Cable Length to Parsec Conversion Calculator: Free Online Tool
Convert cable lengths to parsecs with our free online length converter.
Cable Length to Parsec Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Cable Length).
- The converted value in Parsec will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Length category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Cable Length to Parsec
Converting Cable Length to Parsec involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Cable Length = 6.0019e-15 parsecsExample Calculation:
Convert 10 cable lengths: 10 × 6.0019e-15 = 6.0019e-14 parsecs
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
What is a Cable Length and a Parsec?
A Cable Length (symbol cb), often shortened to cable, is a nautical unit of length, traditionally related to the length of a ship's anchor cable. While its exact length has varied historically and geographically, it is now most commonly defined internationally as one-tenth of a nautical mile (1/10 NM).
This standard definition equates to:
- 185.2 meters (m)
- Approximately 607.61 feet (ft)
- Approximately 202.54 yards (yd)
Other historical definitions based on the fathom also exist.
The Parsec (symbol pc) is a unit of length used to measure the enormous distances to astronomical objects outside the Solar System. One parsec is defined as the distance at which one astronomical unit (AU) – the average distance between the Earth and the Sun – subtends an angle of one arcsecond (1/3600th of a degree). This corresponds to approximately:
- 3.0857 × 10¹⁶ meters (m)
- 30.857 trillion kilometers (km)
- 19.174 trillion miles (mi)
- 206,264.8 astronomical units (AU)
- 3.26156 light-years (ly)
It is derived directly from the method of trigonometric parallax used by astronomers to measure stellar distances.
Note: The Cable Length is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Parsec belongs to the imperial/US customary system.
History of the Cable Length and Parsec
The unit originated from the practical length of a ship's anchor cable (or "shot" of chain) used in the age of sail. Anchor cables were typically manufactured in standard lengths that could be shackled together. This length provided a convenient unit for measuring distances related to anchoring and maneuvering close to shore or other vessels.
However, the length was not universally standardized:
- In the British Royal Navy, a cable was traditionally defined as 100 fathoms (equivalent to 600 feet or 182.88 meters).
- In the U.S. Navy, it was often defined as 120 fathoms (equivalent to 720 feet or 219.456 meters).
With the international adoption of the nautical mile (defined as 1852 meters), defining the cable as exactly one-tenth of this value (185.2 m) created a convenient, decimal-based relationship and became the most common modern standard, sometimes referred to as the "international cable length".
The concept of measuring stellar distances via parallax existed long before the unit itself. The term "parsec" was coined by the British astronomer Herbert Hall Turner in 1913. He sought a convenient unit for astronomers that directly reflected the observational method. The name is a portmanteau derived from "parallax of one arcsecond". It quickly gained acceptance within the astronomical community due to its practical connection to parallax measurements, which were (and still are) a fundamental way to determine distances to nearby stars.
Common Uses for cable lengths and parsecs
Explore the typical applications for both Cable Length (imperial/US) and Parsec (imperial/US) to understand their common contexts.
Common Uses for cable lengths
The cable length, particularly the 1/10 NM definition, remains in use in specific maritime contexts:
- Nautical Navigation & Ship Handling: Measuring short distances at sea, such as the distance between ships in formation, distance off a navigational hazard, distance to a pier, estimating anchor drag, or describing the scope (length) of anchor cable paid out.
- Hydrographic Surveying: Historically used on nautical charts, although meters are now the primary international standard for depth and short distances on modern charts.
- Naval Terminology: Persists in naval traditions and communications for describing close ranges.
- Historical Context: Encountered in older maritime texts, logs, charts, and naval records.
Common Uses for parsecs
The parsec is the preferred unit of distance in professional astronomy and astrophysics:
- Stellar Distances: Measuring distances to nearby stars using parallax.
- Galactic Structure: Describing distances within the Milky Way galaxy (often using kiloparsecs, kpc, where 1 kpc = 1000 pc). For example, the Sun is about 8 kpc from the Galactic Center.
- Extragalactic Distances: Measuring distances to other galaxies and galaxy clusters (often using megaparsecs, Mpc, where 1 Mpc = 1,000,000 pc). The Hubble constant, describing the expansion of the universe, is typically expressed in (km/s)/Mpc.
- Cosmology: Discussing large-scale structures and distances in the universe (using Mpc and sometimes gigaparsecs, Gpc, where 1 Gpc = 1000 Mpc).
Frequently Asked Questions
Questions About Cable Length (cb)
What are the different values for a cable length?
The value depends on the definition being used:
- International Standard: 1 cable = 1/10 nautical mile = 185.2 meters ≈ 607.61 feet. (Most common modern definition)
- British Traditional: 1 cable = 100 fathoms = 182.88 meters = 600 feet.
- US Traditional: 1 cable = 120 fathoms = 219.456 meters = 720 feet.
Always clarify which definition is intended if precision is critical, though the 1/10 NM version is generally assumed today unless otherwise specified.
How many meters are in a standard cable length?
The internationally recognized standard cable length is exactly 185.2 meters.
How many feet are in a standard cable length?
The internationally recognized standard cable length is approximately 607.61 feet. The traditional British cable was 600 ft, and the traditional US cable was 720 ft.
Is the cable length related to the nautical mile?
Yes, the most common modern definition establishes a direct relationship: 1 cable length = 1/10 nautical mile.
Is the cable length an SI unit?
No, the cable length is not an SI unit. It is a traditional nautical unit derived from maritime practice and later linked to the nautical mile. The corresponding SI unit for length is the meter (m).
Is the cable length still used today?
Yes, while meters and nautical miles are standard for most navigation, the cable length (especially the 1/10 NM definition) is still actively used in specific maritime applications like anchoring, close maneuvering, naval operations, and sometimes in recreational boating contexts. It serves as a convenient subdivision of the nautical mile.
About Parsec (pc)
What does 'Parsec' stand for?
Parsec is a blend of "parallax of one arcsecond". It represents the distance at which the parallax angle of a star is exactly one second of arc.
How is a parsec defined?
It's defined based on trigonometry. Imagine a right-angled triangle in space where the short side is the Earth-Sun distance (1 AU). The parsec is the length of the adjacent side when the angle at the distant star (the parallax angle) is exactly one arcsecond.
Is a Parsec bigger than a Light Year?
Yes, one parsec is significantly larger than one light-year.
- 1 Parsec ≈ 3.26 light-years
How many meters or kilometers are in a parsec?
One parsec is approximately:
- 3.0857 × 10¹⁶ meters
- 30.857 trillion kilometers
How many Astronomical Units (AU) are in a parsec?
One parsec is equal to approximately 206,265 AU. This number arises directly from the definition involving radians and arcseconds (specifically, the number of arcseconds in a radian).
Why do astronomers use parsecs instead of light-years?
While both are used, parsecs are often preferred in professional contexts because:
- Direct Observational Link: The parsec is derived directly from the parallax angle, a primary method for measuring distance.
- Historical Convention: It became the standard unit early in the development of stellar distance measurement.
- Convenience: Multiples like kpc and Mpc provide convenient scales for galactic and extragalactic distances.
- Definition Stability: The definition of a light-year depends slightly on the definition of a "year" (e.g., Julian year), whereas the parsec is based on the fixed AU and geometric angles.
Is the parsec an SI unit?
No, the parsec is not an SI unit. The SI unit for length is the meter (m). However, the parsec (along with the astronomical unit and light-year) is recognized by the International Astronomical Union (IAU) and is widely accepted for use in astronomy.
Conversion Table: Cable Length to Parsec
| Cable Length (cb) | Parsec (pc) |
|---|---|
| 1 | 0 |
| 5 | 0 |
| 10 | 0 |
| 25 | 0 |
| 50 | 0 |
| 100 | 0 |
| 500 | 0 |
| 1,000 | 0 |
All Length Conversions
Other Units from Length
- Meter (m)
- Kilometer (km)
- Hectometer (hm)
- Decimeter (dm)
- Centimeter (cm)
- Millimeter (mm)
- Inch (in)
- Foot (ft)
- Yard (yd)
- Mile (mi)
- Nautical Mile (NM)
- Micrometer (μm)
- Nanometer (nm)
- Light Year (ly)
- Astronomical Unit (AU)
- Angstrom (Å)
- Point (Typography) (pt)
- Mil/Thou (mil)
- Fathom (fath)
- Furlong (fur)
- Link (Gunter's) (li)
- Pace (pace)
- Span (span)
- Digit (digit)
- Ell (ell)
- Finger (finger)
- Roman Mile (m.p.)
- Stadion (stadion)
- Chi (Chinese) (chi)
- Shaku (Japanese) (shaku)
- Li (Chinese) (li)
- Toise (toise)
- Bolt (bolt)
- Rope (rope)
- Smoot (smoot)
- Sajene (sajene)
- Ken (ken)
- Wa (wa)
- Vara (vara)
- Aln (aln)
- Cubit (Royal/Egyptian) (cubit)
- Versta (versta)
- Arpent (arpent)
- Ri (Japanese) (ri)
- Klafter (klafter)
- Yojana (yojana)
- Skein (skein)