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As you see in picture a burning match in a container causes suction and this is a Traditional Therapeutic method to relive bone pain.

enter image description here

What is the reason? I think it should be related to gas changes($\ce{O2}$ being used for combustion and etc.), but I am not sure about it.

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When the container is open to the atmosphere and has the match burning in it, the temperature of the air inside is higher than the temperature of the surrounding air. In order for pressure to be equal in the container and outside it, the density of the air in the container is less. When the match is removed and the container placed on the person, two things happen. One, no air can enter or leave the container, and two, the air in the container begins to cool. When the air in the container cools its pressure drops. The atmosphere pushes on the air in the container indirectly through the person, creating what is called suction.

This is similar to drinking through a straw. You are not sucking the liquid through the straw as much as you are removing the opposing force that prevents the atmosphere from forcing the liquid through the straw. The opposing force being the air pressure in the straw.

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  • $\begingroup$ I'm familiar with this user from biology.SE, and for sure he's gonna be asking you for reference! Maybe leaving a link or two wouldn't be such a bad idea! :D $\endgroup$ – M.A.R. Jan 25 '15 at 20:27
  • $\begingroup$ @brinnb MARamezani is right and I won't accept it without a reference. $\endgroup$ – Berne Jan 26 '15 at 12:39

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