Light Echoes Solve Mystery of Tycho's Supernova
Well he had already done a lot of work on parallax measurements for astronomical objects. So when the supernova appeared, and showed no parallax against the moon . . . he was on pretty firm ground stating that the moon was closer to earth than the supernova.
More details in Wikipedia.
Rewriting a Software Product After Quitting a Job?
Ok so you can totally rewrite the software in a couple of months. Lets say you budget for 1 man year of coding.
Now you have software that works but you don't have a product you can sell. Expect to spend a further man year of effort "productising" the software. You need to make the thing bullet proof enough that someone who was not part of the development team can use the thing.
Now you have a piece of equipment that ordinary people can use, but you still won't sell much. Expect to spend a further 3 man years on the service side so that business folk can rely on your company and product.
Pretty much you can expect 6 times as much investment as you spend coding.
Oh and did I talk about timescales and cash flow?
These calculations are why early service/consultancy revenue is so important, and sadly why sales and marketing folk do what they do, and act like they do.
New Denial-of-Service Attack Is a Killer
Some DOS attack on Slashdot in progress?