Is dark energy an artifact?

[Paddy]

People may be aware of the recent research which suggest that the lumpiness of the universe explains the disparity between predicted and measured rates of expansion and that dark energy is not a necessary construct to explain observations. This was briefly reported in AS&T's current issue.

I found a podcast on ABC News Radio's Star Stuff program in which this is elaborated on in a way that I could actually understand. I also found the implications quite fascinating. Here is the link for those that might be interested:

http://www.abc.net.au/newsradio/txt/s2164363.htm

[xelasnave]

Well thanks from me Patrick I do enjoy hearing about anything in this area.
alex

[Paddy]

I thought you might like that one Alex!

[xelasnave]

Well I think it sounds all very nice but if we take away "dark energy" as is the suggestion in the story on the radio..I am at a loss to see how galaxies can hold together... if one wants to explain different parts of galaxies not flying all over the place on the current thinking we need dark matter...why? so based on the notion that there is such a force as attraction we must have more mass available to place where needed to make the current sums using attraction work...

And I say this..add all the dark matter to a galaxy you like so as to hold them together and then you find the outter stars should go even slower than observed... and by adding more mass internally we then have to face the fact that we need to add more dark matter outside the galaxy so the outter stars go as fast as observed..it is like a dog chasing its tail in my view...

It seems we have two propositions..galaxies need dark matter within so as to hold them together but this still leaves the observation that the outter stars are going too fast..so why is that well thats the dark matter on the outside...
whatever you add to the galaxy you have to add heaps more to balance on the outside and I doubt if a balance can be achieved... I bet the math would prove me correct on that idea.


My idea as to gravity pushing upsets so many folk and I can understand that but Mr G upset a lot of folk also and he was finally proved right ..folk think I have not considered the matter fully... well maybe I have considered the matter longer and harder than most..the fact that I speal like a simpleton need not mislead the basic premise.

But if you throw out the notion that there is a force we call attraction and substitue only a pushing force everywhere we can explain why the outter stars move so fast on the one hand and on the other why galaxies hold together... attraction will not hold a galaxy together unless you have gravity travelling at an impossible speed of instant...consider how wide our galaxy... the message of gravity takes some 150,000 to 200,000 years to get from one side to the other and so one must ask why would one side not drift away in ignorance to what is going on over the other side... to me an external push that acts universally seems the only way...and as I undwerstand it this is part of the reason why darlk energy is needed..and as I understand it they see this force as both external and of a push nature.

The other aspect I find strange about the proposition mooted in the radio story is the different ages for different parts of the Universe... I think folk take the dictates of special relativity to describe a reality where as I think they can only describe and interprete the observations of an observer and the observer is the one doing the sums ...

I can not see that this can be seen as what God would see (someone standing outside looking at everything). ...and maybe they mix up special relativity and general relativity here I dont know but it seems that way to me.

Anyways just rattling on here and you all must be used to that..it must give some a laugh thinking I am uninformed and lack understanding... and no offence to those who think I need math to analyse any of this but I recall my first readings of Dr A's stuff and it always seemed to me he described "how things seemed to the observer not how things really were in a "god" view..."

and hence the importance of the observer in any of this stuff...

and so we see a clock on a space ship actually slowing in real terms (special relativity?) when in my view it is a matter of how the observer sees the clock not what is actually happening to that clock.. and here I dont disagree with general relativity it is not relevant to this side of things...generalrelativity will slow or speed up a clock however it seems... mmm my head hurts:whistle:.

but in truth this is hard stuff to understand for me... the math can only ever prove the general premise not change a reality and the general premise seems to me to deal with what an observer sees and I feel it should not be seen as something that alters reality...over all reality not the reality observed by an observer.

and of course special relativity and general relativity works for GPS and I think I understand how the combination of those two considerations work for gps positioning.... and I find no problems or inconsistencies with what I suggest.

I still believe there are no experiments that prove attraction to exist..even the Casmier force to me does not do it... folk will say the casmier effect is clear evidence of attraction but I say it is clear evidence of push:eyepop::lol::lol::lol:...Why say because two things go together that they are attracted when one could say just as easily that they are pushed together.. So why is the difference important? well it comes down to how each of these forces will be communicated..attraction needs a message out and a message in one could expect.. How can an object say "I am here tell me where you are I await the return of a reply" ..so immediately we need the messages to be going double C if we are to end with an all up time of C...

I can suggest how push can communicate a force but I have never found anything out there that suggests how attraction can be communicated..please let me know if its there as this stuff interests me...I think that attraction is something we always took as a given without actually asking anything about it...like the world being flat who would bother to ask if it could be otherwise from the experiences of humans.

So in ignorance I go on..and on:lol::lol::lol:

So Patrick I thank you again as I like this stuff and whether right or wrong at least I think about stuff and try to come up with answers to the questions this stuff raises for me... so it keeps me out of mischief and out of the pub;)


alex:):):)