To check out the physics courses that I mentioned (many of which are free!) and to support this channel, go to https://brilliant.org/Sabine/ and create your Brilliant account. The first 200 will get 20% off the annual premium subscription. The physics survey that I mention is here: https://arxiv.org/abs/1612.00676 If you want to know more technical details, this is a really excellent review article that will tell you all you ever wanted to know about decoherence: https://arxiv.org/abs/1911.06282