LSAT 93 - Section 3 - Question 23

Which one of the following is most strongly supported by the information above?

This is a Most Strongly Supported question.

Superstring theory is a controversial new theory in physics that purports, unlike more established physical theories, to explain the nature and existence of gravity.

Have you heard of the controversial new theory known as superstring theory? What’s so controversial about it, you ask? Get this – it tries to explain the nature and existence of gravity. Yeah, I know – this theory’s asking to be made a fool of. All the more established physical theories know they can’t explain gravity, so they don’t front as if they do. (This last claim about what more established physical theories do is hiding in the author’s use of “unlike” – that means the more established physical theories don’t do what we’re told superstring theory does.)

A major problem with superstring theory is that to test it we would have to build a particle accelerator 100 trillion kilometers long.

Let’s break down what makes superstring theory so naive. First up is how difficult it would be to test what superstring theory is saying about gravity. We’d have to build an impossibly long particle accelerator – your mind can’t even grasp how long this accelerator needs to be. So superstring theory is saying stuff that we can’t test – that’s strike one.

Another problem is that superstring theory has had no success in adequately explaining why the force of gravity is not stronger or weaker than it is.

The next problem is superstring theory has completely failed in explaining why gravity isn’t stronger or weaker than it is. Here’s what I mean. If you jump from a plane, you’ll fall to Earth at a rate of about 120 miles per hour according to Google. But why don’t you fall faster, like 1 million miles per hour? Or 1 mile per hour? Why do you fall at 120 miles per hour instead of some other speed? Why is gravity as powerful as it is, but not more or less? Superstring theory doesn’t adequately explain this. That’s strike two.

Is there a third strike? Maybe, not sure. That’s as far as the stimulus cares to slam superstring theory.

Answer Choice (A) Superstring theory would be more successful if superstring theorists attempted to explain why the force of gravity is not stronger or weaker than it is.

This is a tempting answer, because we do know that superstring’s inability to provide an adequate explanation of why gravity is the way it is counts as one of the strikes against it. But the problem is the strike against superstring theory is for having an inadequate explanation. We’re not criticizing superstring theory for failing to attempt an explanation. We want an adequate explanation – not an attempt that fails.

This answer would have been better if it had said, “Superstring theory would be more successful if it adequately explained why the force of gravity is not stronger or weaker than it is.”

Answer Choice (B) Physical theories that are better established than superstring theory provide better explanations of physical phenomena than does superstring theory.

Be careful about reading too much into the stimulus’s claims about more established theories. Remember, we know that more established theories don’t purport to explain the nature and existence of gravity. This is what made superstring theory controversial – it pretends like it can explain gravity. The more established theories don’t even try to explain gravity. But beyond that, we don’t know anything else about the more established physical theories. Do they give better explanations of “physical phenomena”? Maybe, maybe not. Perhaps superstring theory is actually better at explaining the movement of water, or wind, or temperature, or other physical aspects of the world.

Answer Choice (C) Some physical theory more established than superstring theory has had at least some success in explaining why the force of gravity is not stronger or weaker than it is.

This answer tries to tempt you by using the phrase “some physical theory” and “at least some success.” This kind of weak language is, all else equal, attractive on a Most Strongly Supported question, because it’s easier to prove a statement about “some” things (at least one) than it is about “most” (over half) or “all” (100%).

But despite this weak language, (C) still has no support from the stimulus. We don’t know how successful any other theory is at explaining any aspect of gravity.

In fact, the first sentence establishes that physical theories that are more established than superstring theory do not purport to explain the nature and existence of gravity. They don’t even try to do it.

While this doesn’t, by itself, prove that those theories can’t have success at explaining gravity (because perhaps a theory might successfully explain something that it never purported to explain), it does mean that we have no basis on which to speculate about those theories and their success. If they don’t even try to explain gravity, what reason do we have to believe that one of those theories has some success at an explanation? Simply because they’re more established? But those theories could be more established because they’ve been around longer, or because they are easier to understand, or for any number of reasons that have nothing to do with success at explaining gravity.

Answer Choice (D) A physical theory cannot be true if testing that theory would require us to build a particle accelerator 100 trillion kilometers long.

This goes too far – if it had said that a physical theory has a problem if testing it would require the long accelerator, then it would be supported. But we can’t speak to whether the theory is true or false. We can’t test superstring theory, which is one of its problems. But it might still be correct. We just wouldn’t know whether it’s correct, because we can’t test it.

Correct Answer Choice (E) A theory that purports to explain the nature of a force is deficient if it cannot account for the strength of that force.

If (E) said the following, it would be much easier to select:

“A theory that purports to explain the nature of a force has a problem if it cannot explain why that force is not stronger or weaker than it is.”

This would be supported by the last sentence, which states that superstring theory has a problem because it can’t explain why gravity isn’t stronger or weaker than it is.

But, as you know, the LSAT often speaks about the same concept using different words and phrases. In (E), the LSAT uses the word “deficient” to refer to the concept of a theory’s having a “problem.” And it’s using the phrase “account for the strength” to refer to the idea of explaining why gravity is not stronger or weaker than it is.

Both of these changes are fair. A theory that has a problem cannot be perfect – it’s lacking something. If it weren’t lacking anything, then it wouldn’t make sense to say that the theory has a problem. And a theory that is lacking something is deficient.

The word “account” can mean “explain.” So you can read “... if it cannot account for the strength of that force” as “... if it cannot explain the strength of that force.” This is a slightly more general way of describing the inability to explain why gravity isn’t stronger or weaker than it is. Is it a perfect match? I’m not sure. There might be some difference between explaining why a force isn’t stronger or weaker than it is and “explaining the strength of that force.” But the concepts are close enough for a Most Strongly Supported question, and there is no other answer that has more support.