1. Dear all,
I am a biophysics student and have encountered a problem in understanding rotational diffusion coefficient. Wikipedia says that the units of rotational diffusion coefficient are radian^2/s. However, I have come across many research papers which give rotational diffusion coefficient in inverse seconds. Can someone please tell me how a quantity like rotational diffusion coefficient can be converted from per second to radians squared per second. I would be really thankful for any help.
Amin.  2. Originally Posted by amin_sagar Dear all,
I am a biophysics student and have encountered a problem in understanding rotational diffusion coefficient. Wikipedia says that the units of rotational diffusion coefficient are radian^2/s. However, I have come across many research papers which give rotational diffusion coefficient in inverse seconds. Can someone please tell me how a quantity like rotational diffusion coefficient can be converted from per second to radians squared per second. I would be really thankful for any help.
Amin.
Angles are really unitless, since they are determined by finding the ratio of two distances. However, a full-circle angle may be called 360o or 2 radians. So usually "degrees" or "radians" is written down to mark which value you are using. If the specification is omitted, the odds are that radians are intended. However, you may have to check the derivation to be sure of which system is being used.   