Neutrinos

Answer choices

1. A

   Opposite4% picked this

   Observable matter constitutes at least 90 percent of the mass of

   Observable matter is only adding up to 10% of the mass. The missing 90% is "dark matter", i.e. not directly observable.

   4%
2. B

   Unsupported: incapable35% picked this

   Current theories are incapable of identifying the force that causes all particles in the universe

   The force that causes all particles in the universe to attract is gravity. Is this author saying gravity turns out to be wrong and current theories can't figure what force really does attract particles to another? No, it's saying that they presume gravity is still a correct theory; they're just seeking to find the missing mass so that what we already think of gravity would then successfully account for the shape of structures. If scientists weren't still convinced that gravity was right, they wouldn't be hunting for the missing mass. They would instead accept that the 10% observable matter is really more like 100% of the universe, and figure out a way besides gravity to account for the shapes of galaxies and clusters.

   35%
3. C

   Too Strong: the key7% picked this

   The key to the problem of dark matter is determining the exact mass

   The author would agree that determining the mass is important, but since the upper limit of potential mass for a neutrino is still only going to account for 20% of the 90% dark matter conundrum, it's too strong to say that "THE key to solving dark matter is the exact mass of a neutrino".

   7%
4. D

   Correct48% picked this

   It is unlikely that any force other than gravitation will be required to account for the organization of

   Why this is right

   This is a tough answer to find explicit support for, because the support comes more from what the author didn't say. This relates back to our reasons for rejecting (B) -- the author and the physics community are implicitly accepting that the theory of gravitation is not the problem, not the reason why our calculations only add up to 10% of what we've predicted. The search for the missing 90% is sort of predicated on the assumption that gravitational theory is right. If gravitational theory successfully explains the shapes of the universe, but only if the universe has, say, 100 zillion tons of matter, then when we find out that the observable universe is only 10 zillion tons of mass, we have two options of resolving that: - gravitational theory is wrong to predict 100 zillion or - gravitation theory is right to predict 100 zillion, and we just need to figure out where the other 90 zillion is. Since the passage proceeds from the 2nd assumption, it seems fair to say that neither the author nor physicists are really actively pursuing the idea that gravitational theory is wrong. Even the author's final paragraph accepts that the problem is the missing mass, not gravity's predicted total mass of 100 zillion. - "neutrinos could only account for about 20 percent of the universe's missing mass" implicitly accepts that there is missing mass. - "it may add to our understanding of the role elementary particles play in holding the universe together" is an allusion to the gravitational force, again implying that we just need to find the missing mass to bring it into accordance with gravity's predictions.

   Skill tested: Author Opinion · how this choice captures the passage's function is the move to repeat next time.

   48%
5. E

   Contradicted6% picked this

   Neutrinos probably account for most of the universe’s

   It says the max they would account for is 20% of the missing mass.

   6%