Sidereal Day to Planck Time Conversion Calculator: Free Online Tool

Convert sidereal days to Planck times with our free online time converter.

From:

Sidereal Day

To:

Planck Time

How to Use the Calculator:

Enter the value you want to convert in the 'From' field (Sidereal Day).
The converted value in Planck Time will appear automatically in the 'To' field.
Use the dropdown menus to select different units within the Time category.
Click the swap button (⇌) to reverse the conversion direction.

How to Convert Sidereal Day to Planck Time

Converting Sidereal Day to Planck Time involves multiplying the value by a specific conversion factor, as shown in the formula below.

Formula:

1 Sidereal Day = 1.5983e+48 Planck times

Example Calculation:

Convert 60 sidereal days: 60 × 1.5983e+48 = 9.5898e+49 Planck times

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 Sidereal Day and a Planck Time?

A sidereal day is the time it takes for the Earth to complete one full rotation on its axis relative to the distant, fixed stars. It is approximately 23 hours, 56 minutes, and 4.091 seconds long. This is slightly shorter than the 24-hour solar day, which is based on the Earth's rotation relative to the Sun.

The Planck time (tP) is the unit of time in the system of natural units known as Planck units. It is defined as the time it takes for light to travel a distance of one Planck length in a vacuum, approximately 5.39 × 10⁻⁴⁴ seconds. It represents the timescale below which the known laws of physics, including general relativity and quantum mechanics, are thought to break down.

Note: The Sidereal Day is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Planck Time belongs to the imperial/US customary system.

History of the Sidereal Day and Planck Time

The concept of the sidereal day originates from ancient astronomy. Early astronomers observed that the stars appeared to return to the same position in the sky slightly earlier each day when measured against the Sun's cycle. This discrepancy led to the understanding that the Earth's rotation period relative to the background stars (sidereal) was different from its rotation period relative to the Sun (solar). Accurate measurement of the sidereal day became crucial for precise astronomical observations and timekeeping, allowing astronomers to predict the positions of celestial objects.

The concept of Planck units, including Planck time, was first proposed by German physicist Max Planck around 1899-1900. He sought to define units based solely on fundamental physical constants, independent of human constructs. Planck time is derived from the speed of light in a vacuum (c), the gravitational constant (G), and the reduced Planck constant (ħ). It represents a fundamental timescale inherent to the universe's properties, particularly where quantum effects of gravity become significant.

Common Uses for sidereal days and Planck times

Explore the typical applications for both Sidereal Day (imperial/US) and Planck Time (imperial/US) to understand their common contexts.

Common Uses for sidereal days

The sidereal day and sidereal time are primarily used in:

Astronomy: To point telescopes accurately at celestial objects. Astronomical observatories use sidereal clocks to know when specific stars or galaxies will be overhead or in a particular position for observation.
Astrophysics: For calculations involving celestial mechanics and the timing of astronomical events.
Satellite Tracking: Used in calculations for positioning and tracking artificial satellites in Earth orbit.
Geodesy: For precise measurements related to the Earth's rotation and orientation in space.

It is generally not used for civil timekeeping, which relies on the solar day.

Common Uses for Planck times

Planck time is not used for any practical, everyday measurements due to its incredibly small magnitude. Its significance is purely theoretical:

Theoretical Physics: Used as a fundamental unit in theories attempting to unify gravity with quantum mechanics (quantum gravity).
Cosmology: Relevant in describing the very earliest moments of the universe immediately after the Big Bang, known as the Planck epoch, before which current physical theories are inapplicable.
Black Hole Physics: Used in theoretical discussions about the singularity and quantum effects near black holes.
Fundamental Limits: Represents the shortest theoretically meaningful interval of time according to current understanding of physics.

Frequently Asked Questions

Questions About Sidereal Day (sidereal day)

How long is a sidereal day in standard time?

A mean sidereal day is approximately 23 hours, 56 minutes, and 4.091 seconds (or about 86,164.091 seconds). This is roughly 3 minutes and 56 seconds shorter than a standard 24-hour solar day.

Why is a sidereal day shorter than a solar day?

A sidereal day measures Earth's rotation relative to distant stars. A solar day measures rotation relative to the Sun. As the Earth rotates, it also orbits the Sun. After one full rotation relative to the stars (one sidereal day), the Earth has moved slightly along its orbit. It needs to rotate a little bit further (about 1 degree, taking nearly 4 minutes) to bring the Sun back to the same apparent position in the sky (completing a solar day).

Is sidereal time the same everywhere on Earth?

No, just like solar time, local sidereal time depends on your longitude. At any given moment, different locations on Earth will have different local sidereal times, corresponding to which part of the celestial sphere is currently crossing their local meridian. However, the duration of a sidereal day is the same everywhere.

About Planck Time (tP)

What is the value of Planck time in seconds?

Planck time (tP) is approximately 5.391 × 10⁻⁴⁴ seconds.

Is Planck time the absolute shortest possible time?

It's considered the shortest meaningful time interval according to current physical theories. Below this scale, the concepts of space and time as we understand them are expected to break down, requiring a theory of quantum gravity for description. It's not necessarily the "shortest possible" time, but rather the limit of our current models.

Can we measure Planck time directly?

No, Planck time is far too short to be measured with any current or foreseeable technology. Its existence and value are derived theoretically from fundamental constants.

Conversion Table: Sidereal Day to Planck Time

Sidereal Day (sidereal day)	Planck Time (tP)
1	1,598,295,140,048,228,700,000,000,000,000,000,000,000,000,000,000
5	7,991,475,700,241,144,000,000,000,000,000,000,000,000,000,000,000
10	15,982,951,400,482,287,000,000,000,000,000,000,000,000,000,000,000
25	39,957,378,501,205,710,000,000,000,000,000,000,000,000,000,000,000
50	79,914,757,002,411,420,000,000,000,000,000,000,000,000,000,000,000
100	159,829,514,004,822,850,000,000,000,000,000,000,000,000,000,000,000
500	799,147,570,024,114,400,000,000,000,000,000,000,000,000,000,000,000
1,000	1,598,295,140,048,228,800,000,000,000,000,000,000,000,000,000,000,000

All Time Conversions

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