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Physical matter

  1. Oct 25, 2012 #1
    Is it agreed among the experts that physical matter as observed in nature and generally also space and time(classicality) have the properties they do, only because of the low energy limit that they have now(as opposed to the immense mass, gravity and energy density at the BB or a blackhole)? As an example - ultra high energy collisions of hadrons(physical matter) are theorized to lead to tiny black holes which seem to support the idea that what we observe as a classical universe is just a particular low energy state(of a unified field?) and at ultra high energies completely new physics could be found explaining black holes and singularities? Is the low energy limit responsible for the emergence of spacetime as we observe it and, assuming all of the above is roughly correct, at what energy levels are the respective fields conjectured to lead to its emergence?
    Last edited: Oct 25, 2012
  2. jcsd
  3. Oct 25, 2012 #2
    I really don't understand what your question is (sounds like you're confused about some terminology though), but if you're asking what kinds of physics exist in regimes we know nothing about how do you expect anyone to have an answer?
  4. Oct 25, 2012 #3

    You are making it sound as if high energy physics and colliders haven't been around for decades and no experiemental evidence has been gathered so far. There is nothing new in my statements except maybe mini black holes creation through high energy collisions in colliders, but this is a majority point of view and well established in known physics.

    What is probably unknown(is it?) is the energy level and temperature at which it becomes(will become) meaningful to speak of observable spacetime and matter or vice-versa - the collision energies at which singularities are likely to form and known physics to break down. While it's true that there are grey areas in fundamental physics, there are multiple approaches to unification that all appear to converge around the points i mentioned in the previous post(and at this forum in particular you could find all types of experts - from the so-so run-of-the-mill physicist to the latest research, cutting edge of physics types, hence my questions).

    PP. I am tacitly assuming that spacetime was created at and after the Big Bang and was not pre-existing and infinite in extent, which appears to be the majority view nowadays.
    Last edited: Oct 25, 2012
  5. Oct 25, 2012 #4


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    I believe that the laws of physics take on a different approach when we get to extremely high energies. Or rather, not that the laws themselves change, but that the conditions change and according to the laws we start getting things that we would consider "weird", such as quark-gluon plasmas. The problem is that we don't know the rules well enough to accurately predict what happens above certain energies.
  6. Nov 16, 2013 #5

    Simon Bridge

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    Um - it is more that it is generally held that the World of Known Physics is a subset of all the physics that can be known. In seeking out the rest of physics - the Unknown Physics - we need to look to conditions and situations that are not commonly encountered.

    So we expect to see new results at very low energies - i.e. close to absolute zero - and at energies much higher than we normally expect. We may also see odd things in unusual juxtapositions of circumstances. There's still a way to go in things like life sciences, say, which happen at commonly encountered energies. It's just that if you want to find unusual science you need to look in unusual places.

    Whenever we discover some previously unknown physics we say that we have obtained a more complete understanding of the Universe than we had before.

    Which energies (to get to the question) depends on the field - there is no one answer: exploration at any energy could potentially yield a more complete understanding of physics.
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