LCDM simulation creates realistic spiral galaxy

[shernren]

Go science!

ERIS: World's first realistic simulation of the formation of the Milky Way - YouTube

Astrophysicists report first simulation to create a Milky Way-like galaxy - UC Santa Cruz

[1103.6030] Forming Realistic Late-Type Spirals in a LCDM Universe: The Eris Simulation

 

[philadiddle]

They just knew the result they wanted and made a program to do it. What a waste of 8 months of supercomputer time.

/poe

 

[juvenissun]

I wonder if it shows the center of this galaxy rotates much faster than the edge. Is that true for a spiral galaxy?

 

[KerrMetric]

I wonder if it shows the center of this galaxy rotates much faster than the edge. Is that true for a spiral galaxy?

No it isn't true.

 

[juvenissun]

No it isn't true.

What I am asking is that did that model show a faster spinning at the central part of the galaxy? I think it does by just look at it.

 

[KerrMetric]

What I am asking is that did that model show a faster spinning at the central part of the galaxy? I think it does by just look at it.

I looked at the rotation profile in the paper itself. The final model peaks about 1.34kpc out from the centre and then slowly falls off as you move out. This is basically what the Milky Way rotation profile looks like within error bars.

This flattish rotation profile is what is observed for all spirals that I know of. This was the second motivation for the dark matter hypothesis because you'd expect the profile to fall off as one over the square root of the distance which is not observed.

I said isn't true to your earlier question because you used the words "much faster". In fact a lot of the observed ones carry on rising but it is a hard measurement to make at large distances from the centre and the error bars are pretty large.

 

[Papias]

Juvie wrote:

.....a faster spinning at the central part of the galaxy?

Juvi, are again beating the tired old drum of the creationist PRATT that the spiral galaxy spin shows a young earth? You remember that that PRATT was shown to be silly a long time ago, right?

Kerrmetric is being very nice to take the time to explain it to you again.

Papias

 

[juvenissun]

I looked at the rotation profile in the paper itself. The final model peaks about 1.34kpc out from the centre and then slowly falls off as you move out. This is basically what the Milky Way rotation profile looks like within error bars.

This flattish rotation profile is what is observed for all spirals that I know of. This was the second motivation for the dark matter hypothesis because you'd expect the profile to fall off as one over the square root of the distance which is not observed.

I said isn't true to your earlier question because you used the words "much faster". In fact a lot of the observed ones carry on rising but it is a hard measurement to make at large distances from the centre and the error bars are pretty large.

OK. Thanks.
I said that because what I see on the video. I guess it might be caused by the graphic scale.

 

[juvenissun]

Juvie wrote:



Juvi, are again beating the tired old drum of the creationist PRATT that the spiral galaxy spin shows a young earth? You remember that that PRATT was shown to be silly a long time ago, right?

Kerrmetric is being very nice to take the time to explain it to you again.

Papias

I don't know what PRATT said. You worried too much.

 

[Papias]

PRATT - Point Refuted A Thousand Times.

It refers to common creationist canards that have been shown over and over to be silly. Since this comes up all the time creationist literature, might I inquire as to where you, juvi, got the idea about the spin rate of the galaxy center? Did you just happen to it up, or did you read it in creationist literature?

Papias

 

[juvenissun]

PRATT - Point Refuted A Thousand Times.

It refers to common creationist canards that have been shown over and over to be silly. Since this comes up all the time creationist literature, might I inquire as to where you, juvi, got the idea about the spin rate of the galaxy center? Did you just happen to it up, or did you read it in creationist literature?

Papias

My own observation and common life experience.

 

[philadiddle]

My own observation and common life experience.

Can your own observation ever be trumped by objective evidence?

 

[shernren]

Can your own observation ever be trumped by objective evidence?

There's no such thing as objective evidence, phil; it all has to be interpreted.

Resistance is futile. Assimilation is inevitable.

 

[Papias]

juvi, what, specifically, in your own observation and common life experience is in any way related to galaxy formation?

More to the point, so you are saying that you never heard the creationist argument about the spin rate of the center verses the edge of a galaxy?

Papias

 

[juvenissun]

Can your own observation ever be trumped by objective evidence?

My own observation on things I do not understand is limited. The so-called objective evidence, in this case, are material presented in books and other info media. Of course, they would interpret and modify my understanding from my own observation. However, they will not quench my questions.

 

[juvenissun]

juvi, what, specifically, in your own observation and common life experience is in any way related to galaxy formation?

More to the point, so you are saying that you never heard the creationist argument about the spin rate of the center verses the edge of a galaxy?

Papias

I am a creationist. What did I argue anything about it?

 

[Papias]

OK, let's look at some facts here:

1. Creationist literature often describes a false claim that spiral galaxies have a "problem" with spin rates between the center and the edge.
2. In fact, from the creationist literature I've seen, the most common reason spiral galaxies are mentioned at all is to introduce this falsehood.
3. You don't have to take my own observation and common life experience as believable - you can check this yourself. Simply google ("spiral galaxies", spin, "young earth") or such and see what you get. I just did that, and of the 10 pages listed on the first page of hits, 9 of them discussed this exact PRATT, with 6 of them being creationists repeating the PRATT, and 3 being astronomy supporters debunking the PRATT.
4. When spiral galaxies were brought up on this thread, juvi's first comment is to immediately bring up the very issue of that PRATT, which had not been mentioned on this thread until juvi brought it up.
5. It is well known here that juvi is a creationist (as he stated), who reads creationist literature and hence often posts well known creationist PRATTs.
6. When asked if he got this PRATT from the creationist literature, juvi said that instead he got it from "his own observation and common life experience".
7. juvi is known to have lied on these fora before, such as when he claimed to be a geology professor, or to read the main geology journal (yet be unaware of a major announcment in it).

juvi, given the above facts, do you agree that a reasonable person might suspect you have lied again here?


Papias

 

[juvenissun]

OK, let's look at some facts here:

1. Creationist literature often describes a false claim that spiral galaxies have a "problem" with spin rates between the center and the edge.
2. In fact, from the creationist literature I've seen, the most common reason spiral galaxies are mentioned at all is to introduce this falsehood.
3. You don't have to take my own observation and common life experience as believable - you can check this yourself. Simply google ("spiral galaxies", spin, "young earth") or such and see what you get. I just did that, and of the 10 pages listed on the first page of hits, 9 of them discussed this exact PRATT, with 6 of them being creationists repeating the PRATT, and 3 being astronomy supporters debunking the PRATT.
4. When spiral galaxies were brought up on this thread, juvi's first comment is to immediately bring up the very issue of that PRATT, which had not been mentioned on this thread until juvi brought it up.
5. It is well known here that juvi is a creationist (as he stated), who reads creationist literature and hence often posts well known creationist PRATTs.
6. When asked if he got this PRATT from the creationist literature, juvi said that instead he got it from "his own observation and common life experience".
7. juvi is known to have lied on these fora before, such as when he claimed to be a geology professor, or to read the main geology journal (yet be unaware of a major announcment in it).

juvi, given the above facts, do you agree that a reasonable person might suspect you have lied again here?


Papias

Why do you write so much if I lied before? I won't do that. Dumb!

 

[Papias]

juvi wrote:

Why do you write so much if I lied before? I won't do that. Dumb!

juvi, I'm sorry that your response to my honest question was to call me dumb. To answer your question, polite and honest discussion is valuable, so when the evidence suggests otherwise, it's worth our time, for the benefit of CF, to follow up on it.

Now that I've answered your question, I notice that you still haven't answered mine.

It is, from my previous post: juvi, given the above facts, do you agree that a reasonable person might suspect you have lied again here?

Papias

 

[juvenissun]

juvi wrote:



juvi, I'm sorry that your response to my honest question was to call me dumb. To answer your question, polite and honest discussion is valuable, so when the evidence suggests otherwise, it's worth our time, for the benefit of CF, to follow up on it.

Now that I've answered your question, I notice that you still haven't answered mine.

It is, from my previous post: juvi, given the above facts, do you agree that a reasonable person might suspect you have lied again here?

Papias

I called you dumb. You know I will lie to you, but you still want to talk to me.
I won't be that dumb.

You want me to talk? Then apologize.