Earth Shape
Earth Shape - Related Videos
02:37
Conditions on Early Earth
0 Views •
2020
Around 4 billion years ago, oceans began to condense on earth while volcanic eruptions released nitrogen, carbon dioxide, methane, ammonia, and hydrogen into the primordial atmosphere. However, organisms with the characteristics of life were not initially present on earth. Scientists have used experimentation to determine how organisms evolved that could grow, reproduce, and maintain an internal environment.In the 1920s, the scientists Oparin and Haldane proposed the idea that simple biological...
02:37
Conditions on Early Earth
0 Views •
2026
Around 4 billion years ago, oceans began to condense on earth while volcanic eruptions released nitrogen, carbon dioxide, methane, ammonia, and hydrogen into the primordial atmosphere. However, organisms with the characteristics of life were not initially present on earth. Scientists have used experimentation to determine how organisms evolved that could grow, reproduce, and maintain an internal environment.In the 1920s, the scientists Oparin and Haldane proposed the idea that simple biological...
03:37
Molecular Shape and Polarity
0 Views •
2020
Dipole Moment of a Molecule Polar covalent bonds connect two atoms with differing electronegativities, leaving one atom with a partial positive charge (δ+) and the other atom with a partial negative charge (δ–), as the electrons are pulled toward the more electronegative atom. This separation of charge gives rise to a bond dipole moment. The magnitude of a bond dipole moment is represented by the Greek letter mu (µ) and is given by the formula shown here, where Q is the magnitude of the...
09:03
Morphometric Analyses of Shape: The Analysis Software Toolbox for Craniofacial Shape Quantification in Zebrafish
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2026
This work describes a protocol for quantifying craniofacial cartilage shape using free software (tpsDigs2, MorphoJ, and PAST) to measure changes in facial structure in zebrafish larvae.
02:52
VSEPR Theory and the Basic Shapes
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2020
Overview of VSEPR Theory Valence shell electron-pair repulsion theory (VSEPR theory) enables us to predict the molecular structure, including approximate bond angles around a central atom, of a molecule from an examination of the number of bonds and lone electron pairs in its Lewis structure. The VSEPR model assumes that electron pairs in the valence shell of a central atom will adopt an arrangement that minimizes repulsions between these electron pairs by maximizing the distance between them.
FAQs
Rotation produces equatorial bulging and polar flattening, so a spherical approximation cannot represent Earth equally well at all locations. The resulting oblate spheroid provides a more suitable geometric reference for engineering measurements. Using this shape model helps geodesy, surveying, and satellite positioning account for systematic differences in position and distance calculations across latitudes.
An ellipsoid supplies a smooth mathematical reference, while the geoid follows the irregular mean sea-level surface created by gravity and variations in mass distribution. The separation between these reference surfaces is expressed through geoid heights. Accounting for that separation allows elevation measurements to relate consistently to the physical level represented by mean sea level.
The geoid departs from an ellipsoid because Earth’s gravity field is not uniform. Variations in mass distribution alter the gravitational surface that corresponds to mean sea level, producing local irregularities. These departures matter when engineers compare elevations, integrate surveying results, or transform measurements between geometric coordinate systems and references tied to Earth’s physical gravity field.
A measurement referenced to an ellipsoid can differ from one tied to the geoid because the two surfaces represent different aspects of Earth. Engineers therefore need a consistent reference when combining positions, distances, and elevations. Careful selection and transformation of reference surfaces support reliable geographic information systems, map projections, surveying, and coordination of infrastructure data.
Engineers select an appropriate reference ellipsoid for positioning and use geoid information when elevations must relate to mean sea level. They then apply these references in surveying, geographic information systems, and map projection tasks. This workflow supports consistent terrain measurement and helps infrastructure designs use coordinates and elevations that remain compatible across engineering datasets.
Geoid heights become important when design decisions depend on elevations rather than horizontal position alone. They help connect measurements made relative to an ellipsoidal reference with the irregular mean sea-level surface used to describe physical height. This connection improves terrain measurement and helps engineers coordinate elevation information during infrastructure planning and design.
Satellite positioning and orbit determination require reference models that represent Earth’s geometry and its relationship to measured locations. The oblate spheroid accounts for rotational flattening, while geoid information supports elevation interpretation and coordination with terrestrial data. Using these complementary references helps engineers maintain consistent positioning and connect satellite-derived information with maps and infrastructure measurements.