h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I've decided that my next task should be to write about the star Delta Cephei and the woman who studied it and worked out a way of measuring the universe.

For anyone who thinks that a task like this is just a cut-and-paste job from Wikipedia, you may be interested to hear that the first thing I did was to look at Wikipedia to see what it has to say:

1. The star map showing the position of Delta Cephei has a red ring on it. The ring is in the wrong place.

2. It doesn't mention any woman astronomer.

3. It says that Delta Cephei is a double star, the two components having masses of 4.5 and 54 times that of our sun. I'm immediately suspicious, because 54 times the mass of the sun seems way too big.

So my first task will be to correct the Wikipedia entry, then to write the h2g2 one.

You're correct on the mass. 11 seems to be the correct answer.


http://www.wolframalpha.com/input/?i=mass+of+Delta+Cephei+%2F+mass+of+sun

Delta Cephei has two stars. So if the mass is 11, do they mean the combined masses of the two stars, or just of the brighter star?

Wikipedia itself lists the most massive stars in another article and doesn't mention Delta Cephei B there, so it must be a typo, but what the true value is I don't know. I've seen it listed as 4 on another site, but that's very unspecific. The Bright Star Catalogue gives very detailed positions but not masses, as they are usually difficult to determine and conjectural.

There's also a contradiction in Wikipedia over when its variability was discovered. Will have to investigate further.

Explain again *why* you are attempting to correct Wikipedia?

OOOH! I know the answer to that...

http://xkcd.com/386/

And that's particularly important on Wikipedia because of http://xkcd.com/978/.

TRiG.

Will this article from the Alamagordo News help? It mentions a woman named Henrietta:

http://www.alamogordonews.com/alamogordo-news/ci_21807286/star-delta-cephei-shines-bright

That's very helpful, Dmitri. It is a summary of what I was going to put in my Entry.

Eerily, I've got deja vu. I did all this before and Galaxy Babe thanked me for writing a technical article about a woman astronomer, a subject close to her heart.

Yes, now that I know the name of the woman, I find that I wrote about her and the method in the entry on Tucana, the Toucan constellation.

Hmm. I wonder did I write enough there, or should I expand on it.

Icy, the main reason for correcting Wikipedia is that in order to do it, I have to find out what the truth is. That's also my main reason for writing entries in h2g2 - I need to learn the subject to my own satisfaction before I can write about it.

A40572047

That is beautifully thorough.

I'm looking forward to what you find out.

I can't argue with that, Gnomon. Your articles are always grounded in truth, and if correcting WIkipedia helps then that's great. I just hope some toe rag doesn't undo all your corrections within 5 minutes of you making them.

I've got to agree that the reliability of Wikipedia varies with time and their extremely loose standards of revision allow frequent loss of reliability.

Yes, Delta Cephei, the universe's standard candle, will make a good story. Something for me to work over the next week when I'm on holidays.

I was hoping your next Guide Entry would be on 'Things in Wikipedia that are demonstrably untrue'. Preferably complete with suitable timestamps and suchlike.

That would be an awesome piece of work...

B

Gnomon vs Wikipedia. That would be an interesting battle. But would it be worth it? Wikipedia's main problem is not its unreliability, it's the sheer tedium of it all.

Surely it is a bad idea to point out mistakes in a site/document that is constantly being updated, other than by correcting it. Once it's been corrected, the rant only speaks against the ranter.

What is the point of criticising wikipedia in any case? Wikipedia is you, me and us. I'm quite amazed how well they have vandal-proofed it. It's not worth vandalising any more, if it ever was.

It works well when it collects unchallengeable information (e.g. reference, popular music). It fails when anything is either esoteric (e.g. forefront of science) or liable to interpretation (e.g. history, biography). In the end it fails because people who write, update, review and edit it fail.

Oh and, as Gnomon says, because of the sheer tedium of it all.

I find the entries consisting of technical information very persuasive. They have the air of being written by someone who knows.

I have been involved in a few entries, including one on my teacher John Beckett http://en.wikipedia.org/wiki/John_S._Beckett

Charles Gannon, a friend of mine and John's, is writing a biography of him, and he put the wiki article up after John's death seven years ago. He asked me for reminiscences and I obliged.

The first-hand material was all flagged and questioned by wikipedia, and later removed, probably by Charles himself. They have a policy of 'no original research', and no doubt all the personal stuff will find its way into the book. Once the book is published it can all go back into the wiki article, with the book as reference.

I found this all fairly impressive.