Freethought & Rationalism Archive

The_Gorgonzola · 04-24-2002, 08:53 PM

I was reading about the Bible and Pi at http://www.infidels.org/news/atheism/arguments.html which states:

Quote:

The Bible says pi is 3!
In I Kings 7:23, the Bible says:

And he made a molten sea, ten cubits from the one brim to the other: it was round all about, and his height was five cubits: and a line of thirty cubits did compass it round about.

If you make a molten sea with a circumference of thirty cubits, you'll find that the diameter is 30/pi or 9.55 cubits. Or ten cubits, to round to the nearest integer.

In short, the Bible does not say that pi must be three, unless you are going to assume that the numbers given are accurate to more than two significant figures, which is unjustifiable given the wording.

I think this incorrect. pi=c/d therefore, given a cirumfernce of 30 and a diamter of 10, pi must equal 3.

I don't understand the last paragraph.

Anyone want to help me out?

Gorgo

Toto · 04-24-2002, 09:08 PM

Your profile says you are a "systems engineer". What is your math background?

This seems pretty obvious to me.

The_Gorgonzola · 04-24-2002, 09:20 PM

Quote:

Originally posted by Toto:

This seems pretty obvious to me.

I guess what I'm not understanding is the line "it is unjustifiable given the wording". Is this person refering to the wording of the text? 10 cubits diameter (rim to rim) by 30 cubits circumference (around). Obviously I am missing something.....

Gorgo

DrLao · 04-24-2002, 09:48 PM

Yes, he is referring to the wording of the text. Since only 2 digits are given for both the diameter and the circumference, it would not be justifiable to assume that they are accurate than 2 significant digits.

Toto · 04-24-2002, 09:50 PM

I think it means that it is unjustifiable to assume that the text is referring to numbers that are accurate to more that 2 significant digits, given that it uses words that are whole numbers.

For example, if the Bible said

Quote:

And he made a molten sea, 10.00 cubits from the one brim to the other: it was round all about, and his height was 5.00 cubits: and a line of 30.00 cubits did compass it round about.

then you could be sure that the writer really thought that pi = 3.

But it said ten cubits, and in fact 9.55 cubits would make the math work out. So all you know is that the writer thought pi was close to 3, which it is.

The_Gorgonzola · 04-24-2002, 10:01 PM

GAWD!!! I must be tired!!! Sig figs...duh!! Thanks guys....

Gorgo (feeling rather stupid right now)

[ April 24, 2002: Message edited by: The_Gorgonzola ]</p>

Boro Nut · 04-25-2002, 03:20 AM

Bollocks. They may not have had decimal points but they did have fractions. If it was talking about a 10 sheckle loan you can bet it would quote interest "unto the tenth part thereof".

Boro Nut

Vorkosigan · 04-25-2002, 03:23 AM

This is really a weak contradiction. I wish Asimov and others had never mentioned it.

Vorkosigan

Gooch's dad · 04-25-2002, 05:22 AM

The significant figure argument doesn't wash.

You can't just argue that a 30 cubit circumference would yield a 9.55 cubit diameter, which is 10 to 2 significant digits.

How often do you build something and consider the circumference first? The tank was 10 cubits across. The circumference SHOULD have been stated as 31 cubits. THAT is two significant figures of accuracy. 30 is wrong.

I very much doubt that the Hebrews would have asked someone to build a circular tank and specify the circumference, and leave out the diameter.

DrLao · 04-25-2002, 05:58 AM

Quote:

Originally posted by Gooch's dad:
<strong>You can't just argue that a 30 cubit circumference would yield a 9.55 cubit diameter, which is 10 to 2 significant digits.</strong>

Actually, it isn't. 9.55 is 9.6 to two sig. figs. But they didn't say that there were two sig. figs. They said it is not justified to assume more than two sig. figs. It is possible to read it as having only a single sig. fig. for both circumference and diameter.

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04-24-2002, 09:08 PM	#2
Toto Contributor Join Date: Jun 2000 Location: Los Angeles area Posts: 40,549	Your profile says you are a "systems engineer". What is your math background? This seems pretty obvious to me.

04-24-2002, 09:48 PM	#4
DrLao Junior Member Join Date: Apr 2002 Location: Madison Posts: 39	Yes, he is referring to the wording of the text. Since only 2 digits are given for both the diameter and the circumference, it would not be justifiable to assume that they are accurate than 2 significant digits.

04-24-2002, 10:01 PM	#6
The_Gorgonzola Junior Member Join Date: Aug 2001 Location: California Posts: 37	GAWD!!! I must be tired!!! Sig figs...duh!! Thanks guys.... Gorgo (feeling rather stupid right now) [ April 24, 2002: Message edited by: The_Gorgonzola ]</p>

04-25-2002, 03:20 AM	#7
Boro Nut Veteran Member Join Date: Nov 2000 Location: Middlesbrough, England Posts: 3,909	Bollocks. They may not have had decimal points but they did have fractions. If it was talking about a 10 sheckle loan you can bet it would quote interest "unto the tenth part thereof". Boro Nut

04-25-2002, 03:23 AM	#8
Vorkosigan Contributor Join Date: Jan 2001 Location: Barrayar Posts: 11,866	This is really a weak contradiction. I wish Asimov and others had never mentioned it. Vorkosigan

04-25-2002, 05:22 AM	#9
Gooch's dad Veteran Member Join Date: Oct 2000 Location: Madison WI USA Posts: 3,508	The significant figure argument doesn't wash. You can't just argue that a 30 cubit circumference would yield a 9.55 cubit diameter, which is 10 to 2 significant digits. How often do you build something and consider the circumference first? The tank was 10 cubits across. The circumference SHOULD have been stated as 31 cubits. THAT is two significant figures of accuracy. 30 is wrong. I very much doubt that the Hebrews would have asked someone to build a circular tank and specify the circumference, and leave out the diameter.

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