A question that actually makes me laugh, but .... how long is the ATLAS Detector? Based on the ATLAS page here: http://atlas.cern/discover/detector the detector is 46m long. Based on references like here: http://arxiv.org/pdf/0910.3081.pdf the detector is 44m long. I wouldn't have asked this if I didn't read in my text that ATLAS is 46m long but saw in my figure [taken from the above reference, but pretty much distributed around ] that it was 44m. I wonder who is going to come and say "let's say 45m"