Not-so-random post about randomness

One of the most common misconception about randomness is that it is often confused with uniformity.
Could you tell which is the most random distribution of dots between the two below?

Which is random? (click to enlarge)

The most common answer would be the one on the right, which is wrong. In fact, the pattern on the right is generated by applying a small wobble (or uncertainty) on an uniform distribution. The pattern on the left, instead, has been generated using a pseudorandom [1] number generator in BASH (details in this blog post). Randomness allows for "clumps" to form and it's because of those clumps that the unpredictable behaviour of randomness comes from (unless, of course, you know the "shape" of the random distribution a priori). This appears more clearly whenever we look at the distributions shown above in 1D rather than 2D:

A random and an uniform distribution (click to enlarge)

It is clear that in the case of a uniform distribution, we have a greater level of predictability. Imagine you have a series of events which follows the uniform distribution. You are filling the histograms with events one by one by reaching 5000 events which recreate the distribution above. Whenever you approach higher numbers of events filled if there is a lack of events in one region of the histogram, there will be a higher chance for the next even to fall in that region.

You can picture in practice a 2D uniform distribution by imagining pouring a layer of marbles in a box, one by one. At the beginning their position will look random, because they can move around and take any possible position, but the fuller it gets the less available spaces there are and soon it will be easy to predict which are the only available spots for the next marble to go in.

The key thing is that whenever a position is occupied, it cannot be occupied again. This allows for a level of predictability, and this is not true of random distributions. Randomness is not predictable, its profile is unknown by definition, and it allows for the same position to be occupied again. This caused by the assumption that each random event is independent from the previous (Poisson process). Maybe this is also the reason why we believe uniform distributions to be "random". We are more familiar with those in practice and random events are either mostly abstract or harder to visualize.

This explains tendency of people to estimate randomness wrongly. This happens every time during lotteries. If a number has not come up for a long time, we feel that it is due soon. This is because we imagine random events as uniform. In fact, the probability of picking any number in a lottery is the same for every extraction, making all number equally probable to be picked, and not anyone more probable, because every extraction is independent from the previous.

An equivalent example is found in coin flipping. We feel that repeated head or tail events in a sequence of coin flips is a rare event. In fact, the chance of obtaining heads or tails is still 50% even after any number of heads have come up already. For example, events of the kind: THHTHTTHTTH and TTTTTHHHHH are equally as likely.

I created a computer-generated set of tosses to work out the frequencies of occurrences of repeated heads or tails (details on how this is done are in here). These are the results for 100000 occurrences of 15 tosses each:

 3 repetitions:  93894/100000
 4 repetitions:  64634/100000
 5 repetitions:  34667/100000
 6 repetitions:  16723/100000
 7 repetitions:    7789/100000
 8 repetitions:    3487/100000
 9 repetitions:    1584/100000
10 repetitions:     719/100000
11 repetitions:     332/100000
12 repetitions:     125/100000
13 repetitions:       53/100000
14 repetitions:       18/100000
15 repetitions:         7/100000

15 repetitions would mean having a full set of heads or tails, which seems impossible, but it happens 0.006% of the times. In fact, over 100000 occurrences, it happened 7 times. Close enough.

The data shows that three repetitions is an event which happens almost all the times, with four repetitions more than half of the times. Up to 6 repetitions, in fact, is not that much of an uncommon event. Almost half of the sequence! I am sure it would be hard to define "random" - in the common sense - anything which has more than 4 repetitions, although this simple test shows that it's almost the norm.

Another great example of how bad we are at understanding randomness is given by this small application at Nick Berry's DataGenetics. It will distinguish a randomly generated sequences of tosses (from a real coin) from the ones you made up yourself. It is not infallible, as it is based on the Pearson Chi-squared test (so it cannot always predict which is which) and after some trials it is easy to trick it to make it believe your sequence is random. Yet, I am sure it will give you a better understanding of randomness!



[1] I have used the word pseudorandom because every computer-generated programs simulates randomness. True randomness can only be found in some not completely understood natural phenomena. Being a simulation, there are different "qualities" of generated random numbers. I am not sure about the one used in BASH, but it is usually good to stick with a higher quality random number generator for more serious business (e.g. GSL)

Connection between derivative and integral

I remember that most of my struggle in understanding geometrical properties of calculus in first year undergrad classes was spent in working out why the integral is the inverse operation of derivative.

There are many mathematical proofs of this, which make perfect sense, but their connection is counter-intuitive as they perform seemingly different operations on curves. The derivative finds the slope at any point and the integral sums infinitesimal slabs of area under the curve. All derivatives can be solved analytically, while that is not true for integrals. Integration depends to an additive constant, while derivatives do not. Dissimilarities surely are numerous.

I have recently found this paper I wrote during my undergraduates in the quest to understand the geometrical origin of the connection between. Hope it is of any help to you, if you are having trouble in this like I had. I remember it made much more sense when I - very unrigorously - put it in this simple way:

P.S. for "Derivate" I mean "Derivative"

5 Passwords you should never pick

I wanted to write a post about which passwords are best and how to find a strategy to pick up a good password.
Then I realized that it would be pointless, as at the same moment you tell a strategy to form a good password, it becomes an information manual for crackers and might be implemented in bruteforce methods.

What I will tell you is what are the 5 passwords you should NEVER pick.

1. password, 123456, qwerty and hunter2.

The first two are between the most used passwords of all time. There have been many passwords leaks and the Yahoo leak which was storing unencrypted passwords and usernames (foolish, I know) made possible interesting statistics: on 450,000 passwords leaked, an astonishing 0.38% was 123456 and 0.18% was password. Figure why those are the first passwords a cracker would check.

2. Vocabulary words.

Bruteforcers have already implemented methods to quickly spot those words. Even a random, only-letter 3 characters word would be safer than a vocabulary word.

3. Passwords without numbers.

Using numbers increases the possible characters used from 26 to 36, which becomes hugely significant if combined with a long password.

4. Passwords without capitals.

Using capitals doubles the possible combinations of characters, so from 26 possible permutation we would have 56, which combined with numbers would give 66. Symbols might be used as well to give extra security for smaller words, but many websites do not accept symbols in passwords.

5. L33t speak.

Crackers already know leet speak (even before normal users). They are already used to bruteforce passwords. If you don't know what it is, it is a technique to exchange letters with numbers which look like letters:

O -> 0
I -> 1
Z -> 2
E -> 3
A -> 4
S -> 5
G -> 6
T -> 7
B -> 8

This methods bypasses the vocabulary word check and potentially makes a good encryption, but it has become too popular.

This is the reason for which it is not good to tell encryption methods to form passwords. They will be used in the future generations of bruteforce software. It is much safer to create your own encryption.


Still, I can tell you a common good method which will not spoil much to crackers:

use mnemonics!

Transforming a sentence only known to you into letters and numbers will be as good as a totally random sequence of characters and numbers. For example: 

I hate to wake up at 8 o'clock every Monday

will become:

Ihtwua8o'ceM

which will give ~79 bits of entropy, which is safe enough. It might seem hard to memorize but it's very easy to retrieve if you forget it and as safe as it can get. It would be one of 5.4036 x 10^23 possibilities and would take 1.7135 x 10^13 Years to discover with 1000 checks per second.

Even if this is an excellent method enough (the only problem occurs if someone manages to guess your initial sentence, which completely destroys the safety of this method, but if you did not pick up something common as the first lines of a popular song or poem, it will be safe enough) there are many other ways to create passwords which are easy to remember and require one (or more) encryption methods as the one used above. I will let you have fun with finding your own method.

But why using encryption?

It is a good method to have easy-to-remember but difficult-to-guess passwords. Of course the encryption method must be only known to you and should be memorable enough.

Another good suggestion would be not to use the same passwords for many websites. This is because some websites might not care to store passwords safely (even Yahoo, as we have seen before) and a leak will give your ultra-safe and encrypted password away, which you also accidentally use for your internet banking. Surveys say that around 60% of people use the same password for every service.

There are, of course, also methods to encrypt a memorable password for different websites and then have a set of different passwords with only one encryption method to remember. I will leave you the fun to find a good one.

Now, quickly go to change your password!

The Past and the Future of Computing

It is curious how deeply computers are entering into our life.

Think of only 60 years ago and computers were very young and as big as a room. Most of the people did not own one and did not even know what was that beeping and flashing "devil's machinery".
The high potential of computers was understood soon and they grew big (not in size!) very fast to reach the consumer market in the 80s. They were still very hard to use and the graphical interface was not so graphical at all, as input and output was still mainly text.
For a decade, computers were still in a niche market of electronic lovers and programmers, and they slowly started to enter into families only in the 90s, where one computer was enough and hardly used as well.
The birth of internet was another milestone, which potential only came out later, when bandwidth started getting larger and could be used as a better method of communication than land-line phone.

Today we have smartphones. You can bring them in your pockets, they have quad cores inside and are far more powerful than thousands of old personal computers.
They are incredibly popular and, most importantly, cool.
We use them to perform loads of small tasks and we are getting always more dependent on them. They are our map, our calendar, our camera, our newspaper, our encyclopedia and, mainly, our connection to the world. We can keep in touch with a friend almost instantly, if we wanted to.

As our dependence on technology is increasing, many people wonder if this is a good thing. People are scared that technology is making us dumber, because we let them do tasks, that otherwise we would have to do ourselves, and because we know that we have a source of knowledge readily at our hand. This would let us give up on thinking about the resolution of a problem, as it could be easily looked up over the internet.

Should we give up on technology, then? I do not think that is the right approach to face this problem.
I think the problem lies in how companies are presenting technology to us, and making it addictive, for profit. What are smartphones mostly used for? Sadly, Facebook and Angry Birds. This is a bit of a downer if you think that mankind went to the Moon with computers thousands of times less powerful than our smartphone.
Unfortunately companies are making profit over games on smartphones and I think it is a big waste, as time could be well spent to improve other aspects or make "smarter" programs, which would stimulate better our brain in a less flashy and noisy way.

Also, they should teach us to use it responsibly. Technology has a great potential for doing the most amazing things, if directed in a good direction, and this is a good enough reason to not let it stop from galloping.

This reminds me of the same question we faced with calculators. Using them will not let us practice on simple math which stimulates the brain. Are they a good tool, then? Surely they are, and thanks to them we can do a much better job of calculating, in an incredibly quicker way, but the problems arise when they are getting abused. They should not be used for calculations that can be easily done mentally and, most importantly, they should not let be used to children, who need to learn fundamental mathematics.

At the same time, calculators, and computers, opened up a whole new branch, which otherwise would have not existed: programming, which stimulates logic.
Despite popular belief, technology is not a brain-killer. It can stimulate logic, design and problem-solving skills in ways that were never found before. What kills the brain is the way we use technology, how do producers present it to us.

Computers can now do a number of tasks that we could have never imagined ten years ago. We are way closer (and in many aspects, even over) to the robots age we imagined in the past. Computers can recognize human speech and work out an answer. They can crawl the web to search for information and memorize things in a much better way than humans. Many computers already are unrecognizable from humans when chatting to some testers.

But what about the future?

What scares me most is the potentiality of computers of even programming for us, in a future, which might not be that distant. Like it happened for calculators, doing basic mathematical operations for us, it might as well happen again for programming. It is already becoming easier thanks to graphical editors making it more intuitive, and its evolution could lead to completely eliminate the intervention of the user writing the code.
A smart enough computer could listen to our speech, understand the basic functions we want in a program or a script and build it for us.

This could seem like an end to programming, but if we take the comparison to calculators again, mathematics did not just die with the advent of calculators. The same way, programming could become more accessible to everyone, when the syntactic (and logical) part will be left to do to computers themselves. Creativity would surely benefit from such a change, as everyone would be able to "program", and computers will almost be like servants, being able to potentially write programs that respond to our needs.


In conclusion, I think that we live in very unique and exciting times for technological advance and the future still holds many surprises for us. Stay tuned.

A picture of us all

The thing I like the most in writing science news is that the majority of the news is good news. Think of scientific research. It can only bring progress, and most of it is directed towards discovering things we can do and not things that we cannot do.

Sometimes, though, there are bad news. Exactly a month ago the first man that stepped on the moon died. A pioneer, or better, the pioneer of lunar exploration had complications after heart surgery and left us with one of the most remarkable achievements of humans, not just on the world, but on the universal scale. This is a gift not only appreciated by people in the USA, which launched the Apollo 11 expedition, but by the entire world, and consequently everyone mourned his death.

He did not like to be in the spotlight for his biggest achievement and he dropped his career as pilot (and astronaut) after his big mission. However, he did not stop from looking at the future as he started teaching in the University of Cincinnati in the department of Aerospace Engineering.

If you want to know more about his life, there are plenty of sources, and I would suggest you to do it, as it was a very interesting one, for sure, regardless of his longest trip.
What I am going to talk about here is about one of my favorite pictures of Neil:

Buzz Aldrin on the Moon. You really want to click on this picture to enlarge it.

You might be asking yourself if I it is a typo or not. And you are right, the most visible astronaut in the picture above is Buzz Aldrin, but if you zoom on his helmet's visor, you will notice a familiar reflection:

Zoomed-in visor showing reflections

And this landscape in the reflection is what makes me love this picture.
That is the reflection of Neil Armstrong, right in the middle, taking the picture of Buzz.

It is amazing to think about the trip photons had to undertake in order to form this picture. Coming from the sun, traveling through a distance of 149980571 kilometers, at around a billion km/h, roughly taking 8 minutes, to end up hitting Armstrong's suit.

In all the possible direction they could have been reflected (or absorbed, finishing their trip), they got reflected towards Buzz Aldrin's helmet. Instead of going through the visor, into Buzz's eyes, or (more rarely) being absorbed by the visor itself, they got reflected back exactly towards Neil. In particular, they got reflected towards his camera, and having passed the lens and all the components of the camera smoothly, finally they met their fate getting absorbed by the film, which is now letting us seeing the amazing pictures of men on the Moon.

But that is not all. There are at least other two amazing facts in this picture.

The first, being the "halo" around Buzz's shadow.
If you see the picture of the reflection from the visor, you will notice that the lunar grounds look lighter around Buzz's shadow. An interesting fact, which helps explaining the phenomenon, is that the halo of light is not seen in the original picture (unzoomed) where Buzz's shadow can be seen unreflected.

That is because it is an optical illusion, commonly called opposition effect. It does not just happen on the Moon, as seen here, but the high concentration of regolith on the moon increases the strength of the effect.
The opposition effect happens when the observer (or photographer) is pointing at the opposite direction of the light source (the sun). As regolith has high retroreflective properties, the zone which opposes the sun will reflect much more light and will then be brighter.
All of this, reflected back to us thanks to Buzz's helmet.

It was not just enough having Neil's reflection and a reflected opposition effect, as the picture includes something even more astounding.

Mankind in a shot

All of us are in the pictures as well, as the visor also reflects the Earth in the sky. Highlighted in the picture above, we are all there, on the pale blue dot. I can safely say that this is the only human-made picture which includes the whole of humanity (Michael Collins is in the module, which is also reflected by the visor, on the right) and in general, a picture which includes every living organism known to us.

I need to say it again: I love this picture, and I hope you can fully understand why, now. I will conclude with a touching quote about this very photo, from Buzz Aldrin, which can surely express better than me the beauty of this shot:

"As I walked away from the Eagle Lunar Module, Neil said 'Hold it, Buzz', so I stopped and turned around, and then he took what has become known as the 'Visor' photo. I like this photo because it captures the moment of a solitary human figure against the horizon of the Moon, along with a reflection in my helmet's visor of our home away from home, the Eagle, and of Neil snapping the photo. Here we were, farther away from the rest of humanity than any two humans had ever ventured. Yet, in another sense, we became inextricably connected to the hundreds of millions watching us more than 240,000 miles away. In this one moment, the world came together in peace for all mankind."

Buzz Aldrin - Apollo, Through the Eyes of the Astronauts

The curse of Productivity

It's now clear to me why I eat later and later, and become nocturnal

Of Einstein's genius

This man oozes brainpower. Maybe not in this picture, though.

The real genius in Einstein's work is in the fact that he discovered a fundamental property of the universe from only a few assumptions.
He set the speed of light as constant in different frames of reference and developed the mathematics of Lorentz transforms further to come up with one of the most beautiful theories in physics.

While usually in physics direct evidence and data is studied to deduce a phenomenon, he inductively derived his theory having no evidence at all. He made his own axioms and derived everything again from them. And the best part is that it worked, at least in theory. Despite a few physicist immediately recognized his genius, his theories were not completely recognized by the scientific community at the beginning, especially when the paper for his theory of Special Relativity presented no references. Einstein's reasoning was outside the lines, but sharp, nonetheless, and it proved no mistakes.

Evidences for his special theory of relativity started to come up only much later, around 1932, with the Kennedy-Thorndike experiment testing the dependence of the speed of light on the velocity of the measuring device.
Direct evidences of the general theory of relativity are still feeble, even though it is now a firmly accepted theory.

No, it is not photoshopped

The difficulty in testing this theory (linked to the difficulty to discover it) lies in the fact that we need astronomically strong gravitational fields in order to detect the space-time fabric and its tiny ripples: the gravitational waves. I did not use the word astronomical by chance, as the best empirical evidences come from deep space. Usually quasars (active galactic nuclei), which are very far, but bright x-ray sources, are used as indirect test for the theory of general relativity, as their ginormous gravitational field can bend light. Pictures of galaxies behind quasars could be worked out from their light being bent right into our eyes (or telescopes), forming "rings" of light around the quasars.

A more direct evidence of general relativity would be detecting its evident result: gravitational waves. Unfortunately, these waves are far less energetic than anything we can imagine, making it easy to let them disappear into the much higher and chaotic background of radiation. Experiments exist trying to achieve the impossible through interferometers, but a much more concrete evidence, at least for now, is presented by binary pulsars.

Not the most scientifically
accurate gif I could find,
but surely the coolest.

Binary pulsars move into space and their gravitational field emits gravitational waves, which is a leak of energy from the system. Everything, in fact, emits gravitational waves, but for small (less heavy, to be precise) objects their emission is undetectable. As energy is leaking from the binary system of pulsars, their period of revolution will get slightly slower than usual and with enough time passed, this accumulated time will get significantly big to be measured. This is not a direct evidence, as the energetic leak that slows the period down is not necessary given by gravitational waves, but that is the only phenomenon we know that could cause it, for now, and Einstein's model works really well when applied to these bodies, so it is still evidence, even if indirect.

When I started writing this post, it was meant to be an introduction to one big recent news in science in one of the FSND series. I was so excited writing about how marvelous Einstein's theories are that it got too long and I decided that it would easily be a blog post on its own.

The news regards the recent first visible-light evidence of gravitational waves from a pair of dwarf stars, and I'll now leave you in a pointless cliff-hanger (pointless as the news is already out elsewhere) as I will talk about it in the next Fortnightly Science News Digest on 15 September.

The sad truth with vegetables

Bacon is out of scale

However easy to cook they are, there will always be a meat-alternative which is tastier.

Why scientists will never be popular

There's things that will never change, and one of them is here right in front of our eyes.

I know the news is a bit old, but I've bumped on this link which I saved in my favourites a while ago:

http://www.google.com/trends/?q=scarlett+johansson&ctab=0&geo=all&date=ytd&sort=0

I am curious by nature and I love interpreting data, then one of my favourite services of Google is of course, Google Trends. But this search shows something obvious to any reader. The amount of queries for "scarlett johansson" was ridiculously increased when there was the news that her nude pictures taken from her phone by some hacker and published over the internet. Then, it went back to almost normal after a few days (when people obtained the pictures or could not manage to get them).

I've found this particular search query so incredibly relevant to easily explain two problems:

-   Science will never be popular between the general public, as it is clear that people are interested in something else: porn. And all that comes with it, from nude pictures to light gossip between celebrities. If you ask people to name who won the Academy Awards in 2009 I am sure you'll get more right answers than asking who won the Chemistry Nobel prize in 2009. I can't even name anyone who won the ducking Nobel prize that year, figure how well would do someone not involved in science.

-   Never consider anything on your happily connected-to-the-internet smartphone as safe. If people wanted it, they could easily get something you consider private and share it. And don't think that legal actions will make you justice, as Ms. Joahnsson desperately tried. Anything which is (or has been) on the internet once, is public forever.
Oh, and if you use facebook on your mobile, everything in it is property of facebook, anyway.

How to circumvent the Pirate Bay censorship

The annoying screen many people are
experiencing when trying to access
the domain piratebay.org.

I wrote a post about Pirate Bay being censored in Italy a few years ago. I was disgusted at the time and I provided some methods to get around the block.

When I've heard the same news here, not so long ago, I could not believe it. How ignorant and naive must a government be to think that blocking a torrent website should stop piracy?

I will not go into describing all of the copyright problems and morality of using Pirate Bay, as the debate is big and still going on, but I must comment on how stupid is the choice of blocking it.

First of all, I am against any form of censorship and this alone puts me against that choice.
Most importantly, though, Pirate Bay is only one of the million torrent websites. Stopping one is like vaccinating one person against malaria and thinking of having eradicated the bacteria forever.
On top of that, people will always find way around to such puny barriers, and I will list a few down:

1. This is the most hilarious. There is already a new domain with Pirate Bay on it for UK people:
   
   tpb.pirateparty.org.uk
   
   This might be brought down as well, but no worries.
   
2. Use a web-proxy, such as Anonymouse. This is the "anonimized" link to Pirate Bay:
   
   http://anonymouse.org/cgi-bin/anon-www.cgi/http://thepiratebay.se/
   
   It's as easy as that and safe on the long-term.
3. Use a proxy (there are many) or VPN services as TOR or Hotspot Shield. Which might be even useful to bypass other country-dependent blocks. 

If you want to stop piracy, you need to think of other smarter and indirect ways. We are in 2012 and it is still much easier to download a pirated version of a movie or a game rather than buying it. This means that a service provided by pirates, for free, is better than any one provided by big money-eater production companies, which only good job is putting irrelevant locks and pointless anti-piracy videos on their products.

Take as an example a person wanting to see a movie already out on DVD:

Legal way:
- Find movie on Amazon.
- Look for cheapest price and buy.
- Wait a few days (or more) for the DVD to be shipped and arrive.
- Put on DVD and watch 10 minutes of trailers even if you didn't ask for it (and can't be skipped).
- Watch the same anti-piracy video for the billionth time, even if you know it by heart, and even if, to watch it, you must've bought your beloved DVD in the most legal way possible.
- Finally watch the movie, if you still have some time left.


Illegal way:
- Find movie on any torrent website.
- Look for positive reviews and download torrent.
- Wait 20 minutes.
- Enjoy movie.


Honestly, I would pay for the illegal way.
A big applause to the incompetent, narrow-minded governments, production companies and anti-piracy associations around the world.

Boris bikes

It has been a while since Boris Johnson, current Major of London, introduced the bicycle sharing scheme and I had a chance to use them as well, now.

There are really many advantages in using "Boris bikes" as:

-   It's cheap and easy to rent. You can purchase a day or week access fee and then you are off. The first 30 minutes of renting is free, which is reasonable for any short distance in Central London, more convenient than taking a bus, for which a return ticket would cost almost three times the price of renting a cycle.

-   Cycling is good for your health, etc. etc.

-   You don't need to worry about where to tie down your own cycle, and then no need to worry about cycle thieves (which I'm still thanking for easing my decision towards buying a new wheel and a new saddle).

The downsides, though, can unfortunately be pretty terrible:

-   You can't leave your cycle everywhere and you need to find a docking station and then plan your route in advance, unless you have a lot of confidence in your luck (sometimes they are hidden from the main roads).

-   It is amazing how difficult is to find a cycle at certain times. As many people are using them, the locations in the centre are filled up in the morning and emptied at night, while the opposite happens for locations outside the centre. This is understandable as people go back home at night and go to work in the morning. Unfortunately, I need exactly the opposite (usually: going back home drunk at night and leaving home when I wake up in the afternoon) and it is extremely frustrating and time-wasting looking for the nearest docking station with cycles in it, and it also becomes a problem when you have to leave your cycle and the docking station is full.

I think that I'll continue to use the service, though. Not that I don't mind walking for 20 minutes looking for a non-empty docking station, but maybe the desire to find it full when I need it will regulate my already messed-up body clock.

My (second) take on Facebook

"Once you have shared any information online, even with a restricted audience, you need to consider that as being in the public domain. Although you may be able to control which members of your social circle can see that information, you can't control what they do with it."

-Rik Ferguson

What would have been the best way to celebrate the re-opening of this blog?
Looking at the motivations that moved me to open it, of course!

I've looked at the first post on this blog, back in 2009 and I've been repeatedly pierced by its sharpness. I had some good hate against Facebook, such that I even put the label "hate" to the post and deleted my account. Good move, I'd say now, but I think I rejoined Facebook after a week, if I remember well.

That was only 3 years ago and the world has changed much, and I have as well with it. And so did Facebook. Let's see some of its milestones:

- Facebook is approaching 1 billion users. Humans are bad in judging dimensions, so I'll try to let it picture to you in easier words: one every seven persons in the World (including poor countries) is on Facebook. That is more than three times the population of US.

- A movie has been made about Facebook. If you would have told someone in the nineties that a movie about a website would be shot, they would just laugh at you and wrote about your outrageous idea on their geocities.

- Facebook has decided to go through its initial public offering, and the company could value as much as $105 billion. It hopes to raise $10 billion when it begins to sell its shares and that would dwarf Google's. (Update: it did already!)

- Timeline has been introduced and the general look and workings of Facebook has changed.

In a few words, Facebook has now got power. This is something that did not happen before. We all know what happened to social networking websites as MySpace or Live Messenger. They have been very popular and they are now a cemetery of the past. Will this happen to Facebook as well? I do not think so. It has established well on the internet (and now even the market) and it will be hard to see its end soon thanks to its slick CEO and the huge popularity it has reached. In social networking websites people look for places where they can find most of the friends they know in real life and that is already a huge disadvantage for any other website that wants to take off.

What scares me most is when people say: "Internet is Facebook". If that would be the case in the future, I would officially declare the internet dead. I might be a bit too nostalgic, but the golden period of internet was right at the beginning of Web 2.0. For those who think Internet is Facebook, I can safely say that they have never known the Internet. Nowadays, though, it is difficult to stay away from Facebook as it is the most convenient and free (for now, even if I think it will always be) way to connect with friends. It has cunning traps, though, so if we can't avoid it, what to do?


Use your brain before sharing. This is my philosophy. People should really understand that everything that goes on the internet with their name, can be easily considered public and non-removable from anyone's eyes, for an unlimited period of time. Writing something on the internet is more effective than throwing thousands of flyers off a plane, and that is not an exception on Facebook. Even if something is shared only with a certain group of people, don't take it granted it's safe. In the case of Facebook it's even worse, since everything you share is now in possession of Facebook. The disgusting side of the coin is that it uses it to track your interests so that it shows the perfect advert to you and makes money from it. If you are even fine with that, do not think the information is still safe, as Facebook has changed many times its privacy regulations at its will. The ironic part, though, is that last year it even made public some private photos of its CEO Mark Zuckerberg. So, if even the founder of Facebook is not safe from it, why would you think you are?

Last month Facebook introduced the Timeline. I've seen thousands of people lamenting. Unfortunately they were lamenting for the change of interface. I hope people did also see what Facebook was trying to do. They are trying to get everything from the user's life, trying to reconstruct the events even before we joined facebook. Smart marketing move as Facebook is trying to convince us to give all of our privacy information, for free, with the clever excuse of "improving our social experience". But the scary part comes from the big part of the young population on facebook, who shares irresponsibly every moment of their life. Facebook has become the new diary, but if in the past diaries had locks, now they are more public than an advert board, and held by an external company.

Facebook is not that evil overall (nothing can get as evil as banks) but it is now entering people life more than it should, especially in youngsters. I think a new branch of education should be formed: internet education. This will surely go against interests of Facebook and many other websites, but it is necessary from protecting ourselves from the chaotic dungeon that has now become the Internet.
 

Progresso

La mente è uno degli strumenti più sofisticati di cui disponiamo, ma non lo prendiamo in considerazione e, con un atteggiamento tipico dei nostri tempi "moderni", facciamo fare alla chimica quel che invece potremmo, almeno in parte, far fare alla mente. La chimica è sempre di più la soluzione di tutto. Si è depressi, si è stanchi, si è sterili, si è magri, si è grassi? C'è sempre una pillola inventata - e messa appunto in vendita - per risolvere il problema. Un bambino è agitato? Non serve andare a capire perché. Il Prozac lo calma sia che all'origine della sua irrequietezza ci siano i genitori divorziati che lo trattano come un pacco postale continuamente rimandato al mittente, sia che la scuola cerchi di far di lui quel che lui non è. Il Prozac viene oggigiorno prodotto in confezioni per l'infanzia e negli Stati Uniti decine di migliaia di bambini dipendono ormai dalla somministrazione quotidiana di questo tranquillante per poter funzionare "normalmente".
Lo stesso avviene col dolore. La sconfitta del dolore è considerata una delle grandi vittorie dell'uomo moderno. Eppure anche questa vittoria non è necessariamente tutta positiva. Innanzitutto il dolore ha una sua importante funzione naturale: quella di allarme. Il dolore segnala che qualcosa non va e in certe situazioni il non avere dolore può essere ancor più penoso dell'averlo. Un orribile aspetto della lebbra è che distrugge i nervi capillari dell'ammalato e quello, non sentendo più alcun dolore, non si accorge quando le sue dita sbattono e si spezzano contro qualcosa o ancora peggio, come avveniva nei lebbrosari dei paesi più poveri, quando le dita gli venivano mangiate dai topi, di notte, mentre dormiva.
E poi: eliminando la sofferenza al suo primo insorgere, l'uomo moderno si nega la possibilità di prendere coscienza del dolore e della straordinaria bellezza del suo contrario: il non-dolore. Perché in tutte le grandi tradizioni religiose il dolore è visto come una cosa naturale, come una parte della vita? C'è forse nel dolore un qualche significato che ci sfugge? che abbiamo dimenticato? Se anche ci fosse, non vogliamo saperne. Siamo condizionati a pensare che il bene deve eliminare il male, che nel mondo deve regnare il positivo, e che l'esistenza non è l'armonia degli opposti.
In questa visione non c'è posto né per la morte, né tanto meno per il dolore. La morte la neghiamo non pensandoci, togliendola dalla nostra quotidianità, relegandola, anche fisicamente, là dove è meno visibile. Col dolore abbiamo fatto anche di meglio: lo abbiamo sconfitto. Abbiamo trovato rimedi per ogni male e abbiamo eliminato dall'esperienza umana anche il più naturale, il più antico dei dolori: quello del parto, sul quale da che mondo è mondo si è fondato l'orgoglio della maternità e l'unicità di quel rapporto forse saldato proprio dalla sofferenza. Ma questa è la nostra civiltà. Ci abituiamo sempre più a risolvere con mezzi esterni i nostri problemi e con ciò perdiamo sempre più i nostri poteri naturali. Ricorriamo alla memoria del computer e perdiamo la nostra. Ingurgitiamo sempre più medicine e con ciò riduciamo la capacità del corpo a produrre le sue.

Tiziano Terzani - Un altro giro di giostra (One More Ride on the Merry-go-round, 2004)

Shower

Having a shower is a relaxing moment of the day. Some people sing, others just imagine, but whatever you do, the mind is surely free to think about anything and fly (freely) over a lot of disparate topics, often non-related between each other.

I don't know how, but when I was showering, today, I happened to think about an awesome quotation from Tanenbaum (besides, a Physics doctorate and one of the man that "triggered" Linus Torvalds to write his famous UNIX operative system):

Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway.

What's so interesting about this expression?
Even if it has been used in 1981 on a different context, its irony could still be up to date, since Sneakernet is a still very common practice and couldn't (still) be easily substituted by virtual data transfers (p2p, ftp...).
I've heard new versions of this quote with "hard disks" instead of "tapes", indeed.

The next step on my train of thoughts - during the shampoo - was the realization that I can calculate the actual bandwidth, a kind of average in kb/s, of a car bringing an hard disk.
How? Dimension analysis, obviously!

The dimensions of velocity are: [Length] / [Time] , so to obtain the dimensions of bandwidth [Data] / [Time] it is just necessary to multiply by the data carried and divide by the distance covered.
The result is a formula for the bandwidth depending on velocity of the car v, the distance travelled l, and the data carried d.
${b = \frac{v \cdot d}{l}}$
(if you see incomprehensible signs enveloped by dollar signs, Latex script is not working properly)

If we pick a car travelling a distance of 1000 km at 130 km/h carrying a Terabyte:

${b = \frac{130}{1000}\,TB/h \sim 133\,GB/h \sim 38\,MB/s}$

Quite satisfying.

This is useful (maybe not) but it's not finished.
If you can calculate the bandwidth of a bunch of data travelling in a car, why don't we calculate the velocity of a bunch of data travelling through the wires knowing the bandwidth?
In this case data should be considered like a solid packet, and d is the distance between the host and the server. After some easy math:

${v = \frac{b \cdot l}{d}}$

Wow, you're still reading... crazy. Anyway, that's not all, not yet:
if you pick a value for d (data) smaller than b (bandwidth), it almost doesn't make any sense and the result could be a velocity higher than the speed of light, indeed.
Since the speed of light is an upper limit:

${v = \frac{b \cdot l}{d} \leq c}$

and so:

${b \leq \frac{d \cdot c}{l}}$

that is the absolute upper limit in bandwidth.
If we put numbers, the result still doesn't make any sense.
For example, since the net works in small packets, for a 64 byte packet from a server 7000 km far, the upper limit speed is about 2.7 kb/s.
This result could be useful if we make a small modification to find the time required to transfer that packet at c (dimension analysis again):

${t = \frac{d}{b} = \frac{64\,byte}{2.7\,kb/s} \sim 0.02\,s}$

That is 20 milliseconds: the lowest time physically possible needed to receive something from a distance of 7000 km.
Real timings are about 150ms for good servers, to send and receive, so about 75ms one way, that is in the limits...

Now I ended the shower and then also this small trip around physics and the internet. The result of this brainstorming thoughts? I really don't know, but I still like it.

100 points for the first who analyse relativistic effects on the packets and find how much kilobytes the file loses travelling at that speeds.

Mankind

The very beginning of Genesis tells us that God created man in order to give him dominion over fish and fowl and all creatures. Of course, Genesis was written by a man, not a horse. There is no certainty that God actually did grant man dominion over other creatures. What seems more likely, in fact, is that man invented God to sanctify the dominion that had usurped for himself over the cow and the horse. Yes, the right to kill a deer or a cow is the only thing all of mankind can agree upon, even during the bloodiest of wars.

Milan Kundera - The Unbearable Lightness of Being

Are you right or left brained?

Procrastinating on Youtube, I ended up on this video. Watch it first, following the instructions (and then come back!).

The aim of this video is spotting the rotation direction of the silhouette (clockwise or counter-clockwise). There is no right answer, because it works either way (being a silhouette), and with some effort you can switch her rotation direction.
Surprisingly the first time I saw this video, the dancer was rotating clockwise and it took me some effort to let her rotate anti-clockwise. I say surprisingly because the maker of the video claims that people seeing the silhouette rotating anti-clockwise are right brained and then imaginative, religious, impetuous, risk taking and so on. That doesn't really fit my personality, I would say, but is this test valid?


There aren't any sources about who created this test, then I decided to read some material myself about the sides of the brain and what do real neuroscientists think about the asymmetry of the brain.
Unfortunately, the result is that now I am even more confused.

What I inferred from the small research is that even scientists are not sure if someone can have a dominant part of the brain and there are a lot of contrasting opinions, being the brain one of the most difficult parts of the body to understand.

What is surely known, is that brain is not merely divided in creative side (right-side) and logic side (left-side). Both sides cooperate when someone is thinking, but one can be used more when doing some specific tasks.
Experiments have been done on people who have damages on one side of the brain or on people who have the corpus callosum surgically cut off (such as to alleviate epilepsy). The corpus callosum is the structure that links right and left side of the brain, so missing it, it is like having two separate brains.
It has been discovered that, in general, left brain hosts (for most of right-handed people) most of linguistic skills, and the ability to see details. The general view and the "emotional" side of language are host by the right brain. It is unclear if someone can have a remarkably dominant side of the brain.

However, that is not linked to how much you are creative or logical.
An individual with a certain dominant side of the brain is not necessary inclined to have innate skills in what the dominant side hosts.
We know that there are people more "emotional" and people more "analytic", but it is wrong to consider that the more emotional individual has a right dominant side of the brain and vice-versa.
If you are doing maths you are not only using your left brain and if you are doing arts you are not only using your right brain.

So the answer to "Is this test really valid?" is no.

Nonetheless, the video is cool as it represents how humans perceive shapes and link them to familiar situation. I'll explain:
we see the dancer rotating but it isn't, actually. The image shown is a 2D image, then if you see it as a plane image changing shape, all the parts of the figure are just oscillating.
Since our brain recognize the image as a human, it is seen as a 3D object, so our brain gives her a rotation that could be clockwise or anti-clockwise because the original image is not making any rotation.

The claim of associating a brain side to the interpretation of the rotation is an far-stretched and there is no evidence about it.
What is surely wrong is to presume that a "right brained" person is creative and a "left brained" person is logical.



Main source: New Scientist

Quote from an impossible quoter

Whoever ceases to be a student has never been a student.
- George Iles

I've read this in the "Quote of the day" on my iGoogle and I liked it. It's interesting, though, how it appears to be no info about the author George Iles on the internet. Where does this quote come from, then? We all know that the internet must be true (irony on). After a quick search on gugol, his name only linked to websites about quotes, so that another guy had my exact same question.