Mathematics of Interference

Calculate the angle for the third-order maximum of 580-nm wavelength yellow light falling on double slits separated by 0.100 mm.

ASTR 1000: Survey of Astronomy Class Intro Lecture i2: • Math o Powers of 10 ▪ See lecture slides, tables for powers of ten ▪ Used so we can write big numbers o Scientific Notation ▪ Because astronomy deals with values of both distance and time which span a large range, we cannot write numbers in a conventional manner (rephrase) ▪ A number times 10 to a power ▪ The distance of Alpha Centauri is 23,885,000,000,000 miles ▪ 2.39 x 1013 ▪ The number in front gives the value, the power of ten gives the magnitude o Unit Conversion ▪ Because it’s easier to think in small numbers, we often change units when moving to different scales of astronomy ▪ Instead of the distance to Alpha Centauri being given as 2.39 x 103 miles, we use 4.4 light-years ▪ Converting between units is just multiplying by 1 ▪ The number for the answer might change, but the physical distance or time does not ▪ Easier to process this way ▪ When converting units, we will sometimes move the power of ten into the unit as the prefix: 1 km = 10 m, so k = 10 see lecture slide graph o Formulae ▪ Velocity (v) = distance (d) / time (t) (v = d/t) ▪ E = mc (nuclear fusion) ▪ Newt’s