Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Unifying physics - key challenges?

  1. May 30, 2010 #1
    Hi everyone,

    Like a lot of other people, I'm keen to see physics unified. But there hasn't been much progress on this lately and I'm wondering if we need to revisit some very basic assumptions.

    I've got some proposals that I would like to be challenged on.

    Assumption 1: Atomic nuclei are single particles (there is nothing inside them)

    Evidence against:
    1a. sub-atomic particles have been observed
    1b. atomic collisions have predictable results i.e. if we hit an atom with one thing, we know what will come out the other side

    Assumption 2: 'charge' and 'mass' are two aspects of the same, more fundamental, thing

    Evidence against:
    2a. mass always attracts mass, whereas charges can attract or repel each other
    2b. the two forces involved have very different strengths

    Assumption 3: Light is made up of particles (not waves)

    Evidence against:
    3a. result of double-slit experiment
    3b. inteference patterns (thought..are these the only two pieces of evidence?)

    Assumption 4: The universe is not expanding

    Evidence against:
    4a. red-shift of light from far-away galaxies
    4b. (indirect evidence) Einstein's equations predict a dynamic universe

    Assumption 5: The universe has been around forever i.e. the Big Bang did not happen

    Evidence against:
    5a. there is light/microwave radiation from the early universe coming from all parts of the sky
    5b. we should have run out of hydrogen by now - it would have all fused to make heavier elements

    The way I see it, the first step towards a new theory is to dissect/re-explain the 'evidence against' all of these five assumptions.

    Can you think of any more evidence against these assumptions, or reasons they might not hold? Have I mis-understood anything?

    Thanks
     
  2. jcsd
  3. May 30, 2010 #2

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    I would like everyone in this thread to check the PF Rules about overly speculative posts. If this thread drifts too far in that direction, it will be closed.
     
  4. Jun 1, 2010 #3
    please don't close it up just yet :)

    Some bits of evidence are stronger than others - I'm interested to get views on these to help in working out where the gaps are.
     
  5. Jun 1, 2010 #4

    bapowell

    User Avatar
    Science Advisor

    Subatomic particles have nothing to do with subnuclear particles, which are what you are referring to. Quarks, which are subnuclear particles, have been observed in particle collisions.

    Perhaps, but as you say, they source two different types of interactions.

    Light is made up of particles (photons). The photoelectric effect captures this property of light. The wavelike nature of light results from the quantum mechanical properties of photons (this is also termed 'wave-particle duality').

    4c. Cosmic Microwave background of temperature ~ 2.7 K.
    4d. Big Bang Nucleosynthesis supports a hotter and denser early universe.

    Assumption 5 can only be true if Assumption 4 is true (ie Assumption 5 is refuted by the refutation of Assumption 4). The universe could have been around forever *and* expanding today if it is cyclic, in which case what we perceive to have been a big bang was really the start of the present phase of expansion following a previous state of contraction. But the universe does not appear to be eternal and static, for reasons suggested here and elsewhere.

    What are the deficiencies that you see with the current standard cosmology?
     
  6. Jun 1, 2010 #5
    That was very useful - thanks. Especially for pointing out 4c and 4d.

    I'm looking for simpler and more robust explanations than the ones we currently have.
    For example, if we accept Assumptions 1 and 2 then there is only one fundamental physical force (rather than four), and this should make the unification of the forces much easier.

    In the same way, if we accept Assumptions 4 and 5 (yes, 5 does depend on 4) then the features of the observable universe become much easier to explain. I think so, anyway.

    Any more thoughts?
     
  7. Jun 2, 2010 #6

    tom.stoer

    User Avatar
    Science Advisor

    Assume for a moment that dog, jellyfish and blackbird are the same species (identical, so to speak). This would make biology much simpler - but unfortunately it's wrong. So you have to go back and explain unification in biology via evolution, DNA etc.
     
  8. Jun 6, 2010 #7
    The universe is expanding. The big bang did happen
     
  9. Jun 9, 2010 #8
    accepting 1,2 or 4,5 doesn't give us better explanations or help in uni-faction each on of those 4 forces are there because we observed a group of phenomena which we were able to unify each set in single force which have differing natures, to assume only one of them u would need alot more assumptions and theories to explain all phenomena
     
  10. Jun 12, 2010 #9
    I partly see your point - if we try to simplify one part of physics we might complicate another. But that's conjecture until we actually try it :)

    The question is: where can we find new insight?

    Here are the assumptions again, slightly re-written:
    Assumption 1: Atomic nuclei are single, charged particles
    Assumption 2: 'charge' and 'mass' are two ways of trying to explain one single, more fundamental property of matter
    Assumption 3: Light is made up of particles.
    Assumption 3a: Single particles never behave like waves.
    Assumption 4: The universe is not expanding
    Assumption 5: The universe has been around forever

    To get into detail - what's the evidence against assumption 3a?
     
  11. Jun 12, 2010 #10
    because when they pass through a double slit they produce an interference pattern by making one point per particle, and u also violate the uncertainty principle.
    the wave behavior is because even when u have a point particle u can't know where it is and so it's physics is "spread" over space.
     
  12. Jun 13, 2010 #11
    Hello all, but one.
    Unification in my opinion is not something that can be applied yet. The problem isn’t finding the link between these interactions, its applying better keys to map and itemize the experiments conducted today. Galileo gala lay wasn’t limited by his telescope it was the mainstream understanding. Although he challenged and changed the understanding of our universe at the time, he still was no ware near Einstein’s General relativity. The point I’m making is, could Galileo gala lay discover Einstein’s General relativity with only research Galileo had at the time? For me to think of unification now when so many questions and variables are yet to be figured out, would be time better spent mapping unknown areas of our universe.
    TM
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Unifying physics - key challenges?
  1. Hadron physics (Replies: 3)

Loading...