Airlines offer in-flight Wi-Fi in their flights; however the signal strength can be spotty. Airlines and aircraft manufacturers are continuously striving to improve the connectivity by using wireless devices.
Therefore, engineers at Chicago based Boeing Co. have used sacks of potatoes as their stand-ins for passengers as they worked out to eliminate the weak spots in their in-flight wireless signals. The reason for the limit of Wi-Fi signal is based on physics, the phenomenon called as path loss, it is weakening of signal strength as you travel further away from the source. This loss is attributed to the absorption of signal by moisture in the air, which turns the signal into heat and hence results in less signal power. Further, in space, there is no air and no obstructions so a signal can travel millions of miles from a remote probe back to earth.
This can be attributed to the water content and chemistry of the potatoes that absorbs and reflect radio wave signals similar to the human body, hence, making them suitable substitutes for airline passengers.