Check out the math & physics courses that I mentioned (many of which are free!) and support this channel by going to https://brilliant.org/Sabine/ where you can create your Brilliant account. The first 200 will get 20% off the annual premium subscription. If a particle decays into other particles, how can it possibly be that they are elementary? Doesn't the decay mean that the particle must have been made up of the other particles? And why do particles decay in the first place? These are really good questions which I get a lot. At the end of this video you'll know the answers. Correction to the illustration at 4 mins 25 seconds. The "e" on the left side should be a positron, not an electron. You can support our channel on Patreon: https://www.patreon.com/Sabine 0:00 Intro 1:30 Are the decay products already in the particle? 3:01 Are particles conscious? 3:50 Decay is an interaction 5:18 Why do particles decay? 7:13 Sponsor message