The chain fountain phenomenon, also known as the self-siphoning beads, or Newton's beads is a physical phenomenon observed with a

chain A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A c ...

placed inside a

jar A jar is a rigid, cylindrical or slightly conical container, typically made of glass, ceramic, or plastic, with a wide mouth or opening that can be closed with a lid, screw cap, lug cap, cork stopper, roll-on cap, crimp-on cap, press-on c ...

, when one end of the chain is pulled from the jar and is allowed to fall under the influence of

gravity In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...

. This process establishes a self-sustaining flow of the chain which rises over the edge and goes down to the floor or ground beneath it, as if being sucked out of the jar by an invisible

siphon A siphon (from grc, σίφων, síphōn, "pipe, tube", also spelled nonetymologically syphon) is any of a wide variety of devices that involve the flow of liquids through tubes. In a narrower sense, the word refers particularly to a tube in a ...

. For chains with small adjacent

beads A bead is a small, decorative object that is formed in a variety of shapes and sizes of a material such as stone, bone, shell, glass, plastic, wood, or pearl and with a small hole for threading or stringing. Beads range in size from under ...

, the arc can ascend into the air over and above the edge of the jar with a noticeable gap; this gap is greater when the chain falls further.

History

The self-siphoning phenomenon has been known for some time, and had become a topic of public discussion many times in the past. Science entertainer Steve Spangler presented this phenomenon on TV in 2009. This phenomenon is classically known as Newton's beads. The effect is most pronounced when using a long

ball chain Ball chain is a type of chain consisting of small sheet metal balls connected via short lengths of wire. The balls are hollow and have two small antipodal holes. These holes accept a short length of wire deformed on the end like a rivet so that ...

. The higher the jar containing the chain is placed above the ground, the higher the chain will rise above the jar during the "siphoning" phase. As demonstrated in an experiment, when the jar is placed above the ground and the chain is sufficiently long, the arc of the chain fountain can reach a height of about above the jar. The phenomenon with the rising chain was already described in 2011 as an open problemStatement of problem 3. String of beads: "A long string of beads is released from a beaker by pulling a sufficiently long part of the chain over the edge of the beaker. Due to gravity the speed of the string increases. At a certain moment the string no longer touches the edge of the beaker. Investigate and explain the phenomenon.") for the 2012

International Young Physicists' Tournament The International Young Physicists' Tournament (IYPT), sometimes referred to as the “Physics World Cup”, is a scientific competition between teams of secondary school students. It mimics, as close as possible, the real-world scientific researc ...

(IYPT) and subsequently brought to widespread public attention in a video made by science presenter Steve Mould in 2013. Mould's YouTube video in which he demonstrated the phenomenon of self-siphoning rising beads, and his subsequent proposed explanation on a BBC show, brought the problem to the attention of academics John Biggins and Mark Warner of

Cambridge University , mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Schola ...

, who published their findings in ''

Proceedings of the Royal Society ''Proceedings of the Royal Society'' is the main research journal of the Royal Society. The journal began in 1831 and was split into two series in 1905: * Series A: for papers in physical sciences and mathematics. * Series B: for papers in life s ...

'' about what they called "chain fountain" or "Mould effect".

Explanation

A variety of explanations have been proposed as to how the phenomenon can best be explained in terms of

kinematic Kinematics is a subfield of physics, developed in classical mechanics, that describes the motion of points, bodies (objects), and systems of bodies (groups of objects) without considering the forces that cause them to move. Kinematics, as a fie ...

physics concepts such as

energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat a ...

and

momentum In Newtonian mechanics, momentum (more specifically linear momentum or translational momentum) is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction. If is an object's mass an ...

. Biggins and Warner suggest that the origin of the upward force is related to the stiffness of the chain links, and the bending restrictions of each chain joint. Furthermore, because the beads of the chain can drag laterally within the jar across other stationary links, the moving beads of the chain can bounce or jump vertically when they strike the immobile links. This effect contributes to the effect, but is not the primary driver.

References

Notes

External links

* * * *{{Cite web, last=Hell, first=Timotheus, date=September 26, 2011, title=IYPT 2012 - Problem 3: String of beads (Newton's Beads), url=https://www.youtube.com/watch?v=uf9IOpZ0tc4&ab_channel=TimotheusHell, access-date=29 July 2021, website=YouTube Science demonstrations Articles containing video clips

History

Explanation

See also

References

Notes

External links