What is the shape of the receptive field to which a simple cell in the primary visual cortex responds?

In science and physics what is the standard unit of measure for speed?

An insulated thermos contains 148 g of water at 72.7 ˚c. you put in a 11.7 g ice cube at 0.00 ˚c to form a system of ice + original water. the specific heat of liquid water is 4190 j/kg•k; and the heat of fusion of water is 333 kj/kg. what is the net entropy change of the system from then until the system reaches the final (equilibrium) temperature?

Matter that emits no light at any wavelength is called