See that spike on the right side? That's when he popped the question. You can view a much larger version of the chart, which includes helpful annotations about the evening's events, here.
Redditor sesipikai and his girlfriend spent an evening in the romantic city of Rome. He wore a heart monitor during that time. The results, when charted in Excel, show his excitement levels throughout the evening. As you can see, the proposal was the most thrilling event.
The data is potentially useful. But duplication is essential in scientific research. He should repeat the experiment a few more times to see if this data set is an outlier or a trend.
-via Andrew Ba Tran