Let’s say you’re on a mountain top and a one meter wide stone-iron meteor coming in from outer space zooms past you a few feet away going at some incredible rate of speed before it smashes into the valley far below.
How fast would it have to be going, and how close to you would it have to be to pose a danger to you?
I’m wondering if the simple force of it’s passage would harm you even if it didn’t touch you? Would the sonic boom hurt you?
You seem to grasp the problem. Do not worry about the object, worry about the air around it.
Take your mountain and move it to the moon. As the thingee rushes by, you get no ‘wooosh,’ no heat from friction with the air no sonic boom. Nothing.
So the answer on Earth would be dependant on air density, humdity and other stuff. In space, you could get very close indeed. (One must admit that at Star Trek speeds, even space is too crowded, friction and other thing come into play at near-light speeds.)
The air around the large fastmoving object is important for more than airspeed effects such as knocking you down or off the mountain. Even if the air didn’t whoosh past you at all, the meteor would be heated up by initial contact with the atmosphere and could harm you by radiating heat, which works whether or not there is air in the way.
I said that the even discounting the air next to you (through wind or a sonic boom,) the air in the upper atmosphere could do effectively that, through warming to the point where blackbody radiation is harmfully strong.