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Comment Re:Good for a lot of reasons... (Score 5, Informative) 186

>My question is why L2 and not L1?

Indeed, I have no clear idea, because once an object is located at one of the five Lagrangian points L1-5, very little energy is required to go to any other one.
L1 needs however the least delta-v to be reached from Earth or Moon, and direct radio communications are possible with L1 and L3, contrary to L2 which is hidden by the Moon from Earth. L3, on the side opposed to the Moon would require still a bit more delta-v than L2. L1-3 are dynamically unstable, so a station there would need periodic corrections.

L4 and L5 are more stable than L1 or L2 but require still a bit more delta-v wrt L1-3.

To reach Mars, or any escape from the Earth-Moon system L1_5 are almost equivalent if enough time is available, but L4-5 provide more orbit choice, so more possibilities to choose quick routes.

Note that the station would not need to be located precisely at one of the L1-5 points, but could be on so called halo orbits circling around such a point.

Comment Higgs boson does not explain mass in general (Score 1) 396

Let us remind that while the Higgs boson to some extent "explains" the mass of the heavy particle sector (quarks, thus protons and neutrons), the Higgs boson sheds no light on the mass of neutrinos, nor on the mass of the expected dark matter particles.
Also the particular value of the Higgs mass remains a natural constant escaping explanation.

   

Comment NTP instead of SCN? (Score 2) 100

I wonder why nowadays they use an incrementing limited integer number (SCN), subject to the described bugs, instead of a worldwide consistent and unlimited number like the TIME. The synchronization of the databases respective times can always occur with the NTP service (http://en.wikipedia.org/wiki/Network_Time_Protocol).

Comment Re:Question About Voyager(s)... (Score 4, Interesting) 166

In the linked article I didn't find that "only three" such antennae exist. The deep space network made of three big antennae is able to follow and control Voyager without interruption, but other isolated and big antennae exist and might be used to perturb the spacecrafts, probably with slight modifications.

Germany has a 100 m radiotelescope (Effelsberg), UK a 76m one (Jodrell Bank), Australia a 64 m one (Parkes), and China builds a 300m equivalent one, FAST, to be ready in 2013 (http://en.wikipedia.org/wiki/Five_hundred_meter_Aperture_Spherical_Telescope).

   

Comment Re:NE will get more credible when properly insured (Score 1) 324

Like for cars, deaths are just a part of the bill. To make a proper economic risk evaluation all the costs must be included. I am sure this has been done, but the only rational for not insuring nuclear power plants is that it would not be economically competitive.

Other costs that would make NE not competitive is the dismantling costs, and the waste management costs (100'000 yr is long...). Recently Germany started to redo the evaluation cost for dismantling the closed plants to find that a more accurate estimate is an order of magnitude higher. The same for the Superphenix breeder in France.

 

Comment Re:NE will get more credible when properly insured (Score 2) 324

Precisely, if the risks of an activity cannot be rigorously evaluated, then it should not be declared safe. Any professional certification of an activity requires evaluations. If serious evaluations are impossible then the activity cannot be certified, therefore responsible deciders should discard it.

 

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