Seeing the Unseen

Presentation themes: fulldome

Technological advances are making it possible to obtain increasingly detailed images of objects in the universe, as demonstrated by the latest news from the JWST and Euclid satellites. Some other photometric surveys allow to measure magnitudes of stars or galaxies.

However, these data are sometimes just the starting point for further studies, which deduce quantities that are either imperceptible on our time scales, or simply invisible: gravitational fields, galaxy velocities, dark matter etc.

It's not simple to represent these quantities (scalar or vector fields) while remaining as faithful as possible to scientific data and it can lead to erroneous interpretations that go against what the researchers are saying.

Using the latest results from the CosmicFlows collaboration (which discovered Laniakea, Tully et al. 2023, Dupuy et al. 2023) as an example, we'd like to show how some scientists, in their own research, use representations that are appropriate for planetariums (watersheds, repellers and attractors, and velocity fields, etc.). We'll see, however, that these representations can be misleading, taking a closer look at the case of streamlines and trajectories.

Finally, we take a brief look at the future, with the arrival of Euclid data and possible representations of dark matter or universe expansion.