Πίστη, αποδείξεις και ψέμματα

Αναρωτιέσαι πώς είναι δυνατόν ένας ολόκληρος λαός να παρασύρεται από τα λόγια τσαρλατάνων, ανεξαρτήτως επιθέτου και πολιτικής ιδεολογίας - αριστερής, κεντρώας, δεξιάς. Πώς είναι δυνατόν τόσος κόσμος να πιστεύει παραμυθάκια του στυλ "λεφτά υπάρχουν", είτε λέχθηκε στη δεκαετία του '80 είτε το 2008, ή και αργότερα. Τι είναι αυτό που κάνει τον κόσμο να πιστεύει ευχάριστες ιστοριούλες τόσο εύκολα;

"Πίστη". Αυτή η γλοιώδης λεξούλα καταστρέφει τη χώρα εδώ και δεκαετίες, κάθε μέρα, κάθε βδομάδα, κάθε 4 χρόνια.

"Θα ανοίξω ένα μαγαζάκι, πιστεύω οτι θα τα καταφέρω".

"Με πίστη και ελπίδα, πάλι θα ξεπεράσουμε τις δυσκολίες, πάλι θα σταθούμε όρθιοι".

"Εχει ο θεός και για μας, έχε πίστη, προσευχήσου".

"Αυτός ο πολιτικός/πρόεδρος/δήμαρχος πιστεύω να μας βγάλει από το αδιέξοδο".

Εμετός και αηδία. Ποιος είναι διατεθημένος να οργανώσει τη ζωή του γύρω από ιστοριούλες για μάγους και πρίγκηπες;

Εχουμε μπερδέψει την έννοια της λήψης ρίσκου στις αποφάσεις μας με τη λήψη υπνωτικών. Γιατί, αυτό ακριβώς σημαίνει αυτή η λεξούλα, "πίστη": "Πέφτω για ύπνο και όταν ξυπνήσω το πρόβλημα θα έχει φύγει ως δια μαγείας".

Νομίζω ότι ήρθε η ώρα να ξυπνήσουμε. Να συνειδητοποιήσουμε ότι τα πιο επικίνδυνα ψέματα είναι αυτά που λέμε οι ίδιοι στον εαυτό μας. Να αφήσουμε τη πίστη για λίγο, ή και μόνιμα στην άκρη και να αρχίσουμε να ζητάμε αποδείξεις. Να μην παίρνουμε τίποτα ως δεδομένο. Να σταματήσουμε να κάνουμε το σταυρό μας και να λέμε ότι όλα θα πάνε καλά. Να συνειδητοποιήσουμε ότι το διαμερισματάκι μας δεν είναι απλώς μέρος της Ελλάδας, αλλά η Ελλάδα είναι το σπίτι μας. 

Οταν προσλάμβανες καθηγητή να κάνει ιδιαίτερα στα παιδιά σου έπαιρνες αυτόν που σου έλεγε "Είμαι ο καλύτερος, πίστεψέ με!", ή μήπως το έψαχνες λίγο πρώτα; Το ίδιο να κάνεις και για το ευρύτερο σπίτι σου, την Ελλάδα. Αν δε θεωρήσεις την Ελλάδα ολόκληρη σπίτι σου, τότε κάποιος άλλος θα το κάνει. Και θα το κάνει. Και όταν το κάνει θα σου ζητήσει και το λόγο (αν όχι "διόδια") κάθε φορά που κάνεις πως βγαίνεις έξω από την πόρτα σου. Ηδη διαμαρτύρεσαι που έχει μπει "δερβένεγας" η τρόικα στα εσωτερικά της χώρας σου. Γιατί ποτέ δε σε ένοιαξε πραγματικά που βρίσκει τα λεφτά το κράτος και πληρώνει το μισθό σου. Γιατί ποτέ δε θεώρησες το πεζοδρόμιο έξω από το ίδιο σου το σπίτι ως ιδιοκτησία σου, παρά μόνο προσπάθησες να μεγιστοποιήσεις το προσωπικό σου όφελος σε βάρος των υπολοίπων.

Ήρθε όμως η ώρα να πάρεις την κατάσταση στα χέρια σου. Αγαπάς την Ελλάδα; Απόδειξη! Μόνο που αυτή τη φορά είναι για σένα τον ίδιο, όχι για την εφορία. Όχι εκείνο το γελοίο χαρτάκι κάθε φορά που αγοράζεις ψωμί, λες και είμαστε 5 χρονών παιδάκια που τα μαλώνει ο δάσκαλος όταν δε λένε την αλήθεια. Απόδειξη και επιχειρήματα από τους πολιτικούς σου. Από τους γείτονές σου που αναμασάνε ότι τους βάλουν στο στόμα. Από αυτούς που ρετουητάρουν ότι ταιριάζει στην ιδεολογία που έμαθαν παπαγαλία από το μπαμπά τους.

The Expressive Backpack That Knows What's Inside It

I've always wanted my backpack to have a display that I can use to "broadcast" messages to the people around me. I would love to do the same when I'm driving my car so I can project messages on the road behind my car. I can imagine a message saying "I'm heading to NYC".


At Jansport's hackathon at the Media Lab, we had exactly this opportunity: Design a backpack that you can slide your iPad in and have it display messages for the people behind you. My team also took this to the next level and reused the screen on the backpack to display its contents. Here's the video:

Poem about your misplaced power adapter

Your power strip is white,

find it, you might.

Count on it, I would not,

'cause you delayed asking a lot.

Now other batteries your charger charges,

while your frustration enlarges.

But "borrowing" is bad, even from a troll,

so I hope of charger you will regain control.

Puzzle time: The village emergency

Introduction

I was flying back to Boston and looking at small villages in the middle of nowhere from high above, when a puzzle idea came to mind: If people in a village decided to spread some news among them as fast as possible, how would they do it? I would like it to take as few steps as possible for the news to reach everyone, which means that I'd like to avoid having the same villager being contacted twice because that would be wasteful. A slightly more formal version follows.

The puzzle

A vilage is threatened by a fire during the night when everyone is asleep. One of the villagers happens to wake up (for whatever reason people wake up during the night) and spots the fire. She now has to make sure the village gets notified asap, since everyone else is asleep! But how? Let's assume the following:

• Every house has a phone.


• There are N houses in the village.


• The only way to notify someone is by calling them.


• Every phone call takes 1 minute.


• A house can call another house in parallel with other phone calls (of course!).


• A house can only place one phone call at a time.

What algorithm should the villagers devise to make sure that in such an emergency the whole village gets notified as fast as possible? How many minutes would that take?

Now, don't look at the solution just yet!!!

Here 's a naive solution to build upon. It is the first thing that came to mind in the airplane. Say there are 100 houses. The first house finds out, then notifies 9 houses and each of those notifies in turn 10 houses each, for a total of 100 houses. If phone calls could be placed in parallel, this would obviously only take two steps (or minutes) to notify every one. But how do we do it if only one phone call can be placed at a time?

Solution

Assign to each house a number between 0 to N-1 (thanks Scott!).
Let's assume that house 0 spots the fire first.
Each house i (0<=i<N) will contact house 2^(p+j),
where: p = floor( log2(i) ) and 0<j
The process will terminate for house i when 2^(p+j) >= N.

The following figure illustrates the solution. Think about it like you have a piece of paper that is folded in half as many times as there are steps involved in the gossipping process. Every time you unfold the paper, the houses on one of the folded sides notify the corresponding houses on the other folded side, thus doubling the number of houses that are notified with every unfold.

Each yellow line represents an unfold, starting with house 0 which notifies house 1 in the first unfold action. The adjacent yellow line unfolds house 0 into house 2 and house 1 into house 3, thus 4 houses are now notified. In the next step, houses 4,5,6 and 7 will also be notified by houses 0,1,2 and 3 respectively and so on. In the example shown below where N=100, all houses are notified in a total of 7 steps (or unfolds).

Playing with SparkFun's BigTime Watch Kit

I 've decided to work every year between Dec 25 and the new year day on a fun project that I might feel... tol "embarrassed" to work on on any other occasion. Last year it was an arduino-based game console with a 4x20 LCD screen and 4 buttons (about which I should write sometime). This year it was SparkFun's BigTime Watch, which is an Atmel-baed flavor of the Solder watch. I was already  thinking about throwing together something that I could use as a watch, so this was love at first sight.

The little red box arrived today and I started putting it together right away. Overall, I was very impressed by how well the pieces fitted together, with only minimum effort. This goes especially for the lasercut acrylic plates. The final piece is quite bulky, but there is a lot of space for improvement. I plan to wear it on a daily basis but let's be honest, this is a fun, geeky project and I've set a very low bar on how well it might fare on my wrist. Here are a couple of warnings:

1. The end-result is really bulky and extremely geeky. You might want to think twice before wearing this on a first date.


2. Let's face it: The 4-digit display makes the whole thing look like a time-bomb. I'd think twice before wearingit at an airport!

That said, here are the steps I followed in pictures with captions. It literally took me less than an hour between opening the box and wearing the completed thing on my wrist and I'm definitely not a hardware person.

Analyzing users in Google+ circles

The project is here: http://polychronis.gr/gplusanalyzer/

This started as an effort to look into Robert Scoble's circles to find interesting people. Since the Google+ API is not out yet, I decided not to spend more than 24h on this project, so this is literally how much time I 've spent on it.

You provide the ID of the user you want to analyze and the system looks up (read: uses some weird calls that Google+ makes) the people in the user's circles (information that is made publicly available by the user) and sorts them by the company that they are currently working on. It is very interesting to browse through Scoble's extensive list and find top geeks, bloggers, VCs, even TV stars.

Happy browsing!

Geo.gy: the location shortener

My new project is out: http://geo.gy/

Were you ever in the middle of a conversation and needed to share your location with the other party? Geo.gy is a platform-independent, location shortener service. It uses HTML5 to detect your location, then gives you a short url to a pointer on a map. You can use Geo.gy to add location context to a post, tweet, SMS, anything you want decorated with location context.

Tweets are already geolocated, but location information is hard-coded into individual tweets and when a follower re-tweets your tweet, your location information is lost. Geo.gy allows you to share pointers to location with the same flexibility that imgur.com allows you to share pointers to pictures.




UPDATE: Geo.gy made to no.6 at Ycombinator hacker news!