Physics Help Forum Time vs Speed of Light

 General Physics General Physics Help Forum

 Nov 19th 2015, 01:01 PM #1 Junior Member   Join Date: Nov 2015 Posts: 2 Time vs Speed of Light The units for time obviously came before we knew about the importance of the speed of light. I don't want to upset anyone. This is just a serious thought experiment. Since we now know how important the speed of light is. And with the circular definitions of time or admittedly basing them on movement. Would it be of any use to consider making the speed of light a singular unit rather than a compound unit (meters per sec). This would make the unit for time a compound unit (distance divided by the speed of light, Sp of Lit being the new unit for speed). All other speeds would be designated as a fraction of the speed of light (the new unit of speed). The conventions of history have a way of making concepts confusing. Sometimes you need to understand the history to understand why the conventions are so confusing and then make the effort to comply with an awkward system. With the gas laws it is important to use degrees Kelvin so that changes in temperature are kept proportional. Would keeping speeds proportional be of use anywhere in physics? Is the speed of light important enough to exchange this honor with time?
 Nov 19th 2015, 01:12 PM #2 Senior Member     Join Date: Apr 2008 Location: Bedford, England Posts: 668 I think this is already happening in some areas, Certainly some of the books I have read quite explicitly swap from time to distance and back via the speed of light. Will this will eventually become the norm? I don't know, Possibly in the world of physics if it proves efficacious, Probably not in the general populous since the magnitudes of the numbers would become awkward for describing every day experience. __________________ You have GOT to Laugh !
 Nov 19th 2015, 01:38 PM #3 Senior Member   Join Date: Apr 2015 Location: Somerset, England Posts: 1,035 There is a system of units called natural units where this is all based on fundamental quantities, not only c but also charge, Plank's constant etc. https://en.wikipedia.org/wiki/Natural_units
 Dec 1st 2015, 08:49 AM #4 Physics Team   Join Date: Apr 2009 Location: Boston's North Shore Posts: 1,576 I think that it'd be a very bad idea to change it from what it is. For example; in units where the speed of light is 1 its hard to get a "feeling" for exactly how fast light is moving. Also, once you change that you have to change other things to compensate and that also makes it harder in other areas. This is one of the things you study when you study relativity and electrodynamics as well as other areas of modern physics, cosmology etc. I never liked the way they do those things. I prefer SI units. See https://en.wikipedia.org/wiki/Units_of_measurement
 Dec 23rd 2015, 07:22 AM #5 Banned   Join Date: Dec 2015 Location: Tintagel,.Cornwall, UK Posts: 48 Speed of Light Problem for me here is that I cannot accept that Light "speeds". The M-M disaster showed that the phenomenon could only be a delusion. The real problem was/is how to proceed from there. In a world (1850) where magic still held a tenuous position the whoopee factor triumphed but I sincerely feel that the time has passed for growing up. Ken Green
 Feb 10th 2016, 05:16 PM #6 Junior Member   Join Date: Nov 2015 Posts: 2 Time vs Speed of Light Thank you for all your comments. What I didn't find in your comments or the links provided was any comment on the definition of time being distance divided by the speed of light. Granted this may seem awkward at first but I think it clears up much of the confusion of what time is. It proposes that time is an interval not some abstract concept. Time is the interval that it takes light to travel a distance. The Wiki article on Natural Units led me to the article on Planck Units. Hear it is clear that not just the speed of light is 1 but four other units also become 1. This maintains speed as distance divided by time. I think there is value in just changing the the speed of light to 1 so that time becomes distance divided by the speed of light.

 Tags light, speed, time

 Thread Tools Display Modes Linear Mode

 Similar Physics Forum Discussions Thread Thread Starter Forum Replies Last Post kiwiheretic Light and Optics 8 Nov 19th 2018 01:58 AM philipishin Special and General Relativity 1 Jul 2nd 2014 12:04 PM sant1234 Special and General Relativity 4 Jun 6th 2013 07:23 AM erwinsKat01 Special and General Relativity 0 Feb 25th 2012 03:09 PM cas34 Light and Optics 10 Jan 13th 2011 05:38 AM