As night fell, the steamship headed towards Þórsfjal swayed in the waves. Erik and Freja after listening the story of the landlady, they still stood on the deck, silently watching the sea under the starlight. Suddenly, Erik felt a touch of unease; he heard a booming noise from the bottom of the ship, seemingly much louder than usual. He started to use his knowledge of physics and engineering to analyze the situation.
"Freja, do you hear the sound from the bottom of the ship? It's different from the normal sound of a steamship. I suspect there's a problem with part of the steam engine," Erik said.
Freja looked at him, clearly puzzled. "But how can we be sure?" she asked.
"We can verify it by measuring the speed of the ship. A properly functioning steamship should maintain a steady speed under these wind and sea conditions, and the rudder should make an even sound when it turns. But now we are hearing an irregular sound, which indicates that the ship might be operating unstably," Erik explained, feeling extremely uneasy.
Erik found a sailor, attempting to explain his speculation about the sound from the bottom of the ship, but the sailor's dismissive response left him at a loss.
"Listen, mate, I've been battling at sea for 20 years, and I've heard plenty of these booming noises. You're just a landlubber worrying about nothing," the sailor scoffed.