Fewer and fewer whales exist in the world, becoming endangered, and in the last century people hunted whales in the oceans, leaving few left. Whale meat does not taste good, people do not eat, hunting them in addition to the use of whale baleen to make strings and noble skirts, the most important thing is to extract whale oil. Whale oil is not the oil of whale fat, but the oil in its brain. When oil was not exploited on a large scale and fossil fuels were not yet widely used, the fuel used by European aristocrats for lighting was whale brain oil.
When cetacean brain oil is ignited, it emits a gentle and stable light, which makes the upper class flock to it and use whale brain oil as a lighting fuel on a large scale. For example, the lights of the dance party in the aristocratic castle we see in the movie, or the large crystal chandelier hanging in the middle of the theater, lit with whale brain oil. The development of human civilization is always accompanied by the sacrifice and extinction of certain species, in order to shine brightly in gorgeous coats, we need to kill dozens of martens, just their tails are good-looking. To make our guests feel welcome, we hunt down the behemoths in the sea just because the little grease in their brains looks good when it's lit.
Without the prosperity of the oil industry, without the extraction of kerosene, the fuel that replaces whale brain oil, after we kill all the whales in the sea, which animal will this butcher knife point to? To solve the contradiction in the development of human civilization, only science and technology, the development of science and technology can make human beings no longer need to slaughter other species for their own survival.