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  1. Standard memberbunnyknight
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    25 Jun '20 03:27
    A simple way to see why space can't be empty: Imagine you are in the emptiest space between galaxies and you look around. In every direction you see distant galaxies, which means that at every instant of time the space before your eyes is filled with that visual information -- call it photons or whatever you like -- but it's there, everywhere. Thus, even intergalactic space is filled with some sort of stuff, otherwise you wouldn't see anything.
  2. Standard memberSoothfast
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    @bunnyknight said
    A simple way to see why space can't be empty: Imagine you are in the emptiest space between galaxies and you look around. In every direction you see distant galaxies, which means that at every instant of time the space before your eyes is filled with that visual information -- call it photons or whatever you like -- but it's there, everywhere. Thus, even intergalactic space is filled with some sort of stuff, otherwise you wouldn't see anything.
    Even absent the light from galaxies you mention, there is still vacuum energy.

    https://en.wikipedia.org/wiki/Vacuum_energy

    Vacuum energy is an underlying background energy that exists in space throughout the entire Universe.[1] Its behavior is codified in Heisenberg's energy–time uncertainty principle. Still, the exact effect of such fleeting bits of energy is difficult to quantify. The vacuum energy is a special case of zero-point energy that relates to the quantum vacuum.
  3. Standard memberbunnyknight
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    26 Jun '20 17:51
    @Soothfast

    Vacuum energy? Is that the official scientific name for it?
    I'd prefer to call it MISST (Mysterious Invisible Space Stuff).
  4. Subscribervenda
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    26 Jun '20 18:43
    @bunnyknight said
    @Soothfast

    Vacuum energy? Is that the official scientific name for it?
    I'd prefer to call it MISST (Mysterious Invisible Space Stuff).
    Are we talking dark matter here?
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    26 Jun '20 19:26
    yes GN-z11 is the absolute farthest, oldest galaxy ever discovered..Hubble looked at a spot they thought was "empty space" and found GN-z11... now we need james Webb
  6. Standard memberSoothfast
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    @venda said
    Are we talking dark matter here?
    No, vacuum energy is something else. I'm not a physicist so I can only refer you to the link I supplied above.

    But then again, if there is dark matter (I'm not convinced it exists), maybe it ties in somehow. There's also so-called dark energy. Maybe that plays a role. I haven't read through my own Wikipedia link completely, so I don't know.

    Virtual particles pop in and out of existence in a vacuum all the time, I believe. Maybe they derive from vacuum energy.
  7. Standard memberbunnyknight
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    26 Jun '20 23:03
    @soothfast said

    Virtual particles pop in and out of existence in a vacuum all the time, I believe. Maybe they derive from vacuum energy.
    So actual matter appears, hangs around for a while, then vanishes into nothingness?
    Do you realize the implications of that? It's beyond amazing .... it should blow your socks off.
  8. Standard memberSoothfast
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    @bunnyknight said
    So actual matter appears, hangs around for a while, then vanishes into nothingness?
    Do you realize the implications of that? It's beyond amazing .... it should blow your socks off.
    It has fascinated me since I was 15. Something like this may, perhaps, have given rise to the universe itself. It makes me philosophical, and gets me thinking that "nothing" and "something" are just two sides of the same coin: One concept cannot exist without the other.
  9. Standard memberSoothfast
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    https://en.wikipedia.org/wiki/Virtual_particle

    In physics, a virtual particle is a transient quantum fluctuation that exhibits some of the characteristics of an ordinary particle, while having its existence limited by the uncertainty principle. The concept of virtual particles arises in perturbation theory of quantum field theory where interactions between ordinary particles are described in terms of exchanges of virtual particles. A process involving virtual particles can be described by a schematic representation known as a Feynman diagram, in which virtual particles are represented by internal lines.

    Virtual particles do not necessarily carry the same mass as the corresponding real particle, although they always conserve energy and momentum. The longer the virtual particle exists, the closer its characteristics come to those of ordinary particles. They are important in the physics of many processes, including particle scattering and Casimir forces. In quantum field theory, even classical forces—such as the electromagnetic repulsion or attraction between two charges—can be thought of as due to the exchange of many virtual photons between the charges. Virtual photons are the exchange particle for the electromagnetic interaction.

    Same link, but further down the page, some mention of vacuums:
    In formal terms, a particle is considered to be an eigenstate of the particle number operator a†a, where a is the particle annihilation operator and a† the particle creation operator (sometimes collectively called ladder operators). In many cases, the particle number operator does not commute with the Hamiltonian for the system. This implies the number of particles in an area of space is not a well-defined quantity but, like other quantum observables, is represented by a probability distribution. Since these particles do not have a permanent existence, they are called virtual particles or vacuum fluctuations of vacuum energy. In a certain sense, they can be understood to be a manifestation of the time-energy uncertainty principle in a vacuum.
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    @bunnyknight said
    A simple way to see why space can't be empty: Imagine you are in the emptiest space between galaxies and you look around. In every direction you see distant galaxies, which means that at every instant of time the space before your eyes is filled with that visual information -- call it photons or whatever you like -- but it's there, everywhere. Thus, even intergalactic space is filled with some sort of stuff, otherwise you wouldn't see anything.
    Lee Smolin refers to that as space being discrete. It implies the existent of a theoretical particle called the graviton that makes up space on the planck scale level. This is basically the revival of the Aether. Many physicists avoid acknowledging this because it exposes a flaw in Einstein's claim there was no Aether, something he back peddled on with his own subsequent Aether theory in a vain attempt at damage control.
  11. Standard memberSoothfast
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    @metal-brain said
    Lee Smolin refers to that as space being discrete. It implies the existent of a theoretical particle called the graviton that makes up space on the planck scale level. This is basically the revival of the Aether. Many physicists avoid acknowledging this because it exposes a flaw in Einstein's claim there was no Aether, something he back peddled on with his own subsequent Aether theory in a vain attempt at damage control.
    I like Smolin's books. He really slams string theory in "The Trouble With Physics," and I think rightly so.
  12. SubscriberPonderable
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    @bunnyknight said
    A simple way to see why space can't be empty: Imagine you are in the emptiest space between galaxies and you look around. In every direction you see distant galaxies, which means that at every instant of time the space before your eyes is filled with that visual information -- call it photons or whatever you like -- but it's there, everywhere. Thus, even intergalactic space is filled with some sort of stuff, otherwise you wouldn't see anything.
    You are not by chance an adherent to the ether theory?
  13. Standard memberbunnyknight
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    @ponderable said
    You are not by chance an adherent to the ether theory?
    My problem is that even if I knew the precise definition of what they mean by "ether" it wouldn't help me, because in the end I have no idea what the heck that mysterious "stuff" could be. Another words -- there's insufficient data to arrive at a logical conclusion.
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    @bunnyknight said
    My problem is that even if I knew the precise definition of what they mean by "ether" it wouldn't help me, because in the end I have no idea what the heck that mysterious "stuff" could be. Another words -- there's insufficient data to arrive at a logical conclusion.
    To complicate things, there are several proposed kinds of 'ether' and 'ether' means many different things to different authors and scientists.
    The type of 'ether' that Einstein originally rejected and successfully proved (by relativity) doesn't exist was the type that was logically inconsistent with relativity. But then he later decided that another type of 'ether' that is NOT inconsistent with relativity may (or even does) exist.
    That means, contrary to what stupid metalbrain claims he made in some past posts, he was never wrong about rejecting the existence of ether because the kind of 'ether' he originally rejected is proven to not exist by relativity and the 'ether' he later talked about wasn't that type of ether but a different kind of proposed ether that does NOT contradict relativity thus, contrary to what stupid metalbrain claims, ether did NOT prove Einstein wrong about relativity. Relativity has NEVER been proven simply wrong and relativity is at least in the main correct.

    I don't know why but I have noticed that the internet is full of posts from many ignorant delusionally arrogant laypeople that are an extremely loud minority (or at least I really hope they are just a minority) who think they can prove relativity and Einstein wrong because they think they are smarter than the likes of Einstein. They all give different said 'reasons' or 'arguments' for relativity and Einstein being wrong and all of those so-called 'reasons' and 'arguments' I have read, without a SINGLE exception, are all just complete BS and show almost all of them don't understand the first thing about relativity even though they make out they understand everything about relativity while apparently none of them being able to even handle any of even the simplest equations of relativity. Some have even called Einstein "stupid" or "an idiot"; Such are their ignorant arrogant delusions.
  15. Subscribervenda
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    @humy said
    To complicate things, there are several proposed kinds of 'ether' and 'ether' means many different things to different authors and scientists.
    The type of 'ether' that Einstein originally rejected and successfully proved (by relativity) doesn't exist was the type that was logically inconsistent with relativity. But then he later decided that another type of 'ether' that is NOT ...[text shortened]... . Some have even called Einstein "stupid" or "an idiot"; Such are their ignorant arrogant delusions.
    I read once that someone said to Einstein that only 3 people in the world understood realativity.
    He went quiet, and when asked why he said
    "I am trying to think of the other 2 people"
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