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

Natural selection and prime numbers

The adults [of periodical cicadas] live for a few weeks, but the 'juvenile' stage (technically 'nymphs' rather than larvae) lasts for 13 years (in some varieties) or 17 years (in other varieties). The adults emerge at almost exactly the same moment, having spent 13 (or 17) years cloistered underground. Cicada plagues, which occur in any given area exactly 13 (or 17) years apart, are spectacular eruptions that have led to their incorrectly being called 'locusts' in vernacular American speech. The varieties are known, respectively, as 13-year cicadas and 17-year cicadas.
Now here is the really remarkable fact. It turns out that there is not just one 13-year cicada species and one 17-year species. Rather, there are three species, and each one of the three has both a 17-year and a 13-year variety or race. The division into a 13-year race and a 17-year race has been arrived at independently, n fewer that three times. It looks as though the intermediate periods of 14, 15 and 16 years have been shunned convergently, no fewer than three times. Why? We don't know. The only suggestion anyone has come up with is that what is special about 13 and 17, as opposed to 14, 15 and 16, is that they are prime numbers. A prime number is a number that is not exactly divisible by any other number. The idea is that a race of animals that regularly erupts in plagues gains the benefit of alternately 'swapping' and starving its enemies, predators o parasites. And if these plagues are carefully timed to occur a prime number of years apart, it makes that much more difficult for the enemies to synchronize they own life cycles. If the cicadas erupted every 14 years, for instance, they could be exploited by a parasite species with a 7-year life cycle. This is a bizarre idea, but no more bizarre than the phenomenon itself. 

Richard Dawkins - The Blind Watchmaker

The eye's complexity

The light-sensitive cells ('photocells') are not the first thing the light hits, but they are buried inside and facing away from the light [...]. The first thing the light hits is, in fact, the layer of ganglion cells which constitute the 'electronic interface' between the photocells and the brain. Actually the ganglion cells are responsible for preprocessing the information in sophisticated ways before relaying on it to the brain and in some ways the word 'interface' doesn't do justice to this. 'Satellite computer' might be a fairer name. Wires from the ganglion cells run along the surface of the retina to the 'blind spot', where they dive through the retina to form the main trunk cable to the brain, the optic nerve. There are about three million ganglion cells in the 'electronic interface', gathering data from about 125 million photocells. [...] As you look at the fine architecture of the photocell, keep in mind the fact that all that complexity is repeated 125 million times in each retina. And comparable complexity is repeated trillions of times elsewhere in the body as a whole. The figure of 125 million photocells is about 5,000 times the number of separately resolvable points in a good-quality magazine photograph. The folded membranes on the right of the illustrated photocell are the actual light-gathering structures. Their layered form increases the photocell's efficiency in capturing photons, the fundamental particles of which light is made. If a photon is not caught by the first membrane, it may be caught by the second, and so on. As a result of this, some eyes are capable of detecting a single photon. The fastest and most sensitive film emulsions available to photographers need about 25 times as many photons in order to detect a point of light.

Richard Dawkins - The Blind Watchmaker

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

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.