4 ms·
What you need to understand about this study is that radiation poses a particular risk to structural tissues. A structural tissue is anything where function is
by ackfoo 10y ago
What you need to understand about this study is that radiation poses a particular risk to structural tissues. A structural tissue is anything where function is dictated by form, such as the cardiovascular system or the nervous system (whose function is largely dependent upon the physical layout of the connections between neurons).
Tissues such as the spleen and the lungs are not considered structural because, while they certainly have a physical configuration that is important, their function is distributed identically, or nearly identically, throughout their structure.
If radiation affects one part of a non-structural tissue, it's function is relatively easily transferred to another area.
This is not true of the cardiovascular system; the function of the aorta, for example, cannot be accomplished by a capillary in the leg.
Radiation beyond the magnetosphere can be understood as mainly a point injury. When the highly-accelerated nucleus of a heavy element, for example, passes through a tissue, it causes local tissue damage. This is more important when the tissue is structural, and even more important when that tissue has a limited capacity for repair.
The Apollo astronauts were only beyond the magnetosphere for two weeks or less. Travel to Mars, or habitation on the moon, will both require far greater radiation exposures.
Shielding from highly-accelerated nuclei is currently impossible because they create secondary radiation in any shielding material that is far worse than the original problem.
Long-duration human space flight beyond the magnetosphere is therefore impossible with current technology, despite the hype. We must develop either strong magnetic shielding or genetic modifications to improve radiation resistance before traveling to Mars, otherwise we will arrive with impaired cognition and other infirmities.
Sorry to be the bearer of bad news.
- ch 10y agoSo, ignoring the ethical issues, would there actually be some benefit to space travel if, say over the next couple millennia, there was a deliberate gradual increasing of the background radiation levels on earth? Would that lead to human adaptations that could survive in more radiation hostile environments?
- corecoder 10y agoAdaptations in a couple millennia? I doubt it. I don't think there's much a living being can do to become more resistant to radiations; the most effective trick seems to be being small.
- jostmey 10y agoOver a couple of millennia? All you will do is end up selecting for fitness among the existing gene pool. No new genes will be created. Evolution is a slow process, and it will take far longer than a few millennia for new, innovative genes to emerge that provide resistance to radiation.
- toomuchtodo 10y agoMuch better to discover genes that confer hardiness to cosmic radiation, and modify the genomes of space travelers with CRISPR. Evolution is too slow. We must speed it up.
- kevinwang 10y agoIsn't that just eugenics?
- Retric 10y agoMagnetic shielding does not create secondary radiation. Producing a sufficiently large and strong field is hard but far from impossible just look at ITER for an example. Estimates are something around the size of a dishwasher supplied with ~1-5kw which is far from a deal breaker. The sun is a very predictable source so you can do a lot to shape the field such as placing it on a boom closer to the sun. Also of note Mars is significantly further from the sun which significantly reduces total exposure.
- Amygaz 10y agoWhile radiations from the Sun are important due to its proximity, cosmic radiations from other sources are still very important and harmful
- Retric 10y agoIf you look at: https://en.wikipedia.org/wiki/Cosmic_ray#/media/File:PIA16938-RadiationSources-InterplanetarySpace.jpg https://en.wikipedia.org/wiki/Cosmic_ray#/media/File:PIA1693... You see the basic problem with magnetic shielding is radiation still following field lines. (see: Aurora Borealis/Aurora Australis). This presents three options. You can add shielding for the end cap including for example unspent fuel. You can make your living space a donut surrounding the device. Or put it out on a boom. If your going to use a boom you will be protected from cosmic charged partials as long as your close to the device and inside the inner circle. But, by placing the boom closer to the sun you gain extra protection from solar charged particles. Thus reducing minimum necessary field strength.
- imglorp 10y agoMore details on this dishwasher sized field generator? Would the field radiate from it, or would that drive coils around the ship? If the latter, how big and how many?
- dharma1 10y agoHave there been experiments of animals in high Earth orbit (beyond the magnetosphere) for extended periods of time?
- abandonliberty 10y agoWe just have to stop shipping meatbags around.