Question: What science machines that looked impossible before are being built now

Mike Heyns answered on 6 Oct 2022:

One proposed experiment that I think is awesome is LISA (Laser Interferometer Space Antenna). This is the follow up to LIGO (Laser Interferometer Gravitational-Wave Observatory), which in itself is a near impossible experiment that delivered our first gravitational wave observations, literally measuring the fluctuations of space itself. To give an idea of what was needed to detect the gravitational wave signal, LIGO was able to detect a change in distance of 1/10,000th the width of a proton between its mirrors 4 km apart. This is like measuring the distance to our nearest star accurate up to the width human hair. Now LISA is hopefully going to increase this accuracy by taking the experiment into space.