4th dimension is extension of 3rd dimension. A world within worlds

Discussion in 'Pseudoscience' started by akabrutus, May 2, 2020.

  1. Michael 345 New year. PRESENT is 70 years old Valued Senior Member

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    No

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  3. Write4U Valued Senior Member

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    But if there is a volume of space with an absence of light, would that not affect the density of that volume in some way?

    For one thing there is an absence of photons throughout the entire shadow cone, except for some ambient light refracted from the illuminated sides.

    No difference in temperature, expansion, humdity, ???
     
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  5. Michael 345 New year. PRESENT is 70 years old Valued Senior Member

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    What the above has to do with a shadow being 3D I have no idea

    Density - slight increase
    Temperature - slight decrease
    Expansion - ?
    Humidity - ?
    Earth magnetic field - same
    Earth gravity field - same
    Neutrinos - no change
    UFOs - remain at zero

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  7. Write4U Valued Senior Member

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    A volume is by definition a property of a 3D object, no....

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    Think about this. The idea is not as unique as it sounds. A shadow is a local phenomenon which has a different density as the adjacent lighted area?
     
  8. Michael 345 New year. PRESENT is 70 years old Valued Senior Member

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    I'm thinking but my 3 neurone brain Huwey Dewey and Louie are failing to see what point you are trying to make

    The density of a adjacent area (same dimensions and volume) would be minute and would depend greatly on temperature and heat exchange between the two regions

    A vacuum also has 3D defined area

    Again what is your point?

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  9. Write4U Valued Senior Member

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    Sorry, let me try to explain my perspective.

    Consider the moon for a moment. The difference in temperature of the lit (light cone) side and the dark (shadow cone) side of the moon is about + 300 degrees Celsius

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    260 degrees Fahrenheit
    China's Chang'e-4 to take the far side of the moon's ...

    Clearly anything within the shadow cone of the moon will exhibit the absence of solar warmth, in how many possible ways?

    Will the Solar Eclipse Have an Impact on the Weather?
    BY DENNIS MERSEREAU
    JULY 21, 2017

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    https://www.mentalfloss.com/article/502885/will-solar-eclipse-have-impact-weather


    Does a shadow cause all objects within the cone to gain density and mass?
     
    Last edited: Jul 1, 2020
  10. Michael 345 New year. PRESENT is 70 years old Valued Senior Member

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    Clearly yes. Noted in solar eclipses. Shadow of the Moon moves over the Earth and if you happen to be in the shadow you notice a slight drop in temperature

    Still not clear about what this has to do with a your calling a shadow 2D and my calling a shadow 3D

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  11. Write4U Valued Senior Member

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    A 2D plane has no volume, it is a slice of the cone.
    OTOH , a 3D shadow cone does have "volume" and everything within the volume of the cone is affected in some very specific ways different from the lit part of the surrounding space, including the 2D projection of the shadow. It's cool in the shade...everywhere...

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    You lie in the sun a few hours and you get sunburn. Lie in the shade and you can spend all day on the beach.

    IMO, the volume of a shadow has a real effect on the physical objects inside its cone...

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    ....[[[[

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    ]]]]
    ....

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    Last edited: Jul 1, 2020
  12. exchemist Valued Senior Member

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    You would still have the CMBR and you would still have radiation from the object casting the shadow, unless that object were at absolute zero - which is impossible. So even in shadow there is always radiation.
     
  13. Michael 345 New year. PRESENT is 70 years old Valued Senior Member

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    A slice of the cone would be 3D

    As per a slice of bread

    Insert something in the shadow, ie between light source and original surface where the light was originally finished, you create a shorter shadow, still 3D, between the light source and new inserted object

    Depending on numerous factors what you finish up with from the new inserted object to the original surface, where originally the light finished, I will let you calculate

    Good luck

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  14. Write4U Valued Senior Member

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    I am not disputing that. In fact I stipulated that.
    My impression was that within the shadow cone, conditions are different than in the adjacent lighted areas. I don't think that was an unreasonable assumption......

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    Hence my question if inside the shadow cone, spacetime is denser than when the obstruction is removed and that volume of spacetime is not "in the shadow".
     
    Last edited: Jul 1, 2020
  15. Write4U Valued Senior Member

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    Let me clarify. The cast shadow on a surface is a 2d plane. The entire shadow cone represent a 3d volume. Is that better?
     
  16. exchemist Valued Senior Member

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    OK, so you are asking what difference to the "density" of spacetime it makes if there is a lower intensity of radiation in one volume of space than in another.

    First of all spacetime is not space, and with this business involving shadows you are talking about space. Space has no mass and therefore no density. Radiation has no rest mass either, so no density - unless you mean density of the radiation rather than mass, in which case the answer is obvious.

    I have no idea whether it means anything to talk about a density of spacetime. The term does not seem applicable, but I don't pretend to know my way around general relativity.
     
  17. Write4U Valued Senior Member

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    No, not necessarily radiation, but it seems to me that space behaves differently when cold than when warm, no?
    Space has no mass? No dark matter, no dark energy?
    I am not necessarily disagreeing with you, but it seems to me that space has defined properties and that these properties (whatever they are) of space are affected by temperature.

    How do you define space? Space - Wikipedia
    en.wikipedia.org › wiki › Space

    Does empty space have mass?
    https://www.edge.org/response-detail/26727

    However, it seems that space is not massless. Hence the question stands; "does temperature affect the fabric and behavior of spacetime"?
     
  18. DaveC426913 Valued Senior Member

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    Temperature is a property of collective matter; space in-and-of-itself cannot - by definition, have temperature.

    Unfortunately, as is your habit, you will use weasel words to argue - using a word in one form to mean one thing and then another form to mean another thing.

    So, to be clear: space - in-and-of itself - as distinct from the matter that populates it - has no mass, no matter, no temperature, no dark matter.

    If you forego the sloppiness of usage of terms, you will find the world makes a lot more sense - and so do you.
     
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  19. exchemist Valued Senior Member

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    Yes, that's right - no.

    Space does NOT behave differently when "cold" than when "hot" for the reason Dave gives: it can't be either hot or cold. Without matter, there is no temperature. And by definition "space" means a total absence of matter.

    Space has no "defined properties", so far as I am aware, apart from the values of its dielectric permittivity and magnetic permeability.

    Dark matter is nothing to do with space. If it exists, it is matter, not space.

    Dark energy is a placeholder: we have no idea what it is, if it exists. It's just a fudge factor to make the equations come out right, so far.
     
  20. Write4U Valued Senior Member

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    Well that could be one of my arguments, but that does not seem to be the case.

    https://www.edge.org/response-detail/26727

    Apparently you are not correct in stating that space has a NO measurable properties.
    Space as defined in science seems to have defined properties. See above.
    Apparently you are wrong in a scientific sense.
    So mainstream science has no clue as to what they're talking about? OK.....

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  21. Write4U Valued Senior Member

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    Fudging!
    The pot calling the kettle black. Fudging.
    Wow, they awarded a Nobel prize for "nothing" ?
    Actually, the world makes perfect sense to me. Mathematically speaking, everything has an inherent "value" or "potential". If not, it cannot exist.

    Apparently the universe does not make sense to you! I can't do anything about that.......

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    Last edited: Jul 1, 2020
  22. paddoboy Valued Senior Member

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    The CMBR at 2.73 K is the temperature of space...the relic, left over heat of the BB itself.
    The most obvious property of space is that it expands. It is also a variable quantity linked with time.
    DM certainly is matter, that lacks the properties we see in normal baryonic matter.
    DE makes up about 70% of the universe...fairly substantial, and while we do not know much about it, it does appear to be a property of space, like the CC.
    Space is variable...time is variable, but spacetime is invariant.

    The following article gives some information and thoughts and facts with regards to the energy/density of space.
    http://math.ucr.edu/home/baez/vacuu...asurements that have,9 joules per cubic meter.
    extract:
    "So, when you ask about the energy density of the vacuum, you get different answers depending on whether the person answering you is basing their answer on general relativity or quantum field theory. Let me run through the 5 most common answers, explaining how people reach these different answers:



    1. We can measure the energy density of the vacuum through astronomical observations that determine the curvature of spacetime. All the measurements that have been done agree that the energy density is VERY CLOSE TO ZERO. In terms of mass density, its absolute value is less than 10-26 kilograms per cubic meter. In terms of energy density, this is about 10-9 joules per cubic meter.
      One can know something is very close to zero without knowing whether it is positive, negative or zero. For a long time that's how it was with the cosmological constant. But, recent measurements by the Wilkinson Microwave Anisotropy Probe and many other experiments seem to be converging on a positive cosmological constant, equal to roughly 7 × 10-27 kilograms per cubic meter. This corresponds to a positive energy density of about 6 × 10-10 joules per cubic meter.

      The reason they get a positive energy density is very interesting. Thanks to the redshifts of distant galaxies and quasars, we've known for a long time that the universe is expanding. The new data shows something surprising: this expansion is speeding up. Ordinary matter can only make the expansion slow down, since gravity attracts - at least for ordinary matter.

      What can possibly make the expansion speed up, then? Well, general relativity says that if the vacuum has energy density, it must also have pressure! In fact, it must have a pressure equal to exactly -1 times its energy density, in units where the speed of light and Newton's gravitational constant equal 1. Positive energy density makes the expansion of the universe tend to slow down... but negative pressure makes the expansion tend to speed up.

      More precisely, the rate at which the expansion of the universe accelerates is proportional to

      - ρ - 3P
      where ρ is the energy density and P is the pressure. (This isn't supposed to be obvious: there's a nontrivial calculation involved, and I'm just telling you the final result. The 3 is there because there are 3 dimensions of space, oddly enough.)

      But as I mentioned, for the vacuum the pressure is minus the energy density: P = -ρ. So, the rate at which the vacuum makes the expansion of the universe accelerate is proportional to

      2 ρ
      From this, it follows that if the vacuum has positive energy density, the expansion of the universe will tend to speed up! This is what people see. And, vacuum energy is currently the most plausible explanation known for what's going on.

      Of course, to believe this argument at all, one must have some confidence in general relativity. To believe scientists' attempts to determine an actual value for the energy density of spacetime, one must have more confidence in general relativity, and also other assumptions about cosmology. However, the basic fact that the energy density of spacetime is very close to zero is almost unarguable: for it to be false, general relativity would have to be very wrong."
     
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  23. exchemist Valued Senior Member

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    I don't know why you ask, if you think you already know the answer.

    What I'm telling you is what mainstream science says, to the best of my knowledge.

    I repeat, nobody has any clue at all what "dark energy" may be: it is a just a placeholder label for something not understood.

    I also repeat that space has no temperature, because it contains no matter, as Dave said.

    Now, on the point about whether the vacuum has an energy density (as opposed to spacetime having a density, which is what you asked earlier), this is contentious and unresolved. Theory suggest there may be a non-zero vacuum energy, but there are hugely conflicting ways of estimating it and no observational evidence to resolve this. Linde, who you quote, takes one view but I do not believe it is accurate to represent his view as that of "mainstream science". The Nobel Prize referred to was for the observational evidence of accelerating expansion of the universe, hence confirming the need for the placeholder of "dark energy". It was NOT awarded for any observations about vacuum energy. Linking the two seems to make sense, but remains conjecture unsupported by observation.

    (By the way, since any vacuum energy is zero point energy, it can't contribute to temperature).

    Now, before you go off and trawl the internet for more stuff which you hope will contradict what I have said, I should tell you that I am getting bored with this game.

    Any further reply I make will depend on how interesting I find it to respond. I have no interest in playing tennis for the sake of it, especially with someone who doesn't think or argue straight.
     

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