LSAT 60 - Section 3 - Question 10

Here we have an MSS question which we know from the question stem: The statements above, if true, most strongly support which one of the following, assuming that the widely accepted physical theories referred to above are correct?

We should note that the question stem tells us that we will encounter “widely accepted physical theories” in the stimulus, and that we will have to accept them as true in order to find our answer.

We start with a scientific phenomenon: there’s a black hole with a ring of gas orbiting around it. This ring of gas is emitting an x-ray that’s flickering as 450 times per second. You find yourself stopping right about now and wondering what the heck is going on here. Here’s the thing: I don’t know how gas rings emit x-rays, and fortunately, I don’t have to! It’s very easy to get lost in the science of a stimulus like this but if we just take this stimulus sentence by sentence, I promise you we’ll be able to ascertain everything we need to in order to succesfully answer the question.

The second sentence introduces us to the “widely accepted physical theory” referenced in the question stem. We’re told that the rate of flickering (of the x-rays) can best be explained if the ring of gas has a radius of 49 km. The LSAT is doing something tricky here: they are emphasizing the uncertainty of this theory by noting that it’s widely accepted (not universally) and using the phrase “best be explained” instead of something more definite. Here’s the thing: we don’t need to worry about the accuracy of this theory because the question stem tells us that we are “assuming [this theory] is true.”

So let’s look at these first two sentences together: black hole is orbited by ring of gas, x-rays flickering at 450 times per second, and a theory tells us that this means the ring of gas has a radius of 49 km. We already know that for our purposes, this theory is true. Therefore, we can say confidently: the ring of gas has a radius of 49 km.

Ok onto the third sentence. We’re told that the ring of gas could not maintain an orbit so close (i.e. 49 km away) unless the black hole was spinning. Well what does that tell us? The black hole must be spinning! The final sentence is phrased in such a way to suggest that this last piece of information is paradoxical or hard to reconcile with the previous two sentences–but it’s not! Our first two sentences have demonstrated that our ring of gas is 49 km away, and our third sentence tells us that given this proximity, our blackhole is spinning.

This stimulus is confusing because it is very hard to visualize. I’d definitely recommend drawing a diagram if that helps you. But at the end of the day, we have three straightforward, interconnecting facts: a ring of gas is emitting x-rays at a certain rate, that ring of gas must be 49 km away from the black hole (the black hole is at the center of the circle created by our gas ring, and radius is the distance from the center to the edge of a circle), but the gas ring couldn’t be 49 km away unless the black hole is spinning. Our simple, straightforward synthesis of this information is that the black hole, therefore, is spinning!

Answer Choice (A) We don’t know anything about rings of gas with a radius above 49 km. Our final sentence says that our gas ring couldn’t maintain an orbit so close without the black hole spinning. This doesn’t tell us anything about how the black hole would behave if the radius was larger.

Answer Choice (B) We simply know that there is one ring of gas in a stable orbit around a black hole that emits flickering x-rays. We do not have any conditionals here that tell us that this is the only type of ring of gas that emits flickering x-rays.

Correct Answer Choice (C) Great! This matches up with how we synthesized the stimulus. We have clearly outlined how our stimulus supports this answer choice.

Answer Choice (D) We don’t know what causes the black holes to spin. We know that the spinning of the black hole is connected to our gas ring maintaining a close orbit, but we have no information about a causal link between the x-rays and the spinning of the black hole

Answer Choice (E) We know that if a gas ring is orbiting around a black hole at a radius of 49 km, then the black hole is spinning. We don’t know anything about the way that black holes behave when they are orbited by a ring with a larger radius.