Lambda-CDM theory - Woo or not?

[ben m]

But in the Driver, et. al. paper, they show a lot of the energy excess in the UV band.

Does it? Where? I'm looking at figure 4 and I see the data points (purple, SDSS/Galex) lying right on top of the model (orange) in the UV.

 

[Wangler]

Does it? Where? I'm looking at figure 4 and I see the data points (purple, SDSS/Galex) lying right on top of the model (orange) in the UV.

The excess UV is in the greyed area to the left of Figure 4.

If I understand correctly, if the total cosmic spectral energy distribution is different than what has been assumed, then the distribution of stellar types may have to be revised.

It seems that the changes to aggregate mass won't change my much, however.

 

[ben m]

The excess UV is in the greyed area to the left of Figure 4.

If I understand correctly, if the total cosmic spectral energy distribution is different than what has been assumed, then the distribution of stellar types may have to be revised.

It seems that the changes to aggregate mass won't change my much, however.

That's not quite "excess UV". The left-hand grey area is the (modeled) amount of UV that was emitted by stars, but absorbed by dust before it could reach Earth.

The reason this curve is labeled "data" is that it's obtained by dividing the observed UV/vis curve (fig 4 orange) by the absorption curve (fig 3), rather than by extrapolating a stellar-populations model. The inferred amount of dust-obscured UV is consistent ("in excellent agreement") with the observed amount of reheating of this dust---in other words, the light has been there and observed for a long time, so this correction does not change your estimate of the galaxy's luminosity---it only changes your estimate of how much of that luminosity comes from bluer stars.

To figure out how big a correction this is to luminosity-measurement in the blue/UV, you don't compare the orange line to the grey line. Galaxy luminosity measurements have always included *some* sort of dust correction in the UV/vis---note that this paper cites a decade's worth of work on the topic---so previous estimates of the true UV emission have always been higher than the orange line. Exactly how high? This paper doesn't go into that.

 

[Tim Thompson]

Stars and Baryonic Dark Matter V

I will have more to say later ...

Some of which ben_m has already said ...

The inferred amount of dust-obscured UV is consistent ("in excellent agreement") with the observed amount of reheating of this dust---in other words, the light has been there and observed for a long time, so this correction does not change your estimate of the galaxy's luminosity---it only changes your estimate of how much of that luminosity comes from bluer stars.

And a point I have also made ...

Also note that they are talking about starlight, that is light directly produced by stars. Astronomers already knew long before this 2008 study that starlight is absorbed by dust and the energy re-radiated in longer wavelength infrared photons. So astronomers have long used the infrared luminosity of a galaxy as a tracer for star formation rates. The photons do not directly escape the galaxy as starlight, but the energy does escape, as longer wavelength infrared photons produced by the dust in response to absorbing starlight (the photons that did not escape). So that baryonic mass is in fact already accounted for in the form of a star formation rate, rather than in the form of existing stars. So in fact the study you refer to should have essentially no effect at all on the baryonic mass estimate because the mass represented by those photons was already in the books, just in a different form.

We are having this discussion because Mozina thinks that dark matter cannot be anything but ordinary baryonic matter and that the implication to be drawn from Driver, et al., 2008 is that we have overlooked large amounts of baryonic mass by underestimating the number of stars in galaxies.

How about taking a look at the first link again, and focusing specifically on the fact that galaxies are twice as bright as we first ASSUMED and the small stars are 4 times as numerous as we first thought. Why wouldn't those revelations result in ANY modification of your baryonic mass estimates?

It should not make any difference at all on our baryonic mass estimates, and here is why: All of the mass of all the "missing stars" from Driver, et al., 2008 has in fact already been considered. It's just that instead of bookkeeping that mass as stars already formed, it has been cataloged as gas forming stars.

From Driver, et al., 2008, section 2.3:
"For the CSED to be in equilibrium (and energy conserving), the difference between these two energy values, (0.7 +/- 0.2) x 10³⁵ W Mpc^-3 should not exceed the total emission from dust in the far-IR, the traditional sticking point for optically thin models. Figure 4 also shows a model of the dust emission (red line, Dale & Helou, 2002) that reproduces fairly well the observed data. Integrating the far-IR curve, we obtain a total radiant dust energy of (0.6 +/- 0.1) x 10³⁵ W Mpc^-3, in excellent agreement with our prediction."

Note that in the introduction and in the conclusions section, Driver, et al., 2008 have pointed out the persistent conflict between the assumption of optically thin galaxies (implying that most starlight photons directly escape the galaxy) and the observation of significant far-IR emission (implying that a significant fraction of starlight photons do not directly escape the galaxy but rather indirectly escape as far-IR photons emitted by dust grains heated by starlight). That far-IR emission, which has not been adjusted by Driver, et al., 2008 is the very same emission used to derive star formation rates, and thereby gas masses for galaxies cosmologically. Hence, the effect Mozina is implying, that baryonic mass has been overlooked, is fallacious and therefore the implications of Driver, et al., 2008 have nothing to do with dark matter at all.

All of the discussion about mass & luminosity & classes of stars to add is irrelevant to the question of the total baryonic mass. It is relevant only to the understanding of how the baryonic mass is distributed between stars and the interstellar medium, and to how the stellar mass is distributed amongst the stellar classes.

 

[sol invictus]

Note that in the introduction and in the conclusions section, Driver, et al., 2008 have pointed out the persistent conflict between the assumption of optically thin galaxies (implying that most starlight photons directly escape the galaxy) and the observation of significant far-IR emission (implying that a significant fraction of starlight photons do not directly escape the galaxy but rather indirectly escape as far-IR photons emitted by dust grains heated by starlight). That far-IR emission, which has not been adjusted by Driver, et al., 2008 is the very same emission used to derive star formation rates, and thereby gas masses for galaxies cosmologically. Hence, the effect Mozina is implying, that baryonic mass has been overlooked, is fallacious

I'm confused. It sounds like you're saying that the total luminosity of starlight was already known accurately, because it was based on observed far-IR emission from dust. Is that correct?

If so, I don't understand how you conclude that a re-assessment of the dust absorption as a function of wavelength, which in turn leads to a re-assessment of the mass distribution of stars (fraction of stars in a given mass range), wouldn't change the total mass in stars. Keeping the total starlight luminosity fixed, you can change the total star mass by a huge factor by playing with the the mass distribution. In other words, total star luminosity is not enough information to fix total star mass - not even close.

The problem for Mozphyzics is that the adjustment can go either way - if stars are bluer than previously thought, this reduces the total star mass.

 

[Michael Mozina]

The problem for Mozphyzics is that the adjustment can go either way - if stars are bluer than previously thought, this reduces the total star mass.

Ah, but the sword of physics cuts both ways. The fact it can go either way demonstrates the problems of "dark-sky-religion-physics" sol. The fascinating part of this discussion IMO is the divergence of opinions between a "skeptic" and a "believer" in terms of how we go about solving this brightness problem, and even the divergence of opinions between the "hard liners" like Tim and ben, vs. the more 'reasonable' (from my perspective) approach I've seen from you and Wangler. At least I'm convinced that you and Wangler can see that we CAN add stars to the mix, even if just the larger ones, whereas Tim seems intent on NEVER admitting that adding stars is an option.

The other fascinating thing from my perspective is how this issue illustrates the differences between "conservatism" in terms of favoring "empirical physics" (my preference), and "conservatism" in terms of protecting the "belief systems" that currently exist.

From my perspective Tim seems to be doing everything in his power to simply ignore and/or deny the fact that we can add stars to achieve the same basic goal of increasing luminosity, even if we have to pick and choose their various sizes to fit the data curve.

You and Wangler seem to at least entertain the concept, so long as we stick with large size stars. FYI, I don't believe that would actually decrease the overall mass, but in theory at least, you might come up with a SMALLER number than Tim did, based on his preferred technique.

FYI, that orange line ends because that is where the data stopped, not because there was actually *NO* interference at those wavelengths, they just weren't high enough energy to really worry about in terms of the overall energy output as far as I can tell. The lines also never come into contact, meaning at no wavelength do they every actually meet. More importantly, the doubled amount of light is virtually continuously greater than 100% from 3mm on. It's not like it's just a "small" part of the spectrum that is effected, it's virtually the ENTIRE spectrum that shows this process.

Keep in mind that we haven't even discussed the second paper yet, but that paper suggests that we OVERESTIMATE the number of larger stars compared to the number of smaller ones.

Now, back to the point....

There are no exotic forms of matter known to man. IMO it only makes sense to be "conservative" in terms of "filling in any gaps" in any theory with NORMAL baryonic material, whenever and wherever possible. That "conservatism" is directly related to my preference for KNOWN PHYSICS and KNOWN forms of matter.

Tim's approach seems to be exactly the opposite from my perspective. The "conservatism" is aimed at "protecting the status quo" rather than filling in the gaps of the "dark" parts of his current theory and understanding. It's almost as through he INSISTS that some sort of exotic matter MUST exist. Maybe, and maybe not. We won't know however if we never actually attempt to ELIMINATE the need for exotic types of matter and we constantly favor a "dark matter=exotic matter" approach.

Another thing that this paper demonstrates is that it is unlikely that we even know how to properly count the number of stars in a galaxy, let alone their mass. Ben however seems to believe we've eliminate every kind of baryonic type of matter known to man down to the size of a small moon! This type of 'faith' in "unseen" (in the lab) matter is IMO "fanatical' in the extreme. If we can't properly count stars yet, how can we possibly have eliminated everything down the size of a small moon?

This is actually a fascinating discussion IMO, mostly because it shows the difference between a desire to protect a belief system and a desire to tear it apart. The "skeptic" is always unlikely to take the same path as the "true believer", even if both honestly attempt to address the data. I don't question that fact that Tim's method works, I simply don't believe it's the "best" way to explain the data.

 

[Tim Thompson]

Stars and Baryonic Dark Matter VI

I'm confused. It sounds like you're saying that the total luminosity of starlight was already known accurately, because it was based on observed far-IR emission from dust. Is that correct?

No, only the total energy was already known, not the total starlight. The total energy was known as a sum of the observed star light and observed far-IR dust emission, the latter being entirely thermal.

We know the dust emission is thermal but we don't know if the dust is heated by the process of star formation or by stars already formed. Stars that are already there follow the empirical mass-luminosity relationship (which is a bit more complicated in detail than the approximation I have presented so far, but still allows for a determination of mass from luminosity). The star formation process on the other hand does not follow the same mass-luminosity relationship, but the process is still essentially thermal in the conversion of gravitational energy to thermal energy in the collapse of a proto-stellar cloud, so we can still get a handle on the collapsing gravitational mass.

Clearly this is not going to be exact. However, in the one case we have a stellar mass derived from the direct starlight, and on the other hand, a mass of gas in the process of collapsing to form stars. Both are baryonic, and the gas mass inferred from the star formation rate is going to be similar to (but slightly greater than) the mass of stars already formed (since not all of the gas will wind up trapped in stars).

According to Mozina, the prior underestimation of visible direct starlight means that galaxies are actually more massive than was previously thought, the mass difference being the stellar mass that would be needed to generate the missing starlight. However, my point is that the energy of that missing direct starlight has always been visible as thermal dust emission. That energy has always been assumed to come from the process of star formation heating the dust, and star formation requires a mass of baryonic gas. That baryonic gas has always been included in the mass budget, and offsets the missing stellar mass. The two (gas mass & stellar mass) won't be precisely the same, but it does falsify the notion that there is such a large hole in the baryonic mass budget that needs to be filled.

I hope I did a better job explaining it this time around.

 

[Michael Mozina]

That baryonic gas has always been included in the mass budget, and offsets the missing stellar mass. The two (gas mass & stellar mass) won't be precisely the same, but it does falsify the notion that there is such a large hole in the baryonic mass budget that needs to be filled.

I hope I did a better job explaining it this time around.

Not actually. I'm not even discussing the gas/dust yet, and I assumed that you already accurately accounted for it's mass. Nobody was arguing that point, at least not yet.

You could in fact still double the number of point sources inside the opaque part of the galaxy to double the luminosity of the galaxy, and then lose half of that luminosity to the gas. At no point did you account for the doubling of stars that would be required to double the amount of light, even if you did in fact already account for the gas that absorbs the light from those extra stars.

 

[Michael Mozina]

FYI, I need to preface one point in my previous post. You did in fact account for the luminosity (your way). I'm just saying that from my perspective you could still double the number of stars and achieve the same thing. As sol pointed out you may be able to "fiddle" with the star count percentages and come up with a SMALLER number than you did too. It's all about how one defines "conservatism".

 

[Farsight]

...We are having this discussion because Mozina thinks that dark matter cannot be anything but ordinary baryonic matter and that the implication to be drawn from Driver, et al., 2008 is that we have overlooked large amounts of baryonic mass by underestimating the number of stars in galaxies...

Sounds interesting. Maybe I can help.

Ah, but the sword of physics cuts both ways...

It certainly does. Science progresses, which means that most people are wrong most of the time. Maybe I'm one of them, but I think there's a problem with the Lambda-CDM model, and that there's a problem with what you're saying too.

There are no exotic forms of matter known to man. IMO it only makes sense to be "conservative" in terms of "filling in any gaps" in any theory with NORMAL baryonic material, whenever and wherever possible. That "conservatism" is directly related to my preference for KNOWN PHYSICS and KNOWN forms of matter.

There is an exotic form of matter known to man. We've known about it for nearly a hundred years. It's a gravitational field. It's so exotic that it doesn't consist of particles, and you can hardly call it matter. But think about what Einstein said in The Foundation of the General Theory of Relativity. He said "the energy of the gravitational field shall act gravitatively in the same way as any other kind of energy". There's energy in a gravitational field, and it has a mass equivalence. It causes gravity. People tend to forget about this, sometimes citing the vacuum catastrophe, but IMHO that's a mistake because it flies in the face of general relativity, a robust well-tested theory.

Tim's approach seems to be exactly the opposite from my perspective. The "conservatism" is aimed at "protecting the status quo" rather than filling in the gaps of the "dark" parts of his current theory and understanding. It's almost as through he INSISTS that some sort of exotic matter MUST exist. Maybe, and maybe not. We won't know however if we never actually attempt to ELIMINATE the need for exotic types of matter and we constantly favor a "dark matter=exotic matter" approach.

I've seen a lot of people fiercely defending dark matter in the form of particles likes WIMPs, so I empathize with your sentiment. But I haven't read much of the thread, so I don't know Tim's stance.

Another thing that this paper demonstrates is that it is unlikely that we even know how to properly count the number of stars in a galaxy, let alone their mass...

Yes, but flat galactic rotation curves do stand out as being radically different to planetary orbits. Your miscounting of stars has got to be amazingly wrong to account for that.

This is actually a fascinating discussion IMO, mostly because it shows the difference between a desire to protect a belief system and a desire to tear it apart. The "skeptic" is always unlikely to take the same path as the "true believer", even if both honestly attempt to address the data. I don't question that fact that Tim's method works, I simply don't believe it's the "best" way to explain the data.

In my experience people have something of a tendency to believe in things for which there is no evidence, and to dismiss the evidence that challenges that belief. Religious people certainly do it, but scientists do it too. And so, I'm afraid, so people who consider themselves to be skeptics.

 

[Michael Mozina]

Sounds interesting. Maybe I can help.

It certainly does. Science progresses, which means that most people are wrong most of the time. Maybe I'm one of them, but I think there's a problem with the Lambda-CDM model, and that there's a problem with what you're saying too.

I'm intrigued already. That's a great start!

There is an exotic form of matter known to man. We've known about it for nearly a hundred years. It's a gravitational field. It's so exotic that it doesn't consist of particles, and you can hardly call it matter. But think about what Einstein said in The Foundation of the General Theory of Relativity. He said "the energy of the gravitational field shall act gravitatively in the same way as any other kind of energy". There's energy in a gravitational field, and it has a mass equivalence. It causes gravity. People tend to forget about this, sometimes citing the vacuum catastrophe, but IMHO that's a mistake because it flies in the face of general relativity, a robust well-tested theory.

I guess that depends on how we define the term "exotic" I suppose. You might want to keep in mind that QM does hypothesize a carrier particle for gravity. As I understand it however, it also lacks support in terms of LHC experimentation at the present moment however.

I've seen a lot of people fiercely defending dark matter in the form of particles likes WIMPs, so I empathize with your sentiment. But I haven't read much of the thread, so I don't know Tim's stance.

I lack belief that they exist, he probably does not.

Yes, but flat galactic rotation curves do stand out as being radically different to planetary orbits. Your miscounting of stars has got to be amazingly wrong to account for that.

I agree. They would have to be wrong both in terms of the number and the layout as well. It would almost certainly be necessary to move the bulk of the "dark stars" (ones we cannot directly observe) to the outside edge of the galaxy and the bulk of the larger stars near the central bar.

In my experience people have something of a tendency to believe in things for which there is no evidence, and to dismiss the evidence that challenges that belief. Religious people certainly do it, but scientists do it too. And so, I'm afraid, so people who consider themselves to be skeptics.

I agree. Welcome to the discussion by the way. I look forward to your input.

 

[Wangler]

I hope I did a better job explaining it this time around.

Yes, at least it made it easier for me.

It seems that we already knew the total energy spectrum, and the Driver paper just clarifies where that energy actually comes from.

Drive, et. al., claim there truly is more energy from blue stars. If some of that blue star energy was being shifted to the red, that means we have less actual energy from red stars or protostars.

Unfortunately, the red stars or protostars have lots of mass for a given energy output, and blue stars have lots of energy output for a given mass.

So, more blue stars and fewer red stars and protostars would mean less mass overall, right?

 

[Michael Mozina]

Yes, at least it made it easier for me.

It seems that we already knew the total energy spectrum, and the Driver paper just clarifies where that energy actually comes from.

Drive, et. al., claim there truly is more energy from blue stars. If some of that blue star energy was being shifted to the red, that means we have less actual energy from red stars or protostars.

Unfortunately, the red stars or protostars have lots of mass for a given energy output, and blue stars have lots of energy output for a given mass.

So, more blue stars and fewer red stars and protostars would mean less mass overall, right?

FYI, as you're looking for way to increase the brightness, keep in mind that there is a second paper and article that we're discussing that has a bearing on this discussion:

http://www.jpl.nasa.gov/news/features.cfm?feature=2287
http://iopscience.iop.org/0004-637X/695/1/765

 

[Reality Check]

FYI, as you're looking for way to increase the brightness, keep in mind that there is a second paper and article that we're discussing that has a bearing on this discussion:

http://www.jpl.nasa.gov/news/features.cfm?feature=2287
http://iopscience.iop.org/0004-637X/695/1/765

FYI, Wrangler, This paper is not being discussed. It has already been discussed but unfortunately MM has not understood yet what an initial mass function is. It distribiutes a given initial mass of stars into the various populations.
So Evidence for a Nonuniform Initial Mass Function in the Local Universe; Meurer, et al., The Astrophysical Journal 695(1): 765-780, April 2009) does not change the mass. It changes how it is distributed among the stars.

This was pointed out to MM back on 18th August 2010 by Tim Thompson - over a year ago now!
Dark Matter and Science IV

Once again, he chooses to link to a news report and avoid the science paper (Evidence for a Nonuniform Initial Mass Function in the Local Universe; Meurer, et al., The Astrophysical Journal 695(1): 765-780, April 2009).

Once again, let us look at the abstract of the paper:
...
But the estimation of mass from total luminosity is not going to be sensitive to this distribution, because the same total mass (and therefore the same total luminosity) can be distributed in many ways over the stellar mass function.

The reliance on news articles is a basic flaw in MM's analytical skills. The inability to actually read the news articles is an even bigger flaw, e.g.
Galaxies Twice as Bright as They Seem, Study Finds

The results also mean that there is about 20 percent more mass in stars than previously thought. But since stars make up such a small percentage of the universe to begin with — dark matter and dark energy account for 95 percent or so — it is a small adjustment over all.
“Basically increasing the stellar mass in the nearby universe by 20 percent has little impact,” Dr. Driver said in an e-mail message from Scotland.

The other 2 news articles do not mention any impact on the measurements of the masses of galaxies but the same thing applies.

 

[sol invictus]

There is an exotic form of matter known to man. We've known about it for nearly a hundred years. It's a gravitational field. It's so exotic that it doesn't consist of particles, and you can hardly call it matter. But think about what Einstein said in The Foundation of the General Theory of Relativity. He said "the energy of the gravitational field shall act gravitatively in the same way as any other kind of energy". There's energy in a gravitational field, and it has a mass equivalence. It causes gravity.

Yes, that's true. A more conventional way to say that is, "general relativity is non-linear".

People tend to forget about this, sometimes citing the vacuum catastrophe, but IMHO that's a mistake because it flies in the face of general relativity, a robust well-tested theory.

Umm, what? Not only does it not "fly in the face of GR", it is GR. Linearized GR is Newtonian gravity. The full GR, the theory Einstein wrote down, is the (essentially unique) non-linear extension of Newtonian gravity.

In fact the reason GR has black holes (and Newtonian gravity doesn't) is because the gravitational field acts on itself in GR.

Unfortunately, non-linearities in GR cannot account for either dark matter or dark energy. That would be a neat solution, and has been thoroughly explored - and it doesn't work. That's especially clear for DM, because much of the evidence for DM comes from galactic orbital dynamics, where Newtonian gravity is a very good approximation to GR. But it also doesn't work for dark energy (unless you want to think of the effects of a positive cosmological constant as "gravity acting on gravity", in which case it does account for it).

 

[Michael Mozina]

FYI, Wrangler, This paper is not being discussed.

What RC means is that he doesn't want to discuss the fact that we have evidence that we not only underestimate the LARGEST stars in the galaxies, we grossly underestimate the number of smaller stars as well. He doesn't like to discuss that.

From the link I cited:

This diagram illustrates the extent to which astronomers have been underestimating the proportion of small to big stars in certain galaxies. Data from NASA's Galaxy Evolution Explorer spacecraft and the Cerro Tololo Inter-American Observatory in Chile have shown that, in some cases, there can be as many as four times more small stars compared to large ones.

In the diagram, a massive blue star is shown next to a stack of lighter, yellow stars. These big blue stars are three to 20 times more massive than our sun, while the smaller stars are typically about the same mass as the sun or smaller. Before the Galaxy Evolution Explorer study, astronomers assumed there were 500 small stars for every massive one (lower stack on right). The new observations reveal that, in certain galaxies, this estimation is off by a factor of four; for every massive star, there could be as many as 2,000 small counterparts (entire stack on right).

 

[Reality Check]

What RC means is that he doesn't want to discuss the fact that we have evidence that we not only underestimate the LARGEST stars in the galaxies, we grossly underestimate the number of smaller stars as well. He doesn't like to discuss that.
...snipped another MM "I see bunnies in the clouds" image...

Ohhh - pretty picture MM!


What I mean is that the paper

1. Has already been discussed (over a year ago):
   18th August 2010 by Tim Thompson - over a year ago now!
   Dark Matter and Science IV
2. Does not need to be discussed again because it only redistributes the mass.

I am quite willing to discuss the one paper you have cited that has an actual change in the mass of galaxies.
So MM: What effect does a 20% increase in the mass of galaxies in the local universe have according to your enormous knowledge of physics ?

Are you going continue with your ignorance that galaxies are only 5-20% of the mass of galaxy clusters (the rest of the visble matter is in the ICM).

Are you going continue with your ignorance that that only 4% of the universe is measured to be visible matter? So roughly 0.4% of the universe is in galaxies (see above).
So you are asserting that the masses of galaxies are underestimated by a factor of 250 ! And all you can find is a paper that increases their mass by a factor of 1.2. You do see the enormous problem there?

Are you going to continue to ignore the fact that few people use the very imprecise method of estimating galaxy mass by luminosity and applying it to the universe to get the % of visible matter?
Thsi is because there are a much better ways, e.g. use the CMB and BNN to get more accurate values.
Who needs error bars of +/- 50% whan you can get error bars of +/- 0.5% !

ETA
You need to read Adding up Stars in a Galaxy again and note that it is about the proportion of stars, not the total mass of the stars.
It does not say anything about the number of blue giants unless you think that theses 'certain galaxies' only have 1 blue giant each!
And once again you point to a press release - not the actual science!

 

[Wangler]

You need to read Adding up Stars in a Galaxy again and note that it is about the proportion of stars, not the total mass of the stars.

Can anyone point me to the paper that drove this press release? I am having trouble finding it.

Are they assuming a constant overall energy output while changing the star proportion?

I want to do some of my own calculations of mass sensitivity.

 

[Reality Check]

Can anyone point me to the paper that drove this press release? I am having trouble finding it.

Are they assuming a constant overall energy output while changing the star proportion?

I want to do some of my own calculations of mass sensitivity.

It may be the Evidence for a Nonuniform Initial Mass Function in the Local Universe paper by Gerhardt R. Meurer, et al. who use the GALEX observations and one author is from the Cerro observatory.

Also see the Galaxies Demand a Stellar Recount news article which has the same release date.

 

[Tim Thompson]

Stars and Baryonic Dark Matter VII

That baryonic gas has always been included in the mass budget, and offsets the missing stellar mass. The two (gas mass & stellar mass) won't be precisely the same, but it does falsify the notion that there is such a large hole in the baryonic mass budget that needs to be filled.

I hope I did a better job explaining it this time around.

Not actually. I'm not even discussing the gas/dust yet, and I assumed that you already accurately accounted for it's mass. Nobody was arguing that point, at least not yet.

You are in fact claiming exactly what I said you are claiming, and here you are doing it:

There's a fair number of candidates for a dark matter particle.

Ya, including ordinary matter. I've yet to hear you folks address that "dust" in space revelation from a few years ago, or that revelation that galaxies are twice as bright as first thought, or that "stellar recount" data that that shows that small stars were underestimated by a factor of FOUR! About all I see are papers claiming "SUSY did this in the sky, SUSY did that in the sky". SUSY seems to be dead. What justification do you even have for exotic forms of matter at this point?
{ ... }
IMO it is your fault for failing to consider the fact that your ordinary mass estimated were probably (now known to be) botched to begin with, and no real steps have ever been taken to MINIMIZE the need for exotic types of mass.

How about that dust problem? What about that stellar recount problem? Don't you think it would make sense in light of recent laboratory analysis to go back and revisit your ORDINARY mass estimates with the express intent of minimizing or doing away with exotic brands of matter?

Fact: Dark matter is almost certainly not baryonic, because all baryonic possibilities have been ruled out by direct searches and/or by various other effects it would have produced.

Sorry sol, on this point I simply have to absolutely, positively, without any doubt, disagree with your assessment. Here's why:

http://www.nytimes.com/2008/05/17/science/space/17univ.html
http://www.jpl.nasa.gov/news/features.cfm?feature=2287
http://news.nationalgeographic.com/news/2009/06/090609-most-massive-black-holes.html

There is clear evidence IMO that not only were the original mass estimates WRONG they were wrong by a lot. In over three years I haven't seen your industry budge one single percentage point from their emotional need for "exotic" brands of matter. In fact I've seen no movement AT ALL! That says to me that your industry just isn't interested in admitting their mistakes in their mass estimation techniques.

Spare me the lecture about the Black hole not helping find the missing mass, yada, yada, yada. I'm just noting that the industry hasn't budged a single percentage point in 3 years. That alone says volumes IMO.

Well, there you are, claiming exactly what I said you claimed, that the shortfall in counting stars translates directly into a shortfall in estimating the baryonic mass, and your complaint that "the industry has not budged a single percentage point". It is my explicit claim that "the industry" has not budged a single percentage point because there is no reason to do so. The arguments you bring to the discussion do not, in fact, represent any necessary change in the derived baryonic mass of galaxies & the universe. My argument above falsifies this claim of yours by demonstrating that the mass you think has been overlooked has in fact been included all the time.