How To Protect Yourself From Cosmic Rays If You Ever Happen To Make It Into Space

This one is fun. Remember back in September when the poor commander got lost on Mars and couldn't understand Base's instructions? No? Okay, go here first and refresh your memory. I'll wait... Finished? Then we're ready to move on. Since you've now done your homework, you know that the reason the Mars mission was in jeopardy was that the crew's brains were being scrambled by radiation. Radiation is a big problem that scientists are going to have to figure out before humans start heading out past the protection of the Earth's magnetic field, beyond the orbit where the International Space Station flies above the Earth in relative safety. The Moon and Mars, as we all know, are on the short list for mission possibilities, and spending such long periods of time in space could do more than scramble a few brain cells; if current theories are correct, astronauts could be risking premature aging by heading out into the cosmic ray zone. (That last link leads to an interesting article about space radiation, telomeres, Einstein and pills to repair DNA damage--I followed a link from there to one about what the heck telomeres are, and how they affect aging, with possible implications for human life extension. Pretty interesting if you want to follow some rabbit trails.)

All of that aside, however, what I really want to tell you about is the idea some scientists have for blocking all that radiation, so that no astronautical DNA is damaged in the first place. Patrick L. Barry wrote an article for NASA about how they are looking to make space ships out of a revolutionary new material--you're not going to guess this one in a million years. (Well, okay, I wouldn't have guessed it in a million years.) The material? Plastic. Polyethylene, to be precise. This is what they use to make the plastic trash bags of which we all have an abundance under our kitchen sink.

Most household trash bags are made of a polymer called polyethylene. Variants of that molecule turn out to be excellent at shielding the most dangerous forms of space radiation. Scientists have long known this. The trouble has been trying to build a spaceship out of the flimsy stuff.

But now NASA scientists have invented a groundbreaking, polyethylene-based material called RXF1 that's even stronger and lighter than aluminum. "This new material is a first in the sense that it combines superior structural properties with superior shielding properties," says Nasser Barghouty, Project Scientist for NASA's Space Radiation Shielding Project at the Marshall Space Flight Center.

To Mars in a plastic spaceship? As daft as it may sound, it could be the safest way to go.

According to Barry, one of plastic's big selling points is that when radiation smashes into it, it doesn't produce nearly as much "secondary radiation" as materials like aluminum or lead. That secondary radiation can be just as much of a problem for astronauts as the cosmic rays themselves:

The advantage of plastic-like materials is that they produce far less "secondary radiation" than heavier materials like aluminum or lead. Secondary radiation comes from the shielding material itself. When particles of space radiation smash into atoms within the shield, they trigger tiny nuclear reactions. Those reactions produce a shower of nuclear byproducts -- neutrons and other particles -- that enter the spacecraft. It's a bit like trying to protect yourself from a flying bowling ball by erecting a wall of pins. You avoid the ball but get pelted by pins. "Secondaries" can be worse for astronauts' health than the original space radiation!

Barry says the lighter elements of hydrogen and carbon, the building blocks for those plastic bags, won't completely stop the space radiation, but can fragment that radiation so that it is much less harmful. He uses the example of a chain link fence blocking a snowball. Some snow still gets through, but it doesn't hurt as much. This author has a knack for making scientific-speak understandable, doesn't he? I'll let him tell you more:

Despite their shielding power, ordinary trash bags obviously won't do for building a spaceship. So Barghouty and his colleagues have been trying to beef-up polyethylene for aerospace work.

That's how Shielding Project researcher Raj Kaul, working together with Barghouty, came to invent RXF1. RXF1 is remarkably strong and light: it has 3 times the tensile strength of aluminum, yet is 2.6 times lighter -- impressive even by aerospace standards.

"Since it is a ballistic shield, it also deflects micrometeorites," says Kaul, who had previously worked with similar materials in developing helicopter armor. "Since it's a fabric, it can be draped around molds and shaped into specific spacecraft components." And because it's derived from polyethylene, it's an excellent radiation shield as well.

They're working on ways to address some of the drawbacks that come with polyethylene--like the irritating tendency it has to burn and melt and whatnot. Now, this article is over a year old, and my search on the NASA site didn't lead me to any more updated information, so I can't tell you right now how this research is progressing. Back in August of 2005, no one was sure yet whether plastic really could serve as a shield to make space travel safer, but "hypothetically" polyethylene might be "not just for trash bags anymore."

It's so interesting how many useful discoveries for right here on Earth come out of space research. Man may never fly to the Moon in a plastic rocket. We may never see plastic habitats on Mars, but--and this is important--we can be pretty sure that our garbage will never get cancer from radiation!! That's an encouraging breakthrough, right? Even more valuable, now that we've all read the reports from NASA and know how useful plastic bags can be, we can make the important fashion decision about whether we want to wear plastic bags over our clothes when we go outside, to protect ourselves from cosmic rays. Hey, come on, it's not such a bad idea. If enough of us do it, it could even become trendy. Maybe if we get some Hollywood type to do it first we can all pretend it's actually cool. Then we would just look like lemmings, and not freaks. Hmmm. Let me think about this. Somebody sci fi maybe, but with crossover appeal.... I've got it! Will Smith!! Men In Black, I Robot, Independence Day... yeah, he'd do nicely. Somebody out there want to volunteer to suggest it to him?

Note: Yes, I know I'm being goofy today. I can't seem to help myself. I start out with a perfectly reasonable piece about the science of using plastic as a radiation shield and end up looking to make Will Smith the poster boy for the tinfoil hat brigade (plastic bag, tinfoil hat--same difference.) I'll try to control myself now, but I make no promises. I have a very good excuse. The day started out with snow, and that always gets me a little giddy. Wait a minute... Snow comes from the sky. Cosmic rays come from the sky, too. Maybe I'm so goofy because the cosmic rays are making it past the Earth's magnetic field and sneaking down into my neighborhood disguised as snow!!! This could be a real problem. I better go put on some plastic bags just in case.

Climate Science--Emphasis On Science

A friend asked me to keep an eye out for articles about climate science (emphasis on the science, and not the hype.) I'm happy to oblige. It's a topic I keep an eye on anyway. Beside the fact I have a genuine interest in the state of our planet, both the alarmists and the total naysayers have their entertainment value, after all. However, I frequently can give little credence to what I read, because so little of it is based on experimentation, and so much of it on anecdotal evidence and politics.

At first much of the debate rested in whether the Earth is warming at all. Then it shifted to the cause, as weather records over the last few decades do show a decided warming trend. Some people are still heavily engaged in the "why" debate, but many have moved on to what, if anything, we should/can do about it. Much of the world has simply accepted--It's Our Fault. Eliminate humans and you eliminate the problem. (Making the assumption, of course, that it is a problem.) Since ridding the world of humanity is hardly practical, the next best solution offered by some is to make people stop living the modern life, something very few of the uncooperative scourges of the Earth are willing to do (except the ones who want to take us back to the seventh century, but that's a different topic altogether.) So we spend a lot of time blaming and very little time checking our facts.

Sometimes, however, we get a look at actual verifiable science on the topic. It's very refreshing. Here's an example. SpaceDaily has a look at experiments performed in Denmark that conclusively link cosmic rays to cloud formation, and thus Earth's temperature:

It is already well-established that when cosmic rays, which are high-speed atomic particles originating in exploded stars far away in the Milky Way, penetrate Earth's atmosphere they produce substantial amounts of ions and release free electrons.

Now, results from the Danish experiment show that the released electrons significantly promote the formation of building blocks for cloud condensation nuclei on which water vapour condenses to make clouds.

Hence, a causal mechanism by which cosmic rays can facilitate the production of clouds in Earth's atmosphere has been experimentally identified for the first time.

Here's the lowdown. Scientists filled a large reaction chamber with the appropriate gases to approximate the chemistry of the lower atmosphere. They used ultraviolet lamps to perform the function of the Sun's rays in the equation, and as the "penetrating cosmic rays" did their thing, the scientists monitored the chemical reactions in the chamber with instruments that only "really smart people with degrees and stuff" know how to use. The experiment proved that cosmic rays help facilitate the development of the "stable, ultra-small clusters of sulphuric acid and water molecules which are building blocks for the cloud condensation nuclei. A vast numbers of such microscopic droplets appeared, floating in the air in the reaction chamber." Turns out the rays are very effective at producing these building blocks, and there is now empirical evidence that cosmic rays can have an effect on Earth's climate because of the clouds they help form.

It's interesting how that works. The more rays that get through to Earth's atmosphere, the more low-altitude cloud cover we get. Less rays equal less clouds. Those low altitude clouds drop the temperature here on Terra Firma. Here's the really intriguing bit:

Interestingly, during the 20th Century, the Sun's magnetic field which shields Earth from cosmic rays more than doubled, thereby reducing the average influx of cosmic rays.

The resulting reduction in cloudiness, especially of low-altitude clouds, may be a significant factor in the global warming Earth has undergone during the last century. However, until now, there has been no experimental evidence of how the causal mechanism linking cosmic rays and cloud formation may work.

Did you catch that? When the Sun's magnetic field is strong, we get less cosmic rays. Therefore, one can conclude that when the Sun's magnetic field is strong we get fewer clouds, and the Earth warms. That would link global warming to the cycles of the Sun, wouldn't it? I have read the theory before, and seen data that clearly showed that over the last four hundred years, as the Sun has cycled, so has Earth's temperature, and this experiment is some solid support for that theory. Unfortunately, I can't remember where I read the theory in the first place, but hopefully the SpaceDaily article will give you a good start on the subject.

I still think, of course, that we need to follow all the scientific leads, and find out for sure whether humans really are effecting the climate, or whether natural cycles such as the flux in the Sun's magnetic field are the reason for the temperature shifts we experience over the years. I don't think, however, that we ought to be making rash decisions that shut down the economies of the world because of fears that are as yet unproven. If global warming is a temporary and natural phase of the planet, caused by forces as far away as the Sun, no amount of turning off the air conditioning, riding the bus to work, or staying off of airplanes is going to change that natural rhythm. Of course, theories come and go. I remember being warned as a child that we were going to enter another ice age soon. We see how accurate that prediction turned out to be. I'm all for scientific investigation of the facts, but histrionics are pointless. I read recently that Al Gore told a group at the U.N. that cigarette smoking is a significant contributor to global warming. You tell me which of these two theories--cigarettes, or cosmic rays as realistic causes--has the most likelihood of veracity? Until I see solid scientific proof that smoking is the cause, I'm sticking with cosmic rays.

Hat tip: The Anchoress