I miss my running buddies!!

Without Clara and Stephanie (off at Berkeley and in Florida, respectively) I've been running on my own a lot recently... and when I say "recently" I mean "in the last three days." The loneliness is getting to me already!!

Fun run today, I thought it would be 6 miles, but apparently it was not. It was pretty safe, didn't run through too many sketchy areas (I think Orange Grove is a pretty road).

See the route I ran! East Orange Grove on MapMyRun.

I also started my SURF this week, with a (luckily) very direct application of the methods I learned last semester in Ay 117! So far, I have been writing code that generates a mock noisy spectra of a B-Star (which is basically a very big star!), then playing with this spectra and attempting to extract from it the shift I put it. This part I've done.

Now, the hard part - I need to write code to extract a doppler shift. This is tricky because a doppler shift or a given magnitude has different effects on different parts of the spectrum. If you don't know what a doppler shift is, imagine a firetruck, sirens blazing, passing you as you stand on the sidewalk. As the truck moves toward you, you will hear a shrill siren, which then becomes deeper after the truck passes you. The reason that this modulation occurs is that the sound waves are experiencing a doppler shift. When the truck is moving towards you, each successive sound wave is being emitted at a decreasing distance from you, meaning that this later wave has a "head start" on the earlier one. The frequency of sound waves reaching your ear is thus higher than the frequency at which they are emitted. The opposite is true if the truck is moving away from you - each successive wave has to travel even farther than the one before it.

The same thing happens with light. If a source emitting photons is moving away from us, then the distance between each photon is greater as time goes on. The effect of a doppler shift on the observed wavelength is given in this relationship:


Which is dependent on the wavelength, represented by lambda. At higher wavelengths, there will be more space between successive wave fronts. This is why we cannot say that with a doppler shift, a 10 nm wave becomes a 12 nm wave and a 16 nm wave becomes a 18 nm wave. the 16 nm wave will actually be larger than 18 nm, since as the wave itself is longer, the shift must also be bigger.

To get this working, I need to tackle interpolating functions. AH! Wish me luck!