Dark matter is thought to interact only through gravity. Researchers at Rice University and Leiden Institute are using sensitive detectors to monitor the movements of a sand-grain-sized permanent magnet levitated above a superconductor in an effort to detect this matter. No definitive result has yet been obtained from one month of data.
In the next phase of the experiment, the number of sensors will be increased to distinguish unusual signals from background noise. Even if no detection is made, the research will contribute to the development of models concerning the possible properties of dark matter.
Why it matters
The belief that dark matter interacts only through gravity makes it difficult to observe directly and distinguish it from ordinary environmental effects. For this reason, the value of the experiment depends not only on whether it captures a signal, but also on whether it can demonstrate how reliably extremely small movements can be separated from background noise. Increasing the number of sensors will allow the method to be tested, particularly for researchers interested in the sensitivity of experimental setups and the interpretation of measurements. Even if no definitive detection is made, the data obtained may help assess which observations are consistent with the models used to explain the possible properties of dark matter. The open question is whether unusual movements in subsequent measurements will point to dark matter or to another effect that has not yet been filtered out.