Why is there a normal galaxy sitting at the edge of the Universe? • Hacker News Board

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

#81

Post by outworlder » Wed, Sep 09, 2020, 6:30 PM UTC

depressedpanda wrote: post #64

adventured wrote: post #37

> The thing is, where they found it is not normal: The light we see from it left the galaxy 12.4 billion years ago, meaning we’re seeing it as it was when the Universe itself was only 1.4 billion years old! It's not confusing at all. It's because the long-worshipped, conventional big bang theory is wrong. The universe doesn't have a beginning or end. It's eternal. The original sin of that theory is that it's tainted…

Strong claims, but can you back them up? How do you explain the apparent accelerating expansion of the universe, i.e. that the farther away something is, the more redshifted it gets? How do you explain the cosmic microwave background radiation enveloping us in all directions?

Of course they can't back this up.

What the universe really is, is a simulation. We are trapped in it.

"Lightspeed limit": this is because the simulation has a finite computing power. You can either move in time normally, or you can move in space. If you go to the max allowed speed, there's no processing left over to simulate time, therefore time stops for that entity. At intermediate speeds, slow down time accordingly.

"Planck length": resolution of the simulation. It's discrete, and you can't go any smaller.

"Heisenberg uncertainty principle": another simulation optimization. Instead of simulating all particles, just use a probabilistic function. You actually don't have to simulate it, just the macroscopic effects, unless there's an observation. In which case you can compute either the position or speed of the particle. See also: atom orbitals

"Superluminal" expansion: it's just so we don't try to get to other galaxies, which are only being simulated in a macro scale. This was left by the developer to turn the 'lightspeed bug' into a feature. Also closes bug UNIVERSE-001 where the background radiation was still visible, but other galaxies visibility was off due to performance concerns. Now they can be enabled.

"Dark matter": other civilization experiments that we don't have permissions to see. Still there and interacting with matter. Bug is still in the backlog.

See, anyone can come up with whacky stuff.

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

#82

Post by joshspankit » Wed, Sep 09, 2020, 6:30 PM UTC

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…

It would be interesting to hear your answer to mekkkkkk‘s question

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

#83

Post by rini17 » Wed, Sep 09, 2020, 6:37 PM UTC

PopeDotNinja wrote: post #72

s1dev wrote: post #61

Earlier quoted context omitted.

How do you propose to power a fleet of spacecraft at 550AU? Would you be able to acquire enough RTGs? What about DSN time for the downlink?

And how would you get them out to, and stop at, 550 AU? Voyager 1 and 2 are nuclear powered with RTGs and they are respectively about 150 AU and 125 AU from the sun, and they are going really fast. The Voyager RTGs are also fairly depleted at this point. I’m guessing these spacecraft would need a faster, more efficient mode of propulsion, like a nuclear thruster or ion drive (or Epstein drive?!). One could also get a…

No need to stop at 550AU, the gravitational lens keeps working beyond that(theoretically all the way to infinity).

As for how to get there, yes, innovative propulsion is required. My idea is that the probe would dive close to Sun and use solar energy (sail? electric propulsion?) to accelerate itself out to hundreds of km/s.

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

#84

Post by s1artibartfast » Wed, Sep 09, 2020, 6:37 PM UTC

dumpsterdiver wrote: post #62

vkou wrote: post #22

Earlier quoted context omitted.

No, 13 billion years is the age of the universe. The observable universe is a sphere with a diameter of ~93 billion light years (And is likely to only be a subset of the entire universe).

I have a question: Just over 20 years ago when the accepted view was that the expansion of the universe was slowing down, would you have backed that position with as much certainty as you are backing this one? That the universe is a mere 13.7 billion years old? We cannot prove the absence of light in a place that is already so far away that it's light will never reach us. Do you agree? We can prove what we can observ…

I think you are generally critiquing assumptions that most astrophysicists are not making. Most Theorists would not claim with confidence that the big bang was the first or only one, or that future big bangs are not possible. I think your criticism is more valid for the way the history of the universe is portrayed in news articles and high school text books.

The term "multiverse" is used to describe the collection of multiple universes.Some have speculated that time has no direction in the multiverse and that time in each universe may be different. If our universe is cyclic, it makes sense to reset the clock because it may have run in a different direction last time or next time.

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

#85

Post by dmead » Wed, Sep 09, 2020, 6:42 PM UTC

z92 wrote: post #78

tectonic wrote: post #2

Nice gravitational lens observation! We're hoping to use the same technique with the Sun to observe exoplanets by launching a fleet of small satellites to 547 AU (80 billion km / ~3 light days). The craft would sample the distorted Einstein ring around our Sun from that vantage point, then combine and reconstruct an image of the disk of an Earth-like exoplanet up to 100 light-years beyond, at a resolution of 25 kilom…

> 547 AU For comparison Voyager-1 is now at a distance of 40 AU only.

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

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

#86

Post by lpghatguy » Wed, Sep 09, 2020, 6:45 PM UTC

dmead wrote: post #85

z92 wrote: post #78

Earlier quoted context omitted.

> 547 AU For comparison Voyager-1 is now at a distance of 40 AU only.

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!

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

#87

Post by networkimprov » Wed, Sep 09, 2020, 6:46 PM UTC

tectonic wrote: post #2

Nice gravitational lens observation! We're hoping to use the same technique with the Sun to observe exoplanets by launching a fleet of small satellites to 547 AU (80 billion km / ~3 light days). The craft would sample the distorted Einstein ring around our Sun from that vantage point, then combine and reconstruct an image of the disk of an Earth-like exoplanet up to 100 light-years beyond, at a resolution of 25 kilom…

It's not a new idea... I first heard of it in the intro segment of this Cool Worlds Lab vid

https://www.youtube.com/watch?v=jgOTZe07eHA

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

#88

Post by SahAssar » Wed, Sep 09, 2020, 6:47 PM UTC

pier25 wrote: post #79

dylan604 wrote: post #63

Earlier quoted context omitted.

Which sci-fi author wrote that? That might make for interesting reading if you find it and share with the rest of the class.

https://phys.org/news/2015-10-galaxies-faster.html

That article explains that the galaxies are only moving faster than light from our perspective since every part of space between us and it is expanding.

So, no it's not moving faster than light. The space between it and everything else is expanding.

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

#89

Post by memetomancer » Wed, Sep 09, 2020, 6:47 PM UTC

dumpsterdiver wrote: post #62

vkou wrote: post #22

Earlier quoted context omitted.

No, 13 billion years is the age of the universe. The observable universe is a sphere with a diameter of ~93 billion light years (And is likely to only be a subset of the entire universe).

I have a question: Just over 20 years ago when the accepted view was that the expansion of the universe was slowing down, would you have backed that position with as much certainty as you are backing this one? That the universe is a mere 13.7 billion years old? We cannot prove the absence of light in a place that is already so far away that it's light will never reach us. Do you agree? We can prove what we can observ…

The problem here is that you are taking a simplified layman's description, making naive assumptions about it and then brazenly dismissing the whole of contemporary cosmology as if you have profound insights that went completely over the heads of some seriously smart physicists.

You then make an analogy about "Pangaea" as if you alone are the brilliant shining light of reason, but if you took just a small amount of time to read even Wikipedia you would find, for example, that several super-continents have formed and broken apart over the history of the Earth. The very first section of the Wikipedia article on Supercontinents lists eleven of them! [https://en.wikipedia.org/wiki/Supercontinent#Supercontinents...]

I for one see a lot of problems with your one dimensional analysis and obvious lack of awareness on these topics. In my opinion, your currently insufficient knowledge is akin to believing that the Earth is flat because you can't personally see curvature on the horizon.

Seriously though, I recommend you take the time to read about 'the entire premise of dating our universe', all the many decades of development, criticisms, refinements and confirmations of the current best theory. You'll find that it's an amazing subject, that all of your concerns have been poured over for the past century in great detail, that many brilliant people have worked out fantastically brilliant methods for figuring this out... and then finally, maybe, you'll be ready to read about the various cyclic cosmological models.

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

#90

Post by ddevault » Wed, Sep 09, 2020, 6:49 PM UTC

mekkkkkk wrote: post #74

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…

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.

Local factors (gravity, strong & weak nuclear force) easily overcome the expansion of space. So things stick together.