Starship Asterisk*

Dark matter cannot be lab tested in controlled conditions, so we have no idea of any of the "properties" that astronomers assign to dark matter are valid, and there is no possibility of testing anything. Not strictly true, if the DM particle is one of the postulated weakly interacting par...

That all depends on what you mean by reasonably. :) I have colleagues that study objects several Billion light years away. Obviously though it becomes more difficult to really understand what is going on the furher away you look. However its surprising just how much you can learn from faint smudges ...

bogus billions and billions of years Are you suggesting the world isn't about 4-5 Billion years old? :) The age dating of the Earth doesn't just depend of radioactive dating, the age of the Sun and material from meteorites is also a bit of a give away. Besides the type of radiocarbon dating describ...

Well some modifications of gravity allow extra terms in the gravitional law, only at large distances do these modification cause measureable effects, one of which would be for gravity on the very largest scales to be smaller than expected, making it less able to hold back the expansion of the Univer...

It depends, as far as I know there are several types of radiometric dating, they each use different isotope ratios, these isotopes may or may not be products of nuclear tests. I think you mean the kind of radiocarbon dating done on biological matter. I'm not sure if any of the common products of a n...

Thanks missed the rogue tag on the end. It looks like it could well be due to ice crystals in the upper atmosphere the kind of thing that causes things like haloes around the moon. See here for some examples: http://home.clara.net/rfleet/gbh/mpill1.html http://home.clara.net/rfleet/gbh/mhalo1.html

The moon appearing fuzzy to both you and a camera would imply that the effect is real. I would guess it would be due to strong turbulent winds higher in the atmosphere, its the same kind of thing that makes stars twinkle, but would have to be very very turbulent to make something larger than a point...

SN = Supernovae
BH = Black Hole
MECO = Magnetospheric Eternally Collapsing Object

I'll have a stab. Is 'dark energy' real? If its not something very odd is going on with gravity, or their is some strange systematic in the behaviour of distant SN. What about 'dark matter'? Again if it don't then our understanding of gravity must be off. Do 'black holes' really exist? If actual BHs...

Dark Matter and Dark Energy were invented as factors to fill in the 'missing mass' needed to account for our gravity calculations. Not entirely, the amount of DM required to explain the behavior of galaxies and galaxy clusters is oddly exactly the same amount as is required to explain the shape of ...

Its going to be interesting to see if any positive detections come out from the Dark Matter detectors in the next few years, or if anyone detects gamma rays from the annihilations that some possible forms of Dark Matter are thought to undergo. If we don't see any of these things then people are goin...

The most extraordinary sight, however, would be the 'nearby' galaxy. It would be like that scene near the end of the movie, Star Wars, where a spiral galaxy takes up much of night sky. It really wouldn't be that impressive, your eyes aren't able to add up flux like a telescope CCD does, so the low ...

First off, to the frat party that seems to have taken over this board, get back on topic or go someplace else. If you can't answer Nereids questions, go away and do some research, your frankly borderline misogynist posting of late has no place here. Second kovil, you have succeeded in achieving your...

As I understand it, all galaxys appear to have super-massive black holes at their cores, whereas globular clusters do not. Yes this is true, there is a very well behaved relationship between the mass of a galaxies bulge and the mass of the supermassive black hole found there. (A version of the so c...

The reason why you don't see any discernable structure in GCs is essentially one of scale, they are simply not massive enough to be bound if they didn't form simple spheroids. This is partly because they lack any DM as far we can tell. There are GCs which are slightly non spherical because they are ...

Hi AZJames The orbits of the globular clusters are affected by the Dark Matter. We routinely use the orbital motion of GCs in other galaxies (mostly ellipticals) to infer the properties of DM. You can infer from the amount of light in the galaxies how much mass their is, and when you look how fast t...

It depends on whether they are type 1a or type 2 supernovae, but probably its a combination of having a high star formation rate and the fact that it is relatively nearby and observed regularly so we tend to see more of them.

Would this by any chance be your good self harry? Harry Costas independent researcher Australia Just, how credible do you think any of those people on this list are?, barring Arp and about 3 other very old Astronomers. How many of them has actually studied real astrophysical data? Or published a pap...

Stars may form in regions in similar time frames. But! not all within a galaxy at the same time. No one ever said they did. I said that we routinely see star formation rates of hundreds to thousands of solar masses per year. At that rate you can build up a large galaxy in less than a Billion years....

Harry I repeat my statement where is your evidence? I can cite papers by real astronomers, working in real institutions, that say that everything makes sense. You have never provided any evidence to back up your claims. For one thing stars are not made at the same time. You lack info on star formati...

Harry we have had this conversation before, I see that you haven't paid any attention though. A galaxy cluster is made up of hundreds to thousands of galaxies. They all form stars at the same time , each galaxy can form stars at a rate of hundreds of solar masses per year, how long does it take to f...

Simple Harry, most GCs have ages of greater than 10-12Gyr, and we see the galaxy clusters forming about 6-10 Gyr years ago.

If you read a few real papers you would know this.

I'm talking about galaxy clusters not globular clusters by the way - 2 completely different beasts!

Indeed most of the Globular Clusters were already old by the time your galaxy clusters were virializing.

Harry it does not assume we are at the centre.

It measures distances from us, therefore we appear to be at the centre.

Honestly Harry try to think about things before you type.

I've always liked this for a sense of scale: http://xs511.xs.to/xs511/07042/universe5py.gif I'm afraid there are no pretty pictures, just a logarithmic graph that has the distances to essentially everything of interest in the Universe, from the centre of the Earth right to the CMB, then to the final...