Erdős–Bacon number | Hacker News Reader

Erdős–Bacon number

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48 pointseindiran35 comments

Erdős–Bacon numbers got their start when Simon Singh (reference 1 archived) was having lunch with me, and I observed that mine was 4. He writes for a living, so he wrote a column.

Oddly, I was long ago written out of this Wikipedia article.

There is a reasonable ambiguity about Erdős numbers, as people do publish posthumously with him, based on collaborations while he was alive.

There is also an ambiguity about Bacon numbers. One can take the spirit of the original dorm room bull sessions that started Bacon numbers, or one can take the idiosyncrasies as gospel of the web site that now reports Bacon numbers. For example, a mathematician can appear as themself in a documentary, and gain a Bacon number according to this web site. They defend this by observing that these mathematicians did experience film sets (so do caterers) but the reality is that it's too hard to clean the data. I've been interviewed multiple times for documentaries, and the experience bears no resemblance whatsoever to that of working on and acting in "A Beautiful Mind". The original intent was to count actors with credited speaking roles.

Yup. I have an Erdős number, but despite being a Bacon, no Bacon number to my great dismay.

Thanks for the background! Why did you two choose to make it the sum of the two scores (so L1 distance) rather than L-inf/max?

It seems to me that you'd want to have the minimum value be a 1, representing someone who co-authored a paper with Erdos and appeared in a film with Bacon. The sum will always be at least two though (whatever I guess), but that also (2,2) isn't that far away from the "origin" such that it feels wrong to call it 4 (and similarly 2,4 being 6 seems funny).

I prefer the sum, as it describes the minimum-length path containing all participants. It seems like the intuitive expansion of the concept of the Erdös number.

What role did you play in A Beautiful Mind? I.e. who are you?

Based on [0] and [1] I'd say Professor Dave Bryer.

[0] https://web.archive.org/web/20121112081753/http://www.telegr...

[1] https://simonsingh.net/media/articles/maths-and-science/erdo...

[2] https://www.imdb.com/name/nm1101413/?ref_=ttfc_fc_cl_t41

Yes, Dave Bayer. I was the math consultant, but it's like joining the circus, once inside you do what you can. For one example, when I was a kid my Mom left out a Time Life book on drugs, and my brother and I were fascinated by the various photographs of spiderwebs made under the influence of different recreational drugs. That idea helped shape the "mad shack" in the film. I was also Russell Crowe's hand double, and I had a speaking part in the pen ceremony.

Russell Crowe's hand double? Does he have bad hands or something?

Not having seen the movie, I'm guessing there are scenes where Crowe needs to write some math, and it just looked more convicing by letting an actual mathematician do it for him.

I personally want to thank you. As a mathematician, I always dislike the way maths is displayed in most movies. It was very refreshing to see students compute De Rham cohomology and discuss Galois theory (if I recall correctly) in a major Hollywood production.

Then again, "It's my turn" has a proof of the snake lemma in it! :-) (but the scene is much less realistic)

Not the OP, but I'm guessing that Syzygies is Professor David Allen Bayer. [0][1]

>Bayer was a mathematics consultant for the film A Beautiful Mind, the biopic of John Nash,

"Syzygies" appears to be a reference to a construct in abstract algebra. [2][3]

Dave Bayer is referenced on the version of the Wikipedia page Erdős–Bacon number dated 03:25, 9 February 2013. [4]

>For a time, the person with the lowest known Erdős–Bacon number was Dave Bayer, mathematical consultant to A Beautiful Mind who was on screen in a minor role in the movie. Rance Howard was also in A Beautiful Mind and in Apollo 13 with Kevin Bacon to give Bayer a Bacon number of 2. Bayer wrote a paper with Persi Diaconis, who has an Erdős number of 1 due to a jointly authored 1977 Stanford University technical report, later published in a 2004 compilation. As such, Bayer's Erdős–Bacon number is 4. ...

But there is a tsunami of deletions [5] by Wikipedia User:Cresix [6] on that day, and the text above plus a table that references Dave Bayer is gone.

[0] https://simonsingh.net/media/articles/maths-and-science/erdo...

[1] https://en.wikipedia.org/wiki/Dave_Bayer

[2] https://www.math.columbia.edu/~bayer/papers/

[3] https://en.wikipedia.org/wiki/Hilbert%27s_syzygy_theorem

[4] https://en.wikipedia.org/w/index.php?title=Erd%C5%91s%E2%80%...

[5] https://en.wikipedia.org/w/index.php?title=Erd%C5%91s%E2%80%...

[6] https://en.wikipedia.org/wiki/User:Cresix

Len Adleman was listed as an advisor in the credits of the movie "Sneakers". Is that a connection from the math world to the Bacon world?

My favorite Erdős trivia is that he was an avid amphetamine user.

    Erdős’s friends worried about his drug use, and in 1979 Graham bet Erdős 
    $500 that he couldn’t stop taking amphetamines for a month. Erdős accepted, 
    and went cold turkey for a complete month. Erdős’s comment at the end of the 
    month was “You’ve showed me I’m not an addict. But I didn’t get any work done. 
    I’d get up in the morning and stare at a blank piece of paper. I’d have no 
    ideas, just like an ordinary person. You’ve set mathematics back a month.” 
    He then immediately started taking amphetamines again

My man.

https://www.untruth.org/~josh/math/Paul%20Erd%F6s%20bio-rev2...

"I'm not a drug addict, I just can't function without drugs. Totally different."

Some people have unfortunate brain chemistry/homeostasis, and are keen to adjust it.

It's a real thing.

Hard to separate from desiring the pleasure/illness, to be fair.

Spot on.

Going cold turkey to nothing for a month is not something a typical "addict" could do.

I don't think this is fair. I have ADHD. It is not an exaggeration to say that I can't function without drugs - I have trouble doing literally any task that requires switching focus or making long-term plans (including complex, multi-step tasks like "put on pants, go outside, find a place to eat, and eat some food so you don't starve".)

Specifically, I can't function without prescription amphetamines, in dosages substantially greater than Erdos was taking.

Hanging out with Erdős was probably a ride. He was known for drinking copious amounts of coffee and taking amphetamines non stop. So he probably didn't get a lot of sleep. Now imagine that dude has showed up at your house to live and work with you for at least a few days, but probably a week or two. I wouldn't be surprised if he exhausted a few poor unsuspecting mathematicians.

I’ve never heard of Erdos Bacon numbers. My university professor Dr Tjaden pioneered the Bacon Number and it was a pretty obscure claim to fame he had.

I’m guessing his Erdos Bacon number was 3+1=4. He appeared in a documentary with Kevin Bacon about the 6 degrees of Kevin Bacon, and has a peer at the university with an Erdos of 3. What a world we live in!

If you like science podcasts, in one of the "Infinite Monkey Cage" episodes, I (believe) Stephen Fry was discussing this. Great podcast (BBC).

I was surprised not to see Kip Thorne there. He has been heavily involved with Hollywood for ages apart from being an accomplished scientist.

If you count appearances on TV, I think I have a E-B number of 6, possibly 5.

I'm actively working on getting a finite E-B-S number ...

What is that double-accented o called and how is it pronounced?

For pronunciation, one resource is https://en.wikipedia.org/wiki/Hungarian_phonology#Vowels

That particular diacritic mark is a double accent.

https://en.wikipedia.org/wiki/Double_acute_accent#Hungarian

> "In Hungarian, the double acute is thought of as the letter having both an umlaut and an acute accent"

It's a long o-umlaut. Pronounced like "err" (thinking) or a stretched out version of "ea" from earth.

Incidentally, Erdős in Hungarian means Forester.

It took me a while to understand xkcd #599[1]; now I'm wondering what the current lower bound on someone's Erdős–Bacon Number is today. Anyone know?

[1]: https://www.xkcd.com/599/

Can you ELI5 both? I don't get it.

To get the lowest Erdos number you have to co-author a paper with him but he is dead so that is no longer possible. Unless...

Someone's "Bacon" number is how many films you have to go through in order to go from that person to Kevin Bacon. For example Patrick Stewart's Bacon number is 2. Star Trek: First Contact -[James Cromwell]-> Beyond All Boundaries -> Kevin Bacon.

Someone's Erdős number is the same concept, but applied to coauthorship on research papers.

Someone's Erdős-Bacon number is the sum of those two numbers.

https://explainxkcd.com/wiki/index.php/599:_Apocalypse

Well, Erdos is dead, so you'd have to be in a movie with one of the two people who have a EB number of 3, giving you an EB number of 5. Otherwise, if one of the people who have published a paper with Erdos were in a movie with Kevin Bacon, that would lower their number to two. Somebody born today couldn't do better than 5, and they'd have to move quickly. Kleitman is in his late 80s and Reznik is 66.

Someone born today could co-author a paper with anyone who co-authored a paper with Erdos, and also appear in a film with Kevin Bacon, giving them a EB number of 3.

Somebody films a movie today staring Kevin Bacon and anyone with an Erdős number of 1 and we get a new record holder, E-B number of 2.

When I read this, I immediately began thinking if there is someone I know who has been involved in both science/math and TV/movies and the name that popped up for me was Carl Sagan. Carl Sagan has Erdos-Bacon number of 6.

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