[ExI] Has the mystery of Dark Matter been solved?

[spike]

>... On Behalf Of BillK
Subject: Re: [ExI] Has the mystery of Dark Matter been solved?

On 25 May 2016 at 09:33, Anders wrote:
>>... Likely just to annoy John, there is a recent paper (
> http://arxiv.org/abs/1603.08522 ) arguing the early supermassive holes 
> could be due to direct collapse of gas clouds. I cannot judge the 
> likelihood of this, but it will be interesting to see how it turns out.
>
>

>...Ethan Siegel discusses why black holes = dark matter is unlikely.
<http://www.forbes.com/sites/startswithabang/2016/05/26/black-holes-as-dark-matter-heres-why-the-idea-falls-apart/#687e2a006d7b>

...BillK

_______________________________________________


Ja, however... the best way to look at physics theories is to think of them as analogous to software.  Many or most of us here have written software and gotten it working, then later found it has something in it that isn't working right, some subtle remains bug somewhere, and good luck finding it.  I must allow the possibility that our current theories on the early universe might still have some subtle bug in there somewhere.  

Otherwise, our seeing a black hole merger just a few days after turning on LIGO was one hell of a stroke of luck.

Unless I misunderstood, LIGO has run a total of 18 days so far, and never with full instrumentation (it was a test synchronization with only partial capability running last September.)  LIGO isn't going on line at full capacity for a few months yet.  So... before I can assume our current model is completely correct, I want to wait for at least a couple years of data to come in.  My understanding of the abundance of black holes suggests we wouldn't be likely to see another event like that again very soon.  So what if we turn the thing on and see a merger like that one every couple months?  We will be reviewing our notions on early black hole formation.

spike