原理上，我们可以通过观测所谓的标准烛光(一种天体，它的绝对光度是相同的)来追溯宇宙内的历史。

In principle, one can trace that history back in cosmic time by observing a so-called standard candle, a class of astronomical object whose intrinsic luminosity is uniform.

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因此，它们在性质上的唯一区别应该可通过观测两种香芹酮的气味和旋光仪中旋光度的符号而得知。

Hence, the only difference in properties one should observe for the two carvones are the odors and the signs of rotation in a polarimeter.

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综述了从射电波段到X 射线波段星暴星系的光度和光谱观测特征及其研究的最新进展。

Then, we briefly summarize the photometric and spectral observation properties (from radio to X-ray), and the latest progress of starburst galaxies.

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