Blowing Smoke

A while ago I posted about the Bullet Cluster, and an image which seems to reveal the dark matter within it. Now a new image from Hubble seems to do the same thing for the galaxy cluster CL0024 17.

Dark Matter Ring from Hubble

Now I am personally rather sceptical about the validity of images such as these, although I feel sure that we will see many more of them in the coming years. ‘Showing’ dark matter sounds to me like a dangerous business. It is, after all, dark. I would argue that releasing such images is detrimental to science and astronomy more specifically. To fool the general public into believing that something exists before you are sure of it yourself is not good science.

Now it may be beneficial to model dark matter in the way shown in these images, and this could lead to a better understanding. To release this sort of thing without warning as to the subjective nature of its content is not fair on those who would simply believe it as a photo like any other. After all how sure can anyone be that what is shown here is anything real at all? It is like deducing the nature of the wind from the way birds fly.
There is more to it that just that though. I know so many people who have no clue that many of the images they see from space are false-colour, for example. I also have to explain to people everytime I shown them Andromeda through a telescope, and look back at me confused, that the images they see from Hubble and other big observatories are enhanced, essentially doctored, to make them prettier. Do you think they will understand that this dark matter ring is simply a mathematical deduction? Will they even care?

Maybe I’m overreacting, but I do believe that one of the jobs of any scientist is to report back their findings to the public at large, who ultimately fund them. The PR guys need to get educated as to what this image and the ones that are surely coming our way soon, really mean.

Dark matter is still not a subject that we know much about. Its a mystery – and that is one very good reason it is so interesting. We cannot photograph it because we don’t know where it is. Gravitational lensing tehcniques can begin to help us locate it but don’t let’s be fooled by what the com puters give us at the end of the day. If we start to believe these images are real simply because they look real we will have strayed off the correct path and begin putting garbage into our theories. This is, as my supervisor always says, never a good thing because you end up with rubbish results; garbage in, garbage out.

You can read more over at Astronomy Picture of the Day and the Bad Astronomy Blog.


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