Microsoft has released the WWT.

Free download available here: Experience World Wide Telescope

You’ll need all of the relevant .Net 2.0 cruft to browse the stars.

So far I’m impressed. Essentially operates like Google Earth but with the stars.

Download times are a bit long for the imagery, but that could be the connection here.

Why aren’t you dead?

It would seem logical that since I am living at St. Andrews I should have been consumed weeks ago by the intense gravitational pull of the black hole which resides in the vary building which one of the researchers, Dr. Friedrich König, lectures me every week about spatial and temporal coherence of light waves. Luckily, the “black hole” and white hole are merely simulated as an event horizon. So, I’m still alive and you don’t have to worry about the rest of the earth being swallowed. Check out the article–it presents a number of basic concepts about event horizons, so it’s a good read for beginners. I’ll have to ask my lecturer about his work tomorrow.

A large part of part of scientific research involves the principles of optical and atomic physics through laser-driven saturated absorption spectroscopy. In this experiment a single laser is split to provide both a pump and probe beam to examine the absorption spectra of a vapor cell containing primarily rubidium85 and rubidium87 as shown:

The How.

Initially, one must check for fluorescence within the vapor cell to ensure that the laser intensity is tuned properly. Very precise control of the laser is provided by frequency and temperature (wavelength) locking circuits. Once fluorescence is achieved adjustments are made to the frequency of the laser (adjusting the voltage to the laser’s PZT) to “scan” over the spectra lines of the ground and excited states of rubidium. These lines are observed on a digital oscilloscope. One small change is to be noted: the photodiode in this experiment had two active regions and a subtraction circuit attached to it. This allows for the account of Doppler shifts within the vapor cell while scanning to provide clearer spectra lines.

Once several lines were observed, the best observable spectra lines are recorded. See below (Standard Transition Level Schema) for expected states to be visible in the experiment:

Next, the vapor cell is switched out with another wrapped in coils of wire attached to a power supply in order to observe the effects of a magnetic field generated by the Zeeman shifter on the vapor cell. Once the Zeeman shifter is powered, another absorption line is recorded and saved once again for comparison to the preliminary lines where a splitting of the lines should be observed. See below for a visual representation (Zeeman Level Schema) of the splitting expected.

The Numbers.

Rb85 5P_3/2 Spectrum Lines:

Table 1: No Effect, Rb85 5P_3/2

Zeeman Effect Spacing

The Outcome.

The exercise of this experiment is particularly useful in determining the proper operating frequencies of a laser allowing an individual to create a magneto optical trap or MOT. Principally, one should be able to find the frequencies at which it is possible to slow rubidium atoms both when under the influence of the Zeeman effect and otherwise. Although after considerable trial and error in the short lab window given, we were able to properly align the optical setup with the diode to achieve both a pump and probe beam providing fluorescence, it was difficult initially to locate the spectra lines of the rubidium in the vapor cell. After finally getting clean lines without the Zeeman effect, an average frequency spread was calculated for the Rb85 5P_3/2 transition lines to be approximately 11 GHz with an average spreading of 5.6 GHz/Volt. These findings seem to be valid. However, once the effect was introduced severe noise was clearly visible in the signal on the oscilloscope most likely from building vibration and potentially interference picked up through the effect’s wires. In order to combat this issue, the digital oscilloscope’s snapshot feature was used to prevent movement of the lines while recording data. This may have negatively impacted the Zeeman effect data even though multiple snapshots were taken, as the spectrum was constantly moving on the oscilloscope.

Thus, the first half of the experiment was useful in observing spectra lines. Noise and incorrect data in the second part of the experiment involving the effect resulting in 40% error is unsatisfactory to make any conclusions about the effects of the Zeeman effect on splitting spectra lines. However, the splitting is indeed visible. If the experiment were to be repeated, greater care eliminating noise and alignment should be taken, as well as increased resolution on the oscilloscope in order to achieve a better comprehension of the Zeeman effect. It should be noted that this research was conducted as an undergraduate experiment and the results are not to be considered valid as the experiment was repeated later with greater precision and verification. If there is any incorrect information presented please feel free to send me an e-mail, I’d appreciate it!

“World” Telescope?

What’s so awesome about the WWTelescope is that it seamlessly binds together terabytes worth of data collected from Hubble and various other observatories into one coherent search-able “universe” in an application. Rather than viewing static images, you can actually browse galaxies and our own solar system with accurate image data.

The head of Harvard’s observatory back then [1920’s] argued that the Milky Way Galaxy was the entire universe. Harvard was wrong big time.

With Microsoft’s tool the average user can zoom in on black holes and view astronomic phenomena through all of the spectra of light. Not only can you travel on your own to distant nebulae, but tours built into the data introduce the user to even the most remote yet beautiful images humanity has collected over the last 30 years.

When can I get it?

Soon–this spring, for free! You can watch a video with a bit of the features here. The labor that has gone into this project is incredible, and I can’t wait to experience the universe from the comfort of my chair. Wonder if it shows dark matter?