The gas in galaxy clusters does not flow like honey. Honey is a viscous fluid that flows slowly, while the gas in galaxy clusters consist of mostly hydrogen and helium, is a very thin gas that can easily flow. The difference in viscosity is due to the different densities of the two fluids. Honey is a dense fluid with a viscosity of about 1,000 times that of water, while the gas in galaxy clusters has a density of about 1/1000th that of air, making it very thin and easy to flow.