As a SF-reading teen (think 1950-60s: Asimov, Bradbury, Clark, Dick, Heinlein, Lem, Silverberg, Sturgeon, Van Vogt, etc.), I dreamed of space travel. By the time we started exploring near space it became clear that the notion of space as an empty vacuum was wrong--that beyond the Earth's Van Allen Belt astronauts would encounter significant solar radiation (hence, keeping space stations in low-earth orbits) and that the Sun's heliosphere is only a partial shield for extra-solar radiation. Ever since this discovery, I have been bursting balloons, though I take absolutely no pleasure in it. I merely do so to encourage people to think more about preserving earth, as it may take longer to solve the major issue of radiation shielding--as opposed to the more tractable issues of bone and muscle loss--than our present trajectory seems to indicate for human survival. (Take your pick of apocalypses!) Sure, send forth the robots, but meanwhile take better care of the Earth!

In any case, the following article is more honest about the difficulties than the usual cheer leading. Calculated Risks: How Radiation Rules Manned Mars Exploration: http://www.space.com/24731-mars-radiati ... rover.html

Edit: To be fair, here is one of today's biggest cheer leaders: http://aeon.co/magazine/technology/the- ... w-on-mars/

Cockroaches in space!

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The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Yes, roaches will live through basically anything.

So you two are saying, what?... If any aliens reach Earth they will be descended from alien cockroaches or that Earth cockroaches will reach the stars after we are gone...Some optimistic guys you are!

Seriously, if we do terraform Mars, one of the first fauna that we send should probably be cockroaches, because of their resistance to radiation.

And, as far as our own resistance to radiation goes, IIUC, humans have lived through a number of magnetic pole reversals, with the concomitant weakening of the earth's magnetic field, and, presumably, more radiation coming through.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

According to multiple sources (e.g., NASA: http://www.nasa.gov/topics/earth/featur ... ersal.html ; Universe Today: http://www.universetoday.com/110475/wha ... oles-flip/) the last reversal was about 750 thousand years ago--long before homo sapiens arose as far as I know. The weakening of the magnetic field over the last century is worrisome, or would be if there were not so many other scenarios from which to hide under the bed.

Time to start work on the blockbuster movie script:

http://www.scientificamerican.com/artic ... -expected/

http://sedonanomalies.weebly.com/geomagnetics.html

Hmmm. I thought the reversals were more frequent. Well, hominins, then. Certainly mammals.



Maybe Yellowstone will blow.

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The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

When I step on one, it dies. I know. I've seen it happen.

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- Bantari
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WARNING: This post might contain Opinions!!

I travel thru the dark cold of space, spinning and not feeling it, travelling in time, huge distances very fast. My spaceship is lovely beautiful, and as perfectly adapted to Human life as possibly can be. I am an astronaut or if u prefer cosmonaut on the space ship earth.

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Walla Walla GO Club -(on FB)

We play because we enjoy the beauty of the game, the snap and feel of real stones, and meeting interesting people. Hope to see ya there! お願いします!

Anthony

Buckminster Fuller? I read his book Operating Manual for Spaceship Earth too long ago to remember any specific quotes!