“For me the best answer is not in words but in measurements.” -Elena Aprile
Dark matter is perhaps the most mysterious substance in the Universe. It outmasses normal matter and radiation, which includes all the known particles in the Standard Model, by a factor of 5-to-1. The observational, astrophysical evidence for its existence is overwhelming, and there are a slew of direct detection efforts underway here on Earth. Depending on dark matter’s properties, any number of them might claim success at any point in the near future.
But because we don’t know the properties of dark matter, they could easily all return null results, or results consistent with no dark matter. That isn’t an indication that dark matter isn’t real or doesn’t exist! Rather, it’s an indication that we don’t know what the nature of dark matter is, and a reminder that every one of these experiments is operating under the assumption that dark matter will interact in a way that it’s not yet proven to do so.
It’s important to keep looking, but it’s also important to not oversell the probability of our direct detection efforts bearing fruit anytime soon. Be free to hope, but don’t be overly, foolishly optimistic!