Ask Ethan: Is this actually a hole in the Universe? (Synopsis)

“Youth always tries to fill the void, an old man learns to live with it.” -Mark Z. Danielewski
There are plenty of scientific myths that go around, including many that were generated recently by so-called science communicators that actively harm public knowledge. One of them was a now-famous image of a dark nebula silhouetted against a star field, claiming that this was a hole in the Universe a billion light years across with no matter in it.
Image credit: ESO, of the same object in a composite of visible, near-IR and farther-IR light. Image credit: ESO, of the same object in a composite of visible, near-IR and farther-IR light.
Not only is the image itself a completely different picture -- that of a tiny molecular gas cloud just 500 light years away -- but the study that leads to the conclusion of a "hole in the Universe" has that as only one of many possible interpretations. Far more likely is that we're simply looking at a large, underdense region that's well within the range of what's normal and expected for our Universe.
Image credit: Bill Saxton, NRAO/AUI/NSF, NASA. Image credit: Bill Saxton, NRAO/AUI/NSF, NASA.

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Maybe NASA should have a site that explains images like this.

By Robert Nemiroff (not verified) on 05 Mar 2016 #permalink

Do you not feel fortunate for a site such as this where you can ask a question and get an answer?
:)

If the Big Bang is for real, shouldn’t there be an ever-expanding empty space where it happened? Kind of like this hole?

By See Noevo (not verified) on 05 Mar 2016 #permalink

@See Noknowledge #3: Wow, it's almost as though you never, *ever* read any of the blogs to which you post so logorrhoeically! If you did, you'd know the big bang wasn't the stupidly naive "explosion" you seem to think it was.

By Michael Kelsey (not verified) on 05 Mar 2016 #permalink

What say you, Ethan?

By See Noevo (not verified) on 05 Mar 2016 #permalink

Thanks for the explanation, Ethan. So once again, a site got something wrong. So annoying.
It was discovered fairly recently that Hydrogen Sulphide could kill cancer cells. How was it reported?
Smelling farts could be good for your health
That was an actual headline. I wish I was joking.

By Julian Frost (not verified) on 05 Mar 2016 #permalink

@ Julian

Reminds me a of a movie The Shipping News with Kevin Spacey... so many memorable quotes about news reporters.... :)

Billy: It's finding the center of your story, the beating heart of it, that's what makes a reporter. You have to start by making up some headlines. You know: short, punchy, dramatic headlines. Now, have a look, what do you see?
[Points at dark clouds at the horizon]

Billy: Tell me the headline.
Quoyle: Horizon Fills With Dark Clouds?
Billy: Imminent Storm Threatens Village.
Quoyle: But what if no storm comes?
Billy: Village Spared From Deadly Storm.

---------

Jack Buggit: ...I need a reporter. And you'll do local car wrecks. Take the picture, write the story. We run a front-page photo of a car wreck every week whether or not we actually hav a a car wreck. Now, there's a knack for taking photos that make you feel something. If there's a dark patch on the ground it reads blood whether it's motor oil or Diet Coke.

By Sinisa Lazarek (not verified) on 05 Mar 2016 #permalink

The surface of a balloon explanation doesn't fly. If you deflate the balloon back to the beginning. The singularity. Then expand the universe out from there, what do you end up with. I have been hearing the same generic explanation for. .50
.years.ie I'll ask it again. Start with the singularity. Now start inflation. Now refer back to my beginning. How much sense does it make to say there is no center to the universe.

By Andromeda41 (not verified) on 06 Mar 2016 #permalink

Mr Kelsey. ....start with the singularity. Now expand space time and matter equally in all directions. (Allah big bang ) You end up with a balloon shaped universe. Now if you take our location on the balloon and wish to travel in a straight line to the opposite side of the balloon. Would you not travel through some vast void. Scientists never address getting to the opposite side of the balloon.

By Ronald E Torrisi (not verified) on 06 Mar 2016 #permalink

"The surface of a balloon explanation doesn’t fly"

Balloons float, not fly.

Apart from that, it isn't an explanation it's an analogy.

"You end up with a balloon shaped universe"

Why? Please provide your calculations indicating this.

"now if you take our location on the balloon and wish to travel in a straight line to the opposite side of the balloon. Would you not travel through some vast void."

No. Because there's no direction to get through to that void. It's not in space. Space is the surface of that balloon.

"Scientists never address getting to the opposite side of the balloon."

Yes they do.

Look up "wormhole".

@ #8 and #9: Since you're both the same person, just one answer suffices. If you don't like the balloon analogy (because you can't wrap your head around dimensionality, c.f., _Flatland_), try the analogy of an expanding (rising) loaf of raisin bread.

Picture a load of raising bread the size of a whole bakery, with raisins scattered all through it, just an inch or two apart. The whole loaf is rising, getting larger and larger, and the raisins are getting farther apart. But there is no "center" or "explosion" going on: yeast acts uniformly all through the loaf, and whole thing is getting bigger together. Sitting on any raisin, you'd see all the other raisins getting farther away.

That's a properly 3D example, so maybe it'll be easier on your brain.

By Michael Kelsey (not verified) on 06 Mar 2016 #permalink

An expanding balloon (for which only the surface is reality?)
or a rising loaf of bread (with reality morsels all through it)…

How about a compromise?
How about a donut?
You know, with a hole in the middle?

By See Noevo (not verified) on 06 Mar 2016 #permalink

Because, sn, that donut isn't a valid analogy for this case, no matter how much your lack of understanding (lack of effort to understand is the better ststememt) wants it to be. Why do you think the universe is a torus?

Michael,
Put down the raisin loaf and your speckled water balloons.
You need some perspective, literally.

No one, not even you, can 'properly' explain our spatially three dimensional universe as a two dimensional membrane or surface that somehow expands and curves like a balloon with actual volume while still pretending to call it two dimensional. This is what happens when clever and ambitious people think definitions of words don't actually apply to them because of their fancy sheepskin.

I can wrap my head around spatial dimensionality just fine, It's contradictory bullshit posing as actual comprehension which I find hard to stomach. Conflating a surface (which is three dimensional) with a two dimensional plane (which can never curve without making it a three dimensional construct) is misleading if not outright dishonest in any argument about dimensionality. All topological shenanigans (and curved maths) revolve around an underlying Euclidian geometry (flat space) that clearly defines one two and three dimensional constructions. There are no curved two dimensional planes, there are curved three dimensional surfaces. Curves (just like angles) can only be analyzed or considered in relation to straight lines. If you are going to imply that space is curved, first, you would need an external reference frame that wasn't curved for reference to ascertain the degree of curvature. You don't have this. There is no way to measure or ascertain a curve (or degree thereof) from another curve. Likewise, if you do screw with your space dimensionally (for arguments sake), like say for imaginary gravity waves ripples, etc. everything in that space would be equally screwed with, you have no way to determine it was bending, twisting, tap dancing, etc... including light. Light exists in space just as much as matter does. If matter could possibly stretch or compress with spatial distortion, why would not the light also do so? Is it immune to imaginary spatial distortion for some magical reason? There would be no way to determine if it was or wasn't unless you could actually use some external un-distorted spatial frame of reference.

@CFT #15: You are unfortunately conflating two different things, and railing mightily against the wrong one. The clones from Rockford, Illinois, were complaining that the usual "balloon analogy" for cosmological expansion implied that there must be a gigantic void in "the middle". That's nonsensical, and I presented the alternative "loaf of bread" analogy as a properly 3D alternative, with no void in the middle and no "center of explosion" to confuse matters.

You, on the other hand, are making claims against the reality, or possibility, of intrinsically curved space. Unfortunately your argument is based entirely on the assumption that your Euclidean intuition is a necessary and complete reflection of reality. This is simply an argument from personal incredulity, not a refutation of Riemannian geometry.

If you've got the mathematical background (at least undergraduate coursework through vector calculus), then you should probably look into differential geometry, which is the mathematical basis for understanding all kinds of curved geometries, not merely general relativity.

By Michael Kelsey (not verified) on 06 Mar 2016 #permalink

"No one, not even you, can ‘properly’ explain our spatially three dimensional universe ..."

... to religious nut who insists on not understanding.

FTFY.

"Conflating a surface (which is three dimensional) with a two dimensional plane (which can never curve without making it a three dimensional construct) is..."

...a common technique of explaining complex subjects by a simpler analogy.

You need to work on your understanding a little more.

Michael,
I couldn't care less about where you work,
or how educated you think you are,
Your raisin bread analogy was utter dreck.
It explained absolutely nothing, while injecting a ludicrous comparison that had nothing to do whatsoever of explaining how space devoid of matter can act like yeast bacteria in rising dough (which is matter) to expand. You even tried to rub in a little fake pseudo detail 'yeast acts uniformly ..' etc. In the future, I hope you can actually do better than non-sequitur bullshit, and a condescending 'math is reeeeealy hard' argument absurdum verecundiam. Advanced math is never a cover for a poorly explained theory.

As to your statement
"Unfortunately your argument is based entirely on the assumption that your Euclidean intuition is a necessary and complete reflection of reality. This is simply an argument from personal incredulity, not a refutation of Riemannian geometry"
This is utterly non sequitur as well. Re- read my argument. I stated that for you to analyze a curve, you would need a straight line. If you have no straight lines, you can do precious little with a curve for analysis or measurement.

"Michael,
I couldn’t care less about where you work,
or how educated you think you are,
Your raisin bread analogy was utter dreck."

Nonsequitur there too.

Not caring about either those things isn't an explanation of why you "think" that raisin bread analogy was utter dreck (nor what you mean by it).

If you said you didn't think it helped, then that's your opinion.

You're presending this opinion however as if it were unvarnished fact.

I DON'T CARE if you don't care or know what Michael does. Your claims are bullshit.

As to your statement
“Unfortunately your argument is based entirely on the assumption that your Euclidean intuition is a necessary and complete reflection of reality. This is simply an argument from personal incredulity, not a refutation of Riemannian geometry”
This is utterly non sequitur as well

Look, just because I taught you a new word today doesn't mean you can just go calling things nonsequiturs.

Your "argument" was about dimensions of directions and representations of higher dimensionality orthogonal directions maps incorrectly onto three dimensional orthogonality was not usefully represented.

Therefore a rebuttal based on euclidian (orthogonal three dimensionality) assertions being incorrect at least as far as claiming a priori valid and inviolate, is absolutely correct.

Whether the argument holds accurate you can feasibly defend, but you can't go claiming it non sequitur and ignore it completely.

Try holding the first rather than lazily going for the second option.

The plum pudding expanding is not creating "more plum pudding", the spaces between the bits of plum pudding are getting bigger.

And they're getting bigger everywhere.

So the plum pudding expands and each raisin in the pudding sees every other raisin rushing away.

Where, exactly, is the problem in this analogy?

The only one I can see is that the pudding expands into the outside space whereas for the universe, there is nothing to expand into.

However, since "what space is expanding into?" isn't the query for the analogy, it's hardly relevant.

Wow,
Plum pudding is not space expanding. Plum pudding expanding is an object expanding if it expands at all. End of useless analogy.
But what the hell, I can hand wave too, here goes...

Space is not an object like the Plum pudding is an object. You could consider space as a volume using abstraction, but just because you can do that does not ascribe to it physical properties the same as physical objects with actual extension and mass. If you are going to say a physical object expands, You must consider volume and density, porosity, temperature, mass uniformity etc. If you are going to say a distance expands you are being poetically sloppy at best, merely being euphemistic with your linguistics. Space can not be compressed, or stretched, bent or twisted. It has no physical component or structure that can do or carry any of these things or manipulations mechanically, and any engineer would tell you so, hand waving such badly assigned properties without even a degree of freedom on which to hang it is crappy theory. But, for the sake of your argument, If space COULD be manipulated in any such ridiculous fashion (as the very basis of LIGO assumes and depends upon), you would have no way with which to determine it, as being inside the space, you would be (according to what relativity actually means) equally bent, twisted, expanded, whatever. Inside of said space, light will twist and expand, distort, etc. along with everything else and none will be the wiser, how else could it be? For light to move in deviation to what appeared (within the curved space)to be straight lines, it would have to be informed by some external property that was not distorted like the space you were inside of. The only way you could determine or measure the extent of your deformation in such a speculation would be for you to magically step outside of the distortion (which you can't do, since there is no position 'outside' of the imagined contorted space in which you could hover and observe from, you are a part of the distortion as well) and measure the distortion against some non distorted meter, like using a level against an uneven wall, or a right angle ruler against an untrue corner in a house. If you live by the Relativistic sword, you die by it too Wow.
Hand waving ridiculous situations into existence by decree and then refusing to abide by the logical limitations and constraints imposed by such situations is the hallmark of bad mathematicians pretending to be good physicists, and the absolute fricking nightmare of any engineer trying to work with said pseudo-physicist.

@ CFT

There seems to be a lot of anger in what you are writing, why is that? On the other hand, there are big holes in your arguments, and a lot of misunderstanding of some basics.
On the other hand, you offer no plausible alternatives.

If you come to accept what GR is saying, then yes space-time is in a sense a real physical thing, because "stuff" directly operates on properties of spacetime and spacetime operates back on "stuff". And it works amazingly well... up to "c" scales. Visible proof.. lensing rings for one. So there's that. and now waves.

So if you find all that utterly wrong for some reason...what's the alternative and why? Is spacetime is abstraction.. what are those "abstract" circles around galaxy clusters that bend light like glass or water does? Give a valid alternative that explain all the things and phenomena that GR does and more beyond "c"... otherwise you're just trolling due to your own poorly done homework.

By Sinisa Lazarek (not verified) on 07 Mar 2016 #permalink

"Wow,
Plum pudding is not space expanding"

analogy/əˈnalədʒi/
noun

a comparison between one thing and another, typically for the purpose of explanation or clarification.

as opposed to

example/ɪɡˈzɑːmp(ə)l,ɛɡ-/
noun
a thing characteristic of its kind or illustrating a general rule.
a person or thing regarded in terms of their fitness to be imitated.

I realise you're really desperate to keep your beliefs intact, but your complaint really doesn't exist. analogies are not examples of the thing, they are analogous. Therefore an analogy not being an example of the thing analogised is not a fault with the analogy.

"There seems to be a lot of anger in what you are writing, why is that?"

Does it actually matter, though?

CFT is wrong and digging deeper. Nuff said.

"if you live by the Relativistic sword, you die by it too Wow."

I take it this isn't a LITERAL sword, right? Because Relativistic isn't a sword.

If so, yes, fair enough.

However, problem here is that your attempt to skewer me with it is a failure because you're unable to get past your investment in "Michael is wrong". Apparently because he's educated.

You credited ESO in tis article but failed to tell us which ESO assets were used in this work. If assets of an astronomical organization are involved, they should be credited. As an ardent supporter of ESO, I would like to know which ESO assets were involved.

By richard mitnick (not verified) on 12 Mar 2016 #permalink