Natural units - how and why

Tags: natural, units is offline
Dec17-13, 02:05 PM
P: 1
So I have been going through a book on physics-based mathematics. I have seen the author using natural units (h = c = 1) in formulae. Why is this done? Most importantly, doesn't it mess up the true calculation? For example, take e = mc^2. If I set c = 1, it becomes e = m. So if I am given a mass and have been told to calculate the energy, it's the same as the given mass! How is this all consistent? I don't get the concept. I would be glad if someone would explain it in a simple manner. Thanks in advance!
Phys.Org News Partner Mathematics news on
Math modeling handbook now available
Hyperbolic homogeneous polynomials, oh my!
Researchers help Boston Marathon organizers plan for 2014 race
Shyan is offline
Dec17-13, 02:14 PM
Shyan's Avatar
P: 740
Its not that confusing.We're just saying that,our length scale is somehow that light travels one unit of it in one unit of our time. Or alternatively our time scale is somehow that light travels one unit of our length scale in that time and then say we don't care what are those time and length scales!!!Its the same about h.
And about the formula E=m. Energy is not the same as mass here! Let's say the unit of time and length scales we chose are a and b.Then we have [itex]E(kg a/b)=m(kg) c^2(a/b)[/itex] its just we have c=1 in the unit a/b! and of course our unit of energy here becomes different from joule.We may also alter the unit of mass to an arbitrary one which again changes our unit of energy.
rbj is offline
Dec17-13, 09:25 PM
P: 2,265
there's a wikipedia page on the topic.

that and the page on Planck units, maybe that can help.

Register to reply

Related Discussions
Natural log of units Introductory Physics Homework 6
Natural units High Energy, Nuclear, Particle Physics 10
Natural units! Quantum Physics 9
Natural Units General Physics 0
E=mc^2 in natural units General Physics 6