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Why is there a normal galaxy sitting at the edge of the Universe?

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Re: Why is there a normal galaxy sitting at the edge of the Universe?

#241

Post by ddevault »

noizejoy wrote: post #210
ddevault wrote: post #116

Earlier quoted context omitted.

We don't understand why expansion is occuring, so we can't say for certain. It would be a very long time in the future if that were to come to pass, and that's a whole lot of time for poorly-understood physics to happen in. But yes, it is accellerating, and if it continues to do so, eventually it will overcome gravity. But like I said, this depends on an incomplete understanding of physics, and the current evidence s…

Sometimes a simple upvote just doesn’t seem enough. So here’s a heartfelt Thank You for this and your other explanations - I really appreciate your knowledgeable and thoughtful responses!

Cheers!

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#242

Post by cthalupa »

banmeagaindan2 wrote: post #240
cthalupa wrote: post #236

Earlier quoted context omitted.

>Somebody like Graham Hancock is actually delivering more people to the pipeline of scientific understanding than Richard Dawkins. We don't want to hear it but it's true. This is a pretty bold statement. You are arguing that psuedoscience is resulting more people being scientific than actual science is? Such an extraordinary claim needs some significant evidence behind it.

Is it really an extraordinary claim? In your own experience have you never settled for a poorer model of something, a lower resolution because you feel either you didn't have the cognitive resources to get there or you felt unmotivated? When the topic becomes more complex - this happens to more and more people. If you have a compelling story you may be motivated to sip on the subject. After a time you probably shrug…

I don't quite understand how we go from "Ancient aliens" to "real science" - I've never spoken to someone who believed in that stuff as the jumping off point that later went on to being curious about actual science when they weren't previously.

>Just as many right wingers are going to buy passive houses, closed loop energy, solar panels, Teslas as left wingers.

I also don't know that this is actually true. I as only able to find "what do you want to buy" polling for cars, but in a study surveying actual solar usage, it's 34% democrat and 20% republican.

https://www.autoblog.com/2016/10/26/democrats-tesla-republic...

https://grist.org/article/republicans-are-buying-rooftop-sol...

But I think this is also a false premise - that somehow conspiracy theory nuts have the same impact on public perception of science as one of the most public scientific issues with consensus from tens of thousands of scientists including basically 100% of the leading experts in the field. And the fact that there are long term economic advantages for things like solar, etc. that don't take into account at all whether or not you believe in man made climate change.

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#243

Post by joshspankit »

ddevault wrote: post #164
joshspankit wrote: post #157

Earlier quoted context omitted.

Thank you. If I understand what you’ve written already, the essence of the answer in terms of mekkkkkk’s question (for reference: “ Sorry for also asking a space 101 question, but since the fabric of space is expanding, does that mean that things are getting bigger as well? Naively, it would seem that way. In your balloon example, the dots would get bigger.”), I think the answer would be: Anything held together (for…

>This does produce an interesting side question though: aren’t we (humans) shrinking in relation to the universe? Or, without the click-baity phrasing: isn’t the universe growing without us? Yep.

(thinking emoji)

(thinking emoji)

(thinking emoji)

(mindblown emoji)

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#244

Post by banmeagaindan2 »

cthalupa wrote: post #242
banmeagaindan2 wrote: post #240

Earlier quoted context omitted.

Is it really an extraordinary claim? In your own experience have you never settled for a poorer model of something, a lower resolution because you feel either you didn't have the cognitive resources to get there or you felt unmotivated? When the topic becomes more complex - this happens to more and more people. If you have a compelling story you may be motivated to sip on the subject. After a time you probably shrug…

I don't quite understand how we go from "Ancient aliens" to "real science" - I've never spoken to someone who believed in that stuff as the jumping off point that later went on to being curious about actual science when they weren't previously. >Just as many right wingers are going to buy passive houses, closed loop energy, solar panels, Teslas as left wingers. I also don't know that this is actually true. I as only…

True - but most people never become scientists - not even amateurs - but there exists a flourishing industry of science books for people who are a bit science curious. Scott Alexander used to be a giant Hancock fan - anecdotal I know but he later realized it was sort of bullshit - but still was interested in deep archaeology. I'll call that a win.

On the stats - that's a rabbit hole I won't go down today but every time I've seen people talk about alternatives to the system the left and right become like a long married couple ending each other's sentences.

>And the fact that there are long term economic advantages for things like solar, etc. that don't take into account at all whether or not you believe in man made climate change.

Sure.

> But I think this is also a false premise - that somehow conspiracy theory nuts have the same impact on public perception of science as one of the most public scientific issues with consensus from tens of thousands of scientists including basically 100% of the leading experts in the field.

There I think you're making a mistake. Literary people think Proust is awesome. A lot of people have read Dan Brown. Who is having more impact? You're making a face now - I can see through the interneticals.

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#245

Post by perl4ever »

ddevault wrote: post #70
zemnmez wrote: post #59

Earlier quoted context omitted.

this is because things aren’t ‘moving apart’— space itself is expanding (into what? nobody knows). it’s not that the galaxies are being propelled apart from a force in a particular place either; everything is expanding away from everything else . On the traditional balloon model, the surface of the balloon represents space itself. Those dots on the surface of an expanding balloon are not moving relative to space (the…

In case anyone is confused, I prefer to explain the expansion of space without metaphors. Space itself is getting larger, everywhere, all at once. The scale factor of the universe is getting larger. New space is constantly being "made". Every second, every kilometer in the universe grows by 2.2×10^-18 centimeters. If no other forces were in play, it'd carry everything along with it and pull everything a bit further a…

>Every second, every kilometer in the universe grows by 2.2×10^-18 centimeters. If no other forces were in play, it'd carry everything along with it and pull everything a bit further apart

This sounds like a measurable (in principle) pressure. But you say it cannot be locally observed. So how do we actually know it is happening?

I have heard for many, many years that "space itself" is expanding, but never got a sense of what that meant from all the explanations. It's always sounded to me like doubletalk. Probably because I'm dumb.

What I have heard about observations of the expansion of the universe is that objects appear to be moving away, and I've never been able to understand how we know it is not "ordinary" motion.

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#246

Post by Supermancho »

krapp wrote: post #156
Supermancho wrote: post #155

Earlier quoted context omitted.

> Since there's no frame of reference outside the universe That's unknown. The observable universe is all we know for sure and there's evidence that there is both something beyond what we can observe, which conforms to what we know as space and matter, and something beyond that (whatever existed around the big bang locality).

>there's evidence that there is something beyond what we can observe By definition, there can't be. Evidence implies something we can observe, which would mean it isn't beyond the observable universe.

> Evidence implies something we can observe

That's an arbitrary definition. We can't observe our local past events or even non-local events, yet we use them as theories/evidence depending on context (eg Red Shifted galaxies as evidence of expansion). Reasoning about past events would affect other future events is just as much evidence. That's how physics experiments are generally conducted.

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#247

Post by Supermancho »

Supermancho wrote: post #246
krapp wrote: post #156

Earlier quoted context omitted.

>there's evidence that there is something beyond what we can observe By definition, there can't be. Evidence implies something we can observe, which would mean it isn't beyond the observable universe.

> Evidence implies something we can observe That's an arbitrary definition. We can't observe our local past events or even non-local events, yet we use them as theories/evidence depending on context (eg Red Shifted galaxies as evidence of expansion). Reasoning about past events would affect other future events is just as much evidence. That's how physics experiments are generally conducted.

I can concede that there's not necessarily anything "outside" the spacetime bubble. The evidence of nothing is not the existing of something.

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#248

Post by natch »

erulabs wrote: post #142
natch wrote: post #21

I never understand why articles like this use present tense to talk about past events. It was churning out a lot of new stars.. not is. I guess the “as seen from our current vantage point” is understood, but to me the needless emphasis of that perspective just muddies things, no? Anyone of you downvoters care to enlighten me?

Strictly speaking our observations are not continuous. We pointed a large array at it and then the array probably went on to other work and looked elsewhere - so technically “was” is more correct, since we do not know what it “is” doing, rather only what it appeared to be doing. Either way it’s a pretty uninteresting difference in tense.

I find it a very interesting difference, because it and other fuzzy writing like it has a devastating impact on science literacy, leading to lack of comprehension of concepts. Weak thinking on science in turn contributes to many of the problems we face as societies today.

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#249

Post by ddevault »

perl4ever wrote: post #245
ddevault wrote: post #70

Earlier quoted context omitted.

In case anyone is confused, I prefer to explain the expansion of space without metaphors. Space itself is getting larger, everywhere, all at once. The scale factor of the universe is getting larger. New space is constantly being "made". Every second, every kilometer in the universe grows by 2.2×10^-18 centimeters. If no other forces were in play, it'd carry everything along with it and pull everything a bit further a…

>Every second, every kilometer in the universe grows by 2.2×10^-18 centimeters. If no other forces were in play, it'd carry everything along with it and pull everything a bit further apart This sounds like a measurable (in principle) pressure. But you say it cannot be locally observed. So how do we actually know it is happening? I have heard for many, many years that "space itself" is expanding, but never got a sense…

The motion is consistent with an expanding universe. It gets exponentially greater the further away you go, and everything is moving away from everything else - not away from some "center" position. Also, some of this movement is faster than the speed of light, and the expanding of space explanation is consistent with our understanding of physics whereas proper motion is not consistent with our understanding of physics.

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#250

Post by dmead »

lpghatguy wrote: post #86
dmead wrote: post #85

Earlier quoted context omitted.

Is that number correct? Why not just launch at those starts at that point?

For comparison, the nearest star to us is 268,770 AU away, or around 491 times further away. It would take quite a bit longer to get there!

i guess i was thinking more about the complexity of arranging a constellation of telescopes around sol versus just sending one much closer to a target star.
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