from the are-we-the-good-parallel-or-the-bad-parallel dept.
Scientists have long tried to explain the origin of a mysterious, large and anomalously cold region of the sky. In 2015, they came close to figuring it out as a study showed it to be a "supervoid" in which the density of galaxies is much lower than it is in the rest of the universe. However, other studies haven't managed to replicate the result.
Now new research led by Durham University, submitted for publication in the Monthly Notices of the Royal Astronomical Society, suggests the supervoid theory doesn't hold up. Intriguingly, that leaves open a pretty wild possibility – the cold spot might be the evidence of a collision with a parallel universe. But before you get too excited, let's look at how likely that would actually be.
The cold spot can be seen in maps of the "cosmic microwave background" (CMB), which is the radiation left over from the birth of the universe. The CMB is like a photograph of what the universe looked like when it was 380,000 years old and had a temperature of 3,000 degrees Kelvin. What we find is that it is very smooth with temperature deviations of less than one part in 10,000. These deviations can be explained pretty well by our models of how the hot universe evolved up to an age of 380,000 years.
However the cold spot is harder to work out. It is an area of the sky about five degrees across that is colder by one part in 18,000. This is readily expected for some areas covering about one degree – but not five. The CMB should look much smoother on such large scales.
(Score: 0) by Anonymous Coward on Thursday June 01 2017, @12:29PM (2 children)
right, if you start with the idea that we're in the center of the universe -- which is what the story about the CMBR being a remnant forces you to do -- you'll get your seat at the children's table so you can talk about multiple universes there until you grok what the CMBR has to be.
get that? see.. space is expanding really slowly. if you add more space, it expands proportionally more. if you add so much space that it expands at a rate equal to .. or .. wait for it .. exceeding the speed of light .. then you will wind up with a bubble centered on us showing the hard limit of what we can ever observe -- which just happens to explain why the sky is dark at night.
whats called CMBR is just an 'effect' where the light/radiation has slowed/dimmed so much that we can't tinker up any more detail -- making the pronunciations of what someone wants that edge to look like loud noises from the children's table. nothing here to see but bad reasoning!
(Score: 1, Interesting) by Anonymous Coward on Thursday June 01 2017, @06:12PM
Well, if you really want to get down to it, everybody knows that light isn't from the exact instant photons precipitated out of the aether.
Until we know otherwise we have to assume that space is expanding uniformly. Maybe this cold spot means that isn't true. I don't know. I'm just here in between DevOps meltdowns.
If space is expanding uniformly, yes it's probably true that from some here to some there, across some distance, there are a here and a there relative to which space is expanding faster than the speed of light. So that implies the bubble centered on us you mentioned.
As far as this universes bumping into each other thing, I hope these "scientists" aren't suffering from an affliction I like to call "three-dee-itis." There is not a 3D mass of "unspace" or "metaspace" or whatever you call it that these bubbles filled with "space" are floating in and bumping off each other like balloons in an atmosphere. Maybe. If holographic universe theory is true then, well, it's still not like balloons bumping off each other but that does give us an infinite regress of universes-as-event-horizons-in-universes in three spatial dimensions at all "levels" of a 13th Floor scenario and turtles all the way down.
Also, as far as I know, black holes don't bump off each other. They collide, yes, then you just have a really big event horizon where two smaller ones used to be. So a holographic universe that exists on the 2D surface of a 3D event horizon (a 2-sphere) would experience expansion if it collides with another holographic universe on some other event horizon hologram. Is that what TFS is suggesting?
If not though, something bumping into or colliding with anything implies locality. Locality is a property of this universe. Everybody stop imagining balloons bumping into each other because how on earth can locality be meaningful "outside" of the universe? How can the word "outside" even be meaningful without locality???
Besides, if the holographic universe theory is correct, then why should we consider every black hole a separate universe? It's just a phenomenon all in the same universe. "Event horizon" is a good enough term for me. And conveniently inaccessible, but if that's true, abandon all hope of ever "travelling" to the 3D universe holographically encoded on the 2D event horizon of Sagittarius A* from the 3D universe that Sagittarius A* exists "in." Your mass will get there, but absolutely no information about what makes you "you."
Maybe. Even if you could do that, good luck coming back out intact in on a timescale farther up Sagittarius A*'s gravity well that's not measured in billions and billions of years.
That's enough bogarting for me. Got anther DevOps meltdown about to happen.
(Score: 2) by JoeMerchant on Thursday June 01 2017, @08:42PM
When you look back in time to the CMBR, we are, in fact, in the center of the universe - just as every other observer is in the center of the universe from their perspective. The CMBR is radiation from a certain age of the universe, which reaches us from all directions at the same (rough) age.
Україна досі не є частиною Росії Слава Україні🌻 https://www.pravda.com.ua/eng/news/2023/06/24/7408365/
(Score: 3, Interesting) by JoeMerchant on Thursday June 01 2017, @12:30PM (8 children)
There's this random pattern out there, with variations +/- 1/18,000 across spaces up to one degree, except this one space where it's 5 degrees? There's about 41,250 "square degrees" on a sphere, so a circle 5 degrees in diameter comprises about 0.012% of the sky. Unusual that there's only one - sure, "something" appears to be not going on there, but "collision with another universe?"
Why don't we just call it the belly button of the universe, where the umbilical from the mother universe was cut off.
Україна досі не є частиною Росії Слава Україні🌻 https://www.pravda.com.ua/eng/news/2023/06/24/7408365/
(Score: 2) by JoeMerchant on Thursday June 01 2017, @12:32PM (2 children)
Forgot Pi*r^2 - the belly button is more like 0.05% of the sky.
Україна досі не є частиною Росії Слава Україні🌻 https://www.pravda.com.ua/eng/news/2023/06/24/7408365/
(Score: 2) by chewbacon on Thursday June 01 2017, @11:16PM (1 child)
That's a shit load of sky.
(Score: 2) by JoeMerchant on Friday June 02 2017, @12:36AM
By the time you get back to the CMBR, yeah.
Україна досі не є частиною Росії Слава Україні🌻 https://www.pravda.com.ua/eng/news/2023/06/24/7408365/
(Score: 3, Insightful) by AthanasiusKircher on Thursday June 01 2017, @01:07PM (4 children)
From the summary:
From TFA:
The original article seems to actually specify ~1.9%, which is roughly a 1 in 50 likelihood this could happen by random chance -- even if our cosmological models are all correct (and there's a reasonable chance that we don't know everything about how the distribution is created, so that 1.9% could also be off).
Here's the thing -- does that ~2% chance take into account all possible anomalies of this sort, or only this particular type of anomaly? For example, maybe there's a 2% chance of a "cold spot" this large, but also a 2% of a "hot spot" this large, and also a 2% chance of a "cold ring" or "cold line" or whatever other kind of anomalous blip. You start adding up all the various ways you might have anomalies, and suddenly it seems reasonably likely you'd have SOME sort of "anomaly" in a given universe.
I'm not a cosmologist, so I didn't try to sort out whether this was taken into account in the analysis, but humans have a bad intuitive sense of randomness and like to find patterns. Maybe this is significant -- but it also could just be a fluke. Which makes it even crazier to speculate about collisions with parallel universes, etc.
(Score: 0) by Anonymous Coward on Thursday June 01 2017, @01:36PM (2 children)
I didn't want to believe it, but yet here it is:
https://arxiv.org/abs/1704.03814 [arxiv.org]
I was hoping the misinterpreted p-value was just the media or your fault, but no. Cosmology is pseudoscience now apparently. This p-value bullshit everyone loves because it lets them trick laypeople into thinking they know something is seriously going to destroy civilization:
Fisher, R N (1958). "The Nature of Probability". Centennial Review. 2: 261–274.
(Score: 2) by Zinho on Thursday June 01 2017, @07:54PM (1 child)
And there's our "obligatory XKCD" topic for the thread:
significance [xkcd.com]
I'm also about to post another thread as "obligatory XKCD", gotta call them out on their map projection, which will make this topic a twofer.
Back on topic, are they seriously suggesting that in an infinite number of possible universes the scientists are surprised that we're living in the sizable fraction that has this random feature? 1/50 isn't a whole lot less likely than rolling double 6s on a pair of D6 dice (1/36).
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
(Score: 2) by Bot on Thursday June 01 2017, @11:04PM
So, to recap. Cosmology models currently do not account for 95.1% of total mass–energy content of the universe, ascribed to dark matter and dark energy. The CMB has a cold spot and "the quadrupole and octupole (l = 3) modes appear to have an unexplained alignment with each other and with both the ecliptic plane and equinoxes" (AKA axis of evil).
Calling these "coincidences" and moving on is not a good idea yet. It's more like "we might be a couple details from confirming out models, but we could also be on the completely wrong track".
Account abandoned.
(Score: 2) by bob_super on Thursday June 01 2017, @05:11PM
"Hey, it's only got a sub-2% probability, so it can't be what happened", said no lottery winner ever.
Also, half of the links at the bottom of TFA (I know, sorry, but nice maps and stuff...) are articles about various explanations of the cold spot.
Many of them seem a lot less "hold my doobie, I got this" than this clickbaity collision with parallel universes...
(Score: 2, Insightful) by nivieru on Thursday June 01 2017, @01:49PM (2 children)
Looks like a classic case of Betteridge's law
(Score: 0) by Anonymous Coward on Thursday June 01 2017, @03:27PM (1 child)
Or even Occam's razor, maybe:
-parallel universe!
-random coincidence!
With this choice, i'd go with random coincidence.
(Score: 2) by Bot on Friday June 02 2017, @11:24AM
> Occam's razor
Meatbag pls
Invoking occam's razor adds an unnecessary layer of reasoning that occam's razor removes as such.
Call this the twin blade occam's razor if you wish.
Account abandoned.
(Score: 0) by Anonymous Coward on Thursday June 01 2017, @02:48PM (2 children)
The title is downright moronic. Parallel universe? Why not flying buddha instead?
(Score: 3, Funny) by bob_super on Thursday June 01 2017, @05:03PM
It's the place where the FSM added extra cheese, intending that not all would melt.
(Score: 2) by edIII on Thursday June 01 2017, @11:32PM
Actually, I think they meant literally. As in a universe being what we are in, bounded by the CMB. Not a universe as in the infinite, unbounded area of total existence. If you take it literally, it makes some sense. Two universes (not to be implied as mirror or evil bearded) traveling together glanced off each other.
Although, then they wouldn't be parallel, since they parallel lines don't actually converge or touch. Multi-verse theories can get pretty strange, but in this analogy all "universes" exist side by side with each other. A universe next to ours gave us a "glancing blow" at some point and that is what is causing the anomaly.
To be super fair here, the entire fucking field is 100% speculation without any evidence or testing possible within the lifetimes of anybody in the field. It's all a guessing game till we actually get out there, which is highly unlikely. So until then, guess away :)
Technically, lunchtime is at any moment. It's just a wave function.
(Score: 0) by Anonymous Coward on Thursday June 01 2017, @02:52PM (1 child)
From a scientific standpoint this theory sounds viable but without evidence of multiple universes they are just conjecturing about what we see through an instrument. For all we can prove at this point it could be that God got a split instead of a strike and hit the universe out of frustration.
(Score: 0) by Anonymous Coward on Thursday June 01 2017, @09:05PM
This seems pretty likely, that is very frustrating.
(Score: 2) by inertnet on Thursday June 01 2017, @03:25PM
It looks to me like the CMB map has some hot spots as well.
(Score: 2) by Zinho on Thursday June 01 2017, @08:01PM (2 children)
Map Projections [xkcd.com]
I have to ask why they chose an elliptical projection of the sky (although it could also be pseudoazimuthal, [wikipedia.org] hard to tell without recognizable landmarks in the data set). Kudos for using an equal-area projection at least.
Anyone else think this would make a pretty pattern for a Watterman butterfly? [wikipedia.org]
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
(Score: 0) by Anonymous Coward on Friday June 02 2017, @06:44AM (1 child)
I don't know why, but I can tell you that, AFAIR, every CMB map I've seen has used exactly the same projection.
Just a wild guess, but maybe an equal-area projection makes sense when you're comparing areas :)
(Score: 2) by Zinho on Friday June 02 2017, @05:16PM
Same here, and it's always bugged me a bit. Too much distortion for my taste at the sides, and with no lines marking latitude or longitude I have no idea which way the distortion is going. At a guess I'd hope that they're maybe using Polaris as the north reference, and the ecliptic for the equator; however, there's nothing really constraining them to that. I'm not familiar enough with astronomy to guess what they'd be using as their prime meridian, either. One of the Zodiac constellations?
I just took the time to google it, and it seems they do have an equirectangular projection available [caltech.edu] as well. No indication which latitude(s) are the standard parallel(s); hopefully it's the equator since they're intending it to map onto a dome for projection. They're using galactic coordinates, that puts the galactic plane as the equator and Sagittarius A* as the prime meridian. The things you learn.
Right, no problem there. It's not like they don't have other options [wikipedia.org] to choose from, though. Choosing the one they did with no reference lines drawn in makes it a bit disorienting.
Of course, in the spirit of my XKCD quote, my opinions on the map projections astronomers use are of little consequence to the astronomers; take my nerd rage with a grain of humorous salt :P
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin