More questions on the Universe?

Question by Yul: More questions on the Universe?
Regarding the answers to my previous questions:

So if the universe is the skin of an expanding balloon, does that mean that the black hole at the centre of the universe is in the middle/centre of the balloon? Not on the skin?
Or is the surface all that there is? (I.e. is the concept of the INSIDE of the balloon just a theoretical one?)

Are all the other black holes, which I’ve read about in Wikipedia, on the surface of the balloon or are they all on the inside?

Have all the observations made so far, using the Hubble telescope or any other telescopes or devices or techniques, been along the skin? (Is that why it’s thought light bends as it travels through space?)

Is it not possible to look across the inside of the balloon, i.e. taking a shortcut and looking in a straight line across to another point on the skin without going via the surface?

When astronomers point their telescopes in one particular direction, namely “outward” in relation to the universe’s origin, do they see only stars and planets in our own galaxy?
And is it the same when they look in the opposite direction, towards the origin?
I’m guessing that must be the case for them to come up with the “balloon” idea.

Do they see distant galaxies only when the telescopes are pointed in a plane more or less at right angles to the direction of our outward movement? Are there much more things to see and much much more radio waves detected in that plane?
Is it just a single plane that incoming signals from distant sources are confined to or is there a narrow band just below that right-angle plane which also yields such signals?
In other words is it thought there are some signals which do take a short cut across the inside of the balloon not too far below the skin.

And finally, do scientists have an estimate of the speed at which each galaxy is traveling, radially, in a straight line, away from the centre of the baloon? The speed at which the Milky Way is traveling “outwards”.
I understand a bullet fired from a rifle reaches maximum velocity on or shortly after exiting the barrel. Is it similar for galaxies fleeing a big bang, or is there thought to be no (or less) resistance for them to contend with akin to that provided by the air against a bullet’s progress? Does gravity act against galaxies’ “outward” progress?

So is the Milky Way’s outward/radial velocity constant, or is still increasing, or is it decreasing?

What sort of muzzle velocity are we talking about with the big bang? Near the speed of light? Or much less?

Is it possible there’s light from the big bang travelling with us, or is it thought to have disappeared or was destroyed immediately it outpaced the expanding universe? (Is that a stupid question?)

Thanks for all your help, much appreciated.

Best answer:

Answer by DLM
In the balloon analogy, the ‘skin’ of the baloon is the universe. Nothing exists outside (or inside) of that skin. The analogy is used to show that the universe is *up one dimension* from what we observe. The balloon shows an expanding 2-D curved surface (balloon surface) curved around a third physical dimension and expanding along that third axis. In reality, the universe is 3 physical dimensions expanding along a fourth physical dimension. But the curvature is so gradual, we do no experience it in our lives. This is why we need to scale down the universe to a surface area curving along a vloume… we can’t really show an example of a sphere curving along a fourth physical dimension to form a hypersphere, because volume is the deepest number of dimensions we can envision.

Yes, all observations are along the ‘skin.’ The ‘skin’ is all we can observe. That IS the universe. Unbounded, no center, no edges, no boundaries of any kind. You cannot look through where the universe is not. Don’t take the balloon analogy too literally. It is a tool designed to explain expansion, and unboundedness. The curvature is so gradual, we cannot detect the curvature of the baloon. Every direction we look, is so close to flat, that there is no way to see ‘the other side’.

Add your own answer in the comments!

3 comments to More questions on the Universe?

  • Prometheus

    The idea of the universe being like a balloon is somewhat misguided. In fact it is more like a muffin filled with raisins throughout in a homogenous manner. If the muffin expands, the raisins all move away from each other. In other words it is a three-dimensional analogy of the two dimensional balloon surface.

  • skepsis

    The balloon model of the universe is flawed because it only uses the surface. Some prefer the loaf-of-rising-raisin-bread model, where two raisins inside find themselves farther apart than when the expansion started.

    That black hole is at the center of our galaxy, not the universe. The universe doesn’t have anything we could call the center because we have no way to determine the outer edges. Black holes can form from collapsing or colliding stars. Many galaxies have large black holes at their centers because there is so much matter and gravity there that it often forms them spontaneously. You’ve probably seen those gravity well models that show stars and planets sinking into the skin of space. that’s just a model. The “skin” is actually three-dimensional. The “sinking” is just an analogy for the force of gravity. A black hole has a very wide zone of gravity, but ours doesn’t extend anywhere near our solar system.

    The reason light bends is gravity’s effect on space. Light has no detectable mass, but it is still affected by gravity, and the gravity of a black hole is high enough to keep any light inside from escaping. That’s why it’s black.

    Your idea of looking across the balloon is a kind of description of a wormhole, a theoretical extra-dimensional tunnel from one part of 3D time-space to another. We’ve never seen one, and I doubt we’d find one large enough or stable enough to be practical, but they are predicted by the science.

    What astronomers see are things that used to at the location they are observing. They can’t see them in the present or at any other time because of distance and the speed of light. It takes about a second for light or radio to pass between Earth and the moon. We can only see the sun as it looked eight minutes ago. Messages to the rovers on Mars take several minutes. And messages to the outer planets take hours. The light from Alpha Centuri is over four years old. The Betelgeuse we see was like that in 1996. The farther away we look, the older the light we see, and the farther the objects have moved since then.

    This means we can see into the past, but it’s far away. An experiment several years ago detected the microwave background radiation of the universe from shortly after the Big Bang, all around us, probably the oldest thing we can detect for now. We weren’t sure it existed, but we now have proof that it did happen.

    There are two ways to measure astronomical distance. For nearby stars, we can use parallax, observing a star six months apart, so we see it when Earth is at opposite sides of its orbit and notice the shift against the other stars. Farther away, we use red shift. Because the universe expands, everything is moving farther apart. The farther apart, the faster the movement. But this movement has a doppler effect, like a siren dropping pitch when it passes by. Light from receding stars gets redder. By seeing how far the light has shifted down the spectrum, we can determine how far away a galaxy is.

    The speed of the Big Bang is hard to say because space itself was expanding from zero. The best guess is that the initial inflation increased the linear dimensions of the universe by a factor of at least 10^26 (thats 1 and 26 zeroes) sometime during the first second of the universe. The energy in it expanded with it, meaning it became less dense, so some of the fundamental forces (electromagnetism, gravity, nuclear forces) could be expressed and quarks could form. There was a lot going on in a very short time.

  • uniontera6

    Uniontera number 6-1, hope it helps. This is your so-called 4 dimension.

    Uniontera number 10, hope it helps. This is your so-called black hole.

    Uniontera number 15, hope it helps. This is your so-called 2 dimension.

    Existence is the time expressed by light itself.

    1. When same times met … Arrow A (Cause of Laser / Origin of Death / Reason of Chemical reaction)
    2. When different times met … Arrow B (This is your so-called “Gravity” / Cause of Higgs boson / Origin of Life / Reason of Biological reaction)
    3. The rose line is the beginning light. (result from Genesis 1:3)
    4. The existence of different time. (result from relativity of light)
    5. 2 dimension is not a space. (result from 2-axis, math)
    6. Universe came from nothing. (result from No.5 / cf. Playing with bubbles)
    6-1. A barrier[posititon] exist between the inner and outer bubbles. But universe do not have that barrier. (Cause of Inertia / Reason of Sun / Position of Antimatter / Origin of Fire / cf. Expansion, Conservation of parity, Time-reversal invariance)
    6-2. Nothing is not a no existence. No existence is a zero dimension. There is two zero dimension. One has a position. The other doesn’t have a position. These different positions were connected by something. That “something” is not a what but a way. (Cause of Light / cf. Ether)
    7. Progress / Event / Probability is a time. (This is my trinity.)
    8. Wave-particle duality of light, creation & evolution, uncertainty principle, etc. (result from No.7)
    9. Coalescing of different times. (Cause of Rotation & Spin / Equator has plenty of time. / Origin of Colour / Reason of Reflection / cf. Strong interaction)
    10. Your so-called “Black hole” is a wholly condensed time. (cf. Kerr spacetime)
    11. The reason of your so-called “Magnetic field”. (result from step3 and 4)
    11-1. The reason of your so-called “Dark matter”. (result from step3 to 4 / Energy-Mass duality / cf. Dark energy “step4 to 3″)
    12. The reason of your so-called “Electric field”. (result from the crack of time / Same time’s crack is a different time’s connection. / Cause of Static electricity)
    13. Your so-called “Space” is a crack of time. (result from No.12 / Cause of Lightning / Reason of Refraction / cf. Weak interaction)
    13-1. The reason of your so-called “Capture & Decay”. (result from No.13′s crack of time / cf. Violation of time-reversal invariance)
    13-2. The reason of No.6-2′s “position & none position”. (result from No13-1′s “capture & decay”)
    13-3. The reason of No.13′s space. (result from No.13-2′s “position & none position” / cf. Noneconservation of parity)
    14. Boundary is a crack of space. (result from No.13 / Same space’s crack is a different time’s contact. / Cause of Superfluid / cf. Fractal)
    15. Boundary is nothing. Your so-called “Hole” is a boundary itself. Also, nothing is K=0 temperature. (result from No.14 / cf. Calabi-Yau, Hilbert space)
    16. This is a wall of your so-called “Fire”. (result from No.15) – copyright ⓒ uniontera

    Our nonsense has come from one time. Uniontera is a key.

    English is not my first language, sorry!

    If it is difficult to understand, just remember & enjoy “Hand touching everything is a time”. This is the only one result of uniontera.

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