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# Physics/Air pressure

Question
QUESTION: Hi Steve,

The air pressure we experience is due to the air above us. Say I seal myself in an air tight room, the air pressure is the air above and around me...so if I measure the pressure it will be significantly lower..am I right. If so will I explode ? What If I suck all the air out and hold my breath..will I explode then?
Thanks !

ANSWER: No, air is not like water.  It will not be lower just because you seal it off...if you seal it off then you will be inside a sealed chamber, just like the international space station.  You will not explode.  If you suck out all the air and hold your breath, then dissolved gasses will bubble up inside your bloodstream and you will die...but not explode.  You don't exist under sufficient pressure to explode.

[an error occurred while processing this directive]---------- FOLLOW-UP ----------

QUESTION: Hi Steve,

Thanks..so if I am in a sealed chamber under the ocean, the pressure inside and outside will be different...yes?

Coming back to air, you said that it does not behave like water..in what aspects?

Many Thanks !

The pressure inside and outside a sealed chamber can be different, yes.  They can also be the same, it depends on the pressure of air inside the chamber when it was sealed.

Air is far more compressible than water, which is why the pressure under water is dominated by how deep you go.  Its density is almost 1000 times that of air.  From that fact (the compressibility), air pressure with altitude falls of exponentially instead of linearly...and much slower than water pressure increases with depth.

Physics

Volunteer

#### Dr. Stephen O. Nelson

##### Expertise

I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.

##### Experience

I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Education/Credentials
Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.