Dark Flow

[Demojen]

We can make observations about visible objects, and we can make observations about things that have no visible component at all... observations about what people are thinking for example.

An observation about concepts is not an observation of concepts. While you can make an observation *about* what people are thinking, you can not make an observation of their thoughts. You're not observing something that has no visible component.

Without the method for deducing their thoughts, you aren't making an observation about what people are thinking, rather an introspection of what you yourself are thinking.

 

[aeroeng314]

Again, you're applying your own exclusive definition of visable, transparent and opaque, but use the words in context you will see I did not mention who or what was observing it and for a very good reason.

And that reason would be because you're incapable of making any sense? I honestly have no idea what you're talking about. While I do make a distinction between visible and observable, that's because the article originally said "in a certain sense", so all I needed to do to show that the article wasn't contradictory was show that there was a sense in which it was true. By choosing an appropriate (but not arbitrary) definition of the word "visible", the article is shown to be true.

I definitely didn't choose personal definitions for opaque and transparent, so I don't know what you're referring to there. And I didn't pull that definition of visible out of my ass, either.

"Because I said so" isn't a good enough answer.

I don't believe I ever used that as an argument. Project much?

the definition of visible universe is a defined radius of what you can potentially see either or not you are able to do so, being that EM radiation travels at the speed of light, the distinction is irrelevant.

In the absence of some kind of qualifier to the contrary, I'd agree, visible and observable universe are used interchangeably (although I try to stick to "observable" to avoid any confusion). But that wasn't the issue. The statement in the wiki article was qualified with "in a certain sense" which meant that we weren't using the implied definition. That's why I emphasized that part of the sentence.

Get off wikipedia and think for yourself.

I do think for myself, but I do my best to incorporate thoughts and ideas that are not my own into that process. If I relied purely on my own thoughts instead of actually grabbing knowledge from the outside world, I'd probably end up making stupid nonsense statements like how the universe is transparent and opaque at the same time and then not even bother to explain it.

 

[mycrowsoffed]

Look outside on a windy day. With the naked eye you will never be able to see the wind. You cannot observe it directly as you can a tree. On the other hand, you can observe it indirectly by noticing the effect it has on a tree. You can see a branch being moved or a tree's leaves blowing in the wind.

Dark Matter and Dark Energy shouldn't be thought of as theories yet and now neither should Dark Flow. These are hypotheses that have been postulated to explain things that we have observed, directly and indirectly but we need a lot more time to do a lot more work in order to better understand what it is we are observing. It's not impossible that the cosmos is older, larger and stranger than can be explained by our current Standard Model.

 

[Master_Ghost_Knight]

I will have to conceed this point, since wikipedia isn't what I would call a good source of objective technical information, i.e. the article may not necessarily mirror what the concept that it tried to explain is, and as so it may not necessarilly hold their terminology as strict as we do.

 

[)O( Hytegia )O(]

I watched it and wanted to make myself an hero halfway through.
They babbled back and forth about philosophy and the possibility of it (I'm going to toss out a line and say that it was about 50 minutes wasted) before presenting you with the actual subject (for about 12 minutes) and then ended it with a "Well I don't know."
X.x
I should have spent my time watching something far more entertaining - like Why Do People Laugh At Creationists? Atleast I laugh when it tells me the same things over and over again.

 

[Pulsar]

Disclaimer: although I'm an astrophysicist, I'm not a cosmologist. My understanding of this topic is limited, so don't take my word for it.

As far as I understand it, the dark flow, if it really has a statistical significance, would provide evidence for inflation. The idea is that in the very early universe, local overdensities would attract nearby material, causing 'flows' of matter towards them. Then, inflation took place, and the vast majority of matter is pushed beyond our horizon. This material doesn't affect us or anything else we see in our observable universe any longer, but the original flows of some groups of clusters still exist. After all, thanks to good old Newton and his law of inertia, the clusters continue their motion in the absence of a gravitational force. The dark flow would therefore be a remnant of the very early universe, prior to the inflation period.

Anyway, that's how I see it. Oh, and I saw the last 15 minutes of that BBC documentary. It was crap, they dumbed everything down to the level of a National Geographic doc. Very disappointing.

 

[Deleted member 619]

Quite probably the worst documentary I've seen in a very long time. Aside from the extreme lack of rigour in the language employed, the sum total of the dodcumentary was 'the standard model is not complete'. This is news how? It's long been known that the standard model has flaws, and that we don't have a complete picture. Apart from anything else, the standard model is a product of GR, which is known to be incomplete.

The only thing that was remotely new was this 'dark flow', the extant information concerning which could have been conveyed in an advert break.

Really shoddy programming.

 

[5810Singer]

Really shoddy programming.

You've hit the nail on the head there, H+S.

I remember in the 90s that Horizon, and Equinox (remember Equinox? twas on Chan4) ran an awful lot of these non-documentaries,.......90% of any given doc would be what you already knew, and the remainder was a modicum of new information, followed by a sort "Gosh! I wonder what'll happen next......", ending.

The docs were so lightweight that you could often gleen more scientific knowledge from reading their synopsis in the tv guide.

In the last 5yrs or so I've found British-made science docs to have raised their game massively, but this was a return to the 90s nadir.

How about we bombard the BBC with emails of complaint on this issue?

 

[Prolescum]

My father used to write to the BBC every time they cancelled Star Trek for some crappy sports event; it never worked...

 

[5810Singer]

^^Yea but sports are live, and ST used to get a lower ratings share than "Shit-bours", "Shit-Enders", etc, and so on........

I was thinking of something a bit more pointed, with a greater number of actual physicists, cosmologists, astronomers, etc involved in the lobbying.

I'm just tired of these thrown together pices of claptrap, that dumb-down the subject to the point where it appeals to noone.