Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

James Webb Space Telescope reveals that most galaxies rotate clockwise

smithsonianmag.com

Post reply on HN
Print view View original

261–270 of 318 posts

Re: James Webb Space Telescope reveals that most galaxies rotate clockwise

#261

Post by reactordev »

bbor wrote: post #248
MoonGhost wrote: post #246

Earlier quoted context omitted.

> when viewed from the other side? Nobody has done it so far. We have only theories and hypothesis.

I'm not sure I understand this response -- basically all of cosmology involves theories based only on somewhat subjective interpretations of sensor data targeting far-off objects. So I don't necessarily disagree . But what could possibly happen other than they act like all other physical objects do? It boggles the mind to think how broken physics would have to be to accommodate a second correspondence principle for t…

Except most theory can be observed where this one can’t until we find a wormhole to travel through or break c

Re: James Webb Space Telescope reveals that most galaxies rotate clockwise

#263

Post by EGreg »

ajross wrote: post #225
kmoser wrote: post #201

Earlier quoted context omitted.

Dumber question: would a galaxy that appears to spin clockwise appear to spin counter-clockwise when viewed from the other side? Does this imply that the real question is why galaxies' relative orientations seem to favor more spinning in one direction than the other?

Yes, that's it exactly. There's a net asymmetry in the distribution of galaxy axes. "Clockwise" by itself is a relative term. This seems to be the paper in question: https://academic.oup.com/mnras/article/538/1/76/8019798 That said: I'd wait a bit here. This is a single-author paper by a non-astronomer (he's a CS professor). The sample size seems small (N=263), and the measurement coarse (he's just bucketing galaxies…

Look, if the visible universe is expanding, as we think it is, that is already a direction. Viewing galaxies “from the other side” is not the same in an expanding bubble. It’s like being surprised that many things are redshifted no matter where you look. As for rotations — you could perhaps have some local coriolis force.

The visible universe is redshifted and galaxies are getting further and further away. So jumping straight to “we are in a black hole” is weird

It is far more plausible that there is some coriolis like spinning effect in a higher dimension, even if the universe is flat it could have similar effects to how the earth’s spin makes cyclones all spin in the same direction.

Problem solved. Next?

Re: James Webb Space Telescope reveals that most galaxies rotate clockwise

#264

Post by _kst_ »

The study is based on 263 galaxies.

It should be fairly easy to determine the rotation direction of any (spiral) galaxy we can see, based on reasonable assumptions about the relationship between rotation and the configuration of the spiral arms. There should be thousands or millions of visible galaxies for which this could be determined (out of the estimated 2 trillion galaxies in the observable universe). Perhaps I'm missing something, but why bother reporting a result from such a tiny sample?

It should also be possible to derive more detailed information that just clockwise vs. counter-clockwise. The rotation of a galaxy defines a direction (the galaxy's rotational north pole) and a point on the surface of an imaginary sphere. This could be determined by the galaxy's apparent rotational direction, its orientation, and its position in the sky. It would be interesting to see a plot of those points. In principle, they should be random. (If the points spell out "Go stick your head in a pig", I'll be very sorry that Douglas Adams didn't live to see it.)

Re: James Webb Space Telescope reveals that most galaxies rotate clockwise

#265

Post by vlovich123 »

SkyBelow wrote: post #204
vlovich123 wrote: post #183

Earlier quoted context omitted.

The observable universe is an illusory artifact of being an observer traveling at less than the speed of light. A constant distance in every direction is a sphere. That tells us nothing about the actual structure of the universe. In other words, your observable universe is different than mine and that's both spheres we're in the middle of. That suggests the universe itself probably isn't a sphere.

Is it an illusory artifact or is it all that exists? If it can't be observed, it can't be tested, it can't be verified in any way or ever interacted with, then isn't it just an instances of Russell's Teapot and thus does not exist? What does it mean for science if existence isn't a binary property or one that we set as a truth yet is entirely untestable?

We definitely have reason to believe that there’s universe outside the observable universe. The CMB uniformity suggests that that’s the case as do our theoretical models. The mere fact that two observers have different observable universes indicates it is indeed an illusory artifact.

Just because something is untestable today doesn’t mean it will be for all time. However, the untestability problem has started to creep much more deeply into cosmology and high particle physics in particular - our technology and models aren’t staying enough ahead to provide a lot of fertile testable ground.

Re: James Webb Space Telescope reveals that most galaxies rotate clockwise

#266

Post by joe_the_user »

jfengel wrote: post #254
datavirtue wrote: post #253

Earlier quoted context omitted.

Clockwise? To which observer?

It's arbitrary, but that's fine. The important part would be any asymmetry. The Big Bang implies that there shouldn't be one.

Just to be clear, it's not fine at all in any "this is a fine physical theory".

A statistically unlikely arrangement of cosmic objects relative to earth only - earth in particular, violates not just the properties of the big bang but "the cosmological principle" and common sense. It's a garbage theory, a headline that makes a math person just have a "how stupid do they expect the average person to be" reaction.

Re: James Webb Space Telescope reveals that most galaxies rotate clockwise

#269

Post by drusenko »

jfengel wrote: post #259
askonomm wrote: post #96

Earlier quoted context omitted.

Just thinking about this infinite recursion gives me the mental equivalent of a stack overflow.

The trick is that bigger black holes are less dense. Supermassive black holes can have the density of water. If the universe is gravitationally closed, it would have the density of... well, just look up at night. (Actually much less than that; you see more stars because you're inside a galaxy.) The density makes the scale recursion less mysterious.

That’s interesting! When you are referring to density, are you referring to average density within the event horizon? Isn’t most (effectively all) matter concentrated in the singularity? Would love to hear you elaborate on this thought further.

Re: James Webb Space Telescope reveals that most galaxies rotate clockwise

#270

Post by GoblinSlayer »

datavirtue wrote: post #253
iainmerrick wrote: post #232

Earlier quoted context omitted.

Thank you. That's a shame, it was a cool-sounding story, just unlikely enough to sound plausible.

Clockwise? To which observer?

On pictures Milky Way is usually shown to rotate counterclockwise. As is solar system.
Post reply on HN