#17 - Main Point

[beeryslurs]

Hi. I was stuck between B and D on this one. I've seen people elsewhere said that B was wrong because it was not Planck who demonstrated that radiation exists as particles, but I think you can also see B as saying：

“Classical wave theory, an incorrect formulation of the nature of radiation, was corrected by Planck, and other physicists after Planck performed experiments that demonstrated that radiation exists as particles."

I think the understanding above also makes sense and is supported by the passage? Can anyone help me with this? Thanks in advance.

[Adam Tyson]

First of all, beeryslurs, your username is fantastic.

But your insertion of the extra comma in answer B is not fantastic, I'm sorry to say, because it very definitely changes the meaning of the answer. We need to evaluate the answer as it is given to us, not as it might be interpreted if we were to alter it. While changing it as you did might make it an attractive answer choice, we have to deal with it as it was written. The problem is as others have described it - Planck did not do any experiments, as made clear by the claim at the end of the third paragraph which tells us that "he presented (his hypothesis) without physical explanation."

An important lesson here, and one reinforced not long ago in a case before the Supreme Court involving certain rights of union truck drivers - the placement of a comma (or in this case, the absence of one) can completely change the meaning in crucial ways! (The truckers won because of the lack of an Oxford comma, IIRC).

[beeryslurs]

First of all, beeryslurs, your username is fantastic.

But your insertion of the extra comma in answer B is not fantastic, I'm sorry to say, because it very definitely changes the meaning of the answer. We need to evaluate the answer as it is given to us, not as it might be interpreted if we were to alter it. While changing it as you did might make it an attractive answer choice, we have to deal with it as it was written. The problem is as others have described it - Planck did not do any experiments, as made clear by the claim at the end of the third paragraph which tells us that "he presented (his hypothesis) without physical explanation."

An important lesson here, and one reinforced not long ago in a case before the Supreme Court involving certain rights of union truck drivers - the placement of a comma (or in this case, the absence of one) can completely change the meaning in crucial ways! (The truckers won because of the lack of an Oxford comma, IIRC).

Thank you for your detailed reply!

I understand your point that we should evaluate the answer as it is given to us, but when I read it the first time I just saw it that way (didn't even have a second thought till I knew the correct answer). So without the comma, the orginal answer choice can only mean that Planck did the experiment and nothing else? I just think if there's no comma then there might be two different ways to for test takers to punctuate and understand the sentence, which makes this answer choice ambiguous. I'm not a natvie speaker and I'm really curious. Thanks in advance!

[Christen Hammock]

Hey beeryslurs!

Commas tell us how to group things (in this case, the subjects of the sentence). You're absolutely right that this isn't a well-written sentence either way! The comma you inserted changes the answer to "other physicists after Planck," which indicates that those physicists are in a totally separate group, conducting experiments. The answer choice keeps them all in the same group: "was corrected by Planck and other physicists." That changes the next clause from "Planck performed experiments" to "other physicists after Planck performed experiments."

[jackielsat]

Could you please explain why C and E are incorrect?

[katehos]

Hi jackielsat!

Answer choice (C) is incorrect because it does not fully encapsulate the Main Point of the passage and, arguably, contradicts it. The passage does state that the "physics community was at first quite skeptical" which aligns with the mention of members of the scientific community being critical of his model, but the passage proceeds to say "soon after" Einstein provided evidence for the hypothesis. So, it's hard to say that Planck's model was "slow" to win support! It sounds like the skeptics were quickly proven wrong.

Answer choice (E) is incorrect for a few reasons, but they all amount to factual inaccuracies. For example, (E) implies that Planck and Einstein modified classical wave theory together, when according to the passage this was done separately (first by Planck creating the new theory and then by Einstein subsequently supporting it via experiments). Additionally, even Planck did not create this new theory "in response to experimental results that suggested the energy of radiation is less at short wavelengths than long ones." The experimental results that prompted Planck's contribution showed that short wavelengths had almost no radiation, but we don't know whether this amount of radiation was more or less than the relative amount of radiation from long wavelengths. There's also plenty of evidence to suggest this new theory was not so much a "modification" of classical wave theory, but a new theory entirely that "directly opposed" wave theory!

For each of these reasons, we can eliminate (C) and (E) in favor of answer choice (D), the correct answer!

I hope this helps
Kate

[annabelle.swift]

Hi, I had the same understanding of B as beeryslurs. Can you explain again (and preferably in a different way) how we can know that B should be interpreted as

"Classical wave theory, an incorrect formulation of the nature of radiation, was corrected by Planck and other physicists, after Planck performed experiments that demonstrated that radiation exists as particles" and not as

"Classical wave theory, an incorrect formulation of the nature of radiation, was corrected by Planck, and other physicists after Planck performed experiments that demonstrated that radiation exists as particles."

(If you can point me in the direction of a reference article regarding grammar with commas, that would be helpful!) Thank you!

[Robert Carroll]

annabelle.swift,

Found one!

https://webapps.towson.edu/ows/sentence ... 20SENTENCE

The interpretation that "other physicists" starts a new independent clause is not tenable, because then answer choice (B) does not combine the two independent clauses in a grammatically sound manner. A coordinating conjunction works if there is also a comma.

Robert Carroll