New Mars Forums

Why does the American military have to get involved in space? Worried about an attack from a hostile nation? It all becomes a self-fulfilling prophecy. The Pentagon foresees a hypothetical threat and puts weapons in space. Other countries feel threatened by American power and consequently also put weapons in space, thereby posing the threat which led to the Pentagon putting weapons in space initially. And we all dance around in nice little circles.

I was happy to read about the Chinese space ambitions on www.spacedaily.com. I thought it might finally get the American space program back on track by giving the US some healthy competition. But I had forgotten about the Pentagon's paranoia. Notice by the way, how all articles on SpaceDaily regarding China are in a section named "Dragon Space". Nice and threatening, huh?

I agree that NASA shouldn't limit itself to solely Mars exploration, but from a scientific point of view Mars is much more interesting than the moon. In geological terms, the moon is just a distant lump of icy rock whereas Mars has had and might still have significant geological activity. But as you mention, there are still worthy technological challenges in going back to the moon.

There are links to several interesting articles. But there is one thing that I haven't been able to find. One of Zubrin's arguments is that the earth is continuously bombarded by martian meteorites and that there is a high probability that microbes could survive a trip aboard such a meteorite from mars to earth. Hence, if there are microbes on mars then we have almost certainly been exposed to them already. What are the counter-arguments to this point of view?

Interestingly, the current systems architecture of the MSR mission calls for a passive-earth capture. It has even been described as using the earth as a catcher's mit.

Micheal, I've read several of your posts and I have a couple of points which I'd like to make in the same reply even if they pertain to different topics.

a) The magnetic poles are still changing position today. The magnetic declination is the angle between the geographic north pole and the magnetic north pole and this angle changes every year. You'll find the value on all good maps. The time it takes for the magnetic poles to reverse is on the oder of tens of tousands of years and not hundreds of years. This is directly supported by geological evidence: molten lava from the ocean ridges contain ferro-magnetic compounds that align with the magnetic field and as the lava reaches the ocean floor it solidifies. Thus the compounds show how the magnetic field has changed in the past. It also shows that the earth is much older than a few thousand years since we can observe the rate at which the the ocean plates move apart and hence the rate at which the lava is deposited.

b) There is other evidence besides carbon dating that shows that the earth is much older that a few thousand years. For example, the moon's orbital period around the earth (~29 days) exactly matches its rotation about its own axis. (This is why we see the same face of the moon all the time.) This would be a pretty strange coincidence. The reason is that the interaction of the tidal forces between the earth and the moon has slowed down the rotation of the moon just as they are slowing down the rotation of the earth. We can measure this decrease in angular velocity and in many thousands of years, the earth's rotation will equal the orbit period of the moon, i.e. an earth day will equal a month. (For a full explanation see "Bad Astronomy" by Plait.) This effect takes millions of years to happen and hence the earth and moon can not be a few thousand years old. There are many other examples like this that show the earth to be much older than the Bible suggests.

c) You refer to the "ancients" several times when talking about mars. How old are these ancients? Greek astronomers in bc made tables of the motion of heavenly bodies yet they seem unaware of the regular 104 year mars passage that you mention. Likewise Arabic astronomers. Then in the 16 century Kepler was able to deduce laws of planetary motion from the observed motions of the planets. This means that his data was very accurate. Why is something this spectacular not written about explicitly but only through vague references?

d) Jet streams are horizontal winds, not vertical winds. They are high-altitude, high-speed winds that usually separate the colder winds from the warmer winds. Balloonists use jet streams to travel around the world.

I will be interested in hearing your views and ideas as long as they can be backed up by evidence. If your views require the doctrine of "created antiquity", i.e. that the earth was created to look as if it was billions of years old, or similar ideas then it is impossible to refute any claim that you make and hence, we can not have a scientific discussion.

Isn't it a shame how Hollywood has completely miscolored our perception of the American frontier. No doubt there were certain rugged individuals who lived in lawlessness, but by far the majority were "huddled together and dependent on each other". They might have been free in theory, but in practice their freedom was severely limited by their need for survival.

The case will be the same for Mars for a significant amount of time when resources will have to be supplied from Earth. This will necessitate a very strict society, where resources are rationalized. This doesn't have to be the result of a strict ruling body (government) but rather a natural result of their behaviour and need for survival.

The original article on this effect is actually from 1996. Allegedly, Podkletnov submitted a paper to the Journal of Physics but later retracted it before it was published. It caused quite a bit of controversy back then and Tampere University, where Podkletnov worked, denied all knowledge of anit-gravity research. So I wouldn't hold my breath for this.

Most physicists are also very sceptical about anti-gravity because its is not a force but rather a result of the geometry or curvature of space. Hence you would have to change the geometry of space in order to nullify gravity. Its also inportant to distinguish between something that actually changes gravity and something that merely reduces its effect. For example, levitating an object in a magnetic field can easily appear to counteract gravity.

A couple of points on the generation ship:

1) Compared to a mars mission, the generation ship is too risky from both a financial and scientific point of view. The likelihood of success is very slim and not enough to justify the huge investment.

2) The practical problems associated with mining minerals and metals from asteroids are not something we can solve within the next five or ten years. How do you get near the asteroid without damaging the spacecraft? How do you retrieve the raw minerals? How do you refine them on the spacecraft? Most minerals have to be burnt in air or reacted with other elements to purify them. These are all significant engineering challenges that won't be solved in one try., but will take years of experience. Then of course, there is the challenge of building a spacecraft in orbit large enough to accomplish the goal.