Here begins a blog about my experience deploying to Antarctica to launch the SPIDER experiment. I haven’t kept a blog since Xanga was a thing, but I will do my best to post about my experience so all of my friends and family who have been so excited for this adventure can partake along with me. I plan for this blog to be not too scientific, as I anticipate that most of the people who read it will not be physicists. However, I’m not going down to Antarctica just to sight see, so I might get into some of the details of SPIDER too. By way of introduction:
Who am I?
I’m Anne Gambrel, a fourth year grad student at Princeton in the physics department. I’m from Omaha, and went to college at the University of Tulsa. I’ve never been to Antarctica before (not true of everyone on our team!), and will leave the US on Oct. 16. Our schedule has us launching in mid to late December, and cutting down and packing up by the end of January. So this blog will document about 3 and a half months of life on the Ice.
What is SPIDER?
SPIDER (which isn’t an acronym for anything anymore- it’s just our experiment’s name) is a balloon-borne telescope designed to look at the very earliest light we can see in the universe. You can see what it looks like in the picture below, taken last summer in Texas.
You can see a ring of six circles around the top end of SPIDER. Each of these is the top of an individual telescope. The telescopes are each about 100 lbs, 5 ft in length, and have incredibly sensitive microwave detectors. The light that we observe is not in the visible spectrum, but instead has much longer wavelength- about 2 mm. We use very sensitive superconducting devices to measure the power of that faint radiation. SPIDER uses a lot of interacting subsystems that cooperate to enable our detectors to work and to look where we want to in the sky, but I’ll save those details for another time.
Why do you have to go to Antarctica?
A lot of reasons! We want to put SPIDER on a balloon so we can look at the sky above the atmosphere, a big microwave emitter. Antarctica is a great place to launch a balloon. In the Austral summer, winds set up around the South Pole that keep the balloon rotating over the continent, so that when we cut it down, it lands on the ice, where we can recover it. We also use the 24 hours of sunlight to power the instrument.
What is SPIDER’s goal?
We are trying to detect a very specific pattern in the polarization of the cosmic microwave background. This pattern is a predicted signature of primordial gravity waves. Our best theory about what happened in the very earliest fraction of a second after the big bang is a period of exponential expansion–an explosive growth in spacetime that lasted ~10^-33 s. A lot of models for this theory predict that this rapid expansion would leave ripples in space time–gravity waves–that should be detectable in the cosmic microwave background SPIDER observes. One group, BICEP2, announced earlier this year that they had detected this signature with their telescope at the South Pole. Since then, their conclusion has become uncertain as new data has been published which shows our galaxy emits light with the same polarization property as we would expect from gravity waves. SPIDER, a more sensitive instrument observing more of the sky, should have the best measurement to date of the gravitational wave signature if it is there.
More when I get to Antarctica!
See you on the Ice!