Does the center of the iPad feel hollow

Playing golf I sometimes hit the screen with my fingernail and it feels more hollow than the edges of the screen when I hit it. Anybody else notice this?

I thought, I felt a bump a few times. When I go try to find it it's not there anymore .

I feel it also, although I don't think it's hallow, just it's far away from the bezel.

After a little investigation...sure enough...hollow. First overheating, now this.........

Notice this all the time on my iPad 3. It's just a case of the glass not being supported there. Well. I'm sure it's supported but due to the size of the display it is hollow in the middle as there is less support in the middle than there is at the sides. Completely normal.

I wouldn't say hollow, since this is where the batteries are at.

then would you please explain the activities occurring in the apple cutout....

Not sure what you mean.
The screen sits right on top of the batteries which are shown being removed from the back of the case.
The entire tear down on on ifixit's web site:
http://www.ifixit.com/Teardown/iPad-3-4G-Teardown/8277/1