4D

Today I heard about 4D ultrasounds.  Someone I know has a daughter with a high risk pregnancy.  Every month she has a 4D ultrasound.  This future grandmother told us how amazing the  images she saw in the 4D ultrasound.  She even got a movie burned on a DVD of her granddaughter who is due to be born in February.  Strange, not?  I didn't even know we had four dimensions. One dimension (like a line) I can understand. Two dimensions (like the surface of a sphere) I can get.  Three dimensions (like the space inside a cube) I can get.  But four dimensions?  The future grandmother said the fourth dimension is the images are given in real time.  She said it's like looking inside right at the baby. She could see that her skull hasn't grown together yet.  She could see her little upper lip so clearly she knew the baby would not have a cleft palate.  She said the images were a little spooky to see.  And that got me to thinking.  I had an ultrasound once.  I guess my ultrasound (almost 23 years ago) would be considered a 2D ultrasound.  At first I couldn't see anything at all but suddenly I could see a head and a body when the technician pointed them out.  I could see little eyes.  The baby was laying facing the camera on it's left side.  It's head was on the right side of the screen.   As I watched in amazement, the baby raised it's right arm and pulled it's hand toward it's head and moved it back and forth.  My baby WAS WAVING AT ME!  Waving like it was in a parade.  I started to giggle with joy and we lost the picture.  But it was a very happy moment and a foreshadowing of the vibrant, gregarious offspring I was to have.