-weight: 400;\">\u2014<\/span><span style=\"font-weight: 400;\">developed the wave theory of light, explained the light diffraction phenomenon in a structured mathematical framework, and explained the laws of refraction and reflection. <\/span><span style=\"font-weight: 400;\">Then the British physicist Thomas Young conducted the interference experiment, which settled the matter of the light&#8217;s wave nature. The interference experiment is very similar to the diffraction experiment, but with two slits instead of one. It was assumed that we would see only two light spots on the back-barrier if Newton was right. <\/span><span style=\"font-weight: 400;\">But what happened was otherwise, as there were successive sets of bright and dark spots on the back-barrier after the light passed through the two slits.<\/span><\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><span style=\"font-weight: 400;\">This was an indication of the interference of the two beams of light that came out of the two slits. In some places, the overlap between the two beams was a constructive one, so we get a more bright spot. Elsewhere, the overlap was destructive, and the two beams eliminated each other leaving a dark spot. Thus, there was conclusive evidence that light is waves.\u00a0 <\/span><span style=\"font-weight: 400;\">Then Maxwell came up with his four <a href=\"https:\/\/praxilabs.com\/en\/blog\/2019\/05\/06\/3-most-important-physics-equations-in-history\/\">equations of electromagnetic<\/a> theory, which confirmed that light is electromagnetic waves.<\/span><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><strong>PraxiLabs <a href=\"https:\/\/praxilabs.com\/en\/virtual-labs\">virtual labs<\/a> provides a set of wave experiments<\/strong><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"font-family: tahoma, arial, helvetica, sans-serif; font-size: 12pt;\"><strong><a class=\"maxbutton-3 maxbutton\" href=\"https:\/\/praxilabs.com\/en\/pricing\"><span class='mb-text'>Pick The Best Virtual Plan forYou<\/span><\/a><\/strong><\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-5118 size-full\" src=\"https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/08\/Important-Physics-Discoveries-4.webp\" alt=\"Important Physics Discoveries\" width=\"1024\" height=\"683\" srcset=\"https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/08\/Important-Physics-Discoveries-4.webp 1024w, https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/08\/Important-Physics-Discoveries-4-300x200.webp 300w, https:\/\/praxilabs.com\/en\/blog\/wp-content\/uploads\/2025\/08\/Important-Physics-Discoveries-4-768x512.webp 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"3-_Constancy_of_light_speed_Aether\"><\/span><span style=\"font-size: 14pt; font-family: tahoma, arial, helvetica, sans-serif;\"><strong>3- Constancy of light speed (Aether):<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><span style=\"font-weight: 400;\">After the success and widespread of electromagnetic theory in the nineteenth century, scientists accepted the wave nature of light. Then a new question was asked on the scene, which was (<\/span><span style=\"font-weight: 400;\">what<\/span><span style=\"font-weight: 400;\"> is the nature of the medium that light waves need to propagate?). <\/span><\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><span style=\"font-weight: 400;\">Just as water waves, they need the water as the medium of propagation. And sound waves need air. So, scientists believed that the electromagnetic waves of light will need a medium to propagate through it. They believed that this medium filled all space and even emptiness since light waves were spreading into emptiness as well.\u00a0 <\/span><span style=\"font-weight: 400;\">They believed that this medium filled all space and even emptiness since light waves were spreading into emptiness as well. Scientists called this medium<\/span><span style=\"font-weight: 400;\"> \u201cAether,\u201d <\/span><span style=\"font-weight: 400;\">named after the Greek god of light. <\/span><\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><span style=\"font-weight: 400;\">Since the Earth revolves around the sun at a speed of more than 1000 km per h<\/span><span style=\"font-weight: 400;\">our, th<\/span><span style=\"font-weight: 400;\">e relative movement between the Earth and the Ae<\/span><span style=\"font-weight: 400;\">ther, where light waves move, <\/span><span style=\"font-weight: 400;\">assumed to change the light&#8217;s speed according to the direction the Earth movement in the Aether.<\/span><\/span><\/p>\n<p><span style=\"font-weight: 400; font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\">To clarify, you can imagine yourself on a boat, where the seawater is the Aether, the water waves are the light waves, and the boat is the Earth. Assuming that your boat is moving in the sea, the speed of the sea waves will vary relative to the direction of movement of your boat in the sea.<\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><span style=\"font-weight: 400;\">American physicists Albert Mickelson and Edward Morley conducted an experiment to measure the difference in the light speed caused by the Earth&#8217;s motion relative to the Aether.\u00a0 <\/span><span style=\"font-weight: 400;\">Their experiment used the property of light interference, where a single-frequency light comes out from a certain source. It is separated into two beams<\/span><span style=\"font-weight: 400;\">\u2014<\/span><span style=\"font-weight: 400;\">reflected and refracted<\/span><span style=\"font-weight: 400;\">\u2014<\/span><span style=\"font-weight: 400;\">by a semi-reflective mirror. Then the two beams are combined again using other mirrors, to obtain a constructive and destructive interference. <\/span><span style=\"font-weight: 400;\">The measurements of this interference will determine the change in two beams&#8217; speed. The results of that experiment were shocking, as there was no difference or change in the speed of light coming from any direction. And that means that there is nothing called Aether!<\/span><\/span><\/p>\n<p><span style=\"font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\"><span style=\"font-weight: 400;\">These results led to numerous attempts by scientists to present many theories that may explain what happened. Until Albert Einstein came and published four scientific papers that were a turning point in the <a href=\"https:\/\/en.wikipedia.org\/wiki\/History_of_physics\" target=\"_blank\" rel=\"noopener\">history of physics<\/a>. One of those papers was a paper containing a new theory that presented a new concept of the universe structure (space-time). And it put the laws that control the objects which move in high speeds. <\/span><span style=\"font-weight: 400;\">Einstein built his new theory based on a fundamental point: &#8220;The speed of light in a vacuum is universal physical constant, it is independent of the motion of the source or observer.&#8221; This was the theory of special relativity.<\/span><\/span><\/p>\n<p><span style=\"font-weight: 400; font-size: 12pt; font-family: tahoma, arial, helvetica, sans-serif;\">In the second part, we will highlight another set of the most important physics discoveries.<\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"font-family: tahoma, arial, helvetica, sans-serif; font-size: 12pt;\"><strong>PraxiLabs Virtual Labs include a range of\u00a0<a href=\"https:\/\/praxilabs.com\/en\/3d-science-simulations\" target=\"_blank\" rel=\"noopener\">3D science experiments<\/a>\u00a0in physics, chemistry and biology experiments<\/strong><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"font-family: tahoma, arial, helvetica, sans-serif; font-size: 12pt;\"><strong><a class=\"maxbutton-3 maxbutton\" href=\"https:\/\/praxilabs.com\/en\/request-free-demo\"><span class='mb-text'>Request a Free Demo Now<\/span><\/a><\/strong><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Physics is our tool to perceive the universe and understand the various natural phenomena that surround us. Through our study of natural sciences and physics discoveries that had been made, we were able to harness science for making renaissance and the progress that we have reached now. Therefore, physics is known as the science that &hellip;<\/p>\n","protected":false},"author":3,"featured_media":4470,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_lmt_disableupdate":"no","_lmt_disable":"no","footnotes":""},"categories":[4,8],"tags":[],"class_list":["post-347","post","type-post","status-publish","format-standard","has-post-thumbnail","","category-physics","category-scientific-facts"],"modified_by":"Muhamed Elmesery","_links":{"self":[{"href":"https:\/\/praxilabs.com\/en\/blog\/wp-json\/wp\/v2\/posts\/347","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/praxilabs.com\/en\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/praxilabs.com\/en\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/praxilabs.com\/en\/blog\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/praxilabs.com\/en\/blog\/wp-json\/wp\/v2\/comments?post=347"}],"version-history":[{"count":9,"href":"https:\/\/praxilabs.com\/en\/blog\/wp-json\/wp\/v2\/posts\/347\/revisions"}],"predecessor-version":[{"id":5276,"href":"https:\/\/praxilabs.com\/en\/blog\/wp-json\/wp\/v2\/posts\/347\/revisions\/5276"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/praxilabs.com\/en\/blog\/wp-json\/wp\/v2\/media\/4470"}],"wp:attachment":[{"href":"https:\/\/praxilabs.com\/en\/blog\/wp-json\/wp\/v2\/media?parent=347"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/praxilabs.com\/en\/blog\/wp-json\/wp\/v2\/categories?post=347"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/praxilabs.com\/en\/blog\/wp-json\/wp\/v2\/tags?post=347"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}