Symmetry has been one of the guiding principles in physicists' search for fundamental laws of nature. What does it mean that laws of nature have symmetry? It means that laws look the same before and after an operation, similar ...
General Physics
Jan 24, 2020
32
4638
We can model the motions of planets in the Solar System quite accurately using Newton's laws of physics. But in the early 1970s, scientists noticed that this didn't work for disk galaxies—stars at their outer edges, far ...
Astronomy
Jul 8, 2022
157
3200
Researchers at UCL and the University of Cambridge have discovered a new type of ice that more closely resembles liquid water than any other known ices and that may rewrite our understanding of water and its many anomalies.
Analytical Chemistry
Feb 2, 2023
1
748
Not only does a universal constant seem annoyingly inconstant at the outer fringes of the cosmos, it occurs in only one direction, which is downright weird.
General Physics
Apr 27, 2020
28
16302
Physicists from Lancaster University have established why objects moving through superfluid helium-3 lack a speed limit in a continuation of earlier Lancaster research.
General Physics
Sep 21, 2020
97
6684
Scientists have long studied the work of Subrahmanyan Chandrasekhar, the Indian-born American astrophysicist who won the Nobel Prize in 1983, but few know that his research on stellar and planetary dynamics owes a deep debt ...
Planetary Sciences
Sep 15, 2022
5
2415
Scientists have uncovered a root cause of the growth of needle-like structures—known as dendrites and whiskers—that plague lithium batteries, sometimes causing a short circuit, failure, or even a fire.
Nanophysics
Oct 14, 2019
11
888
The Large Hadron Collider plays with Albert Einstein's famous equation, E = mc2, to transform matter into energy and then back into different forms of matter. But on rare occasions, it can skip the first step and collide ...
General Physics
Sep 3, 2020
4
2382
The outskirts of the Milky Way are home to the galaxy's oldest stars. But astronomers have spotted something unexpected in this celestial retirement community: a flock of young stars.
Astronomy
Jan 8, 2020
8
5105
Much ado was made about the Higgs boson when this elusive particle was discovered in 2012. Though it was touted as giving ordinary matter mass, interactions with the Higgs field only generate about 1 percent of ordinary mass. ...
General Physics
Aug 3, 2022
9
420
In physics, a force is any influence that causes an object to undergo a change in speed, a change in direction, or a change in shape. In other words, a force is that which can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate, or which can cause a flexible object to deform. Force can also be described by intuitive concepts such as a push or pull. A force has both magnitude and direction, making it a vector quantity. Newton's second law, F=ma, was originally formulated in slightly different, but equivalent terms: the original version states that the net force acting upon an object is equal to the rate at which its momentum changes.
Related concepts to force include: thrust, which increases the velocity of an object; drag, which decreases the velocity of an object; and torque which produces changes in rotational speed of an object. Forces which do not act uniformly on all parts of a body will also cause mechanical stresses, a technical term for influences which cause deformation of matter. While mechanical stress can remain embedded in a solid object, gradually deforming it, mechanical stress in a fluid determines changes in its pressure and volume.
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