Riddles, brain puzzles and mathematical problems

[Bridge]

I don't get it. The last rat still receives "512" bottles so it is impossible to find the poison in only 24 hours, wasn't that the point of the puzzle? You said it takes 10-20 hours for the poison to run its course and the scientist only has 24 hours to find the poison, implying that in a worst case scenario it must be done in one go (though it is possible to do it in two in if the poison decides to kill quickly.) Therefore, to satisfy the conditions of the puzzle it must be done in one go. With this method, ruling out 512 bottles is only the first step, you must then divide 512 bottles the same way, and then 256, then 128, etc … until you have only two. Therefore, way more than 24 hours and way more than 10 rats are required.

Time limit. Ooops. I completely forgot. You are right. The method Neptune used can be done with 10 rats but it will take much more than 24 hours because you must wait 10-20 hours for the first rat to die. Sorry for that. It was late when I checked his solution and it slipped my mind.

The riddle remains open. There is a way to do it ON time. Neptune is close.

Hint:The answer is 10 rats (as Neptune predicted), but you have to modify Neptune's method to make it faster

Why is that so? My method involves neither waiting nor knowledge of prior results. Just do all the steps at the same time. I was worried that this wasn't clear with how I worded it in some parts, but it was indeed the intention.

The point is that you have only eliminated half of the bottles by the end of it. You have to repeat the process 9 more times which means you must wait in a worst-case scenario 9*20 = 180 hours/7.5 days and you only have one to find the poison. That's assuming you can do all of the steps at the same time, but then you need to wait worst-case scenario 20 hours. You of course need more than 10 rats to do that too.

EDIT: Either that or I really do not understand the method and how the results can possibly be interpreted in such a way that it singles out one bottle.