Self-study
Superstring theory is a controversial new theory in physics that purports, unlike more established physical theories, to explain the nature and existence of gravity. █ █████ ███████ ████ ███████████ ██████ ██ ████ ██ ████ ██ ██ █████ ████ ██ █████ █ ████████ ███████████ ███ ████████ ██████████ █████ ███████ ███████ ██ ████ ███████████ ██████ ███ ███ ██ ███████ ██ ██████████ ██████████ ███ ███ █████ ██ ███████ ██ ███ ████████ ██ ██████ ████ ██ ███
Summary
Superstring theory tries to explain gravity. Other kinds of physics theories don’t try to explain gravity. One problem with superstring theory is that testing it requires building a particle accelerator 100 trillion kilometers long (which sounds impossible to do). Another problem is that superstring theory hasn’t successfully explained why gravity is as strong as it is.
Strongly Supported Conclusions
We do not know whether superstring theory’s explanation of gravity is correct.
Inability to be tested is a problem for a theory.
Lack of success in explaining why a force is not stronger or weaker is a problem for a theory that tries to explain that force.
23.
Which one of the following ██ ████ ████████ █████████ ██ ███ ███████████ ██████
a
Superstring theory would ██ ████ ██████████ ██ ███████████ █████████ █████████ ██ ███████ ███ ███ █████ ██ ███████ ██ ███ ████████ ██ ██████ ████ ██ ███
Unsupported. A problem with superstring theory is the lack of success it has had in explaining the strength of gravity. But this doesn’t mean theorists haven’t tried. They may have tried and failed.
b
Physical theories that ███ ██████ ███████████ ████ ███████████ ██████ ███████ ██████ ████████████ ██ ████████ █████████ ████ ████ ███████████ ███████
Unsupported. Although superstring theory hasn’t successfully explained the strength of gravity, that doesn’t imply there are other theories that provide better explanations of gravity or other physical phenomena.
c
Some physical theory ████ ███████████ ████ ███████████ ██████ ███ ███ ██ █████ ████ ███████ ██ ██████████ ███ ███ █████ ██ ███████ ██ ███ ████████ ██ ██████ ████ ██ ███
Antisupported. We’re told that more established physical theories don’t even attempt to explain the nature and existence of gravity.
d
A physical theory ██████ ██ ████ ██ ███████ ████ ██████ █████ ███████ ██ ██ █████ █ ████████ ███████████ ███ ████████ ██████████ █████
Unsupported. The fact superstring theory can’t be tested doesn’t mean it can’t be true. It could still be true, even if we can’t confirm that it’s true.
e
A theory that ████████ ██ ███████ ███ ██████ ██ █ █████ ██ █████████ ██ ██ ██████ ███████ ███ ███ ████████ ██ ████ ██████
Strongly supported. We know superstring theory hasn’t been able to explain why gravity isn’t stronger or weaker. That means it hasn’t been able to “account” (explain) for the strength of gravity. We also know this is a “problem.” That means it’s a deficiency in the theory.