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In order to justify my Idea, I will first give some explanation of how solar sail craft navigate.  Solar sail craft that want to travel to the outer solar system will not use their sails to reflect the light directly back at the sun.  If a sailcaft did this, it would do the equivalent of reducing the sun's gravity slightly.  Unless the sail is able to completely counteract the Sun's gravity (and this seems to be beyond the technology of the near future) the sailcraft will travel in an elliptical orbit that would bring it right back where it started.  In order to travel outward, the sailcraft must increase its rotational momentum.

All sailcraft designs that I have seen would increase rotational momentum by angling the sail so that reflected light has momentum in the rotational direction.  The amount of momentum that a photon imparts to the sail in the rotational direction is proportional to the sin(2x) where x is the angle between the photon's path and the normal to the sail.   However, as the sail is angled, it also looses angular size as seen from the sun.  The angular size of the sail is proportional to cos(x).  The maximum value for sin(2x)*cos(x) is approximately .77 and occurs at about x=36.26 degrease.  Therefor the maximum thrust of a traditional sail in the rotational direction is .77*sail area*pressure of light.

This thrust can also be used to decrease the orbital momentum.  Decreasing the orbital momentum decreases the centrifugal affects of the rotation and allows gravity to pull the ship closer to the sun.  This affect has been called tacking, though the concept is completely different from the way a sailboat tacks.

My Idea for a solar sail design would be to have the primary solar sail stay perpendicular to the path and reflect the light onto a smaller secondary sail that is between the ship and the sun.  The secondary sail could then either reflect the light in the orbital direction, or (probably easier) reflect the light back at the ship where tertiary sails or mirrors would direct the light in the proper direction. 

I realize that the secondary sail would make the sailcraft more complicated, and that it might be difficult to keep the light focused correctly, but those seem to be simple engineering problems that can probably be overcome.  If this idea works correctly, the craft would generate 30 percent more useful thrust than it could with the primary sail alone.  The increased power output seems to me to be enough that the idea should at least be investigated.

I think the wind normally blows from the West to the East in Iraq.  Dust and smoke would more likely effect Iran and India than Eastern Europe.

This is easily done by a disc that reflects light, but not by a bubble pushed by the solar wind.  With the (non-dusty) plasma sail, it is only possible to create a force directly away from the sun.  This means that if you want to decrease your orbital velocity, you need a different way of doing it. 

In addition, generating force directly away from the sun is not always the easiest way of getting farther away from the sun.  If the force created is much less than the force of the sun's gravity, the vehicle will not be able to get to the outer planets at all.  Contrast this with a light-reflecting solar sail, which can use light to gain rotational energy, and eventually reach any orbit. 

Since the plasma sail creates a force that directly counteracts the sun's gravity, it can be thought of as a method of artificially reducing the suns gravity.  However, this is all that it does.  According to some calculations I did, the force of gravity on 1 kg at 1 au from the sun is about the same as the pressure of the solar wind on 6 km^2 of space.  A plasma sail would not be 100% efficient, so it would probably need at least 10 km^2 of sail area/kg in order to completely counteract the sun's gravity.  If this is achievable, then the technology could be very useful for things like deep space probes.  Otherwise, I think its capabilities would be too limited to be very useful as a stand-alone technology.  It is possible that it might be used in a hybrid with another method of propulsion that would give it the necessary maneuverability.

When two hydrogen atoms fuse to create a helium atom, none of the protons or neutrons are destroyed.  However, the helium atom does have less mass than the combined masses of the hydrogen atoms.  This decrease in mass is actually what created the energy due to E=mc^2.  Mass and energy are actually the same thing, and it is possible to convert mass to energy and vice-versa.  The process is reversible, and scientists have successfully created particles (with the associated antiparticles) by concentrating energy until it creates matter.  However, there is greater entropy when there is more energy and less mass, so natural reactions tend to decrease mass and increase energy.

With regards to a fusion reactor, I am sure that it is possible, but the engineering difficulties are greater than soph thinks.  With fission, all you have to do is get a bunch of rod of enriched Uranium, and they will naturally heat up when you put them close together.  The amount that they heat up can be easily controlled by simply putting dividers between the uranium rods to separate them when you want to slow down the reaction.  The heat from the Uranium is then used to boil water, which turns turbines in the same fashion as generating power from coal.  It is really quite simple, and anyone who can get enough uranium can quite easily make a working fission reactor that generates power.

With a fusion reactor, however, the reaction happens at an extremely high temperature that would instantly vaporize any material that it contacts.  Therefore, the reaction must occur in a magnetic field, and very powerful lasers are required to sufficiently heat up the hydrogen.  With fusion, it is necessary to carefully control the output of the lasers and the nature of the magnetic field in order for the reaction to occur.  Then you have to also worry about carefully adding more hydrogen to the reaction to keep it going.  Finally, you have to actually convert the energy from the fusion into electrical/mechanical energy, which may not be as easy to do as it is in fission.  Presumably the engineering difficulties will eventually be solved, but I am not sure if it can ever be made as simple and reliable as fission.

Regarding plasma sails, it is an interesting concept and it would be nice to prove it works.  I think that it is a method of propulsion that could become reliable and economical.  However, if it relies on gravitational "tacking", then there are limits to the accelerations and velocities that are possible, which could become very inconvenient in the outer solar system.  Therefore there will always be a niche for other methods of propulsion that allow more flexibility and maneuverability.

It looks like the US might use tactical nuclear weapons against Iraq.  These would be small nukes launched against military targets rather then large bombs targeted at cities, so they would not create as much devastation as people would expect from a "nuclear event".  I think that a giant "destruction of the world" type of nuclear exchange is unlikely.  The only use of nukes against civilians that I think is likely would be in an India-Pakistan war.  I don't think that it is very likely that terrorist will acquire nukes any time soon, though it is likely that they will use chemical and biological weapons.

North Korea has been rational with the US.  Or at least not completely irrational.  They are developing nukes and missiles with the idea that they can use them as bargaining chips in an attempt to get financial assistance from the US.  They did not shoot missiles at the US, they shot them into the Pacific Ocean.  Would you rather have them test the missiles by launching at a land target?  They do not yet have the capability of even getting them to the US.  North Korea is not one of the friendliest countries in the world, but they are not insane enough to attack China for no reason.

With regards to Egypt and Libya's missile capabilities, Libya's longest ranged missile has a range of 590 miles.  This means that southern Italy, Greece, Albania, parts of Bulgaria, and parts of what used to be Yugoslavia are potentially within missile range.  Egypt is not even on our "potential enemies" list.  Their best missiles have a range of 300 miles, though they may be working on an 800 mile missile.  The new missile would essentially allow them to attack the same areas of Europe that Libya can attack. 
While they can indeed attack parts of Europe, they cannot attack Germany, France, or the UK.  Of course, France and the UK both have the capability of nuking any city in the world.

What you don't seem to understand is that governments usually try to act in their own self interest.  Just because a country can attack a much more powerful country, doesn?t mean they will.  If a country has nothing to gain and a lot that they almost certainly will lose as a result of a war, they will try and avoid the war.

According to the Center for Defence Infromation, http://www.cdi.org/products/almanac0102.pdf, the UK and France together have 96 warships and 111 support ships.  The US has 200 warships and 200 support ships.  NATO has a total of 660 warships and 858 support ships.

Why would North Korea launch a missile at China?  China could easily defeat North Korea.

Japan's military is supposedly designed for "defense", but then again so is America's military... which hasn't stopped us from participating in at least 193 military interventions since WWII.

Which Arab countries have missiles that can reach Europe?  Iraq's longest ranged missile, the Al Abbas variation of the Scud-B, only has a range of 500-560 miles.

Europe's military technology is not quite as good as ours, but the difference between Europe and the Arab countries is much larger than the difference between the US and Europe.

The Arab countries' militaries are a joke.  The only countries that they are a serious threat to are each other and Israel (and Israel has consistently defeated them).  China and North Korea pose more reasonable threats, but even if we downsized our military considerably, we could protect our Asian allies.  In addition, we are currently on good terms with China, while North Korea is impoverished and struggling to feed it's people.

Whatever gave you the idea that the European countries had no militaries?  Their militaries aren't as strong as ours, but they are powerhouses compared with the rest of the world.

Top 10 yearly military expenditures (based mainly on 2000 figures):
1. US            $343 billion
2. Russia       $56 billion
3. Japan        $45 billion
4. China         $39.5 billion
5. UK             $34.5 billion
6.  France       $27 billion
7.  Germany     $23.3 billion
8.  India          $15.9 billion
9/10 South Korea and Taiwan  12.8 Billion each
Other NATO:   $62.3 billion
All rouge nations(Iraq, Iran, Syria, North Korea, Cuba, Libya, and Sudan):  $14.4 billion

Top 5 nuclear powers:
1. US           7519 warheads
2.Russia       6860  warheads
3.France        384 warheads
4.UK              185 warheads
5.China            20 warheads

Saying that Europe has to worry about being invaded by Arab countries is a little like saying that the US should worry about being invaded by Canada.  Except that Canada actually has a border with the US.  China poses a more credible threat, though again the European countries don't border China, and our NATO allies probably have a combined strength greater than that of China anyway.

How is Iraq a threat to the US?  The US is responsible for 4/9 of the World's military expenditure, spending about $400,000,000,000 per year.  Iraq spends 1/300 of this amount.  The US has enough nuclear weapons to destroy the world several times over.  Iraq has no nuclear weapons, though the US alleges that they have chemical and biological weapons (Iraq denies this, which is supposedly what the conflict is all about).  The US has ICBMs and stealth bombers that can destroy Iraq before Saddam even realizes what is happening.  Iraq posses no means of directly attacking the US mainland.

Saddam isn't stupid or crazy.  Even assuming he has biological or chemical weapons, he would not give them to terrorist for several reasons: 1. Terrorist are generally not very trustworthy, so Saddam cannot be sure that they will not be used against him.  2.  If he did give weapons to terrorist, and the US tracked them back to Iraq, Saddam would not be able to survive the repercussions. 3.  Saddam does not really gain anything from an attack on the US.  4.  Saddam and the Iraqi government are not religious extremists (actually, this was one of the reasons for Iraq's war with Iran).  5.  It would be hard for Iraq to replace any chemical weapons that it gives away due to the weapons inspectors, sanctions, and the fact that the US will not give Saddam any more chem. weapons. 

Based on all this, I really don't see how Iraq poses any credible threat to the US.

The Earth rotates about once every 23.8 hours.  This means that the stars will be in the same position with respect to the Earth every 23.8 hours.  However, the Earth is also going around the sun, so the Earth has the same position with respect to the sun every 24 hours.   The system was designed so that the length of rotation with respect to the sun is exactly 24 hours, so leap days are not necessary.

A couple of years ago, there was an extra second added to the length of a day.  This was because the Earth is not rotating as fast as it used to. The rotational energy of the Earth is gradually being transferred to the moon though gravitational interactions, thus slowing down the earth's rotation.  That means that the Earth is now taking slightly more than 24 hours to rotate with respect to the sun, so more extra second will have to be added to days in the future to keep our clocks and the Earth in sync.