Watched a show on a PBS version of Nova's Inside Animal Minds.
A dog can sense smells of one part per trillion. That would be like us tasting a tablespoon of sugar dissolved in two Olympic sized swimming pools.
A dog on the show always new within minutes every day when his master returned home from work. He would always stand on the couch watching.
An hour glass has a top chamber with sand that drains precisely into a bottom chamber. Emptying the top filling the bottom. You can tell time by how much sand has drained from the top.
In the morning the house is filled with the scent from the master. The scent dissipates during the day much the same way as the hour glass's top chamber dissipates the sand. The dog has learned to memorize the scent level of when the master returns home daily.
To test the theory the master worked out midday at the gym and his workout clothes were brought home and wafted throughout the house. The first time in years the dog wasn't waiting for his master.
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Topic: Dog can use his nose as his personal clock (Read 587 times)