[ExI] Dark matter

[BillK]

On Tue, Feb 19, 2013 at 8:30 PM, Adrian Tymes  wrote:
> And?  People keep saying that as if it's good reason for disbelief,
> but the data - such as that Hubble shot - seems to substantiate
> that there's a lot more ordinary matter than we have yet seen.
>

It's not called 'dark' because it is not radiating. We can see dust
clouds because dust blocks or reflects light.

But we can see right through dark matter. 'Dark matter' doesn't
radiate light OR absorb light (or react with any electro-magnetic
radiation). We can only infer it's existence from seeing gravitational
effects, so we can calculate the required missing mass.

Nobody yet knows what it is.


BillK