What do you know about Titanic

Metin Tolan is a physicist. In his lectures at the TU Dortmund, he tries to get the students excited about theoretical content by applying it to football, to James Bond - or to the downfall of the Titanic. He is the author of the book "With Physics into Downfall". How long was the braking distance of what was once the world's largest ship? Why did the sailors in the lookout see the iceberg so late? And why is it Costa Concordia on the wrong side? A conversation about the predictability of ship accidents.

Süddeutsche.de: Mr. Tolan, you are Professor of Experimental Physics at TU Dortmund University. How did you come to terms with the Titanic too busy?

Metin Tolan: I was very excited about the Cameron movie Titanic. There is a scene in it in which ship designer Thomas Andrews is asked how much time there is before the ship sinks. "An hour, maybe two," he replies. I asked myself how he knew that, sat down, did the math - and came to the same conclusion. Much of the catastrophe can be explained with the help of physics.

Süddeutsche.de: Did you also find out if the Titanic should inevitably have sunk as a result of the collision with the iceberg?

Tolan: She wouldn't have, at least in theory. When you roll up this sinking, you always have to ask yourself why the designers at that time considered the ship to be unsinkable. There are good reasons for this. The Titanic was technically up to date, had 15 watertight bulkheads that separated 16 compartments from each other in the fuselage. Even if four of these compartments had flooded, the ship would still have remained afloat. And such a serious accident, such a large hole, was simply impossible to imagine.

Süddeutsche.de: So would it have been better if the first officer, William Murdoch, had driven straight onto the iceberg instead of trying to avoid it?

Tolan: That is what these ships were actually designed for. If you calculate how much steel can be compressed, you get the result: In the event of a head-on collision, a maximum of the first two sections in the bow would have been dented. The Titanic would not have sunk, there would have been more time to evacuate the ship. But as logical as it sounds from today's perspective, it was just as impracticable back then.

Süddeutsche.de: The order was: "Hard port!". Murdoch tried to drive past the iceberg.

Tolan: Imagine you are standing on the bridge and you have to give the command! If you drive fully towards the iceberg, around 200 people, mostly staff, will die in the bow. You say: "Guys, let's try everything to get around it somehow." And it almost worked. It was very close. Today, 100 years later, there are sophisticated ways of simulating such a maneuver on the computer. But even that would not prove that the Titanic maybe not got past the iceberg after all. The problem was: you simply saw the iceberg far too late when it was only 300 meters away.

Süddeutsche.de: Nobody on board knew where the binoculars were, and the scouts in the crow's nest had no binoculars either. Was that the crucial point?

Tolan: Sure, binoculars would have been good, but you should have seen such a large iceberg earlier even without it. 500 meters away would have been enough to get past it. It is surprising that they saw the iceberg so late.

Süddeutsche.de: Some scientists say a rare weather phenomenon could be to blame, a super refraction. It works like an inverted mirage and blurs the horizon.

Tolan: I do not think so. As a physicist, I always start from the most probable theory. And that is a different one: it was a moonless night, there was only relatively little light. The sea was calm, so the sailors couldn't see any waves that would have broken on the iceberg. And I suspect they were twice as unlucky.

Süddeutsche.de: In what way?

Tolan: Under certain conditions, icebergs form that are not as beautifully white as we know them, but rather bluish. Icebergs are formed when the snow that falls in Greenland is compressed by new snow. Then ice forms, it slips and gets into the water. Icebergs are usually white because the air bubbles in them reflect all of the light. Under certain weather conditions, particularly few air bubbles are trapped. Then the light penetrates and only the most energetic rays come back: the blue ones. If it was really such a bluish iceberg on the night of April 14, 1912, the sailors would have had a hard time seeing it.