# Viscosity of liquid hydrogen and its effect

The dynamic viscosity of saturated liquid hydrogen at atmospheric pressure is roughly $$\mu_{LH_2} = 1.3\times10^{-5}~Pa.s$$. For the same conditions, its density is $$\rho_{LH_2}=70.8~kg/m3$$, so the kinematic viscosity of LH2 of saturated $$LH_{2}$$ is equal to $$\nu_{LH2}= \mu_{LH_2}/\rho_{LH_2} = 1.8\times10^{-7}~ m²/s$$. (source NIST)

If we look at air now, we see that at 15 °C, the viscosity of air is $$\mu_{air}=1.8 × 10^{-5}~Pa.s$$ and its kinematic viscosity is $$\nu_{air} = 1.5 × 10^{-5}~m^2 /s$$.

So one can see that comparing those fluids for the conditions I provided that : $$\mu_{LH_2} \approx \mu_{air}$$ (very roughly) but $$\nu_{LH_2} \ll \nu_{air}$$.

Question : If my hand was at 20K, would waving my hand through this liquid hydrogen feels like waving my hand through the air because of the "similar" dynamic viscosity or would I feel way less resistance because of the very dissimilar kinematic viscosity ? This question Kinematic Viscosity touches on this topic but do not expand enough with its addendum since I am talking about a solid body through a fluid.