Exposing PseudoAstronomy

March 11, 2012

Did the Moon Sink the Titanic?


Introduction

Earlier this week, with the 100th anniversary of the sinking of the Titanic coming up next month (April 14, 2012), a new report is out claiming that the moon “helped” to sink the Titanic.

What this is really saying and what the media is trying to say and what the real effect may have been are all somewhat different things.

Tides

To understand the story, you need to know about tides. We can go back to Newton for his Equilibrium Theory of Tides and the people who improved upon it t get a rough background. In its simplest formulation, tidal intensity is not caused by the inverse-square law of gravity (the gravity from an object falls off as 1 divided by the square of the distance, so if you’re 2x farther away, the gravity is 1/4 as much), but rather an inverse-cube. So the closer you are to what would cause tides, the tidal effects are larger. Similarly, if you’re farther away, then they’re significantly smaller.

On Earth, tides are caused both by the moon and the sun. The sun’s tidal effects are only about 40% as much as the moon’s. If the sun and moon line up, then their effects combine and we get spring tides. If the sun and moon are at right angles (during a first or third quarter moon), then their combined effects are diminished and you get neap tides.

The other component of this story is that the moon is on a slightly elliptical orbit around Earth, and Earth is on an elliptical orbit around the sun. We’re closest to the sun in the month of January, and the moon’s closest point to Earth moves around with time.

The Basic Idea

The basic idea of this story is that the Titanic set sail (not that it had sails) in April, 1912.

On January 3, 1912, Earth was at perihelion – its closest approach to the sun. One day after that, on on January 4, 1912, the moon was full, and it was also (according to this work) at perigee (its closest approach to Earth). The Time article I linked to at the start of this post claims, “the moon just happened to make its closest approach to earth in 1,400 years.” That is not correct, since by definition, it must make its closest approach to Earth once an orbit. It might have been the closest approach at the most full phase in 1400 years, but that’s a different issue.

What this all means is that we had strong tides from the lunar and solar tides adding up (spring tides), and the individual components of each were particularly strong because the moon was its closest and we were closest to the sun.

What the authors (Donald Olson, Russell Doescher, and Roger Sinnott) of this study claim in the magazine Sky & Telescope (or what one of my former professors used to call “Try-and-sell-a-scope” due to all the ads), is that these particularly high tides affected iceberg migration patterns. They suggest that icebergs frequently become grounded in shallow waters around Labrador and Newfounland (Canada). The particularly high high tides could have freed some of them. Including the one that struck the Titanic.

Final Thoughts

To me this is a “just so story.” Yes, it’s possible. I don’t know how probable it is as it requires an unknown and uncharted iceberg being maybe freed due to high tides and then happening to be the one that struck the Titanic. There’s no way to prove it and I don’t think even the original authors are really saying “This IS what happened.” But the media is tending to report it that way.

In the end, it’s possible, and with the 100th anniversary of the Titanic’s sinking coming up in 33 days from writing this, I expect more kinds of stories about it to come out over the next month. The thing to remember about many of these “this could have happened!” stories is the “could” part. Maybe yes, maybe no. But you’re going to hear about them because that’s what the media does before some anniversary that they think will sell.

4 Comments »

  1. It almost sounds like a situation of Time saying “Titanic’s 100th Sinking Anniversary is coming up, let’s see if we can come up with an alternate, but plausible, version of events. That should sell some magazines!”
    As you said, the Moon Hypothesis seems plausible, but I prefer to err on the side of human stupidity/arrogance. Those in charge of the Titanic thought it was unsinkable and therefore treated it as such. Nature proved them wrong, in my opinion.

    Comment by Jay Pea — March 13, 2012 @ 10:29 am | Reply

  2. haha try and sell a scope . hilarious . but i love that magazine too

    Comment by Walter Walkie — March 13, 2012 @ 11:22 pm | Reply

  3. I work in the same department as two of the researchers in the article but am not affiliated with their work.

    I think the point you’re undervaluing is that of experience and psychology. If you’re an experienced captain who has made a particular voyage many times, you might just start trusting your instinct above other evidence. If you’ve made the run over the course of years and have seen minimal ice, you’d be likely to believe the threat was minimal or the observers were mistaken. Showing that an extremely rare astronomical event preceded this tragic error is important; major accidents are usually a cascade of smaller errors that on their own would not end in tragedy.

    Agreed that the press is sensational, but I don’t think you should write-off this work so quickly.

    Comment by pj — April 13, 2012 @ 6:08 am | Reply

    • Hi PJ, thanks for finding me and giving your input. I don’t necessarily disbelieve that this couldn’t have been some factor, it’s more that in my opinion this is on that 1% level. In the end, it hit an iceberg, and if they had been watching better, if the captain hadn’t been going so fast to get to New York early, it likely would not have ended as it did. Basic caution and more lookouts I think are a much bigger factor than especially high tides four months earlier.

      Comment by Stuart Robbins — April 13, 2012 @ 4:13 pm | Reply


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