Dark matter - a solution?

So this week I've been off work - yipee! I figure I should post something because, well, I'd be just too much of a slacker if I didn't. I'm not sure where this post will go just yet, as I started it with no particular topic in mind again.
I had another week off a couple of weeks ago, and although I did get around to doing some writing, it wasn't on here and I felt bad for not getting around to it. The thing is I usually like to write about a particular topic but to be honest, I think if I just realise that if I dive in and start writing, something always comes out.
The writing I did do was for my book, which I've mentioned previously. I'm happy that I'm actually getting some stuff done with it now - I'm about 4 or 5 chapters in so far, so I am *actually* writing it.

OK, so the big news is I *may* have come up with a solution for the missing weight in the universe problem. I'm not kidding.
For those of you not acquainted with the problem or who don't take a passing interest in science, the problem is thus:
'They' (meaning scientists,) weighed the universe. Yup, weighed it. I'm not sure of the specifics of how, but basically they looked at all the stuff we can see - stars, planets, galaxies etc and calculated how much mass is should all contain. Then they calculated how much the universe actually weighs, using how much gravity there is. The assumption being that certain astrophysical phenomena, such as spiral galaxies being bound together instead of the stars and planets flinging off into space, would require a certain amount of gravity. Makes sense. However, knowing how much gravity is exerted by a body of baryonic matter, (i.e. normal, tangeable 'stuff' like planets or stars or you or a chicken salad sandwich,) they totted it all up and fell short. Way short. The stuff we can see does not account for the gravity in the universe. It's about one sixth of the density required, or some people put it at 10% of the weight that it should be in order to match up.
That left people scratching their heads as you might expect. It's like stepping on the scales and finding out you now weigh 100 stones, (1,400 pounds for you American types or 635 kilos for you Europeans out there,) instead of 10 stones, (140 pounds or 63.5 kilos,) and yet physically, you don't look any different.

...

Well, I left writing this blog to come back to it and during my time away I checked into it and it appears my theory is bunk.
Basically I had been walking around the science museum a few weeks back and I saw a quote from Einstein saying that even photons have mass when they approach the speed of light. (I'm starting to womder if I remembered it wrong.) Since photons normally travel at the speed of light, it occurred to me that the universe is filled with light. Even if the average photon had an incredibly small mass, the abundance of these particles would mean their sum could end up weighing a fair bit. Since light is invisible - it's only the things it interacts with that we can see and since the scientists who weighed the universe were weighing what they can see, it seemed to me that light would be an obvious candidate for being overlooked.
According to several websites, photons have no mass under the modern definition - from USA Today's website:
A: No, photons do not have mass according the present definition of mass. The modern definition assigns every object just one mass, an invariant quantity that does not depend on velocity, says Dr. Matt Austern a computer scientist at AT&T Labs Research. Under this definition, mass is proportional to the total energy, Eo, of the object at rest.
"A particle like a photon is never at rest and always moves at the speed of light; thus it is massless," says Dr. Michael S. Turner, chair of the Department of Astrophysics at the University of Chicago. (http://www.usatoday.com/weather/resources/basics/wonderquest/photonmass.htm)

But hang on, there are two issues there:
One is that as you approach the speed of light, mass increases doesn't it?
Well, apparently not. This is the old terminology of 'relativistic mass', which is no longer used. Obviously under that description, the faster you go, the more mass you have, but light (photons,) would have to be massless, otherwise it's mass would be infinite and the universe would go squish.

Secondly, the good Doctor mentions that photons are never at rest - except now they are. A recent experiment brought a photon to complete rest by firing it through a Bose-Einstein condensate of Rubidium. The previous slowest speed for light was 38mph, which is still unbelievably slow.
Anyway, it might be an idea to weigh the little bugger while it's in there, as we might yet find out that the missing weight of the universe is not due to dark matter, but the sum of the weight of all normal, invisible light.
If so, you can contact me through this blog to give me my Nobel prize.


Further reading on photonic mass can be found here:
http://www.desy.de/user/projects/Physics/ParticleAndNuclear/photon_mass.html
for those of you who are interested.