Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

X-ray Imaging

X-ray Imaging

German physicist Wilhelm Röntgen (1845–1923) was experimenting with electrical current when he discovered that a mysterious and invisible "ray" would pass through his flesh but leave an outline of his bones on a screen coated with a metal compound. In 1895, Röntgen made the first durable record of the internal parts of a living human: an "X-ray" image (as it came to be called) of his wife’s hand. Scientists worldwide quickly began their own experiments with X-rays, and by 1900, X-ray was widely...

Variation in Acceleration due to Gravity near the Earth's Surface

Variation in Acceleration due to Gravity near the Earth's Surface

An object's apparent weight is its weight measured by a spring balance at its location. It is different from its true weight, the force with which the Earth pulls it, because of the Earth's rotation. Mathematically, an object's apparent weight equals its true weight minus the centripetal force that keeps it in a circular motion along with the Earth's surface every 24 hours.
The difference between the true and apparent weights is proportional to the square of the Earth's angular speed. Since the...

Relative Motion Analysis - Acceleration

Relative Motion Analysis - Acceleration

A slider-crank mechanism converts rotational motion from the crank into linear motion of the slider or vice versa. This mechanism consists of three main parts: the crank, the connecting rod, and the slider. The movement of the slider-crank is an example of general plane motion as the fluctuating angle between the crank and the connecting rod. Consider a segment AB where point A is at the end of the slider and point B is on the diametrically opposite end to point A, on a crack. The variance in...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Universal Modified Newtonian Dynamics Relation between the Baryonic and "Dynamical" Central Surface Densities of Disc Galaxies.

Physical review letters·2016

Same author

Testing the MOND paradigm of modified dynamics with galaxy-galaxy gravitational lensing.

Physical review letters·2013

Same author

Global deep-MOND parameter as a theory discriminant.

Physical review letters·2013

Same author

Gravitational Cherenkov losses in theories based on modified Newtonian dynamics.

Physical review letters·2011

Same author

Does dark matter really exist?

Scientific American·2002

Search research articles

Related Experiment Video

Updated: May 18, 2026

X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging

X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging

Published on: September 11, 2011

Testing MOND over a wide acceleration range in x-ray ellipticals.

Mordehai Milgrom¹

¹DPPA, Weizmann Institute of Science, Rehovot 76100, Israel.

Physical Review Letters

|October 4, 2012

Summary

Modified Newtonian Dynamics (MOND) accurately predicts the gravitational fields of elliptical galaxies NGC 720 and NGC 1521. This study offers strong evidence for MOND, challenging the need for dark matter in galaxy dynamics.

Area of Science:

Astrophysics
Cosmology
Galactic Dynamics

Background:

Gravitational fields of elliptical galaxies were measured to large radii.
Previous MOND tests were primarily conducted on disk galaxies.

Purpose of the Study:

To test Modified Newtonian Dynamics (MOND) in elliptical galaxies.
To compare MOND predictions with observed gravitational fields.

Main Methods:

Hydrostatic balance of hot gas was assumed for measurements.
Dynamical mass runs were analyzed in the context of MOND.

Main Results:

MOND accurately predicts the dynamical mass runs for NGC 720 and NGC 1521.
A significant mass discrepancy, increasing with radius, was observed, consistent with MOND.

More Related Videos

Use of a Linear Accelerator for Conducting In Vitro Radiobiology Experiments

Use of a Linear Accelerator for Conducting In Vitro Radiobiology Experiments

Published on: May 26, 2019

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

Published on: April 13, 2016

Related Experiment Videos

Last Updated: May 18, 2026

X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging

X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging

Published on: September 11, 2011

Use of a Linear Accelerator for Conducting In Vitro Radiobiology Experiments

Use of a Linear Accelerator for Conducting In Vitro Radiobiology Experiments

Published on: May 26, 2019

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

Published on: April 13, 2016

Conclusions:

The study provides strong evidence supporting MOND in elliptical galaxies.
These findings have significant implications for the dark matter versus MOND debate.