This passage is excerpted from material published in 2001.
In 1998 scientists using the neutrino detector in Kamioka, Japan, were able to observe
several thousand neutrinos—elusive, tiny subatomic particles moving at nearly the
speed of light and passing through almost everything in their path. The Kamioka findings have potentially far-reaching ramifications. They strongly suggest that the neutrino has mass, albeit an infinitesimal amount. Even a tiny mass means that neutrinos
would outweigh all the universe’s visible matter, because of their vast numbers. The
findings also suggest that a given neutrino does not have one stable mass or one stable
identity; instead it oscillates from one identity or “flavor” (physicists’ term describing
how neutrinos interact with other particles) to another. This oscillation may explain
why, although the Sun is a large source of neutrinos, detectors capture far fewer solar
neutrinos than the best theory of solar physics predicts: the neutrinos may be changing
to flavors undetectable by detectors. Finally, while the standard particle-physics
model—which describes all matter in terms of twelve fundamental particles and four
fundamental forces—does not allow for neutrinos with mass, there are theories that
do. Further experiments to confirm that neutrinos have mass could help physicists
determine which, if any, of these theories is correct.
- According to the passage, one significant implication of the discovery that
neutrinos have mass is that such a discovery would
A cast doubt on the solar origins of many of the neutrinos that reach Earth
B help to establish the validity of the standard particle-physics model
C indicate that most of the visible matter of the universe is composed of
neutrinos
D entail that the total weight of all the visible matter in the universe is less
than that of all the neutrinos in the universe
E mean that the speed with which neutrinos normally move can be slowed
by certain types of matter
The correct answer as per the answer key is D. But how do we have evidence for that? The last sentence of the passage suggests that the evidence that proves that neutrinos have mass will help determine which of the two theories are correct. One theory is “standard particle-physics
model” which say neutrinos don’t have mass whereas the other theory says it can have mass. So if we the discovery will help prove that neutrinos have mass, it will essentially invalidate the “standard particle-physics model”. So shouldn’t the answer be B? “help to establish the validity” can indeed be inferred to mean “prove it wrong” in the context of proving that a model or theory is not valid so answer B should be closer to correct answer than D?