# Stuart_Armstrong comments on Another problem with quantum measure

• We could not have an in­finite pool of mea­sure to draw on, be­cause if to­tal mea­sure was in­finite, then any finite pieces could not in­ter­act with­out break­ing lin­ear­ity.

Can you ex­plain?

And, again, just be­cause you can dou­ble the to­tal amount of mea­sure in your rep­re­sen­ta­tion, doesn’t mean that this num­ber is phys­i­cally mean­ingful. If the num­ber was ar­bi­trary to be­gin with, there’s no rea­son to as­sume that chang­ing it is mean­ingful.

But you’re dou­bling the to­tal amount of mea­sure rel­a­tive to the to­tal mea­sure of the rest of the uni­verse, a change that is non-ar­bi­trary for many de­ci­sion the­o­ries.

• Sup­pose I start with a big blob of mea­sure in a bor­ing uni­verse, that is slowly turn­ing into uni­verses like ours. Lin­ear­ity says that the the rate at which uni­verses like ours ap­pear is pro­por­tional to how big the big blob of mea­sure is.

In fact, this is cru­cial to call­ing it “mea­sure” rather than just “that num­ber in quan­tum me­chan­ics.”

So if the rate of uni­verses like our ap­pear­ing is pro­por­tional to the size of the origi­nal blob, as we make the size of the origi­nal blob in­finite, we also make the rate of uni­verses like ours ap­pear­ing in­finite. We can­not have a finite num­ber of uni­verses like ours, but an in­finite blob of mea­sure turn­ing into them—we can only have a pro­por­tion­ally smaller in­finite amount of uni­verses like ours. This re­quire­ment gives us back our old limi­ta­tions about even­tu­ally run­ning into a max­i­mum.