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Parasang

Parasang is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Parasang rather than just read about it. In short: The parasang (Persian: فرسنگ, romanized: farsang), also known as a farsakh (Arabic: فَرْسَخ, romanized: farsaḵ), is a historical Iranian unit of walking distance, the length of which varied according to terrain and speed of travel. The European equivalent is the league.

Parasang — main illustration
Parasang — illustration

Key takeaways

  • Parasang belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Parasang to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Parasang from memory before moving on to harder problems.

Reference excerpt

The parasang (Persian: فرسنگ, romanized: farsang), also known as a farsakh (Arabic: فَرْسَخ, romanized: farsaḵ), is a historical Iranian unit of walking distance, the length of which varied according to terrain and speed of travel. The European equivalent is the league. In modern terms the distance is about 3 or 3½ miles (6 km).

Historical usage The parasang may have originally been some fraction of the distance an infantryman could march in some predefined period of time. Mid-5th-century BC Herodotus (v.53) speaks of an army traveling the equivalent of five parasangs per day. In antiquity, the term was used throughout much of the Middle East, and the Old Iranian language from which it derives can no longer be determined (only two—of what must have been dozens—of Old Iranian languages are attested). There is no consensus with respect to its etymology or literal meaning. In addition to its appearance in various forms in later Iranian languages (e.g. Middle Persian frasang or Sogdian fasukh), the term also appears in Greek as parasangēs (παρασάγγης), in Latin as parasanga, in Hebrew as parasa (פרסה), in Armenian as hrasakh (հրասախ), in Georgian as parsakhi, in Syriac as parsḥā (ܦܪܣܚܐ), in Turkish as fersah, and in Arabic as farsakh (فرسخ). The present-day New Persian word is also farsakh (فرسخ), and should not be confused with the present-day farsang (فرسنگ), which is a metric unit. The earliest surviving mention of the parasang comes from the mid-5th-century BC Herodotus (Histories ii.6, v.53, vi.42), who defines the measure to be equivalent to 30 stadia, or half a schoenus. A length of 30 stadia is also given by several later Greek and Roman writers (10th-century Suidas and Hesychius, 5th/4th-century BC Xenophon Anab. ii.2.6). The 6th-century AD Agathias (ii.21) however—while referring to Herodotus and Xenophon—notes that in his time the contemporary Persians considered the parasang to have only 21 stadia. Strabo (xi.xi.5) also notes that some writers considered it to be 60, others 40, and yet others 30. In his 1st-century Parthian stations, Isidore of Charax "evidently [used for schoenus] the same measure as the Arabic parasang (while in Persia proper 4 sch[onii] equal 3 par[asang])." The 1st-century Pliny (Natural History vi.26) noted that the Iranians themselves assigned different lengths to it. The Bundahishn (GBd XXII), a 9th/10th-century text of Zoroastrian tradition, glosses Avestan language hathra as equivalent to a "parasang of 1000 paces" (a Roman mile), and then defines the parasang as the distance at which a man with good eyesight could determine whether a beast of burden was black or white. On the authority of older sources, the 14th-century Qazvinian historiographer Hamdullah Mostofi recorded that in the 10th century the north-eastern parasang was 15,000 paces, the north-western one was 18,000 paces, and that of the south-west was merely 6,000 paces (but the "true" parasang, so Mostofi, was 9,000 paces). Recalling local legend, Mostofi states the unit was defined by the mythological Kai Kobad to be equal to 12,000 cubits. Following the 30-stadia definition of Herodotus and Xenophon, the parasang would be equal to either 5.7 km (Olympic measure) or 5.3 km (Attic measure). But in 1920, Kenneth Mason of the Royal Geographical Society deduced that the parasang used in Xenophon's Babylonian travel accounts was equal to only 2.4 miles (3.9 km). A mid-1960s search for the Parthian city of Hekatompylos based on distances given in mid-4th-century BC chronologies of Alexander's conquests generated empirical estimates of ten stades to the English mile (1.609 km), and three miles to the parasang (4.827 km). "Whatever the basis of calculation, theoretical values for the stade and the parasang must be sought which do not greatly exceed [those] estimates." A 1985 suggestion proposes that the parasang and Attic stade were defined in terms of the Babylonian beru, an astronomically derived sexagesimal unit of time and linear distance. At 1 beru = 60 stadia = 2 parasang, the parasang could then "be expressed as 10,800 'common' [i.e. trade] Babylonian cubits, or 18,000 Attic feet, both figures exactly." A 2010 study of the term parasang in Xenophon's account of Cyrus the Younger's late-5th-century BC campaign against Artaxerxes II demonstrated that the length of Xenophon's parasang varied with weather and the terrain across which the army travelled. The parasangs were longer when the road was flat and dry, but shorter when travel was slower. The term has survived in Modern Greek in the stereotypical expression "απέχει παρασάγγας", i.e., "it is parasangs away", meaning that something is very far away from something else, particularly in terms of quality. As Hebrew 'parsah' (pl. parsoth), the parasang also finds use in the Babylonian Talmud, in several uses, for instance in a description of the biblical ladder to heaven, the width of which is given as 8,000 parsaoth (Chullin 91b). In the commentary of Pesachim 9, the 4th-century Rabbah bar bar Hana, on the authority of the 3rd-century Rabbi Johanan, gives ten parsoth as the distance that a man can walk in a day. The farsang was also used as an Ethiopian unit for length. The Ginza Rabba, a religious text written in Mandaic, typically measures distances in parasangs.

References

Explanatory notes

Citations

Works cited

Illustrations

Parasang: 1814 map of Persia during the Qajar dynasty, with scale bars in the bottom left corner for both British Statute Miles and "Persian Farsangs or Parasangs"
1814 map of Persia during the Qajar dynasty, with scale bars in the bottom left corner for both British Statute Miles and "Persian Farsangs or Parasangs"

Worked examples

Example 1 — a first encounter with Parasang

Start with the simplest possible case. Write down what Parasang claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Parasang before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Parasang ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Parasang

In research
Parasang appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Parasang in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Parasang is common in secondary-school and first-year university syllabi. It links to neighbouring topics Human-based units of measurement, Obsolete units of measurement, Persian words and phrases, so understanding it makes those chapters shorter.
In everyday life
Look for Parasang outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Parasang in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Parasang means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Parasang out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Parasang in simple terms?

The parasang (Persian: فرسنگ, romanized: farsang), also known as a farsakh (Arabic: فَرْسَخ, romanized: farsaḵ), is a historical Iranian unit of walking distance, the length of which varied according to terrain and speed of travel. The European equivalent is the league.

Why does Parasang matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Parasang?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Parasang.

Tags

  • Human-based units of measurement
  • Obsolete units of measurement
  • Persian words and phrases
  • Standards of Iran
  • Units of length

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