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Author Topic:   Requesting Math Help/Feedback for my Web Page
dwise1
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Posts: 2970
Joined: 05-02-2006
Member Rating: 3.5


Message 1 of 2 (820366)
09-19-2017 3:39 PM


I would like to have some help and feed-back about the math I am developing for one of my web pages.

On my site, I just uploaded a new version of my Earth's Rotation is Slowing page which addresses the common creationist "leap second" claim. That claim was created 1979 (the year of its earliest occurance) and was soundly refuted in 1982, but it's still with us nearly four decades later.

Here's the original version by Walter Brown in 1979:

quote:
Atomic clocks, which have for the last twenty-two years measured the earth's spin rate to the nearest billionth of a second, have consistently found that the earth is slowing down at a rate of almost one second a year. If the earth were billions of years old, its initial spin rate would have been fantastically rapid—so rapid that major distortions in the shape of the earth would have occurred.

The actual rate at which the earth's rotation is slowing down is 1.4 to 2 milliseconds per day per century, meaning that after 100 years a day would have become longer by 1.4 to 2 milliseconds. Another statement of the actual rate is given as 5 milliseconds per year per year, which would make Brown's rate of 1 second per year per year about 200 times too great.

Brown's mistaken rate is because he did not know what leap seconds are nor what purpose they serve. Another problem with his claim is that the dire consequences he gives for his inflated rate are pure hand-waving with absolutely no indication that he had performed any actual calculations. I traced one line of descent from this claim in which the next link, R. L. Wysong (1980), employed hand-waving to describe the ancient earth as spinning so fast that it would be a "flat pancake", but he left out what the rate of slowing down was supposed to be. The rest of the versions of the claim descended from that one and leadin up to Kent Hovind were just restatements of Wysong's version devoid of any actual rate and consisting purely of hand-waving.

However, Hovind also has a second version, a long version from his seminar videos, based on a different rate he got from his local newspaper: one millisecond per day per day. He also includes the calculated length of a day 6,000 years ago based on that rate, which I calculate to be over 18,000 times greater than the actual rate (which I determined to be about 55 nanoseconds per day per day).

There's more information and links to sources on my page at http://cre-ev.dwise1.net/earth_rotation.html.

I should also point out that CRR had messaged me with complaints about the previous version of that page, many of them spurious. However, he was correct in that I had made a mistake in my description of Walter Brown's claim, though I found that the statement in question was very much in line with Hovind's second claim, though I was off that by about a factor of two -- it's covered in the text and also in the caveat at the top of the page.

Among other things, that raised a more general set of questions about the mathematics involved in these claims:


  1. How do the different claimed rates really compare? They're all in different units, so I will need to convert the rates to common units in order to properly compare them. Therefore, I will need to ensure that I perform those unit conversions correctly.

  2. What are the consequences of those different rates? The treatments of this claim that I've found which present actual calculated values deal in the length of a day or the number of days in a year when we go this far into the past. I will need to ensure that I perform those calculations correctly. There might also be a question of whether there's a better way to evaluate a claimed rate.

  3. So, are the models that I will be working with valid and are there better models to use? For example, a creationist inflated rate can lead to a day of length zero a few millions of years ago, which seems to indicate that that approach may be flawed or at the very least rather limited.

    For example, I could start with the earth's current rotational velocity (about 7.2921150×10-5 radians per SI second) and translate the rate of slowing to the same units. Then I could calculate the earth's rotational velocity at any point in the past. This would also require a method for converting rotational velocity to the length of a day then.

  4. Also, my approach will be primarily algebraic. If the problem lends itself more to calculus or to another mathematical method, you could point that out to me.

At present, my "Doing the Math" section is only a statement of what I plan for that section and that I have a lot of work to do in preparing it.

Just to intercept an obvious point: Yes, I do realize that the rate at which the earth's rotation is slowing is not a constant rate. First, the earth's rotation varies day-by-day due to many different factors, sometimes even speeding up. It is only over a long period of time that we have that rate of 1.4 to 2.0 milliseconds/day/century. But even then, geological evidence shows that even that rate has varied in the past (in part due to the distribution of the continental land masses, as I understand it). I feel justified in this discussion to assume a constant rate going back billions of years because that is the very same assumption that the creationists make in their claim.

I look forward to working with any interested parties on this project. I intend for this message to be the topic proposal. I will follow it immediately (ie, before topic approval) with the first part of the problem: unit conversions of the rates.

I have written my first message describing the unit conversion methods I've been using so far. I could post it either before or after this topic has been approved. For the moment, I will wait until after.


  
AdminPhat
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Message 2 of 2 (820369)
09-19-2017 4:06 PM


Thread Copied to Dates and Dating Forum
Thread copied to the Requesting Math Help/Feedback for my Web Page thread in the Dates and Dating forum, this copy of the thread has been closed.
  
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