Please register and log-in to create and edit pages

User Tools

    Please register and log-in to create and edit pages

Site Tools


Main Menu

Main menu
Click categories to expand

Other categories


A-Z listingplugin-autotooltip__plain plugin-autotooltip_bigA-Z listing

This is an alphabetical index of all content pages.


Also see

Importance Ratingsplugin-autotooltip__plain plugin-autotooltip_bigImportance ratings

In a departure from the usual Wiki format, Wikenigma assigns 'Importance Ratings' to some pages.

The idea is to separate articles which are considered (by the editors) to cover exceptionally important unknown issues from those which (although also u…

Newsplugin-autotooltip__plain plugin-autotooltip_bigNews

[ newest at the top ]

• Mar. 2021 : Many thanks to the The British Library, which has now begun permanently archiving the contents of Wikenigma.

• Jan. 2021 : A milestone of 600 unknown articles has been reached.

• Oct. 2020 : A milestone of 500 unknown article…

Contactsplugin-autotooltip__plain plugin-autotooltip_bigContacts

Use this form to send a message to Wikenigma . . . [ * note: all fields must be completed ]

Legalplugin-autotooltip__plain plugin-autotooltip_bigLegal

Content in general

Please note that in common with other publicly editable wikis, this website is not responsible for content posted by the public. Nevertheless, the ongoing editing process should be able to remove unsuitable content in a reasonable time. If you…

Donate/Sponsorplugin-autotooltip__plain plugin-autotooltip_bigDonate to Wikenigma . . .

The best way to donate is by adding new original content !

That can either be by contributing to an existing article, or by creating a new page with an as-yet-unlisted 'Known Unknown'.

Any registered user can create content.

Registerplugin-autotooltip__plain plugin-autotooltip_bigRegistration

At present, only registered users can create and edit articles.

If you'd like to register as a contributor, please request a password.

When filling in the form, make sure you supply a valid e-mail address, as the login password will be sent to that addre…


Wikenigma supports:


Utilities
rss / xml feed
sitemap file
A-Z listing (archived)plugin-autotooltip__plain plugin-autotooltip_bigA-Z listing (archived)

This is an older, partial A-Z listing intended for search engines only.

Last updated : May 2021

For an up-to-date list see A-Z listing in the Main Menu

'Abracadabra' etymology

Acamprosate

Acrocyanosis

Acupuncture

Attention-Deficit / Hypera…

Wikenigma - an Encyclopaedia of Unknowns Wikenigma - an Encyclopaedia of the Unknown Science

Proton Mass Calculations

The mass of a proton has only been calculated to an accuracy of around 4% - (roughly 938 MeV/c2 or 1.672 × 10-27 kg). The constituent particles - quarks and gluons - which make up the proton have individual masses that add up to only around 1% or so of the measured mass (which can be determined accurately with specialised devices called Penning traps , see: Phys. Rev. Lett. 119, 033001 )

In order to explain the missing 99%, the constituent particles are thought to be 'vibrating' (and otherwise interacting) at near light-speed - which, because of relativistic effects, increases their apparent mass (plus the interaction-energy of the strong nuclear forces that hold the proton together).

The picture is further complicated by the fact that protons (and neutrons) have (on average) three quarks each. Because they are in constant 'motion', calculating the forces between them invokes the classic 'Three Body Problem'.

In order to simplify the calculations, researchers instead work on the basis that the quarks are in pairs - called 'diquarks'. This is a known oversimplification. Even so, the calculations are so complex that supercomputers are needed. And the accuracy of the calculations still has a 4% error margin.

See Wikipedia

Notes:

1) Similar lack of precision affects calculations of the mass of neutrons.

2) Since most of the mass of matter comes from the protons and neutorns which it contains, it follows that around 99% of the mass of all matter is derived from relativistic (i.e. near lightspeed) effects.


Also see : Proton radius puzzleplugin-autotooltip__plain plugin-autotooltip_bigProton radius puzzle

Until 2010, measurements (backed up by theory) had put the radius of the proton at about 0.87 femtometres, but in that year, experiments at the Max Planck Institute of Quantum Optics in Germany found a 4% discrepancy.

And in 2016, new experiments …


    Share this page :

X

Dear reader : Do you have any suggestions for the site's content?

Ideas for new topics, and suggested additions / corrections for old ones, are always welcome.

If you have skills or interests in a particular field, and have suggestions for Wikenigma, get in touch !


Or, if you'd like to become a regular contributor . . . request a login password. Registered users can edit the entire content of the site, and also create new pages.

( The 'Notes for contributors' section in the main menu has further information and guidelines etc.)

Show another (random) page

DOKUWIKI IMPLEMENTATION DESIGN BY UNIV.ORG.UK MAY 2021