Thursday, September 6, 2007

785 Stresses on Mars

Message no. 785[Branch from no. 784] Posted by Thomas Culhane (1311520071) on Monday, April 9, 2007 5:57pm Subject: Re: Patricia Friedrichs Relational Summary Chapter 5 Noise

Hey, wow! What a marvelously written and informative relational summary Pat! I learned so much from what you wrote and the web sites you sent us to that I am all asmiles! I have to admit, I hadn't given any thought to the acoustics of the rarefied atmosphere of the Martian environment, so this was a real eye opener (ear opener?)!

I thought the youtube video of NASA's simulation of what the Rover went through on its voyage to and landing on Mars was absolutely stunning! To think that we put that little cute creature on another planet and that for several years now it has been faithfully rolling around investigating the hills and plains of a forbidding planet is just amazing. It is like a child in so many ways. Watching the animated footage of how it got to its current home I felt "so, we have proved that aliens visit other planets -- except the aliens are our offspring!"

When I last visited JPS laboratories with a high school science class I was teaching, my friend Sami Asmar, the manager of the radio science group that put the rover on Mars, showed us some of the rovers that were going to be launched to the red planet. They were being tested in the parking lot. It was great to see them then and to think that a couple of them actually made it!

Thanks for sharing that!

A thought about noise stress on Mars -- keep in mind that no human beings will be walking around on the surface of Mars without a pressure suit that has radio communications. When indoors, the colonists will be in pressurized rooms (just like the pressurized cabin of a 747 jumbo jet!). The atmosphere in every environment in which human beings will live and work have the earth combinations of nitrogen, oxygen, argon and carbon dioxide at 1 atmosphere of pressure. Thus the sound transmission will be very similar to that on earth.

If somebody were to venture outside in a non-pressurized suit they would freeze to death and have all their fluids boil away long before noise stress (or the lack of noise) would have any effect.

Think of Mars as the opposite of scuba diving. In scuba diving you always wear some kind of suit and pressurized gas tank that delivers air using a regulator to protect you from the surrounding environment and give you the kind of air you are used to at the surface. Underwater you are surrounded by fluids at a high pressure, on Mars by fluids (gases) at a low pressure. So you would have a gas tank and a regulator to regulate the composition and pressure of the gas you breathe.

When we are scuba diving the acoustic environment is also very different than in the air. Because water is denser sound travels farther (whales can "talk" around the world!). On Mars, where it is less dense, sound travels a shorter distance as you indicate.

There are always stresses in coping with an alien environment, whether that environment is here on earth (underwater, on a mountain top) or on Mars. But I think the experience of your eutopians is going to be more like that of passengers on a big airplane -- depending on the size of the habitat they live in, they will get varying degrees of claustrophobia, by I don't expect them to suffer from the different atmospheric conditions on Mars unless there is a breach in the walls or doors of the habitat.

The thing that would probably most affect our Martian colonists is the lack of a suitable gravity! Being a third the size of earth Mars has about a third the gravity, meaning we will all be bouncing around (a hundred and fifty pound person will only weigh 50 pounds!). It could be great fun though!

The best books I can recommend on what colonizing Mars will be like is the award winning trilogy by Kim Stanley Robinson "Red Mars", "Green Mars" and "Blue Mars" -- the story of how, over hundreds of years, people terraform the red planet so that it eventually resembles earth and people CAN walk around outside without any pressure suits!

These are some of the best entertaining novels ever written about the adventure our children may embark on!

Thanks for a great, thought provoking post!

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