Geodesy article - How many errors can you find

I'm going to venture a guess that you are preparing to politely inform the editor that what the French expeditions did was to attempt to determine by measurement the lengths of arcs of a degree of LATITUDE (not longitude, please) on the meridian near the equator and in Lapland.

I trust that you will also complain as nicely as possible that no mention was made of Pierre Bouguer (whose discoveries of gravity anomolies are useful today, even in Oklahoma, when oil is being hunted) or of how the entire problem of the measurements of the arcs led to scientific and mathematical discoveries that remain useful today.

Thank you Ken for once again acting as a sounding board and confirming my thoughts.
I value your expertise.

I spent several hours composing several emails, with diagrams, trying to explain that they were measuring Latitude difference.
Not Longitude. The "meridian [longitudinal] arc" was merely a reference line.
All differences in Longitude are ZERO at the Pole.
N/S=Up/Down, E/W=Left/Right etc. etc.

Respectfully and did not resort to baby-talk. Just trying to help.

(In fact Longitude could not be measured accurately until much later due to difficulty in getting and transporting accurate time. John Harrison's Chronometer)

Finally she replied thus:

I've rechecked by sources prompted by your messages. Both biographies of La Condamine and Maupertuis say that they chose to measure the length of a meridian [longitudinal] arc.

I just could not get through to her.
She is a UCLA Professor!

Lastly, after one more email from me...

Since it is you who initiated this correspondence and have sustained it, I think it is you who should stop writing.

I found this to be highly ironic considering the theme of the article which is to use the Scientific Method of Proof to resolve an argument.

Her way was to use the method reminiscent of that used by my sister
when we were kids. That is, "go away and don't talk to me anymore".
She, however, would also cover her ears and start singing to obscure my voice.

Of course I may have also suggested that she should refrain from writing articles on topics that she could not comprehend. Oh well.

---

Check these out and compare with article.
What would be true:

For a given difference in Latitude for a given amount of Angular Distance
(ex. 1 degree difference in Latitude)

-AND-

For one measurement at/near the POLE and one at/near the Equator.
(ex. 89N to 90N and 0N to 1N) i.e. two measurements

which one would be show a shorter or longer Ground Distance (say Sea Level) if the Earth was
an Oblate Spheroid (Tomato shape per Newton) ummm say like WGS84

(i.e. NOT a Prolate Spheroid or Japanese Eggplant)

Also, if they were equal distances what would that show?

All calculations must be done longhand with no HP41 allowed.
Can't use any of the many Geodetic Inverse programs out there.
(just kidding 😀 )

Thanks to any and all who perform this reality check for me.

PS Yes I am composing a letter to the Editor. Respectfully.

> Finally she replied thus:
>
> I've rechecked by sources prompted by your messages. Both biographies of La Condamine and Maupertuis say that they chose to measure the length of a meridian [longitudinal] arc.
>
> I just could not get through to her.

Do we need further confirmation that it is possible to be right in such a wrong way as to obviate the point? Think back to your early dating experiences, man!

What you needed were simply the differences in latitude observations by which the French expedition computed the length of a degree along the meridian near the equator, citing the original authors of the report.

People's Beliefs

Bob,

I can appreciate your desire to right the erroneous article. In the face of all adversity, I myself continue to attempt corrective actions against the bucket loads of manure that are thrown at the American public. The inaccuracies seem even more trangressive when uttered by someone with scholarly laurels.

Generally the last person to understand the nature of the errors is the perpetrator themselves. The hint of arrogant and lofty pseudo-intelligence only makes the mix smell even worse.

Although I'm not a big fan, Ted Nugent once said, "Stupid people need to be able to say anything they want, whenever they want. That way we will all know who the stupid people are."

There is some validity to his statement. However, I personally think it's really funny coming from Ted Nugent...

In this particular case, maybe it's best to let "stupid people say stupid things..".

"Cold hearted orb that rules the night,
removes the colors from or sight.

and which is an illusion."

You and I decide and agree the author is wrong. Find solace in that agreement. Truth is eternal.

Sweet Jesus...I'd rather try and put the toothpaste back in the tube than talk "facts" to a postmodern academic.

In short, we live in the postmodern world, where everything is possible and almost nothing is certain.

Václav Havel
The Need for Transcendence in the Postmodern World (1994)

Now, Bob, this is way out there. You are going to, through logic, correct a female? One from academia?

(Let me see here, is Bob in Colorado.. no. He is from Southern Calif., hmmm could be the Acapulco Gold, blowin' in his face!)

Women, sometimes choose to peek down the barrel of a gun... the wrong way. Don't ague with them! It's hormones, not logic makin 'em act like that!

A man cannot win, when arguing with hormones!

🙂

(Note to self, I am gonna need that for future reference....)

This fits right in with my thread on entitlement or whatever it is called.

Certain people will fight to the death defending something that deep down inside they know is wrong.

I hate to be the bearer of bad news, but the lady is correct. As you approach the pole, the length (linear measure: feet, meters, miles, light-years, etc.) of a meridian gets shorter. It was this verification by measurements on the earth's surface that solidified an ellipse as the best model of the earth.

An ellipsoid has a major axis and a minor axis. Our earth models put the minor axis between the poles and the major axis to the equator. Had Newton's proposition not been the correct one, the axes would have been reversed.

As you go north from the equator along a meridian, the average radius of the ellipsoid becomes shorter. Moving northward along a meridian, the radius decreases, and arcs subtended by angles from these shorter radii also become shorter. This has to happen because, at the pole, the radius is the semi-minor axis. And this is what the two expeditions mentioned in the article verified by actual measurement.

As to the parallels, they become shorter northward regardless of whether the earth is a sphere or an ellipsoid, so they offer no evidence of the ellipsoidal shape of the earth.

Send the lady a note of apology, attached to a nice bottle of wine.

It doesn't matter if you are wrong or right, as long as you end the argument.

"Since it is you who initiated this correspondence and have sustained it, I think it is you who should stop writing."

BTW, you can google "Charles Marie de la Condamine degree of latitude" and find several sources that realize that measuring an angle on the meridian means you are measuring a degree of latitude. That's how I was taught it, my Geodesy class in college, as well.

Nate's comment although in jest was a sexist comment. Talk about ignorance and sense of entitlement is very relevant.

FWIW, I enjoyed the article and commend the author for making this topic entertaining and informative. The "quibble" here that the author did not specifically state that the measurement was of the length of a degree of latitude along the meridian is valid. The actual field measurements were made using this guidance.

There are a good number of books on these surveys. The good professor captured the gist of issue. I believe it will inspire more interest in the survey and related issues. Good on her.

In closing, I like the snarky comment by Voltaire "...Maupertius went to the ends of the earth to find that which Newton discovered from his desk." See Mazer's "The ellipse: a historical and mathematical journey."

And I might add, they named the cookie after Newton, not Mau-how do you prounounce his name?

You don't go to Safeway looking for a box of Fig Maupertius cookies.

Oh, I see now. She said "...a degree of longitude..." instead of a degree along a meridian. A degree of longitude is, indeed, an east-west concept and you are, indeed, correct.

The good professor said it better in her email, but don't send an apology and keep the wine for yourself.

One of the most, and probably the most, level headed and common sense persons I know is a woman. I usually enjoy Nate's viewpoints but this one's a bit backwards.

[sarcasm]It's a well know fact that Irene Fischer only worked on the WGS 66 Ellipsoid three weeks out of the month[/sarcasm]

What's her email? It's not listed on the page.

http://www.history.ucla.edu/people/emeriti-ae-1/emeriti?lid=441

>..."The challenge that postmodernism posed to historians became the central theme of Telling the Truth about History which Appleby wrote with Margaret Jacob and Lynn Hunt in 1994."

Pretty funny book title. If I knew any more about her I'd almost be tempted to call someone presumptuous who writes a book titled "Telling the Truth about History".

I'm pretty much a fly-speck on the wall of her world...and her in mine. The chances of me ever running into her are like two bottles in the ocean, placed there at opposing poles, colliding. I'll let her be outstanding in her field, and I'll be out standing in mine.. 😉

In my little brain

It would totally figure that she was right all along!

N