*Originally posted by twhitehead*

**I am curious. Is the calculator easier to use than a computer or does the computer simply not give you the accuracy you need? If you did the formula in Excel for example would it not be accurate enough?**

I use excel at work, and know about the formula insertion, etc., but not sure if DMS is included, I have to be able to go from DMS to decimal format. I assume excel would have at least the same decimal accuracy as my old trusty 48. For the paper I am writing, I will have to eventually go to excel or mathcad, something on that order, at least to get the data in something other than pen and inkðŸ™‚ Using the 48, compared to the regular casio, the whole calculation turned out to be about 6 or 7 steps, half the # for the algabraic unit. I am calculating the difference between what a parallel beam would do going through a gravitational lens V what a diverging beam from a distant stat would do, that is to say, where the focal points are located when you go outwards from the sun, say two laser beams magically collimated to a very narrow beam, and you can adjust where over the surface of the sun you aim the beams, right at the surface, one beam skimming the left side of the sun, the right beam skimming the right side, the laser beams meet about 52 billion miles out in space away from the sun, following the beams. But if you do the same thing and now they are one radii above the surface, the beams meet at a distance 4 times greater, about 200 billion miles out. The thing I am working on is how that effect varies when you consider real life stars, whose radiation is radially distributed. That means that as you do the same thought experiment the light from the star as you go away from the surface of the sun, is diverging away from the sun. That means the diverting angle from the distant star has to be subtracted from the converging angle of the gravitational lensing so it leads to the conclusion there is a limit as to how far away from the sun light from a distant star can be focused. My earlier work just based on the casio led me to believe the focus effect leads to a beam of focused energy the same length as the distance to the star, like Alpha Centauri making a beam of focused light on the opposite side of the sun that would reach out 4.3 light years and then peter out, but the increased accuracy of the HP48 has led to somewhat different results. I am only a couple days into it now, since each angle diversion from the star needs to be compared one on one to the conversion effect of the focusing of the sun, but with the HP it is a lot easier. This is just the opening round for me and I would of course want to be able to go to a program like excel that can do the job all in one go, mapping the focal line point for point and for any arbitrary distance but for now doing it manually is good enough, it give me time to think about what I am doing step by step and seeing if it passes a reality test, and that I am at least not barking up the entirely wrong tree.