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Cosmic Radiation Speeds up Aging in Space?
SpaceAdmiral writes "The Theory of Relativity tells us that the faster a person travels the slower time passes for that person relative to someone left on Earth. This means that traveling at high velocities in a spacecraft should reduce one's aging. However, recent research suggests that cosmic radiation may counteract that anti-aging effect. Iron-nuclei radiation affects the aging of cells, which is possibly one of the reasons astronauts who have been to the Moon tend to get cataracts about 7 years earlier than other astronauts."
The article (and the summary) are merely speculating that when close-to-c travel is possible, the radiation might counter the "anti-aging" effect of Einstein's paradox.
It merely provided an example of the radiation possibly causing an acceleration of aging. This does not mean the astronauts in question were majorly affected by relativity.
If I may:
This means that traveling at high velocities in a spacecraft should reduce one's aging.
No it won't. I will reduce the appearance of time's progression on a person, from everyone outside that persons sphere of perspective. They will still have lived the same amount of relative time as someone else would have.
You weren't clear, and it sent shivers up a lot of people's backs.
Mod me down with all of your hatred and your journey towards the dark side will be complete!
The classic example in neuroscience is the case history of Phineas P. Gage.
Space travel and Space Stations have provided us with a burgeoning catalogue of studies on the impact of extended stays in space on our and other metabolisms. The Biomedical Results From Skylab are an example of earlier studies. Space promises unique biological insights.
"Academicians are more likely to share each other's toothbrush than each other's nomenclature."
Cohen
As for the situation of a guy travelling at 0.99999c for a while and then coming back to Earth at the same speed, the two trips do NOT cancel out. The difference is that the traveller was accelerated to that speed, then deaccelerated until he stopped relative to the Earth, and then accelerated back to 0.99999c in the opposite direction, and then deaccelerated again (we hope) when he reached the Earth. You can't just magically reach a given speed -- you have to be accelerated to that speed, and that's where the situation of the traveller is not the same as the situation of the Earth.
1) warp 1 is usually considered to be the speed of light, not 1/2 c.2) time dialation is not linear. At 0.5 c, time would be slowed by a factor of 1/sqrt(1-0.5**2) or only about 15%, not 50%.
Hey Slashdot,
"How LOWWWWWW can we go?"
This is "recent" research. Sheesh. I remember hearing about cosmic radiation's effect of aging when I was like 4 yrs old. (I just turned 30.)
Anyways, can someone please review the articles for some relanvancy to life. I mean, sheesh, this is a known issue. It's why one of the discussions regarding all deep space missions revolves around how best to shield the crew from cosmic radiation.
*yawn*
Oh yes, btw,...let me show you this great new revolutionary idea I've come up with.... I call it the "Space Shuttle"
If humans could only react to sound, then Einstien would likely have said that nothing goes faster than sound because we can't percieve it faster than sound.
If you are going to pontificate on a subject you might want to spend a little time actually studying it first. Einstein's idea that the speed of light was independent of observer had a lot to do with the results coming from Maxwell's equations and the null results of the Michelson-Morley experiment. Only a dilettante could think there was a useful analogy to the speed of sound in this context.
It is also worth noting that time dilation and lorentz contaction are effects of special relativity that are verified on a daily basis in particle accelerators everywhere around the world. It is not a subject on which one holds an opinion except insofar as how you want to explain the overwhelming amount of independently measured results.
This part of physics has now been around for over a century (Einstein's first paper on relativity appeared in 1905) and the math behind it has been around even longer. There aren't too many books on differential geometry for the layman but there are many good sources of information about relativity theory by Kip Thorne, John Wheeler and others.
The whole point of relativity is that time is "relative". If I am travelling at 0.8c then I still age at exactly the same rate as I would on earth. Its just that 50 years to me might be 150 years to everybody back on Earth. We all still age exactly the same way in our own frame of reference. Its only when someone looks at me through a telescope that they realise I still look young whilst they have aged.
The article is really only about the pervasive threat of radiation that humans face if they leave the Earth and its protections behind. They genuflect about time dilation which is a consequence of relativistic physics but don't even try to explain. What we have known theoretically and have verified experimentally for about a century is that space and time are mixed together in a very algebraically specific way when viewed by different observers who are in relative motion. One consequence of this theory is called time dilation which means that each observer in relative motion sees the others' time as being dilated (slowed down) relative to what he experiences in his own frame of reference. I know this sounds paradoxical but it is nicely explained in Spacetime Physics by Taylor and Wheeler, Gravitation by Misner, Thorne and Wheeler and many other sources (maybe check Wikipedia).
What is quite incredible is that if we could build a ship capable of constant 1 g acceleration we could travel just about anywhere in the universe in what appears to be about 40 years to people on the ship (see chapter 6 of Misner, Thorne and Wheeler for the mathematical details). Of course it is worth noting that all our space exploration has been conducted with ballistic missles which are nothing like a spacecraft capable of constant 1 g acceleration. There is significant reason to doubt that it is possible to build such a device. But it is true that humans are quite comfortable with 1 g acceleration (that is equivalent to the force of gravity at the Earth's surface). I think that it is beyond merely remarkable that relativistic physics guarantees that if our range would be so great if only such a spacecraft could be built.
What this article and a much more complete similar article in Scientific American (March 2006 page 40)explain is that radiation puts a severe damper on the ecomonics of space travel. Pioneers of space flight have been flying by the seat of their pants when it comes to radiation shielding. Frankly I suspect it is a second order problem in the cosmic quest. If we could devise a starship capable of constant acceleration then just encase the whole thing in as sufficient water or something similar to duplicate Earth's protective atmosphere. Assemble it in space far up in Earth's gravity well with material mined from asteroids. Of course there is still the issue of inventing those darn dilithium crystals.
Imagine traveling to another galaxy and returning in less than one hundred years as experienced in your reference frame while the Earth has aged about 4 billion years. Who says we can't have time machines? The only problem is that they are all one way, into the far future. Check these musings in Kip Thorne's book Black Holes and Time Warps
It's a bigger rock (13x larger than helium), and it causes more extensive damage in the cell when compared to helium nuclei. I don't think the exact element is too important. The damage is related to mass and kinetic energy. Iron is just a relatively common element, being the waste product of large stars.
Mea navis aericumbens anguillis abundat