You want your mirror large in order to resolve small angles and small objects. The smallest angle you can resolve is lambda/D where lambda is the wavelength of light you are using (400nm for near-UV blue) and D is the diameter of your mirror or lens.

So suppose you have satellite in 100km orbit around the moon with a 2.4meter aperture (like Hubble) using 400nm light. Then the smallest angle you can resolve is 0.034 arcseconds and you cannot resolve features smaller than 16mm. If you use red light (600nm) then you cannot resolve features smaller than an inch.

You are oversimplifying things. Yes, slow moving charged particles (such as electrons or Helium nuclei) can be easily shielded. However, fast moving particles are much harder to shield against as they create showers of new particles (of lower energy) upon collision.

The spectrum of these particles extends way up - scientists are busily observing particles with energies on EeV scale (roughly what a moving golfball has), though these are quite rare.

Neutral particles, like gamma rays, can only be shielded by a bulk material - the penetration depth depends on density.

Lastly, we have we have direct visual observation of cosmic rays by astronauts on Apollo missions and ISS.

In summary - being in space is kinda like being on a battlefield - if your general did not screw up the chance of being hit by an artillery shell is quite small. But this does not mean it cannot happen.

I am glad you liked it.

One other way to look at this is that if you try to maximize some function describing performance this decreases the uncertainty in function value (as the first derivative is 0) at the cost of increasing uncertainty in function parameters (i.e. everything else).

And unlike share price risk is good deal harder to quantify..

Another similar history lesson: demise of the Westinghouse company

Try Alt-F2 ;) Hint =2+3 starts a calculator that knows units and other extras

All *.gsfc.nasa.gov sites I tried to access are down - Fermi data, some catalogs, etc.

I looked up his entry on Wikipedia, which is why I mentioned batch files and not Visual Basic ;)

For once we have a line of scientific discussion and you are complaining ?

What do you expect ? The guy says he "wrote software for 8 years". This probably means Quick Basic and batch files.

Heh :) I don't know who invented this first. I found this trick in a manual for Chinese workers after spending a few hours reading all about making reliable SMT connections. Most manuals describe "ball of solder" technique where you use a small iron tip to carry a ball of solder to each pin and then make sure that pin and pad wick the solder in. Rather tedious, and I had to retouch connections often.

There is a trick for soldering fine pitch cases like MSOP or TQFP: just soak it all nice in solder without worrying too much about bridges. You want to make sure that enough solder gets between the pins and pads. Then use copper braid to soak all the extra solder off. In a way, you are just giving your part a localized solder bath. Make sure to use large tip for your iron - at least a few mm or a knife.

What do you mean ? The instruction set manual gives not hints of this. It even has a scatter/gather instruction.

It will make it possible to execute 10^18 instructions per second.

There is a flaw in your argument - the population of United States is growing much more slowly. So at some point everyone will be trained. Wouldn't that be nice ?

There is not much description in the article, but I don't think it is a Geiger tube, as that requires high voltages and is fairly bulky. This is probably some sort of silicon detector.