# Imagination of Duff's theory

1. Nov 23, 2011

### exponent137

In article
http://iopscience.iop.org/1126-6708/2002/03/023
Duff claims that elementary units physically does not exist. It is easy to imagine that a kilogram, a meter and a second are all expressed in one unit, for instance second. But it is not easy to imagine, how to calculate without use of any unit?
Are here any examples?

2. Nov 24, 2011

### rbj

here's another link to the same paper:
http://xxx.lanl.gov/abs/physics/0110060

and this is another paper from Duff about essentially the same issue.
http://arxiv.org/abs/hep-th/0208093

Duff is not saying anything about units, per se. what he is saying is that dimensionful physical constants are not fundamental but, ultimately, expressions of the units we choose to express these constants with. and that Nature doesn't give a rat's a what units humans (or whatever other intelligent being) decides to use for units.

Duff is saying that it is operationally meaningless in physics to talk of variation of dimensionful parameters such as $c$ or $G$ or $\hbar$ or $\epsilon_0$ or $k_B$ (all these physical constants go away when Planck units are used) but it is meaningful to detect a variation in dimensionless parameters such as $\alpha$ or $m_p/m_e$.