Maybe 500 could be a Captain America Clownfish finding Stark shirt. But the fact remains that it takes an extremely long time to actually break down to no longer be Styrofoam. This kid and his team have created a way to mitigate this. Don’t lose track of the forest for the tree. The big picture is still amazing even if one small line is off a bit. The science of today is held with such reverence that they could flat out lie about something and their mass will believe them. Yes, because the estimate of how long nuclear fallout would hang around when nobody had seen nuclear fallout or used atomic weapons before is totally relevant to the estimate of how long styrofoam will take to break down.