University of Oxford
My research focuses on designing, building and using telescopes to make observations of the relic radiation from the Big Bang, known as the cosmic microwave background (CMB). Observations of the CMB provide a unique opportunity to measure the fundamental numbers that describe our universe, such as the amount and types of matter and energy it contains, how old and how big it is, and what its future evolution might be. These observations allow us to test the theories of formation and evolution of the structure in the universe.
The Big Bang model is currently our best theory for the origin and evolution of our universe. It says that about 14 billion years ago, the universe that we see today was only a few millimetres across and was incredibly dense and hot (many times hotter than the centre of our Sun). As the universe has grown older, it has expanded and cooled to become the cosmos that we see today. Now, wherever we look in the sky, we can still detect the CMB, the very faint afterglow of the Big Bang, at a temperature of less than three degrees Celsius above absolute zero. The CMB is not quite completely smooth however; there are small variations in its temperature, of a few parts in 100,000. These fluctuations are due to tiny variations in the density of the very early universe, which have since collapsed under gravity to form all the galaxies and stars that we see in the universe today.
However, because the fluctuations in the CMB are so small, measuring them is not easy and specialised telescopes using techniques at the forefront of technology have to be built. This is the focus of my research.
My work impacts society in several ways - astronomy, and especially cosmology, fascinates the public and helps draw students, both at school and university levels, into studying physics and other sciences. The technology required also has applications outside of pure science with potential spin-offs in areas such as satellite communications and security imaging.