Good bye hyperdrive. It turns out we can't depend upon going close to the speed of light to make our trip seem shorter.
Speed kills: Highly relativistic spaceflight would be fatal for pas...
Highly relativistic speeds are desirable for interstellar travel. Relativistic time dilation would reduce the subjective duration of the trip for the travelers, so that they can cover galaxy-scale distances in a reasonable amount of personal time. Unfortunately, as spaceship velocities approach the speed of light, interstellar hydrogen H, although only present at a density of approximately 1.8 atoms/cm3, turns into intense radiation that would quickly kill passengers and destroy electronic instrumentation. In addition, the energy loss of ionizing radiation passing through the ship’s hull represents an increasing heat load that necessitates large expenditures of energy to cool the ship. Stopping or diverting this flux, either with material or electromagnetic shields, is a daunting problem. Going slow to avoid severe H irradiation sets an upper speed limit of v ~ 0.5 c. This velocity only gives a time dilation factor of about 15%, which would not substantially assist galaxy-scale voyages. Diffuse interstellar H atoms are the ultimate cosmic space mines and represent a formidable obstacle to interstellar travel. [emphasis mine]
Tags: radiation, space travel, speed of light
Permalink Reply by Ruth Anthony-Gardner on February 14, 2013 at 11:11pm
Permalink Reply by leveni on February 15, 2013 at 12:09am Damn, we'd be cooked like a chicken in a microwave oven. Let's hope they can actually build those proton-electron shields.
If this were SF rather than the real world, we could handwave some unobtanium into existence....
Permalink Reply by Tom Sarbeck on March 5, 2013 at 1:23am Ha! The Repubs will never lets us tax rich folks enough to pay for all this!"

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Posted by Debra Stevenson on May 21, 2013 at 2:37pm 0 Comments 0 Likes
There is a video of the Pope's 'exorcism' caught on film. The man isn't demon possessed, there are likely no 'real' demons. He's just delusional and doesn't want to accept personal responsiblity for his own behavior for his own dysfunctional life.
Brandi Amari Williams
Posted by Debra Stevenson on May 21, 2013 at 2:28pm 2 Comments 1 Like
There is an ad that reads ' Do you support 'traditional' marriage? Vote Now"! .
No, I don't support 'traditional' marriage because there is no such thing. I support heterosexual and same-sex couples marry each other legally , yes. 'Traditional' marriage promoters largely do not believe that heterosexual women are co-equal to their husbands. Their only purpose in 'traditional' marriage is to sexually satisfy their husbands if they can and raise children and do all…
ContinuePosted by matthew greenberg on May 21, 2013 at 12:18pm 5 Comments 0 Likes
i've got no problem with everyone saying "merry christmas" on christmas day. however, they've turned it into an entire holiday season where it lasts a month or more. in those situations it should be perfectly acceptable to say "happy holidays" or call it a…
ContinuePosted by Two Cult Survivor on May 21, 2013 at 11:30am 0 Comments 0 Likes
I posted the bulk of this on another thread, but wanted to add some context separately.
I finally confronted my faith and embraced the fact of my atheism late last August, 2012. Days after I revealed my "epiphany" to a few friends who knew me from another message board, my sister died from Lou Gehrig's Disease (which pissed her off because she hated catching a disease from someone she never f---ed).
THAT was my sister, understand? She was a beautiful, life-loving, potty-mouthed…
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