1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

LHC and seeing (simulating) particles

  1. Jun 30, 2013 #1
    Sorry if this question is stupid, but how particles are simulated (seen) in the LHC like this

    does not that contradict with uncertainty principle ?
    Can we actually see particles ?
  2. jcsd
  3. Jun 30, 2013 #2
    No.You don't actually see particles. What happens is the particles leave tracks in detectors and that data is changed into something that can be illustrated with a computer.

    Seeing is a biologgical process of photons entering the eye and being processed by the brain. In reallity we only really "see" light. When it is said that we "see" something what we mean is that what we are observing is interacting with light and its the light coming from the object that we see.

    Consider a tunneling electron microscope. Current is established through the tip of a needle, the strength of the current being a function of the distance between needle and the sea of electrons which comprise the outer conduction electrons in matter. That current is recorded and then the data displayed on a computer screen the like. What is illustrated by the computer is a representation of the surface of matter. In this way we can "see" the atoms that comprise the surface of the material we are analyzing. But what we're really looking at is an averaged out representation of what is being analyzed.

    Make sense?
  4. Jun 30, 2013 #3
    Thanks, It makes sense now.
    but what if there are particles out there that does not interact with electric current, is not that possible ? wont these particles be left unrecognized although they are actually there ?
  5. Jun 30, 2013 #4


    User Avatar
    Staff Emeritus
    Science Advisor

    Ah, but if we DON'T see these particles, then we will see a loss of energy and know that such particles exist. That is actually one of the goals of some of the detectors.

    And yes, there are already particles that do not interact via the electromagnetic force. They are called neutrinos. They can still be detected because they interact via the weak force and can impart momentum and energy into other particles that also interact via the weak force. You'd basically see a particle somewhere in the detector get hit out of nowhere and then see a trail as that initial particle hits others. Knowing what type of particle got hit, you can calculate the energy of the collision and determine what hit it.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook