Offset

Offset

A little threat,
yet troublesome,
has entered me,
I need more tea!
My former self:
a silhouette,
offset a bit,
I'd like to quit.

The Algorithm

The Algorithm

--- algorithm (noun) ---
A well-defined procedure consisting of a finite number of consecutive steps. Often confused with its realization (implementation).


--- The Algorithm (proper noun) ---
A musical project that blends electronic music with progressive metal. Often confused with random noises.


--- algorithm (example) ---
def is_alive()
    return flip_coin()

def life()
    while(is_alive())
        go_outside();
        take_pictures();
        persist();
    decay();

Aren’t algorithms fascinating? Well-defined procedures that solve well-defined problems – often with the goal to find the most efficient solution. It’s the single most important thing that amazes me in computer science.

My most favorite problem in algorithmics is one of the most simple ones. Suppose you have a short word, let’s call it T. Additionally, a long text S is given. The task is to determine whether the word T is contained within the text S. Thus, we want an algorithm for a simple search! Suppose the word T contains n distinct characters; for example T = “alive” has a length of n = 5. Similarly, the text S has a length of m, for example, S = “The tree is alive.” has a length of m = 18 (including the spaces and the period).

The most simplest algorithm aligns T at the first position of S and compares all n characters of T to the first n characters of S, which requires n comparisons (in other words, for our above example we answer the question whether “alive” and the first five characters of S are identical. Hint: they are not). Afterwards, the word is shifted to the next position of S and the comparison is repeated. This happens for all m starting characters of S. The problem? This will take a total of m times n comparisons which already amounts to 90 comparisons for our little toy example.

But what other solution could there be? There are many. None of them are easy to understand (at least for me), but all are fascinating. The first one I learned was the KMP algorithm, which performs mind-boggling reuses of previously obtained information about differing characters. The fascinating part: It only needs (roughly) m + n comparisons! A speed-up that determines whether we are able to browse the internet or not, whether we can perform research on molecular data or not, and whether we can advance as a technological species or not. Algorithmic design makes or brakes today’s society (at least for now, until climate change kicks in – always end on a positive note, right?).

Ways of Water

Ways of Water

Blurry shapes are stirred around,
mixed in motion, give a notion
of the hidden world above.
Day and night are intertwined
and realigned by breathing air:
a little water love affair.

The Endgame

The Endgame

The most important thing about Chess is to keep the king safe. It gets castled behind its pawns and is protected by all pieces. A comfy life, no worries, and no ventures onto the board. It remains inactive. In fact, it remains rather lifeless.

Until the endgame approaches and things start to change: Pieces have fallen left and right, the board is a vast and empty plain, pawns gain importance as they may promote, and – finally – the king abandons its safe place to become more active. To get involved in the game. To get involved in life.

Not every game of chess reaches its endgame.

Fruit flies exist for ten days, sparrows for two years, snails for eight years, and bowhead whale over 200 years. Every ten years our chance of death doubles. We have an awful lot of time to think about what happens afterwards. Until we don’t.

Changing Seasons

Changing Seasons

One season passes, the next approaches. One life phase transitions into another one. Snow covers clutter of the past, a fresh canvas onto which new ideas may be painted. Which shall remain unchanged? What must be adjusted? The past is frozen in place, but now and again color persists and defies the whiteout. Lonely figures reach high, rooted deep, yet fragile and delicate. Preparations for a period of hibernation begin, with the aspiration of a fresh awakening.

A Barcode of Life

A Barcode of Life

Barcodes are commonly used for the identification of items. Many standards exist but, in general, barcodes must be universal, unique, and easy to process. The standardization of barcodes grants great benefits, not only for everyday shopping: A unique identifier facilitates and simplifies the ordering and processing of goods all over the world.

Similarly, the distinct identification of organisms and their relationships is one of the major goals in the life sciences. What would be more suited than a barcode – a barcode of life?

Many genetic regions have been proposed for the use of being such a barcode. For eukaryotic species, the 18S gene is most commonly used today; a rather short fragment of ribosomal RNA that is evolving slowly and allows the reliable identification of most species. It is surrounded by highly conserved sequence regions that simplify the sequencing process. By this, the analysis of 18S RNA from the environment delivers a comprehensive overview of all present species, equivalent to scanning a barcode of all organisms.

Harztouren

Harztouren

Irregularities give rise to normality. I’ll be back to English in the next post.

Im Juni 2020 ging es für uns in den Urlaub. Damals frisch verliebt, stimmte ich gerne der angestrebten Urlaubsplanung zu: Also, ab ins Gebirge. Das Richtige. Also zumindest das Richtigste was wir einfach so erreichen können, die Alpen. Quasi am Alpenrand geboren, war ich das erste Viertel meines Lebens (wobei diese Rechnung nur ohne einen voreiligen Tod aufgeht) eigentlich nie so richtig dort. Ein großer Fehler, denn auch die Berge haben anscheinend ein Plätzchen in meinem Herzen reserviert. Sobald wir dort waren, zwischen den erhabenen Gipfeln und tiefen Tälern, fühlte ich eine große Zufriedenheit. Und die Gipfel ziehen mich an. Ich sehe einen Gipfel und plötzlich will ich nur noch hinauf. Steiler Anstieg? – Egal. Wetter? – Egal. Hauptsache hoch, und zwar so hoch es geht.

Falls man mal nicht in den Alpen ist, gestaltet sich das Ganze etwas anders: Hier im flachen Norden ist das höchste der Gefühle schon bei 1141 Metern über Null erreicht und man steht mit 84 prozentiger Wahrscheinlichkeit in den Wolken. Aber wen interessiert schon Statistik – gefühlt sind es mindestens 93 Prozent. An den anderen Tagen bietet der Brocken dagegen wunderbare Ausblicke und ein echtes ‘Oben-Gefühl’, das meinen Gipfeldrang kurzfristig bändigt. Ebenfalls seit 2020 sind wir daher auch eifrig am Stempel sammeln, zumindest mit periodischer Eifrigkeit: Der Herbst und Winter hat es uns besonders zugesagt im Harz; wenn Nebel die Seen umschließt und Laubwälder der tieferen Lagen Farbspektakel bieten.

Dennoch, ich freue mich auch schon wieder auf den nächsten Urlaub in dem wieder zwei- und dreitausend Meter bewältigt werden können. Der Kopf so frei, wie die Alpendohle im Auftrieb und das Herz so voll, wie der Bauch in der Adventszeit.

Woodlands

Woodlands

Frigid air blows through the woods,
blows rigid thoughts away;
and gray clouds pervade the vale,
play with remaining leaves.
Draining anger and despair,
the trees take always care.

Egyptian Geese

Egyptian Geese

I regularly visit our local lake and another park with two small ponds. What do they have in common? All year long they are both inhabited by at least one couple of Egyptian Geese, which are normally endemic to the southern half of Africa. So what brings them up here?

Egyptian Geese have been hold captive in Europe since the eighteen hundreds and individuals were set free or escaped from time to time, resulting in a small group of wild individuals. Starting in 1970, a fast expansion of these animals occurred along the river Rhine, which also led to a well-maintained population in Germany. Even more so, they continue to spread around Europe and take over urban areas. They can be rather aggressive, especially towards mallard ducks, and seem to have found an environment that favors their species. Sometimes they even displace larger birds from their nests and breed there themselves.

One couple in our city just had its second litter this year, which seems rather odd given that temperatures are dropping rapidly. Maybe the warm autumn mislead their instinct.