Q28

[leroyjenkins]

Why is A incorrect?

In lines 40-41 we are told

"...it is impossible to predict even the general destination of the particle given its starting point. "


The only difference between answers A and B is that:

A. In A, the reaction is unpredictable even if we know the starting point is the same in both experiments.

B. In B, the reaction is unpredictable because we cannot reproduce the starting point.

I can see why B is correct because of what is stated in lines 5-9.

But isn't A also supported, since in lines 40-41 were are told, even if the starting point is given, the destination is unpredictable? The language used in 40-41 ("given the starting point") suggests that, even if we have the same starting point, the results are unpredictable.

Can anyone help explain why lines 40-41 do not support A?

[tommywallach]

Hey Leo,

Your explanation of the difference here is perfect, and indeed, the whole question revolves around that slight difference.

In (A), the starting conditions are the same.
In (B), it's impossible to have similar starting conditions.

But in the example given, the issue is that we can't create similar starting conditions, because "even the least change in the starting conditions--no matter how small, inadvertent, or undetectable--can alter results radically." That word undetectable means we wouldn't even know if we'd changed the starting conditions. In other words, it's impossible to know if we have the same starting conditions.

Hope that helps!

-t

[deedubbew]

How do you recommend we avoid the trap that Leroy fell into? I think a lot of people would look at the same line reference that he saw and decide that it is right without thinking that we would have a to make deduction from a line in the first paragraph. Morever, the line you referenced doesn't pop out as much as the line Leroy found.

[Aquamarine]

I chose C, but the answer is B.
I can't still find out what the difference between B and C.
Why is C wrong and B an answer?

Can someone explain me?
Thanks!

[kristinfabella]

I narrowed it down to (B) and (C) and incorrectly chose (C).

I've probably been reading this passage too long and am missing something.

Am I understanding this correctly?

(B) says it's impossible to produce starting conditions that "in fact exactly the same"

(C) says it's impossible to produce starting conditions that are "even approximately the same" from one experiment to the next

Is (C) wrong because if it IS possible to produce conditions that ARE approximately the same?

[maryadkins]

Yep. Exactly. We aren't given any suggestion that it wouldn't be possible to approximate the same starting conditions, we just know that they can't be perfectly replicated (see Tommy's post above).

As for (D) and (E), which haven't been discussed yet on this thread, these are contradictory to the passage, which is about NOT having consistent results.