This has the makings of a very long thread, but here's my starter for ten anyway. Feel free to decimate my humble opinions all ye beady eyed vultures out there!
On a social level the disaster had an enormous effect on the US and Britain. As
Walter Lord points out in "A Night To Remember" for 100 years after Waterloo, an era of relative peace in Europe, man had gone about creating ever more ingenious and technical monuments to his genius and this culminated in many ways with the Titanic, the largest ship in the world and "practically unsinkable" (as described in an immensely respected maritime journal of the day).
The Titanic was a symbol, conscious or not, of mans conquering of the elements and increasing invulnerability.
The mood of the Edwardian era was extremely optimistic and it was felt that in time no objective could not be acheived. The cynicism of today was not so apparant in those long ago years.
There was also a strict class code on both sides of the Atlantic with the rich generally looked upon by the poorer classes as their "betters". There was a much greater divide between the rich and the poor in those days and the poor, as a (very) general rule, accepted that the rich had certain privelages, even rights, in the course of their lives which were not open to them. This was borne out on the Titanic by a number of third class passengers (Olaus Abelseth for one) who were merely happy to be allowed on deck never mind getting into a boat. Even the layout of the Titanic ensured that in the event of disaster First and Second Class Passengers had easy access to the lifeboats, while for Third class passengers (stranded at the bow and stern of the ship)the options were much less obvious.
When the Titanic sank, the air of pride and self confidence in the Anglo Saxon world was severely dented. Here was the worlds largest, safest liner, American owned and British run, sinking on her first voyage and taking with her some of the great notables of the day.
The fact that the ocean liner in the first part of the 20th century was not merely a mode of transport but a source of immense national pride, and that the Titanic sank in the middle of a shipbuilding race between Germany and Britain (which was a major precipitator of the First World War)also deeply wounded the British and American psyche.
It is hard to think of any event occuring in the modern world which could equal the shock of the sinking of the Titanic.
The unquestioned view of the richer classes also took a major battering, with the pillorieing of J
Bruce Ismay, chairman of the White Star and the ridicule and scorn poured on Sir Cosmo Duff Gordon being extraordinary events at the time. After the First World War all these attitudes would be really swept away in the trenches of the Western Front but the Titanic opened a huge seam.
The question of how important money really was was also examined by preachers and ordinary people alike. As Lord asked, if money was worth so little on the night of the sinking, how much was it worth for the rest of the year?
The disaster was even seized upon by the suffragette movement with campaigners writing to newspapers questioning the "women and children first" policy used to fill the boats on the night.
The ridiculously outdated laws concerning lifeboat provision were changed after the disaster...no more complicated equations, simply lifeboats for all. Other major maritime laws (eg. 24 hour radio watch) were passed following the disaster, and an international ice patrol was set up to monitor icebergs which passed in to shipping lanes. Most of the laws passed, and the patrol, are still in force today.
In my opinion the most important effect of the sinking of the Titanic was a sweeping away of complacency and the dawn of a new cynicism, where everything wasn't OK in the world and that if it was possible for a ship of the magnitude of the Titanic to disappear after a brush with ice in the middle of the night, how could anybody be certain of anything ever again.
Hope this helps
Fire at will!
Sam