Go to Home Page
You are here
Go to Reference Section
Go to Directories Section
Go to Community Section
Go to Fun Section
Go to Science Store
Go to About PhysLink.com
Club PhysLink
   Not a member yet?
   Get Free Membership
    Remember me
   Forgot your login?
Top Destinations Menu
 Ask the ExpertsAsk the

 Physics and Astronomy Departments DirectoryUniversity

 Discussion ForumsDiscussion

 Online Chat Online

 FREE Einstein eCardsEinstein

 PhysLink.com Science eStoreScience


Chikrii Word2TeX Software

Click here for a free 2-week trial

Become a Sponsor


What force in the universe is the strongest or the most powerful?

Asked by: Regal Patel


There are four fundamental interactions that we know of. These four interactions account for all observed forces. These interactions are: Strong Nuclear, Electromagnetic, Weak Nuclear and Gravitational.

The strongest of these four is the Strong Nuclear. However, since this interaction operates at a very short range inside the nucleus (as little as 1 fm - which is a femto-meter or 10-15 meters) it is not the sort of force that we experience in everyday lives. This interaction acts between the nucleons (particles in the atomic nucleus - protons and neutrons which are made of quarks) and it is responsible for keeping the nucleus together. This interaction is mediated by so called gluons.

Strong Nuclear100Short (1 fm)Gluons (G)
Electromagnetic1LongPhotons ()
Weak Nuclear10-10Short (1 am)W+, Z0, W-
Gravitational10-40LongGravitons (g)

The next strongest interaction is the Electromagnetic one which we actually experience in everyday lives - from being 'zapped' in the dry winter weather when you walk across the carpet and then touch something metal, to lightning, to your mobile phone, to seeing light and to the very monitor on which you are reading these lines. Since this is the strongest force that actually touches our lives, physicists usually assign the strength of 1 when they talk about relative strengths of all four interactions. On this scale the previously mentioned strong nuclear force would be 100, or one hundred times stronger than the electromagnetic. The electromagnetic interaction is mediated by photons.

Then comes the Weak Nuclear which like the strong nuclear acts only at small ranges (at about 1 am - 1 atto meter = 10-18m). This interaction is also about 1010 times weaker than the electromagnetic and is responsible for the beta decay of particles and nuclei. Weak nuclear interaction is mediated by the exchange of so called intermediate vector bosons (W+, Z0, W-)

Gravitational interaction is the weakest of the four. In fact gravitational interaction is about 1040 times weaker than the electromagnetic. Are you surprised? Well, this disagreement between our perception and the actual strength of the forces is due to the fact that gravity fills our lives on a minute to minute basis and that it is an always attractive force (as compared to the electromagnetic which can be attractive and repulsive - and therefore cancels itself often.) Gravitational interaction is mediated by gravitons - which are the only interaction carrier particles that have not been discovered to date.

Answered by: Anton Skorucak, M.S. Physics, PhysLink.com Creator

go to the top  

All rights reserved. © Copyright '1995-'2004 PhysLink.com