What is Year: Definition and 999 Discussions

A year is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked.
A calendar year is an approximation of the number of days of the Earth's orbital period, as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars; see below. For the Gregorian calendar, the average length of the calendar year (the mean year) across the complete leap cycle of 400 years is 365.2425 days. The ISO standard ISO 80000-3, Annex C, supports the symbol a (for Latin annus) to represent a year of either 365 or 366 days. In English, the abbreviations y and yr are commonly used.
In astronomy, the Julian year is a unit of time; it is defined as 365.25 days of exactly 86,400 seconds (SI base unit), totalling exactly 31,557,600 seconds in the Julian astronomical year.The word year is also used for periods loosely associated with, but not identical to, the calendar or astronomical year, such as the seasonal year, the fiscal year, the academic year, etc. Similarly, year can mean the orbital period of any planet; for example, a Martian year and a Venusian year are examples of the time a planet takes to transit one complete orbit. The term can also be used in reference to any long period or cycle, such as the Great Year.

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  1. J

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    Hi guys, I am a first year IB student and I need to give hand in my research question for the extended essay today, the only thing is that I don't really know what I could do it on. The extended essay is basically a 4000 word research project. I was going to do it on photoelasticity, but when I...
  2. J

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  3. Xiothus

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  4. D

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  5. jselms99

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  6. notgoodatphysics

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  7. K

    B Exploring the Standardization of One Light Year Distance | PF Forum

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  8. russ_watters

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  9. olgerm

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  10. J

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  11. E

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  12. D

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  13. Manuel Cardoso

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  14. A

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  15. J

    B Exploring the Possibilities: A Pre-13.8 Billion Year Old Galaxy

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  16. E

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  17. bigmike94

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  18. AliAllyMac

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  19. ZapperZ

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  20. Darrencc

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  21. G

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  22. X

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  23. shivajikobardan

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  24. BillTre

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  25. shivajikobardan

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  26. Camden

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  27. aspiringastronomer

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  28. F

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  29. H

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  30. Astronuc

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  31. Simon Peach

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  32. jedishrfu

    B 3700 Year Old Babylonian Tablet of Trigonometry Tables

  33. B

    MHB How Much Would I Earn If I Worked 4 Weeks On and 4 Weeks Off?

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  34. Asker321

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  35. kyphysics

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  36. N

    What is the Linear Equation for Dollar Value of a Product Over Time?

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  37. BalinesePhysicist

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  38. A

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  39. C

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  40. Barracuda

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  41. anemone

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  42. C

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  43. T

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    How to make the most of a gap year during the Covid-19 era? =========================================================== Hello Everyone, Thanks for reviewing my thread. I am opening this thread to get insights into my future prospects for a career in Physics in the era of Covid-19. I...
  44. Averagesupernova

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  45. StevieTNZ

    What would you like for Christmas this year?

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  46. CherryB

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  47. ScienceGuy42

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  48. poudyalb

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  49. E

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  50. P

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