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Mind blown!

There's a re­al­ly awe­some thread at Red­dit called "What's the most mind-blow­ing fact you heard/read in your life?" where com­menters are post­ing well... that.

It's a great read! But there are a few here and there that are a bit un­de­serv­ing of the ti­tle, be­cause they are just wrong :-)

Here are a cou­ple from the be­gin­ning of the thread (it's got over 4000 posts now).

"There has been no ev­i­dence sug­gest­ing the uni­verse is not fi­nite. If we as­sume the uni­ver­site is in­finite, then it is cer­tain that ev­ery sin­gle pos­si­ble com­bi­na­tion of events has hap­pened some­where in the gal­axy. In an al­ter­nate area, all of hu­man his­to­ry is the same, ex­cept you don't de­cide to post this thread. With cer­tain­ty."

—Moth­er­sRape­Horn

Be­yond con­fus­ing the gal­axy with the uni­verse, let's think this a bit.

It's fun­ny, but I re­mem­ber read­ing some­thing like "if the uni­verse is in­fi­nite then ev­ery­thing that is pos­si­ble has cer­tain­ly hap­pened some­where" in a cheap sci­fy book­let maybe 30 years ago.

In that sto­ry, that rea­son­ing was used to jus­ti­fy a naked cy­clops that walked in space, IIR­C. It was found by a star­ship called SKY-11111. If any­one has read that sto­ry, he has my sim­pa­thy (I should write about how hard it was to read sci­fi when I was a kid, beg­gars can't be chooser­s!)

But the prob­lem here is just a ba­sic mis­un­der­stand­ing of prob­a­bil­i­ty.

Let me ex­plain with an ex­am­ple: Con­sid­er the odds of some­one spend­ing a year flip­ping a fair coin and get­ting "head­s" ev­ery time. That's some­thing very un­like­ly. Let's call that prob­a­bil­i­ty P1.

Now, let's con­sid­er the prob­a­bil­i­ty of "there has nev­er ev­er been a per­son that flipped a fair coin for a year get­ting on­ly 'head­s', and there nev­er will be", and call that P2.

Now, if the uni­verse is large, P1 will grow. As there are more peo­ple, there is a larg­er chance of some­one de­cid­ing to waste a year and then there is a tiny chance of him be­ing in­cred­i­bly ... (well, not luck­y, see how he spent his year!) but let's say, con­sis­ten­t? And get­ting heads all year.

What the heck, let's say P1 is now 50%, so it's not even un­likey.

But that means P2 is al­so 50%, since it's true ex­act­ly as of­ten as P1 is false.

Now, which one of these two things will hap­pen "With cer­tain­ty"? See? Like­ly is not the same as sure, un­like­ly is not the same as im­pos­si­ble, and adding an in­fin­i­ty does­n't do the trick here.

So, re­al­ly, even if the uni­verse is in­finite, and even if it were crowd­ed with peo­ple, there are lots and lots of things that are nev­er go­ing to hap­pen.

I find that more mind­blow­ing than the orig­i­nal, but that's just me.

Here's a sim­pler one:

If you took all of the sil­ver the Span­ish mined from Cer­ro Ri­co, you could build a bridge from Po­to­si, Bo­livi­a, to Spain. If you took the bones of all the In­di­ans (about eight mil­lion) who died in the mi­nes, you could build an­oth­er bridge back to Po­to­si from Spain. Cer­ro Ri­co has been so thor­ough­ly mined that there is an en­tire moun­tain next to it of the rub­ble ex­tract­ed from it. The In­di­ans call this sec­ond one "the moun­tain that weep­s."

—tofketv

Here I am guess­ing he is great­ly over­es­ti­mat­ing the amount of sil­ver ex­tract­ed from Cer­ro Ri­co.

Spain is rough­ly 8800km away from Cer­ro Ri­co. A 2-me­ter wide path, 20cm thick would mean 3520000 cu­bic me­ters of ma­te­ri­al­s. That's much much less than a bridge would use.

Cer­ro Ri­co is about 4800 me­ters tal­l.

So, this means the ma­te­ri­al for that path would be enough to build a col­umn with square base 27 me­ters wide, and as tall as Cer­ro Ri­co, of pure sil­ver.

That would be, con­sid­er­ing sil­ver has a spe­cif­ic weight of 10490... 36924800000000 kilo­grams of sil­ver. That is... well, that's a lot of sil­ver.

How much sil­ver? Well, in dol­lars, that would be $27508976000000000

In any case, the thread is great fun, and ev­ery­one who has, say, a young kid should read bits of it ... with a skep­tic eye open ;-)

No, 10/10/10 is not that special, either

To­day is 10/10/10 (or rather 10/10/2010 which does­n't look so cute, right?) and again there's a flood of "this on­ly hap­pens ev­ery 100 years! OMG!".

At least this time it's cor­rec­t. How­ev­er:

How of­ten is 10/11/10 go­ing to hap­pen? How of­ten did yes­ter­day's 10/9/10? Ev­ery 100 years, too. In fac­t, ev­ery date writ­ten in that for­mat will hap­pen once ev­ery 100 years, be­cause that's the way dates work!

Oh, you may say, the spe­cial part is that the three num­bers are the same, sil­ly!

But then again, last year we had 9/9/9 and next year we'll have 11/11/11 (much cool­er than 10/10/10!) so ... no, not that spe­cial.

OTO­H, to­day (at 10P­M) my kid and I will see the first ev­er episode of Ben10 Ul­ti­mate Alien (hey, 5 10s!) for the first time and that... well, that has nev­er hap­pened be­fore, and will nev­er hap­pen again. That, friend­s, is spe­cial.

Another reason to attend PyCon Argentina

You can get a free Is­sue of PET: Python En­tre To­dos our python mag­a­zine.

400 will be print­ed thanks to BBLUG, Py­ConAr and Py­Day Rafaela.

I hope I can get a few for my­self, be­ing the mag­a­zine re­spon­si­ble ed­i­tor and ev­ery­thing :-)

And if you won't be there: it's CC-by-nc-sa so you can print it too!

Rst2pdf 0.16 is out!

Fi­nal­ly, a new re­lease of rst2pdf!

You can get it at its site: http://rst2pdf.­google­code.­com

rst2pdf is a tool to con­vert re­struc­tured text (a light, cool markup lan­guage) to PDF us­ing re­port­lab in­stead of La­TeX.

It has been used for many things, from book­s, to mag­a­zi­nes, to brochures, to man­u­al­s, to web­sites and has lots of fea­tures:

  • Font em­bed­d­ing (T­TF or Type1 fonts)

  • Cas­­cad­ing Stylesheets

  • Ex­treme­­ly flex­i­ble plug­in ar­chi­tec­­ture (y­ou can do things like ren­der the head­­ings from ar­bi­­trary SVG files!)

  • Sphinx in­­te­­gra­­tion.

  • Con­­fig­urable page lay­outs

  • Cus­­tom cov­­er pages via tem­­plates

  • And much, much more...

The big­gest change in 0.16 is sure­ly the im­proved sup­port for Sphinx 1.0.x so if you are us­ing Sphinx, you re­al­ly want this ver­sion.

Al­so, it has a ton of bug­fix­es, and a few mi­nor but use­ful new fea­tures.

Here's the whole changel­og if you don't be­lieve me:

  • Fixed Is­­sue 343: Plugged mem­o­ry leak in the RSON pars­er.

  • Fix for Is­­sue 287: there is still a cor­n­er case if you have two sec­­tions with the same ti­tle, at the same lev­­el, in the same page, in dif­fer­­ent files where the links will break.

  • Fixed Is­­sue 367: ger­­man-lo­­cal­ized dates are MM. DD. YYYY so when used in sphinx's tem­­plate cov­­er they ap­­peared weird, like a list item. Fixed with a mi­nor work­around in the tem­­plate.

  • Fixed Is­­sue 366: links to "#" make no sense on a PDF file

  • Made de­f­i­ni­­tions from de­f­i­ni­­tion lists more sty­lable.

  • Moved de­f­i­ni­­tion lists to Split­­Ta­bles, so you can have very long de­f­i­ni­­tion­s.

  • Fixed Is­­sue 318: Im­­ple­­men­t­ed Do­­main spe­­cif­ic in­­dex­es for Sphinx 1.0.x

  • Fixed In­­dex links when us­ing Sphinx/pdf­builder.

  • Fixed Is­­sue 360: Set lit­er­al.­­word­Wrap to None by de­­fault so it does­n't in­­her­it word­Wrap CJK when you use the oth­­er­­wise cor­rect ja­­pa­­nese set­t­ings. In any case, lit­er­al blocks are not sup­­posed to wrap at al­l.

  • Switched pdf­builder to use Split­­Ta­bles by de­­fault (it made no sense not to do it)

  • Fixed Is­­sue 365: some TTF fonts don't val­i­­date but they work any­way.

  • Set a valid de­­fault baseurl for Sphinx (makes it much faster!)

  • New fea­­ture: --use-num­bered-links to show sec­­tion num­bers in links to sec­­tion­s, like "See sec­­tion 2.3 Ter­mi­­na­­tion"

  • Added stylesheets for land­s­cape pa­per sizes (i.e: a4-­­land­s­cape.style)

  • Fixed Is­­sue 364: Some op­­tions not re­spec­t­ed when passed in per-­­doc op­­tions in sphinx.

  • Fixed Is­­sue 361: mul­ti­­ple line­breaks in line blocks were col­lapsed.

  • Fixed Is­­sue 363: strange char­ac­ters in some cas­es in math di­rec­­tive.

  • Fixed Is­­sue 362: Smarter au­­to-en­­clos­ing of equa­­tions in $...$

  • Fixed Is­­sue 358: --re­al--­­foot­notes de­­faults to False, but help text in­­di­­cates de­­fault is True

  • Fixed Is­­sue 359: Wrong --­­fit-back­­­ground-­­mode help string

  • Fixed Is­­sue 356: mis­s­ing cells if a cell spawns rows and col­umn­s.

  • Fixed Is­­sue 349: Work cor­rec­t­­ly with lan­guages that are avail­able in form aa_bb and not aa (ex­am­­ple: zh_c­n)

  • Fixed Is­­sue 345: give file/­­line in­­­fo when there is an er­ror in a raw PDF di­rec­­tive.

  • Fixed Is­­sue 336: JPEG im­ages should work even with­­out PIL (but give a warn­ing be­­cause sizes will prob­a­bly be wrong)

  • Fixed Is­­sue 351: foot­note/c­i­­ta­­tion re­f­er­ences were gen­er­at­ed in­­­cor­rec­t­­ly, which caused prob­lems if there was a ci­­ta­­tion with the same text as a head­­ing.

  • Fixed Is­­sue 353: bet­ter han­dling of graphviz, so that it works with­­out vec­­tor­pdf but gives a warn­ing about it.

  • Fixed Is­­sue 354: make todo_n­ode from sphinx cus­­tom­iz­a­ble.

  • Fixed bug where nest­ed lists broke page lay­out if the page was smal­l.

  • Smarter --in­­line-links op­­tion

  • New ex­ten­­sion: fan­­cyti­tles, see //ral­si­­na.me/we­blog/­­post­s/B­B906.html

  • New fea­­ture: tab-width op­­tion in code-block di­rec­­tive (de­­faults to 8).

  • Fixed Is­­sue 340: end­notes/­­foot­notes were not styled.

  • Fixed Is­­sue 339: class names us­ing _ were not us­able.

  • Fixed Is­­sue 335: ug­­ly crash when us­ing im­ages in some spe­­cif­ic places (looks like a re­­port­lab bug)

  • Fixed Is­­sue 329: make the fig­ure align­­men­t/­­class at­tributes work more like La­­TeX than HT­M­L.

  • Fixed Is­­sue 328: list item styles were be­ing ig­nored.

  • Fixed Is­­sue 186: new --use-float­ing-im­ages makes im­ages with :align: set work like in HT­M­L, with the next flow­able flow­ing be­­side it.

  • Fixed Is­­sue 307: head­­er/­­foot­er from stylesheet now sup­­ports in­­­line rest markup and sub­­sti­­tu­­tions de­fined in the main doc­u­­men­t.

  • New pdf_­­toc_depth op­­tion for Sphinx/pdf­builder

  • New pdf_use_­­toc op­­tion for Sphinx/pdf­builder

  • Fixed Is­­sue 308: com­­pat­i­­bil­i­­ty with re­­port­lab from SVN

  • Fixed Is­­sue 323: er­rors in the con­­fig.sam­­ple made it work weird.

  • Fixed Is­­sue 322: Im­age sub­­sti­­tu­­tions did­n't work in doc­u­­ment ti­­tle.

  • Im­­ple­­men­t­ed Is­­sue 321: un­der­­line and strikethrough avail­able in stylesheet.

  • Fixed Is­­sue 317: Ug­­ly er­ror mes­sage when file does not ex­ist


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