My sister's boyfriend showed me a nifty chart which presents the size of by distance from a television before your eyes begin to notice the difference of 1080p resolution. Just out of curiosity, we measured the length of my living room and looked at the chart to see how large of a television I would need. The distance between my couch and television is a bit shy of 20ft... off the chart!
The chart goes up to 130 inches, or approximately 11 feet. But an 11 ft diagonal measurement doesn't really mean anything to me other than "big ass TV"*, so I decided to dig out my high school math skills to help me put it into perspective. Assuming a standard 16:9 wide screen display and some liberal number rounding:
I would need a television that's almost 6 ft tall, and 10 ft wide if I wanted to see Jay Leno's crow's-feet in high definition!
I only have 8 ft ceilings so that gives 2 ft of clearance above it, and the room is 16 ft wide so I'd have 3 ft of clearance on each side (just 6 inches wider than the width of my door casings). That's not a "big ass TV"... that's my wall!
I realized two things after running the numbers: First, that was a great real-life example to answer the question "when will we ever use this stuff?" we were all asking our teachers when we were learning algebra. Secondly, I wonder how many people are wasting money on all the latest and greatest video technology. I'm glad I don't own a Blu-ray player, or I'd now be scratching my head wondering "when will I ever use this stuff?"
* For my friends in metric countries, that's "big arse television"