O que faz a água sair da torneira?

Desde que fiz o texto "Sobre Torneiras",várias pessoas já entraram no blog buscando a resposta da pergunta: O que faz a água sair da torneira? Mal sabem as pessoas que fazem essa busca, que este é o blog de um físico, e como bom físico, eu vou tentar explicar da maneira mais complicada possível o porquê da água sair pela torneira!

Isto ocorre devido a um princípio básico da hidrostática, chamado princípio dos vasos comunicantes. Vasos comunicantes é o termo utilizado para designar um sistema de dois ou mais recipientes interligados por dutos fechados, ou seja, todo o sistema de água de uma cidade, é um grande sistema de vasos comunicantes. E segundo a hidrostática, caso o líquido no interior dos tubos seja homogêneo, ele deve atingir a mesma altura em todas os recipientes que se interligam, como ocorre na figura abaixo.


O que faz com que a altura seja sempre a mesma é a pressão. Tanto a pressão atmosférica, quanto a pressão gerada pelo peso do próprio líquido dentro dos recipientes.

Imagine agora, se colocarmos um furo, abaixo do nível do líquido, em cada um dos recipientes. O líquido vai começar a vazar, e se inserirmos um regulador de vazão após o furo, então teremos uma TORNEIRA!!!

Concluindo: Para uma torneira funcionar, temos que ter um sistema de vasos comunicantes, onde a fonte de água, deve estar sempre a uma altura mais elevada que todas as torneira, ou chuveiros, ou qualquer outro aparato que verta água. Caso contrário, não sairá água das torneiras. Por esse motivo, é que todas as caixas d'água existentes, sempre ficam no topo dos edifícios, ou então, são as estruturas mais elevadas em cada região!

É tão simples, que eu nem consegui complicar, e colocar integrais no meio! Bah! :P

Diablo III

It is saturday, 9:20AM, and I am already awake. For a week I have been following some unknown evolution at Blizzard Website. I knew today we would have a bombastic announcement about some unknown game already in development.

I went to their website, and for my surprise, I finally found out what game was the secret all about.


...and there you will find even the first cinematic teaser trailer, and what a tease is that! Also a gameplay trailer, and some scattered information about the game. I can not hold my excitation! But I will need to wait, until 2010, maybe sooner, maybe later, to play this game... But this bombastic information already made my day!!

Strange Sightings

... and so it came to pass that I was inside the bus, going to the University, wondering about something already forgotten, and then over the window I saw it... There... Something that should not be there. Was that my mind playing a trick on me? Was it the true face of reality? Or just the hidden face of Insanity making an ephemeral appearance in my mind? I do not know...

I saw it inside a car that just passed by. For a glimpse of a moment I thought I have just seen something that should not be... I closed my eyes for a while, then blinked two or three times, and looked again... I was not mistaken. There was something very amiss driving that car. There seemed to be an aura of wrongness around that figure, something non-euclidean surrounding that thing... And just in the midst of that aura of insanity was the thing I can not even start to describe, even though I still can see that which should not be clearly in my mind...

That thing was driving the car. It was humanoid, but what else? No tentacles that I could see, though. But I saw it as something shaped by the hands of Entropy Itself... It was not only horrid, but also decayed as I have never seen before... A zombie of some sort driving a car!! How dead was that, I have no idea! Fortunately for me, the sighting was a very rapid one, but I can not take it out of my mind... Am I going insane or are there truly zombies amongst ourselves? And that aura surrounding it, what was it?

And the small green footprints, of a large humanoid beast I have seen in my way home, while I was crossing the Human Sciences Building (FAFICH)? Was that someone's doing, or another trick played by Reality on me?

And there was something else I cannot recall, maybe a selective amnesia to keep my mind from another trauma...

Shall I trust everything I see? Or are really things that are not true!? Or maybe too TRUE to be perceived by common eyes!? Things that the people's mind just filter to not shatter!? Why me??

It can only be The Cube!! I know... It is the Cube hunting me, even in my dreams... And I though I was free... The Cube's minions are after me, after so long, but who are they!? Can I escape? At least, I have not seen any of those Evil Squirrels anymore... It can also be The Rock, or maybe both!! I hope I am not doomed... I will run away... Where? I cannot tell yet, but I will be free from The Cube invisible clutches again... I swear I will!!

Or maybe Entropy is just showing me something... Something that I already know (?), but I have not seen yet...

Os Mil Metros

Finalmente, pela primeira vez, eu consegui nadar 1000m durante a aula de natação!! Fiquei até feliz hoje por causa disso!! \m/,

Tudo porque eu resolvi acompanhar, a menina que estava nadando na raia ao lado da minha. Eu comecei a nadar antes dela, e estava uns 50m na dianteira, e a menina chegou. Começou a nadar, foi nadando, e me alcançando. Quando eu estava nos 500m ela já estava nos mesmos 500m. Consegui por um tempo me manter no mesmo ritmo que ela, mas ela não se cansava, e acabou me passando! Por fim, ela nadou os mesmos 1000m que eu, mas quando ela terminou, eu estava a uma raia de distância. Eu não me importei nenhum pouco, e fiquei bem feliz de ter conseguido os 1000m!! No final, eu fiquei tão empolgado, que ao invés de fazer os últimos 25m na tranquilidade, eu usei minhas últimas forças, nadando "crawl" o mais rápido possível. Não preciso nem dizer, que sai da piscina com o coração quase saindo pela boca, e demorou algum tempo pra eu recuperar o fôlego.

Foi ótimo, e vou tentar acompanhar outras pessoas mais vezes, pra superar meus limites. E quem sabe um dia, eu não acabo deixando essa mesma menina pra trás, respirando espuma. :P

Só pra constar, na minha 1a. aula de natação este ano, eu nadei 500m, e parei por causa de uma mega cãimbra... Finalmente, consegui dobrar a distância! =D

Lost - 4a. Temporada

Ontem, eu finalmente assisti ao último episódio da 4a. temporada de Lost. A 4a. temporada, até agora, foi a melhor temporada sem dúvida alguma, a mais intrigante de todas. E o episódio final, não deixou nada a desejar. O final poderia muito bem ser o final da série, mas não foi, e abriu uma nova trama... Só o futuro dirá sobre as próximas temporadas.

E sobre o final da 4a. temporada eu só tenho um comentário a fazer: "PUTAQUEPARIU, BÁTIMA!!!"

E após assistir, eu fiquei mais de 1h pensando no final, que apesar de ter explicado algumas coisas, me deixou, ao mesmo tempo, totalmente estupecfato!! Durante todo esse tempo, repeti o comentário acima a cada 10 segundos, seguida várias vezes de outras interjeições de espanto, e palavras de baixo calão! Não de maneira revoltosa, mas sim como maneira de expressar a minha satisfação, e ao mesmo tempo meu assombro...

Agora é hora de esperar ansioso alguns bons meses até o início da próxima temporada...

Broken Quasi-Stability

...and when you think your insanity has reached an optimal quasi-stable level, one to which you are fully satisfied, then, suddenly it happens, and your mind starts to play new tricks on you, and madness starts to grow and reshape itself again...

I do not like stagnation, but every time it breaks, I have to learn how to be more and more misleading...

The normal world, which was once the only reality known, is just a faint shadow of the Truth. Before the eyes, just a semi-transparent veil over the unfathomable... Something so alien the mind can barely grasp an ephemeral piece of understanding without shatter... The ephemeral turns to be so deep that seems to be Infinity, and maybe It is that... What remains? Nothing else, but_

I don't think I can pass as a normal person anymore, but who cares? My Peace lies where I am, never in the same place... A wanderer... A daylight dreamer... Dreams or Nightmares? Irrelevant. The only known path, should be cautiously taken, a misstep and obliteration follows.

What I have seen today? Just the usual Purple Tentacle trying to takeover the world.

Instead of writing this, I should have been reading a paper to prepare a seminar... Towards Understanding Massive Star Formation... The usual.

...and oblivious to the world around it, it plots, hidden, unknown, waiting for the time to reveal another ephemeral piece of the Ever-Changing Puzzle, and destroy another quasi-stable view of an already deranged, disarrayed and unstable Reality...

Spread Firefox

Portal

This weekend instead of preparing a seminar I have to present next friday, among other things I played a game called Portal. Portal is a game that came inside a bundle of games called The Orange Box. It is a first-person puzzle game, and it is an amazing game. One of the best, and terrifically funny games I ever played.

In this game you play a female character, who is a test subject inside a science facility runned by a AI called GlaDOS. During the game, the character learns how to use portals to cross various test chambers, and while this happens, GlaDOS makes various comments trying to "help" you with each chamber. The first test chambers are very straightforward, and exist only to teach you the basics of using portals. But they get trickier and trickier until the end of the game. To generate portals you have a Aperture Science Hand-held Portal Device, that can create blue portals or orange portals. Blue and orange portals represent each side of a portal, so if you enter the blue side, you will leave in the orange side, and by placing both portals throughout the chamber you can solve the puzzles. You also have to use some basic laws of physics like momentum conservation to solve some of the puzzles. It took me around 5 or 6 hours to finish the game. It was a very fast game, but an excellent one, and hilarious to say the least.

Here is the game trailer to give you an idea about the game.

The Aperture Science Computer, also known as GlaDOS, is one of the best and funniest characters in any game in my humble opinion, and the Weighted Companion Cube will never be forgotten! If you plan to play this game in the near future and do not like spoilers, DO NOT watch the next video. It is the ending song and might spoil your game play. If you do not care, just watch it, and have fun listening to that. It is fun, but will be funnier if you have already played the game. The song is called Still Alive.