一直以来，著名的《日出·印象》就像谜一般，因为没人知道克劳德·莫奈当时的创作角度是什么。《日出·印象》描绘的是一轮生机勃勃的红日映照下的港口景象，该港口位于阿尔弗尔市的诺曼底海岸。该作品掀起了印象派运动，它的创作地点及时间还一度成为学者们口中争论的对象。如今，多亏了德克萨斯州立大学的天体物理学教授唐纳德·奥尔森，我们才得以了解到《日出·印象》的创作时间： 1872年 11月 13日早上 7点 35分。
An aspect of Claude Monet’s famous painting Impression, Sunrise has long been a mystery. The canvas depicts pink morning light reflecting off the harbor in the Normandy coast port of Le Havre. The work gave the Impressionist movement its name, yet scholars have debated exactly where and when it was made. Now, thanks to Texas State
University forensic astronomer Donald Olson, we know the answer: November 13, 1872, at 7:35 A. M.
莫奈本人将该作品的时间标注为 1872年，而他的旅行记录显示：更准确的时间可能是 1872年。由于画作中的颜色朦胧，笔调散漫，我们很难看出莫奈画中描绘的季节。一些艺术历史学家甚至还认为这幅画作实际上描绘的不是日出，而是日落。
Monet himself dated the painting to 1872 but records of his travels suggested 1873 might be more accurate. The hazy colors and loose brush strokes make it difficult to tell the season depicted. Some art historians even argued that Impression, Sunrise is actually showing a sunset.
奥尔森通过对阿尔弗尔市的旧时地图和照片进行研究，分析莫奈作画的角度及所画景物的位置，从而确定出莫奈作画时所在旅店房间的具体位置。尔后，他住进莫奈所住的房间，并从那测量出太阳的运动情况和潮汐的涨落时间。根据这些信息，奥尔森确定出了当画中的船和太阳的相对位置与现实中的船和太阳的相对位置相符时的可能时间点。他后来又将这些数据与天气预报结合起来考虑，最终精确出莫奈创作《日出·印象》的时间。你可以这样说，此时的奥尔森就是当时的莫奈。
Olson analyzed angles and views in vintage photographs and period maps of Le Havre to determine the exact hotel room Monet painted in. He then calculated the sun’s movements as seen from the room, as well as the times of the tides. This information told him when boats matching those in the painting might have been in harbor with the sun in the right position. Combining all this data with weather reports, Olson was able to pin down the timing of Impression, Sunrise. You could say Olson is right on the Monet.
