Reading Comprehension

PT121 · S2 · P3 · Q16 Neutrinos

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According to the theory of gravitation, every particle of matter in the universe attracts every other particle with a force that increases as either the mass of the particles increases, or their proximity to one another increases, or both.

(Written summary below video)

Topic

Neutrinos and the Dark Matter mystery

Frameworks

Problem / Solution Answer a Question

Main Point

Question / Problem The observable matter in the universe only adds up to about 10% of the mass that would be needed for gravity to account for the observable structures in the universe. So given that we believe in gravity, and we believe we're correctly observing structures, where is the other 90% of the universe's mass?

Answer / Solution Neutrinos seem to account for about 20% of it, but more broadly the discovery that a tiny particle's crazy small mass might still add up to something significant (because of how numerous that type of particle is) is making scientists think that maybe the tiny masses of elementary particles is a big part of the missing mass.

Summary

P1 - Background on gravity, introduction to Curious Problem

After briefly summarizing what gravity means, this paragraph establishes the 90% missing matter conundrum, and says that cosmologists have postulated something called 'dark matter', which seems to just be a placeholder name.

P2 - A potential Solution that seemed non-viable

This paragraph introduces neutrinos as one possible answer/solution that cosmologists had considered, but ultimately rejected since they assumed that neutrinos had no mass.

P3 - New research brings back hope to possible Solution

This paragraph presents new research that suggests that neutrinos do have mass, so they're back as a contender for this dark matter problem we're trying to solve.

P5 - Implications of New research

The author's take on where we're at usually comes in the final paragraph of Science passages. Here, it sounds like neutrinos are promising as a Partial Solution, and they're also opening up new lines of inquiry that are potentially an encouraging step forward in the process of trying to find the Whole Solution.

Topic

The search for "dark matter" and the possible role of neutrinos in accounting for missing mass in the universe.

16.

As described in the last paragraph of the passage, the cosmologists' approach to solving the dark matter problem is most analogous to which one of the following?

  1. A child seeking information about

    Bad Match

    This book sounds like one-stop shopping. We don't want one solution. We want a group of things together that could be the solution. Neutrinos don't solve the problem on their own, but neutrinos and other things like neutrinos could solve the problem.

    19% picked this

  2. A child seeking to earn

    Bad Match

    This is like saying, "Physicists couldn't figure out how to solve the dark matter problem, so they decided to work on time travel instead." Or, it's like saying, "Neutrinos weren't the answer, so they're turning to elementary particles instead". But that second one, while closer, is still off, since neutrinos are part of the solution. This answer would be more like "the kid can't earn enough money to buy a bike, so he buys 20% of a bike (the two wheels) now and he'll get some money elsewhere to buy the rest of the bike."

    11% picked this

  3. A child hoping to get

    Weak Match

    Scientists were hoping that neutrinos could account for the missing dark matter, but it's only going to explain 20% at most. Nevertheless, it's a productive step forward. "i wanted a complete explanation but only got a 20% explanation" is a pretty weak match for "I wanted a dog but I got a cat".

    14% picked this

  4. Correct

    A child seeking money to

    Why this is right

    The kid seeking money is like the physicists seeking the 90% missing mass. They don't get it all from neutrinos (just 20%), just as this kid doesn't get all the money he needs from his first sibling. But, the physicists are encouraged to go looking at other elementary particles (relatives of the neutrino) to scrounge together some more mass, just as the kid consults other siblings hoping to scrounge together more movie money.

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

    54% picked this

  5. A child enjoys playing sports

    Bad Match

    I'm not sure how to even give this a charitable reading. A kid "enjoys playing sports with the neighbors"? How do we match that up with anything. Scientists enjoy the fact that neutrinos account for up to 20% of the missing mass? But someone else shuts that down and says "you have to do this first"? We can't match that up.

    1% picked this

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