Changes

Jump to: navigation, search

E=mc²

1 byte added, 2 April
/* A Topical Example: Speed of Extremely Energetic Neutrinos */HTTP --> HTTPS, replaced: http://www.bbc.co.uk → https://www.bbc.co.uk
The mass of a neutrino is about 0.44x10<sup>−36</sup>kilograms. (Normally all of these things are measured in more convenient units such as Giga-electron-Volts, but that makes implicit use of E=mc<sup>2</sup>. If we don't accept that, we have to do the calculations under classical physics, using SI (meter/kilogram/second) units.) The neutrinos were accelerated to an energy of about 17GeV, or .27x10<sup>−8</sup>Joules. If one did not accept relativity and had to use classical physics and the classical formula <math>\mathrm{E} = \frac{1}{2}mv^2</math>, one would get v=110x10<sup>12</sup> meters per second. This is about 370,000 times the speed of light, something that scientists would certainly have noticed. In fact, with special relativity, the speed is just under the speed of light, such that the neutrinos should be received at the detector about .26x10<sup>−24</sup> seconds (.26 yoctoseconds) later than the speed of light itself. This is far too small to measure&mdash;15 orders of magnitude smaller than the resolution of the GPS signals in the experiment.
Later [http://news.sciencemag.org/2012/02/official-word-superluminal-neutrinos-leaves-warp-drive-fans-shred-hope%E2%80%94barely?ref=hp reports] started to resolve the mystery, and it is now accepted that the neutrinos behaved properly. But a BBC reporter made the incorrect statement that [httphttps://www.bbc.co.uk/news/science-environment-17364682 the neutrinos travelled at precisely light speed]. This was a simple misstatement, by .26 yoctoseconds.
The issue was discussed at length at Conservapedia.<ref>http://www.conservapedia.com/Talk:Main_Page/Archive_index/102#Faster_than_light_neutrinos</ref><ref>http://www.conservapedia.com/Talk:Main_Page/Archive_index/102#The_final_nail_in_the_coffin_of_relativity.3F</ref><ref>http://www.conservapedia.com/Talk:Main_Page/Archive_index/102#Another_Blow_to_Relativity</ref><ref>http://www.conservapedia.com/Talk:Main_Page/Archive_index/109#Neutrinos_now_obey_speed_limit</ref><ref>http://www.conservapedia.com/Talk:Main_Page/Archive_index/111#Neutrinos</ref>
Block, SkipCaptcha, bot
55,152
edits