{"id":304,"date":"2015-01-28T12:47:50","date_gmt":"2015-01-28T17:47:50","guid":{"rendered":"http:\/\/sites.williams.edu\/scientephic\/?p=304"},"modified":"2015-10-18T19:44:01","modified_gmt":"2015-10-18T23:44:01","slug":"ask-a-physics-student-what-is-energy","status":"publish","type":"post","link":"https:\/\/sites.williams.edu\/scientephic\/news\/ask-a-physics-student-what-is-energy\/","title":{"rendered":"Ask a Physics Student: What is Energy?"},"content":{"rendered":"

Today we continue our “Ask A Science Student” series. For the previous response, click here<\/a>.<\/p>\n

Ask a Science Student, Part 2: Physics<\/strong><\/p>\n

By Matt Radford ’16<\/em><\/p>\n

Energy has many different forms. Electrical, thermal, and mechanical kinetic energy are all forms associated with moving objects. Potential energy is dependent on an object\u2019s position in a field, such as apples hanging in a tree, or an object\u2019s position relative to its parts, such as a drawn longbow. An apple also has digestible energy, usually measured in calories. Other units of energy commonly found in day-to-day life include the watt-hour, which probably shows up on your electricity bill, and the British Thermal Unit, which is likely mentioned on any air conditioning unit.<\/p>\n

<\/p>\n

To define energy, physicists use the unit of the joule. \u00a0The work done on an object by a force of one Newton over a distance of one meter is equivalent to transferring one joule of energy to the object.\u00a0Another measure of the energy of a system is its mass. Einstein\u2019s famous says that mass and energy are just two sides of the same mass-energy coin. However, the observed amount of matter in our universe \u2013 stars, black holes, galaxies \u2013 doesn\u2019t account for nearly enough of the mass-energy required for our universe to behave the way it does. \u201cDark\u201d energy is the makes up the rest of the universe, and it contributes to the expansion of the universe. It is less dense than ordinary matter, but it is of roughly uniform density across space, and it accounts for over two-thirds of the universe\u2019s mass-energy.<\/p>\n

In describing energy, physicist Richard Feynman said that \u201cit is important to realize that in physics today, we have no knowledge of what energy \u2018is.\u2019 We do not have a picture that energy comes in little blobs of a definite amount. It is not that way. It is an abstract thing in that it does not tell us the mechanism or the reason for the various formulas.\u201d<\/p>\n

Image source: http:\/\/www.hdwallpapersnew.net\/apple-tree-desktop-wallpapers\/<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

Today we continue our “Ask A Science Student” series. For the previous response, click here. Ask a Science Student, Part 2: Physics By Matt Radford ’16 Energy has many different forms. Electrical, thermal, and mechanical kinetic energy are all forms associated with moving objects. Potential energy is dependent on an object\u2019s position in a field, … Continue reading Ask a Physics Student: What is Energy?<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":922,"featured_media":307,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"ngg_post_thumbnail":0,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[21878,65457],"tags":[],"class_list":["post-304","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","category-physics"],"acf":[],"_links":{"self":[{"href":"https:\/\/sites.williams.edu\/scientephic\/wp-json\/wp\/v2\/posts\/304","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.williams.edu\/scientephic\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sites.williams.edu\/scientephic\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sites.williams.edu\/scientephic\/wp-json\/wp\/v2\/users\/922"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.williams.edu\/scientephic\/wp-json\/wp\/v2\/comments?post=304"}],"version-history":[{"count":6,"href":"https:\/\/sites.williams.edu\/scientephic\/wp-json\/wp\/v2\/posts\/304\/revisions"}],"predecessor-version":[{"id":322,"href":"https:\/\/sites.williams.edu\/scientephic\/wp-json\/wp\/v2\/posts\/304\/revisions\/322"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sites.williams.edu\/scientephic\/wp-json\/wp\/v2\/media\/307"}],"wp:attachment":[{"href":"https:\/\/sites.williams.edu\/scientephic\/wp-json\/wp\/v2\/media?parent=304"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sites.williams.edu\/scientephic\/wp-json\/wp\/v2\/categories?post=304"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sites.williams.edu\/scientephic\/wp-json\/wp\/v2\/tags?post=304"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}