Fifth Force ..

[kaulnikhil]

Before 1986 physicists believed they could describe
the universe in terms of four universal forces.
Experiments then suggested, however, a flfth
universal force of mutual repulsion between particles
of matter. This fifth force would explain the
occurrence in the experiments of a smaller
measurement of the gravitational attraction between
bodies than the established theory predicted.
Which one of the following, if true, most strengthens
the argument that there is a fifth universal force?
(A) The extremely sophisticated equipment used
for the experiments was not available to
physicists before the 1970s. (
B) No previously established scientific results are
incompatible with the notion of a fifth
universal force.
(C) Some scientists have suggested that the alleged
fifth universal force is an aspect of gravity
rather than being fundamental in itself.
(D) The experiments were conducted by physicists
in remote geological settings in which factors
affecting the force of gravity could not be
measured with any degree of precision.
(E) The fifth universal force was postulated at a time
in which many other exciting and productive
ideas in theoretical physics were developed,
[spoiler]
Why is C wrong ..If the fifth force is an aspect of gravity ... wouldn't it help in the measurement of gravity ???[/spoiler]

[linkinpark]

I picked B,

with C, don't know if my reasoning is correct - if fifth force was aspect of gravitational force doesn't it indicate that it was existing force and not new ?

[kellygreen]

I lean toward B also. What's the official answer?

I guess C is wrong because the question asks for something that supports the existence of a 5th force, but C would say that instead of a 5th force, the physicists are just noticing something that's already part of gravity, one of the other 4 forces, so it actually hurts the argument for a 5th force.

[Testluv]

The correct answer is definitely choice B. We can use the denial test. What would happen to the argument if previously established results WERE inconsistent with the notion of a fifth force? Then, the argument that there is a fifth force would definitely be weakened. Because the denial of chioce B clearly weakens the argument, choice B must be a strengthener.

@kaulnikhil: look at the scope of the argument; the question stem instructs you to find a choice that will strengthen the argument that there IS a fifth force--not that gravity can be measured.

[kaulnikhil]

Thanks a lots guys ...OA is B

[kaulnikhil]

Thanks a lots guys ...OA is B

[vinni.k]

Today, I came across this question from veritas prep, and I would be glad, if any expert can help in negating choice C.

My stand on C:-
I believe that if i negate choice C, it is incorrect as an answer because some is very broad term in negation. Some can mean 99 scientists suggest and 1 scientist does not suggest or 1 scientist suggests and 99 scientists do not suggest.

Hence, it is incorrect (not strengthening or weakening. But I am looking for an explanation from expert.

Thanks & Regards
Vinni

[vk_vinayak]

Why is A wrong?

Is it because of 1970s? If 1986 (instead of 1970) was mentioned in A, will it be correct?

[ice_rush]

Hi vk_vinayak,

even if the year were to change to 1986 in (A), it would still be wrong.



hope this helps.