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Using the Long Wavelength Spectrometer on Keck, we have imaged the gravitationally lensed radioquiet quasi-stellar object QSO 2237]0305 at 8.9 and 11.7 km for the Ðrst time. The mid-IR Ñux ratios are inconsistent with the optical Ñux ratios but agree with the radio Ñux ratios and with some published gravitational lens models. These Ñux ratios indicate that the IR emission is not a †ected by microlensing, which rules out the synchrotron emission model. The IR emission is likely produced by hot dust extended on a length scale of more than 0.03 pc. The spectral energy distribution further implies a narrow range of dust temperatures, suggesting that the dust may be located in a shell extending between D1 and 3 pc from the nucleus and intercepting about half of the QSO luminosity.

Students in introductory physics courses are likely to have views about physics that differ from those of experts. However, students who continue to study physics eventually become experts themselves. Presumably these students either possess or develop more expertlike views. To investigate this process, the views of introductory physics students majoring in physics are compared with the views of introductory physics students majoring in engineering. In addition, the views of physics majors are assessed at various stages of degree progress. The Colorado learning attitudes about science survey is used to evaluate students’ views about physics, and students’ overall survey scores and responses to individual survey items are analyzed. Beginning physics majors are significantly more expertlike than nonmajors in introductory physics courses, and this high level of sophistication is consistent for most of undergraduate study

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