posted by Maria .
Why does tha physicist believe," a measurement without a quoted error is meaningless "?
Suppose you tell your friend that you have an object that is 90.4 cm +/- 0.1 cm long. That means you think the length of the object is closest to 90.4 cm but it could be as little as 90.3 cm or as much as 90.5 cm (or any value between those extremes). On the other hand you might quote 90 cm +/- 1 cm so it means you think the object is closest to 90 cm but it could be as little as 89 cm or as much as 91 cm (or values between). Therefore, without knowing the possible error you have an estimate of the length of the object but that's all it is; i.e., an estimate.