As described in the last paragraph of the passage, the cosmologists' approach to solving the dark matter problem is m...

Rachel on May 30, 2015

Question

I'm having trouble understanding why the answer is not a?

1 Reply

Melody on June 1, 2015

We are told that even at the highest estimate of the mass of the neutrinos, we can only account for about 20 percent of the universe's "missing" mass. But, the last paragraph states that even though this does not account for all the dark matter, it is enough info to help us alter our picture of the universe. The last line here is key, telling us that if the evidence is valid, then it can be added to our current understanding of the role of elementary particles in holding the universe together.

Thus, the neutrinos are one piece of the puzzle in understanding the way the universe is held together.

The analogy in answer choice (A) does not mirror this sentiment. Finding the instruction for a game, i.e. the explanation of the way the universe is held together, from one source, i.e. a book, does not adequately display the parceled out sources that will eventually make up the whole explanation of the way the universe is held together.

Rather, answer choice (D) better exemplifies this by illustrating a situation where a child needs many different pieces for his goal, i.e. money from each of his siblings to have enough to go to a movie. Even more, the child is given money from one sibling that is not enough, which we can compare to the neutrino explanation--though it is evidence that will help go towards our understanding of how the universe is made up, it only makes up 20% of the universe's missing mass. So we need more info.

Therefore, answer choice (D) is the best analogous situation to the cosmologists' approach to solving the dark matter problem described in the last paragraph of the passage.

Hope that clears things up! Please let us know if you have any other questions.