Fermi Rumour

1 collaborator

Tevfik Uyar (Author)

WHAT IS IT?

This is an Agent-Based Model of rumour spread adapted for galaxy-wide communication.

HOW IT WORKS

Spread of a rumor starts from one village, the initial spreader (source of rumor or the "news"), calling another village, chosen randomly, at time t0, and thus the process of spread of the rumor is initiated. For enumeration and analysis of the process, the village making the call is named as a "Spreader" (designated by Sp); all the rest of the villages are named as "Ignorant" (designated by Ig) at the beginning. The target village learns the "news" and becomes another spreader, so its status is transformed into a spreader (Ig -> Sp). In every step, spreaders continue making a new call to a randomly chosen village and goes on until calling a village which is not an Ignorant, either a spreader (Sp) or an uninterested "Stiffler" (designated by St). At this point, the caller (a Sp) converts to a stiffler (Sp ->St) because of thinking that the "news" has already been well-spread all over the villages.

HOW TO USE IT

We created an ABM including two additional features for rumor spread by using the easy application advantage of agent-based models when compared to analytic mathematical models. These features are (i) the stop criteria (how many interactions Spreaders need for converting to a Stiffler) and (ii) the conversion probability (the probability of being a spreader after communicating with another spreader). A civilization may continue to search for other civilizations even so it communicated with one. So, stopping after only one interaction may not be a realistic. However, communication (or visiting) may be expensive because of requiring extensive time and resource usage, so repeating this behavior several times may not be preferable. Therefore, ability of adjusting the stop criteria provides us with testing the different willing levels of civilizations. On the other hand, we cannot be sure that each civilization is surely going to be a spreader when they are informed once. Some civilizations may have not be passed evolution process that leads them being curious and eager to communicate with others. The conversion probability refers to the probability of being eager to search for more.

THINGS TO NOTICE

Original settings are stop criteria = 1 and conversion probability = 100%.

THINGS TO TRY

Every setting must be tried.

EXTENDING THE MODEL

N/A for now.

NETLOGO FEATURES

N/A

RELATED MODELS

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CREDITS AND REFERENCES

ABM: Created by Dr. Tevfik Uyar https://orcid.org/0000-0003-0124-6910 https://github.com/zamanusta https://twitter.com/tevfik_uyar

Inspired by Prof. Dr. Mehmet Emin Ozel

Belen, S. and Ozel, M. E. (2012) "Fermi acmazi icin yeni bir cozum onerisi," in XVIII. Ulusal Astronomi ve Uzay Bilimleri Kongresi. Malatya, Turkey, pp. 319–322.

Daley, D. J. and Kendall, D. G. (1965) "Stochastic rumours," IMA Journal of Applied Mathematics (Institute of Mathematics and Its Applications), 1(1), pp. 42–55. doi: 10.1093/imamat/1.1.42.

Ozel, M. E. (2016) "Fermi’s Paradox and Mathematical Theory of Rumours: A Possible New Solution?," Publications of Astronomical Society of Bulgaria, 5(1), pp. 6–13.

Comments and Questions

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Click to Run Model

turtles-own [
  spread ;;is a spreader or not
  ignorant ;; is an ignorant or not
  encounter ;; to keep how many times encountered with a non-ignorant
]

globals [
  number-spreaders
  number-ignorants
  number-stifflers
  rate
  rate-ignorants
  rate-stifflers
  rate-spreaders
]

to setup
  clear-all
  ask patches [ set pcolor black ]
  set number-ignorants (number)
  set rate-stifflers 0
  set rate-ignorants 1
  create-turtles number [
    setxy random-xcor random-ycor
    set color blue
    set spread 0
    set ignorant 1
  ]
  ask n-of 1 turtles [
    set color yellow
    set spread 1
  ]
  reset-ticks
end 

to go
  ask links [die]

  ask turtles with [spread = 1] [
    set encounter encounter + 1
    act-spread
  ]
  update-globals
  if not any? turtles with [spread = 1] [
    ;; For logging activate the following three lines
    ;;file-open "C:\\FERMI.txt"
    ;;file-print (word conversion-probability";"stop-criteria";"rate"\r\n")
    ;;file-close
    stop
  ]
  tick
end 

to act-spread
  ask one-of other turtles [
    ;;choose random one
    ;;show (word myself "->" self)
    ifelse ignorant = 1 ;; if choosen one is an ignorant
    [
      create-link-from myself [set color yellow] ;; create a yellow link
      if conversion-probability > random 100 [
        set spread 1 ;; make it a spreader
        set ignorant 0 ;; make it non-ignorant
        set color yellow ;; make it yellow
      ]

    ] ;;else
    [

      if withdraw? [ ;; is it a stiffler?
        ;;show "açıkı"
        set encounter encounter + 1
        if encounter >= stop-criteria [
          set spread 0
          set color gray
        ]
      ]
      ask myself [
        if encounter >= stop-criteria [
          set spread 0
          set color gray
        ]
      ]
    ]
  ]
end 

to reset
  set number 1000
  set withdraw? true
  set stop-criteria 1
  set conversion-probability 100
end 

to update-globals
  set number-spreaders (count turtles with [spread = 1])
  set number-ignorants (count turtles with [ignorant = 1])
  set number-stifflers (count turtles with [(spread = 0) and (ignorant = 0)])
  set rate number-ignorants / number
  set rate-ignorants number-ignorants / number
  set rate-stifflers number-stifflers / number
  set rate-spreaders number-spreaders / number
end

There are 10 versions of this model.

Uploaded by	When	Description	Download
Tevfik Uyar	about 5 years ago	Small fixes.	Download this version
Tevfik Uyar	about 5 years ago	Small fixes.	Download this version
Tevfik Uyar	over 5 years ago	Solve encoding problems.	Download this version
Tevfik Uyar	over 5 years ago	Encoding?	Download this version
Tevfik Uyar	over 5 years ago	Info update.	Download this version
Tevfik Uyar	over 5 years ago	Info update.	Download this version
Tevfik Uyar	over 5 years ago	MT model correction.	Download this version
Tevfik Uyar	over 5 years ago	Small fix	Download this version
Tevfik Uyar	over 5 years ago	Small fixes	Download this version
Tevfik Uyar	over 5 years ago	Initial upload	Download this version

Attached files

File	Type	Description	Last updated
Fermi Rumour.png	preview	Preview for 'Fermi Rumour'	over 5 years ago, by Tevfik Uyar	Download

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