physics + math
CONSEQUENCES OF RESEARCH
? RETHINK UNIVERSE
threshold for an electron that was emitted due to a neutrino interaction, it continues moving and hits an extremely sensitive device. It is balanced precariously between two different states, as though on the tip of a pin. When a little bit of energy is added by the electron, there is such a sharp phase transition of this device (i.e. the pin tips over to one side), that it is possible to measure exactly how much energy was added, and thus find the energy of the single electron. By examining this energy, physicists will be able to count the number of neutrinos that interact with the tritium. A fully functional prototype of this experimental model has been constructed, but the PTOLEMY team is still working on improvements to the tools. Once constructed, this experiment could result in a number of drastically different observations about the universe. First, detecting too many neutrinos could possibly contradict the Big Bang theory, the long accepted theory of the history of the universe. In fact, this observation would suggest that there wasn’t just a single Big Bang: perhaps these neutrinos came from multiple other Big Bangs. Or, if
330 neutrinos and antineutrinos per cubic centimeter
✓
? ? ? ν? ? ?
THEORIES VERIFIED
RETHINK NEUTRINO
“[Neutrinos are] a tiny ingredient of the universe that makes it all work.” — Professor Tully no neutrinos are found, we may simply need to reconsider the lifetime of the neutrino – perhaps most of these relic neutrinos have decayed in the past 13 billion years. Furthermore, PTOLEMY has the power to capture a special type of predicted neutrino that cosmologists think may explain the mysterious substance that we cannot see or detect, dark matter, which is thought to make up about 85% of the total mass of the universe (the other 15% comes from normal matter, like the atoms that make up our visible universe). Although still in its beginning stages, this experiment will create a great new observational machine, which, over time, will be used to quantify more and more observations about the universe. Currently, the biggest experimental challenge is keeping the experiment, especially the device that is balanced between two states, at a very low temperature (ten times colder than deep space) to achieve the desired precision. This has never been done before with
such a large experimental setup, but physicists at PTOLEMY are working on achieving these extremely low temperatures. The techniques and tools from PTOLEMY will contribute to many areas of science and imaging processes that require high precision energy measurements. Detecting these elusive relic neutrinos could finally experimentally verify (or contradict) a prediction that has been accepted for quite some time on theoretical grounds. Understanding these relics from just a second or two after the predicted Big Bang would allow us to experimentally probe the very beginning of matter formation in the universe, preempting a crucial time in which the most fundamental ingredients of our universe were formed. And although neutrinos seem so insignificant, as if the universe would just behave quite the same way it does without them, it turns out that they are, in the words of Professor Tully, “a tiny ingredient of the universe that makes it all work.”
PTOLEMY 19