I've thought about the result of applying strict physics to gateways. Considering the barometric pressure differences between any two remote points, especially with altitude differences thown in, is not insignificant, most gateways would have a strong wind blowing in one direction. There have been mentions of heat or cold through a gateway, but no mentions of wind. I account for this by assuming that there is some aspect of the gateway that balances pressure (of course, then how do people or other objects get through?). I think this one falls into the category of belief suspension for sake of the story.