Comment The illusion might have added to the many reasons (Score 5, Informative) 166
The 'optical illusion' might have added to the many reasons that the Titanic sank on its maiden voyage but it certainly was not the main cause. The ship was legendary at the time before it had even made its maiden voyage. The largest and most elaborate and ornate vessel of its time. A floating palace. A moving island on the sea. The Titanic.
The ship's captain and others postulated that running the ship at full speed from its last stop in Europe all the way to America would make enormous headlines. If the ship arrived in New York ahead of schedule by a day it would be a media sensation and basically the best advertising that they could buy. So the ship's operators plowed through the ocean at the fastest possible speed (which was a common practice though).
To make things worse the ship's operators both ignored and missed warnings about dangerous fields of ice that they were approaching. An area of ocean crowded with frozen solid and tremendously large icebergs. A nearby ship, the Californian, stopped near where the Titanic sank that night, only a few miles away, because they were extremely cautious and nervous about smashing the ship into a mass of ice. So they waited to resume travel until the morning. The Californian even sent messages to the Titanic warning them of the ice fields. Those messages were essentially ignored.
At the time that Titanic was built it was considered unsinkable. There had been accidents in the past where large ships had smashed head first into icebergs and stayed above water. And the Titanic had been built stronger, sturdier, and tougher than any ship ever made. The Titanic's captain even said before the first voyage, "there is no condition which would cause a ship to founder. Modern shipbuilding has gone beyond that".
The ship is going full speed. It's traveling into an area where there are icebergs the size of small islands. The lookouts are not equipped with binoculars and are not aware of what kind of field they are traveling into. The moon is black so there is no light over the ocean. The water is completely calm so they can't hear waves crashing against the icebergs to warn them (years later it is then known that calm water indicates fields of ice). And by the time that the lookouts spot the iceberg...they are traveling full speed right for it and there isn't enough time to turn. They were traveling full speed, blind, deaf, and into a death trap.
The ship smashes into the iceberg and grinds its side into the mass of ice tearing a few small holes into the side of the ship. The tears are only a few feet long and inches wide but the ocean water is relentless. The Titanic was designed to survive the front two below deck compartments flooding with water. Or any other four compartments located below deck flooding completely. Instead, the first five compartments are almost instantly flooded from ocean water raging through the breaches, the ship is doomed. The ship will sink in less than two hours and there is nothing to stop it. Trapped in the middle of the ocean with nowhere to go and lifeboats for less than half of the passengers.
While there were only half as many lifeboats as would have been necessary to save everyone, over two-thirds of people on the ship were not able to escape. One reason is that people were so zealous about the "women and children" first rule that they were sending half empty lifeboats off of the ship without loading any men on them. Also they were loading lifeboats according to your travel class. First class passengers were more likely to be saved. Third class passengers had to wait their turns. That's why for the blockbuster Titanic they had a first class woman paired with a third class man. Those two had the best and worst odds of surviving the disaster based on lifeboat placement.
So no it wasn't an optical illusion. It was a series of many things that contributed to the Titanic sinking on its maiden voyage. Poor lookouts. Dangerous speeds. Lack of modern understanding of calm water indicating dangerous conditions. No moonlight. Purposefully ignoring warnings of dangerous conditions including icebergs. Even without an optical illusion that ship unfortunately still sinks.