Dumb astrophysics question for clever twats

Dumb astrophysics question for clever twats

Postby Rum » Mon Dec 04, 2017 7:38 pm

It seems that cosmology is a bit stuck at the moment, what with the expansion of the universe speeding up, the puzzle of 'dark matter' and so on. I've even been reading of late that the size of the universe may be much much larger than what we see given the time that light has had to travel since the big bang.

I'm probably thinking too narrowly here, but here's the thing. Assuming that at any point in the universe you look out from it seems to be about 14 billion light years big, do we not inhabit a universe many times 14 billion light years big?

I'm beginning to wonder if the 'shape' of the universe is not what it appears to be.

But I know nothing. Thoughts from clever cloggses would be helpful.
Elon Musk: Mars will need pizza joints, great bars - Mars Bars".
User avatar
Rum
Absent Minded Processor
 
Posts: 33259
Joined: Wed Mar 11, 2009 9:25 pm
Location: South of the border..though not down Mexico way..

Re: Dumb astrophysics question for clever twats

Postby JimC » Mon Dec 04, 2017 8:14 pm

One possibility is that the universe we observe is just one of an infinite number, each budding from a quantum scale event in an existing universe, blossoming into a universe via its own big bang. A Metaverse like an infinitely branching cluster of grapes...
Nurse, where the fuck's my cardigan?
And my gin!
User avatar
JimC
The sentimental bloke
 
Posts: 56757
Joined: Thu Feb 26, 2009 7:58 am
Location: Melbourne, Australia
About me: To be serious about gin requires years of dedicated research.

Re: Dumb astrophysics question for clever twats

Postby Sean Hayden » Mon Dec 04, 2017 8:27 pm

--reported, for excluding most of humanity.

Rum, see me after class.
"The Americans from the North, at least the great part of those I have seen, eat only salted meat, bread made by themselves out of corn meal, coffee, and homemade cheese. To these the greater part...add strong liquor, for they are in general, in my opinion, lazy people of vicious character. " --José María Sánchez ~1827
User avatar
Sean Hayden
Microagressor
 
Posts: 7419
Joined: Wed Mar 03, 2010 3:55 pm

Re: Dumb astrophysics question for clever twats

Postby Brian Peacock » Mon Dec 04, 2017 9:18 pm

The universe could just be really, really big, and bounded, or it could be infinitely big, and unbounded. The universe could be finite or it could be eternal. No-one knows for sure, but everyone agrees it's expanding. If you like having your brain fried try this idiot's guide to the expansion of the universe...

Scale Invariance and the Cosmological Constant.
.


"It isn't necessary to imagine the world ending in fire or ice.
There are two other possibilities: one is paperwork, and the other is nostalgia."

Frank Zappa

"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT


.
User avatar
Brian Peacock
Tipping cows since 1946
 
Posts: 17825
Joined: Thu Mar 05, 2009 11:44 am
Location: Location: Location:
About me: Ablate me:

Re: Dumb astrophysics question for clever twats

Postby JimC » Mon Dec 04, 2017 9:21 pm

How many Americans still think the whole shebang was created 6000 years ago?
Nurse, where the fuck's my cardigan?
And my gin!
User avatar
JimC
The sentimental bloke
 
Posts: 56757
Joined: Thu Feb 26, 2009 7:58 am
Location: Melbourne, Australia
About me: To be serious about gin requires years of dedicated research.

Re: Dumb astrophysics question for clever twats

Postby Brian Peacock » Mon Dec 04, 2017 9:29 pm

As of May 2017, 38%.

WASHINGTON, D.C. -- The percentage of U.S. adults who believe that God created humans in their present form at some time within the last 10,000 years or so -- the strict creationist view -- has reached a new low. Thirty-eight percent of U.S. adults now accept creationism, while 57% believe in some form of evolution -- either God-guided or not -- saying man developed over millions of years from less advanced forms of life.

his is the first time since 1982 -- when Gallup began asking this question using this wording -- that belief in God's direct creation of man has not been the outright most-common response. Overall, roughly three-quarters of Americans believe God was involved in man's creation -- whether that be the creationist view based on the Bible or the view that God guided the evolutionary process, outlined by scientist Charles Darwin and others. Since 1982, agreement with the "secular" viewpoint, meaning humans evolved from lower life forms without any divine intervention, has doubled....

http://news.gallup.com/poll/210956/beli ... w-low.aspx
.


"It isn't necessary to imagine the world ending in fire or ice.
There are two other possibilities: one is paperwork, and the other is nostalgia."

Frank Zappa

"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT


.
User avatar
Brian Peacock
Tipping cows since 1946
 
Posts: 17825
Joined: Thu Mar 05, 2009 11:44 am
Location: Location: Location:
About me: Ablate me:

Re: Dumb astrophysics question for clever twats

Postby L'Emmerdeur » Mon Dec 04, 2017 10:04 pm

Rum wrote:It seems that cosmology is a bit stuck at the moment, what with the expansion of the universe speeding up, the puzzle of 'dark matter' and so on. I've even been reading of late that the size of the universe may be much much larger than what we see given the time that light has had to travel since the big bang.

I'm probably thinking too narrowly here, but here's the thing. Assuming that at any point in the universe you look out from it seems to be about 14 billion light years big, do we not inhabit a universe many times 14 billion light years big?

I'm beginning to wonder if the 'shape' of the universe is not what it appears to be.

But I know nothing. Thoughts from clever cloggses would be helpful.


[T]he furthest things we can see are more than 46 billion light years away. While we are not the center of the universe, we are at the center of this observable portion of the universe, which traces out a sphere roughly 93 billion light years across. [Source]


But wait ....

Just because the part of it we can see is indistinguishable from flat doesn’t mean it’s intrinsically flat in its entirety. But it does mean that the Universe is far larger than we’ll ever see. Even taking the minimum allowable estimate for the size of the Universe means that, at most, less than 0.0001% of the volume of the Universe is presently or will ever be observable to us. [Source]

[Emphasis mine - L'E]
User avatar
L'Emmerdeur
 
Posts: 1251
Joined: Wed Apr 06, 2011 11:04 pm
About me: Yuh wust nightmaya!

Re: Dumb astrophysics question for clever twats

Postby Rum » Mon Dec 04, 2017 10:07 pm

(Edit: response to last but one post)

This is one major reason why Merica will cease to be the king of the pile in the next generation or two.

Thanks for the responses guys. I am pretty up to speed with the latest thinking on this from a lay person's perspective. I am looking for answers of course where there aren't any yet. I really wish I had studied my physics a bit harder at school - I'm sure it would add a dimension of appreciation that the lack of maths/physics excludes one from.
Elon Musk: Mars will need pizza joints, great bars - Mars Bars".
User avatar
Rum
Absent Minded Processor
 
Posts: 33259
Joined: Wed Mar 11, 2009 9:25 pm
Location: South of the border..though not down Mexico way..

Re: Dumb astrophysics question for clever twats

Postby Rum » Mon Dec 04, 2017 10:17 pm

L'Emmerdeur wrote:
Rum wrote:It seems that cosmology is a bit stuck at the moment, what with the expansion of the universe speeding up, the puzzle of 'dark matter' and so on. I've even been reading of late that the size of the universe may be much much larger than what we see given the time that light has had to travel since the big bang.

I'm probably thinking too narrowly here, but here's the thing. Assuming that at any point in the universe you look out from it seems to be about 14 billion light years big, do we not inhabit a universe many times 14 billion light years big?

I'm beginning to wonder if the 'shape' of the universe is not what it appears to be.

But I know nothing. Thoughts from clever cloggses would be helpful.


[T]he furthest things we can see are more than 46 billion light years away. While we are not the center of the universe, we are at the center of this observable portion of the universe, which traces out a sphere roughly 93 billion light years across. [Source]


But wait ....

Just because the part of it we can see is indistinguishable from flat doesn’t mean it’s intrinsically flat in its entirety. But it does mean that the Universe is far larger than we’ll ever see. Even taking the minimum allowable estimate for the size of the Universe means that, at most, less than 0.0001% of the volume of the Universe is presently or will ever be observable to us. [Source]

[Emphasis mine - L'E]


Mind melting here. I'm struggling with what I have until now believed the limit of observation (approx 14B light years) was compared to the proposition in the underlined bit.
Elon Musk: Mars will need pizza joints, great bars - Mars Bars".
User avatar
Rum
Absent Minded Processor
 
Posts: 33259
Joined: Wed Mar 11, 2009 9:25 pm
Location: South of the border..though not down Mexico way..

Re: Dumb astrophysics question for clever twats

Postby L'Emmerdeur » Mon Dec 04, 2017 10:30 pm

Rum wrote:Mind melting here. I'm struggling with what I have until now believed the limit of observation (approx 14B light years) was compared to the proposition in the underlined bit.


It's due to the observed continued expansion of the Universe. The quoted part you've underlined is preceded by this:

The strange thing about space is that it’s expanding. And that expansion can occur at more or less any speed — including faster than light speed — so the most distant objects we can see were in fact once much closer to us. Over time, the universe has shuffled distant stars and galaxies away from us as if they were on an extremely rapid conveyor belt, and dropped them off in far away locations.

Strangely, this means that our observational power is sort of “boosted” and the furthest things we can see are more than 46 billion light years away. ...
User avatar
L'Emmerdeur
 
Posts: 1251
Joined: Wed Apr 06, 2011 11:04 pm
About me: Yuh wust nightmaya!

Re: Dumb astrophysics question for clever twats

Postby JacksSmirkingRevenge » Mon Dec 04, 2017 11:51 pm

L'Emmerdeur wrote:
Rum wrote:Mind melting here. I'm struggling with what I have until now believed the limit of observation (approx 14B light years) was compared to the proposition in the underlined bit.


It's due to the observed continued expansion of the Universe. The quoted part you've underlined is preceded by this:

The strange thing about space is that it’s expanding. And that expansion can occur at more or less any speed — including faster than light speed — so the most distant objects we can see were in fact once much closer to us. Over time, the universe has shuffled distant stars and galaxies away from us as if they were on an extremely rapid conveyor belt, and dropped them off in far away locations.

Strangely, this means that our observational power is sort of “boosted” and the furthest things we can see are more than 46 billion light years away. ...

If it all carries on at an increasing rate, then the observable universe will get smaller and smaller until there's nothing close enough to see. It'll all just disappear?
Sent from my Interositor using Twatatalk.
User avatar
JacksSmirkingRevenge
Grand Wazoo
 
Posts: 13509
Joined: Thu Feb 26, 2009 6:56 pm
Location: Perfidious Albion
About me: Half man - half yak.

Re: Dumb astrophysics question for clever twats

Postby pErvinalia » Tue Dec 05, 2017 1:10 am

What bugs me about all this malarky is that we're told we can't use space-time itself as a reference field, yet we can reference it plenty enough when we declare that it is expanding. The other thing I always struggle with is the concept that when we see things that are say 14billion light years away we are looking back to the beginning of the universe. Where does this suppose that the light has been hanging around in for the last 14 billion years? It should have been way past us to the outer reaches of the universe. Shouldn't there also be a giant hollow in the centre of the universe? Unless the expansion is greater further from the 'centre' of the universe.
Sent from my penis using wankertalk.
"The Western world is fucking awesome because of mostly white men" - DaveDodo007.
"Socialized medicine is just exactly as morally defensible as gassing and cooking Jews" - Seth. Yes, he really did say that..
"Seth you are a boon to this community" - Cunt.
"You know you blokes didn't criticize Obama. You're lying. - Forty Two. Umm - viewtopic.php?f=22&t=42144
User avatar
pErvinalia
Off his meds
 
Posts: 42445
Joined: Tue Feb 23, 2010 11:08 pm
Location: dystopia
About me: Now with 50% less ranting!

Re: Dumb astrophysics question for clever twats

Postby L'Emmerdeur » Tue Dec 05, 2017 2:21 am

pErvinalia wrote:What bugs me about all this malarky is that we're told we can't use space-time itself as a reference field, yet we can reference it plenty enough when we declare that it is expanding.


I'm not sure where you picked that up. How is space-time being used as a reference in regard to the expansion of the Universe?

The evidence that the Universe is expanding is fairly straight-forward. All galaxies outside the local group, no matter in which direction astronomers look, are moving away from us. Those that are farther away appear to be moving away at a higher speed, which is consistent with an expanding Universe.

pErvinalia wrote:The other thing I always struggle with is the concept that when we see things that are say 14billion light years away we are looking back to the beginning of the universe.


Not exactly. Astronomers can observe objects that existed in a much earlier era, but not all that close to the beginning. The most distant (and most ancient) object observed so far is the galaxy GN-z11. It's approximately 32 billion light-years away and its light took about 13.4 billion years to reach us. When that light left GN-z11, the Universe was already about 400 million years old.

pErvinalia wrote:Where does this suppose that the light has been hanging around in for the last 14 billion years? It should have been way past us to the outer reaches of the universe.


The light has been travelling to us during those 13.4 billion years, while the Universe continued to expand. The light waves have been 'stretched' as they travelled by the Doppler effect.

pErvinalia wrote:Shouldn't there also be a giant hollow in the centre of the universe? Unless the expansion is greater further from the 'centre' of the universe.


There is no evidence that the Universe has anything we would be able to recognize as the centre. See the 'raisin pudding/raisin cake' analogy--from any object in the Universe an observer will see all other objects (aside from those in the immediate neighborhood that are gravitationally bound) moving away from the observer. Again, objects that are farther away are observed to be moving away at a higher speed.
Last edited by L'Emmerdeur on Tue Dec 05, 2017 2:36 am, edited 1 time in total.
User avatar
L'Emmerdeur
 
Posts: 1251
Joined: Wed Apr 06, 2011 11:04 pm
About me: Yuh wust nightmaya!

Re: Dumb astrophysics question for clever twats

Postby L'Emmerdeur » Tue Dec 05, 2017 2:31 am

JacksSmirkingRevenge wrote:If it all carries on at an increasing rate, then the observable universe will get smaller and smaller until there's nothing close enough to see. It'll all just disappear?


For a very long time, the observable Universe will be much as we observe it now. However, at some point in the long distant future, it will appear to any observers in the Milky Way/Andromeda galaxy (we're on a collision course) that it is the only galaxy in the Universe.
User avatar
L'Emmerdeur
 
Posts: 1251
Joined: Wed Apr 06, 2011 11:04 pm
About me: Yuh wust nightmaya!

Re: Dumb astrophysics question for clever twats

Postby Brian Peacock » Tue Dec 05, 2017 3:08 am

BTW Rum. There's no dumb questions, just better questions. :D
.


"It isn't necessary to imagine the world ending in fire or ice.
There are two other possibilities: one is paperwork, and the other is nostalgia."

Frank Zappa

"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT


.
User avatar
Brian Peacock
Tipping cows since 1946
 
Posts: 17825
Joined: Thu Mar 05, 2009 11:44 am
Location: Location: Location:
About me: Ablate me:

Next

Return to Science, Technology & Environment

Who is online

Users browsing this forum: Bing [Bot], Google [Bot] and 3 guests

cron