On those days when furrowed rows of clouds line the entire sky, I’ve noticed (while driving*) that the rows of clouds ahead and behind me will always be oriented perpendicular to my direction of travel. Yet, the clouds on the sides of me will be oriented parallel to my dirction of travel. When I turn a corner, the clouds are still perpendicular to me. Am I nuts, or is this a known phenomena? If the latter, does it have a name?
*While standing outside my car, these same clouds in the west or east seem to orient in furrows running north-south while clouds to my north or south seem to orient in furrows running east-west. However, I have less data with this observation as I only noticed this more recently than what I see in a car.
I WAG it is from my earthly perspective looking around at a curved sky? Also, I realize clouds are actually 3D, but (IMHO) a cloudy sky seems to be 2D. Thus, perhaps there is some distortion here, or what is perceived as distortion?
Anyone else ever notice this…or am I a few fries short of a combo meal?
I don’t see what the puzzle is, here. It sounds to me like you’re saying that the lines of clouds are mostly parallel to the horizon, but what’s the illusion in that?
Take a CD jewel case, large side parallel to the floor, about level with your forehead, out about an arm’s length. Observe the apparent shape. Now imagine that it’s a cloud, so it’s difficult to determine which parts are closer than others.
I’m just getting a chance to follow-up on this thread. Yes, regardless of the direction I face, the rows of clouds appear parallel to the horizon. Yet, why should this be? Why don’t the rows of clouds appear to radiate from one point outwards, or simply be furrowed rows that cross the sky like furrowed rows across a field. In the field example, there is no doubt in which direction the rows run. In contrast, it almost appears that the observer is at the center of a circle, and the rows of clouds circle about the observer. But, why should this be? Surely, it is an illusion. The clouds should cross the sky like a tractor plowing a field. I wager the illusion is because the sky itself appears curved? By this, I do not mean the domed sky over us per se, but the clouds to which I refer all appear to lay in the same horizontal, circular plane, if you follow me.
Recently visiting the great plains of the western US states, there are many days with endless rows of clouds equally distributed across the unobstructed sky (from horizon to horizon in all directions) allowing me to study this observation further…and further convincing me it must be some kind of illusion. In fact, if I lined people up across the plains like “Hands Across America”, I wager each observer would think the clouds were centered about him or her. This really blows my mind as I find it hard to wrap my mind around what is happening here.
I am hoping the SDMB will take a closer look at my question, and maybe relay some of their own observations to help me understand what is happening here?
Clumps of clouds when viewed nearly edge on will look like a line parallel to the horizon, like the jewel case mentioned in the post right above yours.
It is well known among soaring pilots that thermals and the cumulus clouds resulting from convection will sometimes organize into “cloud streets” aligned with the wind direction. Not always, but often enough that it is generally good advice to fly in a cross wind direction if you find yourself in heavy sink on a clear sky day. If you consult n soaring pilots as to why this is so, you will probably get n^2 theories.