The folks over at MacStories noticed their 2008 Macbook Pro getting a bit drowsy when they let their iPad get too close (see video below). What seems to be happening is placing the iPad over the lower right hand rest area of the Macbook Pro makes it to go to sleep. Repeating the procedure then wakes it up. Odd indeed, but explainable.
It’s seems to be a magnetic switch that activating to put the Macbook Pro to sleep when the lid is closed. If you take a paper clip and place it about 1/3 of the way down the right edge of the Macbook Pro screen it will stick to it. There are also a bunch of magnets along the top edge of the screen, but those appear to be there just to hold the Macbook Pro lid shut when it’s closed.
The sleep switch also seems to be magnetic and about the same distance down along the right edge of the Macbook Pro top case just behind the right speaker grill. It does appear to be a little further in, more toward the keyboard so I assume it gets pulled out to the edge when you close the lid activating the switch. Now the key to triggering it with the iPad is to place the back of the iPad, specifically the area just under the iPad speaker holes, over that section of the Macbook Pro. Viola! The Macbook Pro should go to sleep. I believe it’s the magnets in the iPad speakers that act like the magnets in the Macbook Pro lid and cause the Macbook Pro to think you shut just the lid effectively putting it to sleep. No mystery, no magical forces, just science.
Maccast listener Connor really deserves the credit for discovering this quirk. He emailed me about 3 weeks ago to say he was seeing this behaviour when he got an iPhone 3GS near that part of a 15″ Macbook Pro. At the time I couldn’t repeat the behaviour, but I was able to confirm this with my 15″ Macbook Pro and my 32GB Wi-Fi iPad.