The butterfly thing was never more than a slogan, and a misleading one.
The real story about tornadoes in six months time is that if you compute God’s Deterministic Will backwards from 1 July, then the part of the state space described by “tornado in Texas” has been smeared out and folded over so much by the time you get back to 1 January, that there is no human-possible measurement that can separate that part of the state space from the rest. In particular, there will be no butterfly-flapping event to attribute the tornado to, in the sense that the tornado shows up if and only if the butterfly flaps.
Similarly, if you take the part of the state space on 1 January described by “this butterfly in Brazil flaps its wings” and project that forwards, it will be so smeared out and folded over as to overlap all the tornado and non-tornado events on 1 July.
It especially does not mean that you can set out to produce a tornado by provoking a butterfly somewhere to flap its wings.
The butterfly thing was never more than a slogan, and a misleading one.
The real story about tornadoes in six months time is that if you compute God’s Deterministic Will backwards from 1 July, then the part of the state space described by “tornado in Texas” has been smeared out and folded over so much by the time you get back to 1 January, that there is no human-possible measurement that can separate that part of the state space from the rest. In particular, there will be no butterfly-flapping event to attribute the tornado to, in the sense that the tornado shows up if and only if the butterfly flaps.
Similarly, if you take the part of the state space on 1 January described by “this butterfly in Brazil flaps its wings” and project that forwards, it will be so smeared out and folded over as to overlap all the tornado and non-tornado events on 1 July.
It especially does not mean that you can set out to produce a tornado by provoking a butterfly somewhere to flap its wings.