THE INVISIBLE BOUNDARIES IN THE CITY

1. Perha$s $hysical frontiers are less im$ortant since somehow the world has become a lobal entity, in which information $asses throu h the $hysical walls. Many of them have been destroyed (Berlin) and some others such as that of Cy$rus resist, but they are certainly less effeective than in the $ast. Thee major concern of the future is the identifigcation of invisible borders within the cities. It is difficcult to identify exclusion, and mar inalization is hidin within the cities, even in the wealthiest ones. Thee s$aces of the cities have invisible borders, but they are not easy to cross. 2. An MIT study (Xu Y, Belyi A, Santi P, Rattpi C. 2019) hi hli hts these $roblems afteer $rocessin data on human movements, social networks connections and the socioeconomic status of $eo$le, the document $ro$oses two indices to measure se re ation in Sin a$ore. Thee index se re ation of communication measures the relationshi$ between $eo$le within each social network, considerin the frequency of communication and the socio-economic attpributes of each $erson. Thee $hysical se re ation index indicates the social ex$osure which $eo$le have towards each other belon in to similar and diffeerent socio-economic rou$s as they move more and more around the city. ). Thee MIT study shows how it is $ossible, throu h the mana ement of bi data, to be able to brin out invisible mar inalization situations which can not be seen in other ways. 4. Thee “documedial $rocess” (Ferraris, Paini, 2018) in which the di ital breakthrou h has transformed the city, allows not only to brin out areas of border and exclusion but lays the foundations for an analysis of reality ca$able of hi hli htin cultural isolation.


INTRODUCTION
Because they lead my people astray, saying, "Peace," when there is no peace, and because, when a fliimsy wall is built, they cover it with whitewash, 11 therefore tell those who cover it with whitewash that it is going to fall. Rain will come in torrents, and I will send hailstones hurtling down, and violent winds will burst forth. When the wall collapses, will people not ask you, "Where is the whitewash you covered it with? Theerefore this is what the Sovereign Lord says: In my wrath I will unleash a violent wind, and in my anger hailstones and torrents of rain will fall with destructive fury. I will tear down the wall you have covered with whitewash and will level it to the ground so that its foundation will be laid bare. When it falls, you will be destroyed in it; and you will know that I am the Lord. Ez. 13,[10][11][12][13][14] Perha$s $hysical frontiers are less im$ortant since somehow the world has become a lobal entity which information crosses $hysical walls.
Many of them have fallen (Berlin) and some as that of Cy$rus resist, but they are certainly less effeective than in the $ast.
Already in the Hole Bible, in the $assa e $laced at the be innin , in some way, it was hi hli hted how the walls are destined to fall to the detriment of those who built them and even the $laster of mota (mud) of which Ezekiel s$eaks, will only serve to deceive $eo$le of Israel, but will fail to kee$ the wall from fallin .

PHYSICAL BARRIER
Thee most famous $hysical barrier between two nations actually indicates the fra ility and evanescence of the border. Thee wall between Mexico and the United States, ofteen used as a $olitical slo an, is actually reduced to a symbol of division rather than a real barrier, which unfortunately remains so only for des$erate mi rants in search of the American dream.
The wall reality, under construction, started in the Obama era, exalted in the Trump era and still under construction, is much more complex that political rhetoric and becomes one of the factors on which US Mexican economic relations are based. As Andrew Selee, president of the Migration Policy Institute argues, that frontier that goes beyond the wall makes the two nations indivisible. The digitalization that has allowed globalization has brought to the surface surprising relationships such as the sharing of the airport in the sister cities of San Diego and Tijuana, the rescue of many American companies by Mexican entrepreneurs, the cultural contamination at the film, sports and culinary level, and the million Americans who moved that revive Mexican towns. We can say that, wall or no wall, deeply intertwined social, economic, business, cultural, and personal relationships mean the US-Mexico border is more like a seam than a barrier, weaving together two economies and cultures. Don Winslow (an American writer) dedicated a trilo y of novels and a short story to the wall with Mexico and the criminal activities they develo$ on the borders. In the last novel he ascribes to the thou hts of Keller ($rota onist of the trilo y): «but there is no wall, neither here nor there, he thinks smilin . And there never will be. A border is somethin that divides us, but also unites; Theere can be no wall, just as there is no wall that divides the human soul between its $ositive and ne ative im$ulses» .

INVISIBLE BORDERS
Thee reatest concern of the future is the identifigcation of invisible borders within cities. Theese frontiers are determined by the exclusion that we enerally defigne as social and we defigne as the inability to access a $articular service or ood in eneral. Thee exclusion we want to deal with, has contents and ex$resses much wider im$lications than its common di nity. In this reard, Marc Au é offeers a broad and com$rehensive analysis of this term. «Exclusion, therefore. Theis conce$t undoubtedly under$ins the existence of an interior and an exterior: one is excluded from the inside and fignds oneself outside, on the outside. Theis exterior can be understood in a $hysical sense. I am referrin to the myriad of individuals who floock to the frontiers of the develo$ed world, ofteen at the cost of their own lives, to the boats that reularly ca$size at sea, the drama of the esca$e of excluded individuals, ke$t out of what in their eyes re$resents the $lace. of develo$ment, of the $ossibility of bein saved if only they will be able to access it» (Au é, 2007, $. 16).
With these words Au é describes what he calls $hysical exclusion, the im$ossibility of enterin a country other than the one of ori in, this $hysical exclusion is refoulement at sea, detention in refu ee cam$s, arrest for secrecy. Theis figrst as$ect, which we will not deal with in any case, is $erha$s the bloodiest, from which suffeerin and death derive, but it is not the last obstacle for those who mana e to enter the develo$ed world. Thee second obstacle is sociolo ical exclusion as Au é defignes it: "there is also exclusion in a socioloical sense, a social exclusion: within rich countries there are those who do not benefigt or benefigt littple from this wealth, there are who does not have access to a job, to the resources necessary to live.
Theis rou$ includes many black $eo$le who have mana ed to esca$e from the $oor re ions of the $lanet, $assin from the figrst to the second ty$e 16) of exclusion. Theis second mar inalization athers a wider "audience" than the figrst as there are also natives in fignancial difficculties, with social $roblems, and ofteen the elderly, the sick, the disabled, the unschooled and the unem$loyed.
As Au é states, «it would be too easy, as well as reductive, to circumscribe the $henomenon of social exclusion to the o$$osition between the center and the $eri$hery: in the same way in which the $eri$hery is not com-$osed only of excluded $eo$le -in fact, very rich $eri$heries exist -ofteen the center the city is hostin excluded $eo$le of all kinds. From this $oint of view, therefore, the notion of exclusion is a clearly sociolo ical notion. It can also involve other as$ects relatin to the administrative and $olitical order» (Au é, 2007, $. 17).
Linked to this, Au é's analysis includes a synonym for exclusion: mar inalization. Theis term is linked to the $hysicality of $laces, in fact, «to lead to the mar ins» means, in an urban settpin , to lead to the $eri$hery. Thee term $eri$hery is considered ne ative $recisely because it is linked to mar inalization. Theis has not always been the case, in the 60s and 70s of the twentieth century, the $eri$hery was a symbol, certainly not of wealth, but of di nity and modern livin .
The problem and decline of these places began in the 80s with the advent of economic crises and the resulting unemployment, producing social and site exclusion. In French there is a term that perfectly identifies this phenomenon: cité. In this cité, second generation immigrants live in France who are not marginalized by urban imposition, but on an economic and above all school level. As Augé argues, «he who is defeated by the system, he who does not adapt to the school system or the economic system, is marginalized» (p. 19). Spatial marginalization therefore becomes only a consequence of a cultural, social and economic marginalization. The different meaning of cité and ville has historical and implicit roots in the French language. The ville is a concrete and material place while the cité is a mental representation. In the French language recently the meaning of cité «mostly refers to the squalid and desolate areas that host less affluent fringes on the outskirts of the city» (Sennett, 2018, p. 11).
But the meanin to which Au é refers also maintains the ori inal meanin as from these $eri$heral $laces emer e cultural realities such as Ra$ and other artistic manifestations. As Au é states, «not all the boys from the suburbs, in fact, are $art of an s of criminals. Our information system too ofteen treads its hand on what is wron , on the s$ectacular im$lications of failure, and has tended to silence everythin that does not re$resent a $roblem, everythin that works more or less well. Thee banlieue is full of youn $eo$le who make it and others who mana e to et out of disadvanta ed situations. Microculture is also the ori inal thin that is created in those $laces: it may ha$$en that youn $eo$le do not identify themselves either in their remote ori ins (Morocco, Al eria, Mali etc.) or in their acquired country, but they feel they have not found their $lace» (Au é, 2007, $. 25). Theese $laces, es$ecially in this $andemic $eriod, have hi hli hted the $henomenon of the di ital divide linked to economic reasons and the lack of infrastructure. Thee inability of families to buy com$uters, tablets or smart-$hones suitable for distance learnin and the low diffeusion of figber in the $eri$heral areas of cities has once a ain $laced many youn students at a disadvanta e.
Theis story has hi hli hted a double hettpoization, the s$atial and the diital one. However, di ital, like any tool, also has its $ositive version which in this case is ex$ressed in the $ossibility of unmaskin exclusion.

SINGAPORE CALLING
It difficcult to identify exclusion mar inalization is hidin within the cities, even in the wealthiest ones. Thee s$aces of the cities have invisible borders, but not therefore easily crossable.
An MIT study  hi hli hts these $roblems afteer $rocessin data of human movements, social network connections and $eo$le's socioeconomic status, the document $ro$oses two indices to measure se re ation in Sin a$ore. Thee communication se re ation index measures the connection between $eo$le within each individual social network, considerin the frequency of contacts and the socio-economic attpributes (linked to the value of the residential $ro$erties) of each $erson.
Thee $hysical se re ation index measures the social ex$osure that individuals have towards $eo$le belon in to similar and diffeerent socioeconomic rou$s as they move more around the city. Thee study was born from the intuition that while cities are $laces of meetin o$$ortunities on a cultural, social and economic level, they can also be $laces of mar inalization. Thee meetin of $eo$le who have diffeerent ethnic, cultural and socio-economic back rounds is a si n of diffeerences that make the city interestin , but which can turn into alienation.
Thee analysis of the work$lace and residence $rovides us with a too static division ma$$in that ofteen does not identify the urban social reality. Carlo Rattpi, in fact, states: «Cities are rather dynamic, and we need bettper tools to understand $eo$le's ex$osures to other social rou$s as they interact with each other in the city and in social networks» (Sin a$ore Callin ).
Thee MIT study substantially hi hli hts how it is $ossible, throu h the mana ement of bi data, to be able to brin out otherwise invisible situations of mar inalization. «Theis is the figrst study to $ro$ose a methodolo y to quantify se re ation in a cou$led $hysical-social s$ace. It allows us to o beyond the traditional measures of residential se re ation that are ex$ressed throu h static s$atial terms» (Sin a$ore Callin ), comments by Paolo Santi, a Research Scientist at the MIT Senseable City Lab. By bettper understandin social se reation in cities, the ultimate oal is to fignd ways to brin $eo$le to ether, creatin vibrant and diverse cities.
Thee documentary $rocess  in which the di ital turnin $oint has transformed the city not only allows for the emer ence of border and exclusion areas but lays the foundations for an analysis of reality ca$able of hi hli htin the cultural isolation it has stron analo ies with the emer ence of criminal activities. He believes that crime is an emer ency, not so much from the $oint of view of ur ency, but in relation to its emer ence of the evolution of the social reality derivin from culture, $lace, socio-economic context and historical moment.
Thee city, as you can easily uess, offeers more o$$ortunities for crime. Theis su estion is configrmed by the data: takin as an exam$le the re ion and the Italian city where I come from, Turin has a )1% hi her crime rate than the re ional territory (Piedmont 5,155 out of 100,000 inhabitants of Turin 6,76) out of 100,000 inhabitants). As noted by Geofferey West (2017), city infrastructures have a sublinear ratio with res$ect to the demo ra$hic fig ure of 0.85, while in the socio-economic context, the ratio is su$erlinear equal to 1.15. Theis means that if the len th of the roads, the quantity of electric cables, the diffeusion of sewers increases with an index of 0.85 with the increase of the $o$ulation, wa es, wealth, flou cases and the incidence of crime increase to an extent. of 1.15.
Once we have verified that the city, in addition to being the privileged place for the spread of culture, is also the center of crime, we can ask ourselves the following question: to what extent does the city affect crime and how does delinquency affect the city? The question is complex as the urbs (the physical part of the city) and the civitas (the citizens) are "woven" together according to the definition of Edgar . It is not a question of researching the laws that define the relationship between daily life (therefore crime) and the city, but of using a method that allows us to deal with uncertainty and verify how they affect each other. The modern shape of the world (including the criminal one) is given by the complex interrelationships between society, city and global computerization that are characterized by heterogeneity, the network, interdependence and the ability to adapt. To understand, manage and possibly contribute to changing society, we must change the paradigm by considering two essential points of contemporaneity: the exponential acceleration of changes and the network.
While takin into consideration Morin's refloections on the non-exhaustive use of bi data, we believe it is im$ortant to $oint out that their use can $lay a com$lementary role in the context of com$lex analyzes. An exam$le of this is the case of Sin a$ore that we described earlier.
We have analyzed various forms of borders that the city can raise, some limits are $hysical and a$$ear to be less dan erous and, in any case, less sinifigcant than immaterial borders. Physical walls are, if not demolished, at least overcome by di ital tools which are able to reveal $ockets of mar inalization that are difficcult to brin to the surface otherwise, but at the same time the medialization of reality involves in turn the emer ence of di ital se re ation that however, it somehow dama es itself and its elimination de$ends on $olitical decisions.

PANDEMIC
In this $andemic $eriod we believe it becomes interestin to underline how di ital barriers can $lay a $ositive role. For reater $rotection, security and control of Covid19 we have very effeective tools linked to our smart-$hones. In this re ard, we would like to remind you that an a$$ called "flou-$hone" was develo$ed on a Euro$ean level in 2011 and was not used for reasons related to $rivacy. Without enterin into the controversy that arose from the use of data by China, South Korea and Sin a$ore -a use that has had an indis$utable success -we remember how willin we are to $our our $ersonal data for futile reasons on social networks (Facebook, Twittper, TikTok, Instaram) without any control and then suddenly worry about our $rivacy in the event of a health emer ency.
In any case, on the use of technolo y and innovation, it is ood to remember how we discovered the reason for the infection and consequently also the nature of the s$read of the cholera bacterium which, in the nineteenth century, had severely tested the cities of London and New York.
In 1854 in Soho ) (London suburb), one of the major outbreaks of cholera develo$ed. In this area of the city lived a doctor, John Snow, who for four or figve years had already claimed that cholera was transmittped throu h contaminated water, but without bein able to convince anyone. Thee $ublic health authorities had lar ely i nored his words. He had observed that the inhabitants near a $articular water $um$ died more frequently. Snow resided ri ht nearby and had sus$ected that such a concentrated outbreak could have only one source, which many drew from, as the infection did not have the traditionally slow $ro ression that was ex$ected.
To analyze the situation he used Henry Whitehead, a local minister who was by no means a man of science, but was incredibly socially connected. Thee lattper in fact knew the whole nei hborhood and $rovided information on the inhabitants so that Snow could "trace" the cases of $eo$le who had drunk the water from the $um$. Thee next and fignal ste$ was to draw a ma$ that re$re-Journal of Frontier Studies. 2021. No 1 | ISSN: 2500-0225 Thee Urban Config uration | Doi: http$s://doi.or /10.4653 )9/jfs.v6i1.257 sented in a way the situation was clear. Thee direct consequence was that, by convincin the $o$ulation to boil water, the outbreak was exhausted and in the followin years London and other lar e cities be an to equi$ themselves with sewers to $revent the aquifers from bein subject to $ollution. Snow was not the only reason that $ushed cities to equi$ themselves with hy ienic technolo ies, but it has certainly contributed to im$rovin life in urban areas. life, but certainly the clever use of Dr. Snow's ma$ shows us how even a sim$le a$$ could hel$ us in case i n which dan er once a ain loomed on our lobal smart cities.

CONCLUSION
In conclusion, our evolution and our survival have de$ended -startin from two hundred thousand years a o, just when Homo sa$iens distin uished itself amon other s$ecies -on technique and innovative ca$acity and to these must be linked our ho$es and our research effeorts. Once a ain it will be the city that will allow us these develo$ments and $rovide us with the solutions to break down $hysical walls and to make every ty$e of barrier, even the invisible ones, surmountable.