I’ve been intrigued by this graph of the Ambient Cosmic Electromagnetic Radiation:
Fig. 9. Overall estimate for the continuous cosmic background radiation. The data in Fig. 8 were used to derive upper and lower limits at all frequencies, which is proportional to the spread in this splatter plot. Where the background is well measured the line is narrow, and it becomes thicker in regions where the uncertainties are larger.
— Hill R, Masui KW, Scott D. The Spectrum of the Universe. Applied Spectroscopy. 2018;72(5):663-688. doi:10.1177/0003702818767133
I suppose there is some way of calculating the total power represented by a complex integration but that’s above my pay grade. So I decided to get a baseline estimate of the power by simply multiplying the highest amount of power displayed that is common to all frequencies - $10^{-14} W m^{-2} sr^{-1}$ - times the total number of frequencies, $10^{26}$ which yields an unrealistic result of $10^{12}W m^{-2} sr^{-1} s^{-1}$.
The math seems pretty straightforward but the results don’t make sense. Am I screwing up the analysis or…? I’m beginning to suspect that it is wrong to assume that electromagnetic radiation is emitted at all possible frequencies as implied in the plot. Any ideas?
The units are already in Watts per square meter per steradian so the power is in the curve.
I don’t know if multiplying by 10^26 is sufficient because the power spreads across frequencies. From the basic E=hf, higher frequencies have linearly more energy. To get from frequency to power though you also need intensity. By using a log scale for frequency those values on the right are already partly ‘integrated’ over a wide spectrum.
What the graph doesn’t show is intensity measured, but it is implied in the interpretation. If the intensities of all frequencies had hypothetically been equal (some fixed number) then the curve would have increased linearly up on a linear x-scale (E=hf), and logarithmic upward on a log x-scale like for this graph. Clearly it isn’t because high-frequency intensities drop off significantly.
We could simply say it looks like a half-sine and integrate. Peak of the sine at value $$10^{-6}$$. That gives a crude total value of ~ $$2x10^{-4} W/m^2/sr$$ But it’s not a sine curve though so the answer is off.
The fact that it briefly peaks and then drops away means the intensities of the higher frequencies are MUCH MUCH lower than the intensities of the lower frequencies. Intensity more likely follows an $$e^{-x}$$ downward curve or typical blackbody spectrum with ~ $$e^{-ax}$$ after the initial peak. That blackbody curve would be recognisable on a linear x-scale. If the frequency scale had been linear, those high frequency powers would be hitting near zero from after 10^15Hz.
The /sr part of the units is easy to get rid of - multply by 4π for spherical total. Then we have a graph of W/m^2 measured on the surface of a sphere of radius 1m. But we won’t need that if we assume a black-body. We just need to know where is the peak.
For the rest - assuming a blackbody curve - we can use Wien’s law: ν_max = 5.88 × 10¹⁰ × T. The graph visibly peaks at ~10^11 Hz, but contorted due to log-x plot. Known figures quote for CMB v_max as ~1.6x10^11. This gives the familiar T=2.75 from the above equation.
The power of the CMB is: $$P=σT^4$$ with σ=Boltzman and T=2.75 just calculated.
$$P=3.128×10^{−6} W/m^2$$
This is the total power arriving from all directions (the full 4π sky), not just from one direction.
@Francois-Zinserling Thank you but your remarks don’t address the point. All the frequencies of the spectrum have a minimum incoming power of $10^{-14} W m^{-2} sr^{-1}$ according to the plot. If that is accurate then the minimum total incoming power across the entire 10^{26} spectrum is $10^{12} W m^{-2} sr^{-1} s^{-1}$. This again seems unrealistically high - a trillion watts!
I kind of expected that the more mathematically inclined here would have jumped at the chance to point out some obvious error in my analysis or math but so far nothing. As with the calculated result I’m not sure what that means. In addition to the possibility that not all frequencies in the spectrum carry power, another thought has occurred to me.
Is it possible that the total power of a wide spectrum has less cumulative effect than the same total power concentrated in a narrow frequency band? Power is power so $10^{12} W$ should have the same physical effect whether it comes in a narrow or wide band shouldn’t it, or should it? I guess it’s time to revisit basic electromagnetic theory.
@budrap00 note that the vertical scale of the graph is $\nu I_\nu \ {\rm W m}^{-2}{\rm sr}^{-1}$, not what you have in mind i.e. the specific intensity $I_\nu \ {\rm W Hz}^{-1} {\rm m}^{-2}{\rm sr}^{-1}$ which would be the right quantity to integrate over a frequency band.
Hill et al. explain their unusual scale in §2.1.
The math is straightforward but the graph is presented in a strange way (looks strange to me anyway…) You have to do the integration in narrow frequency bands.
E.g. for the CMB peak around $\nu_p = 1.5\times 10^{11}$ Hz, in a band between $\nu_a = 10^{11}$ Hz and $\nu_b = 3\times 10^{11}$ Hz, the graph gives $\nu_p I_\nu \approx 5\times 10^{-7} \ {\rm W m}^{-2}{\rm sr}^{-1}$.
Dividing by $\nu_p$ and multiplying by the bandwidth $\Delta \nu = \nu_b - \nu_a = 2\times 10^{11}$ Hz gives
$$ I_\nu \approx \frac{5\times 10^{-7}}{1.5\times 10^{11}} \ 2\times 10^{11} \approx 6\times 10^{-7} \ {\rm W m}^{-2}{\rm sr}^{-1}. $$
This is slightly overestimated (by a factor 2) because I used the peak value $5\times 10^{-7}$ rather than the real shape of the spectrum. But the number makes sense.
Another example for the CXB peak around $\nu_p = 10^{19}$ Hz, in a band between $\nu_a = 5\times 10^{18}$ Hz and $\nu_b = 2\times 10^{19}$ Hz, gives
$$ I_\nu \approx \frac{10^{-10}}{10^{19}} \ 1.5\times 10^{19} \approx 1.5\times 10^{-9} \ {\rm W m}^{-2}{\rm sr}^{-1}, $$
400 times less power than in the CMB peak.
Unfortunately the authors of the paper don’t provide an excel spreadsheet of the curve. You have to do everything by hand for each band of interest.
However if you want the total power in that spectrum, the CMB is much more powerful than everything else combined! So the answer is given above by @Francois-Zinserling .
@budrap00 as @RedshiftDrift also says above: the confusion is in the scaling of the graph. It is an interesting way to find value in something that is almost zero though.
It appears to be a basic function of an x-y graph but the logarithmic x-scale makes it complicated because the power is not measured at discrete frequencies. It’s measured across a band of frequencies. Narrow band for low frequencies but comparatively very wide band at extreme high frequencies. So if you want to spread the x-scale back to a linear scale, you will have to distribute the power of the graph amongst each new point that you add on the x-scale.
On the graph it looks like there is ~ the same amount of power at 10^9 as there is at 10^25 but if you break the 10^25 region into little 10^9 bands, each band will contain very little power.
I got something wrong in my last message. Here’s the better take: the y-axis label would be a bit clearer if it were written as Hz × W·m⁻²·sr⁻¹ / Hz, so you don’t need to calculate the traditional “area under the curve.” So @budrap00, you don’t need to multiply (10^-14 W·m⁻²·sr⁻¹) by (10^26 Hz - 10^7 Hz) in your example above. The 10^-14 W·m⁻²·sr⁻¹ already is the power per area you’d normally associate with that “bottom rectangle.”
@RedshiftDrift @Francois-Zinserling @ericcosmos I took it as a given that this is a plot of observed power inflow over various frequency ranges against the frequencies the power was observed at. That interpretation is consistent with the y-axis units being labeled as W·m⁻²·sr⁻¹. Any value on the y-axis can represent an actual measurement but does not specify the frequency at which the observation was made. The chart then plots the measured power against the frequencies at which they were observed.
That seems to be the whole intent of the paper - to stitch together existing inventories of the measured power inflowing from the night sky over the entirety of the electromagnetic spectrum - and therein lies the problem. Obviously no inventory can be made of the individual frequencies, of which there are 10^26. So the relevant question is, how much of the full EMR spectrum actually carries power? In other words does the electromagnetic spectrum have a continuous power distribution as the chart implies, or is it discontinuous with significant parts of the spectrum carrying no power?
As a first guess I think it is more reasonable to assume discontinuity and on that basis attempt to determine what the nature of that discontinuity is like. Is there a regular pattern of power/no power frequencies and if so at what scale? Given the unrealistic seeming result of assuming continuity, the discontinuity has to be significant to get the total inflow down to some reasonable level - the caveat there being how you decide what is reasonable. The only way to determine that I would think is not by assumption but meticulous observation.
It is possible that some indication of where the no-power gaps lie might be present in the raw data that the paper relies upon. It’s been a while since I actually read the paper so I’m going to give it another look in case the authors already gave this issue some consideration.
BTW @RedshiftDrift I think your statement that “the CMB is much more powerful than everything else combined” is not necessarily true. It depends on how much total power there is in the vast real estate between the CMB at 10^11 and the range that extends out to 10^26 Hz. Under the continuous power assumption there is vastly more total power in that range (as depicted in the graph) given, as @Francois-Zinserling points out, the logarithmic scale used for the x-axis. If you make the x-axis linear the CMB spectrum amounts to a minute fraction of the total spectrum. How much total power is actually present over that broad range beyond the CMB is, I think, an open question.
There are more than 10^26 possible frequencies, by the way, so I’m not sure why you’re treating the spectrum as if it needs to be chopped into 1 Hz bins.
@RedshiftDrift speaking of the spreadsheet of the curve, turns out this is pretty easy now! I asked AI to find 1,000 points along the curve and make a spreadsheet, and it worked. AIfind1000points.csv I plotted the 1,000 extracted points below in black so you can see they matched the original curve pretty well.
After that, I divided each point by the frequency to get the specific intensity, basically undoing what the authors had done to the data.
Now you can just calculate the area under the curve @budrap00. The fun part is that the cosmic microwave background absolutely dominates. It has more power than everything else combined.
@ericcosmos >There are more than 10^26 possible frequencies, by the way, so I’m not sure why you’re treating the spectrum as if it needs to be chopped into 1 Hz bins.
We don’t have to chop distances into meters either. Are you really that unfamiliar with physics that you are unaware there are standard units? Maybe you should, you know, brush up your physics before you’re tempted to ask another clueless question.
As to your second plot, it is a physically meaningless redundancy. Let’s take this from the top. The authors converted specific intensity to intensity so they could produce a graph of intensity per frequency (which is specific intensity) over the whole spectrum. Every point on the plotted curve represents a specific intensity. What you have done is divide specific intensity by frequency producing a plot of intensity per frequency per frequency which is just some physically meaningless math.
Hey @budrap00 , wash your mouth before speaking !! It seems to me that @ericcosmos is far more competent than you when it comes to physics (and mathematics).
@HanDeBruijn Not for the first time we have a difference of opinion. But then you are a mathy guy so maybe you can explain the physical meaning of intensity per frequency per frequency.
@ericcosmos good work!
Of course AI can do routine jobs, but ‘Real Intelligence’ has to check the results. Your AI found a large spread in the CXB spectrum where the curve is quite narrow, and a small spread at 10^15 Hz where the data from the paper has a large spread! I think it “sees” unsaturated colours as significant data.
I made this high-contrast version from the image in the paper.
I asked Claude to give me two sets of data, one for the top and one for the bottom of the black region. It had trouble with the labels but I manually corrected the points that were off.
Then I calculated the geometric mean and the result is quite good!
spectrum_envelope_c.csv
For @budrap00 who doesn’t understand log-log scale, here’s a lin-lin version where the area under the curve is proportional to the power contained in the band.
“The CMB is much more powerful than everything else combined” is true, as the graph visually shows.
And finally @budrap00, “a graph of intensity per frequency” is not specific intensity. The correct description is “a graph of intensity as a function of frequency (which is intensity)”.
By not understanding how to read a graph you get an absurd “specific intensity per frequency” and then blame the error on others.
Obviously, astrophysical measurements don’t have a resolution of 1 Hz! The best spectrometers for astronomy have a resolution of about 1000, so that curve shows the power within frequency bands that split the entire spectrum in no more than 10000 points. High resolution stellar spectroscopy has a resolution of 1000000 and no gap has ever been seen in starlight. Your assumption of discontinuity is ridiculous, heterodyne laboratory measurements show continuous spectra to micro-hertz (and even below for atomic clocks); no discontinuity has ever been detected.
@ericcosmos Fair enough. I apologize to you and everybody for my needlessly grumpy response. I did take my own advice and brushed up my physics, specifically the meaning of spectral intensity which seems to be more commonly referred to as spectral radiance.
Radiance is just the total power per square meter per steradian, observed or emitted. Spectral radiance (intensity) breaks that total power out into its individual frequencies. I can find no indication that the per frequency term of spectral radiance implies an actual division which would be like dividing apples by oranges - difficult to interpret physically. Per frequency in this case is just an accounting notation.
@RedshiftDrift >here’s a lin-lin version where the area under the curve is proportional to the power contained in the band. “The CMB is much more powerful than everything else combined” is true, as the graph visually shows.
First of all, even a casual glance shows this to be a lin-log graph but that’s a trivial matter although it plays a part in your transparent attempt at, what might be called, graphical dissembling. This is a the graphical equivalent of cherry picking the data to fit your conclusion. On second glance it appears that the y-axis is also non-linear but in a very peculiar way.
The only thing your graph depicts is the peak of the CMB and all the rest of the spectrum is essentially reduced to zero by your choice to essentially compress the data below 5.0E-8 into what would otherwise be a linear increment to 1.0E-9. The result being that all the inconvenient data that might spoil your narrative is effectively zeroed out on the graph.
And all that zeroed out data is important in the context of a linear x-axis which runs out to $10^{26}$. As the calculation that caused me to originate this discussion showed, if you assume the spectrum is continuous as it appears in the graph that implies an enormous amount of total power across the entire spectrum. This is a matter of scale and the scale in this case is enormous.
Consider the units of a linear scale in terms of powers of ten. To go from 1 to 10 requires 9 additional units, the jump from 10 to 100 requires 90 additional units, from 100 to 1000 it’s 900 additional units, etc. Now consider the jump from $10^{25}$ to $10^{26}$. That requires $9\times 10^{25}$ additional units. If those are units of frequency and those frequencies contain a minimum of $10^{-14} W m{^2} sr^{-1} Hz^{-1}$ then the total radiance (intensity) for $10^{26}$ frequencies is $10^{12} W m{^2} sr^{-1}$ as previously calculated. That surprising result represents a minimum calculated for convenience - the actual radiance (total power) would be much higher.
What to make of that result was the motivation for this discussion and I want to get back to that issue. Nobody has provided a convincing argument that the analysis or math are wrong. If the result is correct given the full spectrum assumption then there are as I see it two possibilities that might align the result with observations.
One is a frequency gap, meaning the continuous spectrum assumption is wrong. I don’t particularly like it but it is certainly not ruled out by @RedshiftDrift’s analysis which, if I’m interpreting it correctly, accounts for only $10^{7}$ frequencies - a minute fraction of the $10^{26}$ total.
The second possibility is that all that spread out power does not sum effectively as it would if delivered in a narrow band. I’m not particularly fond of that explanation either but at that point I’m out of ideas. Anybody else?
Bud, have you heard of anger management? 😄 If you’re going to spend that much energy on something, save some for the Big Bang crowd.
Louis, thanks for the feedback. The high-contrast image was a great call. That was a really clever idea. (Minor nitpick: isn’t that plot linear-log rather than linear-linear?) The CMB truly is the biggest component of the ambient cosmic electromagnetic radiation, and anyone can see it right there on the graph. I’ve been wondering about where the CMB actually comes from, too. In the DemystifySci video you linked, they mentioned carbon as a typical blackbody. Do you know if there’s much carbon outside the Milky Way? Is it possible that there’s carbon out there that’s just naturally heated to 2.7 K?
Just as I was starting to write the linked post I accidentally uploaded it so I just opened the edit function and finished, but when I reposted it looks like Github treated it as on old post. so: https://github.com/orgs/a-cosmology-group/discussions/376#discussioncomment-17385358
@budrap00 I think I know where is the incorrect assumption. I mentioned in my first post something like we cannot view this as a graph of y=f(x). It is not a ‘function’ but a graph with a peculiar choice of units and scaling. Not bad at all, but clearly confusing as hell.
If you break the $$10^{26}$$ bar into 10x $$10^{25}$$ bars they won’t each have $$10^{−14}$$. If the measurement was taken across a $$10^{26}$$ band you will not get the same power or energy result if you only measure across a $$10^{25}$$ band. Or more correctly you have to divide the $$10^{−14}$$ between all 10 of them - crudely they now each read $$10^{−15}$$. (10 x smaller). If you keep dividing up the x-axis right down to $$10^9$$ bars, there’s hardly any W left to divide. It is near zero compared to the CMB reading at ~ $$10^9$$.
One correction to some other statements above that “The CMB is much more powerful than everything else combined” is the caveat to add: “The CMB is much more powerful than everything else combined when measuring empty space” This may seem like an obvious statement.
Despite trying to help AI, Claude wasn’t able to read correctly the scale from the graph. The values listed by AI are roughly half of what the graph says :disappointed: The above graphs produced using Claude are too low by a factor of 2. I just caught that now. Again this justifies my general distrust for anything touched by AI…
In my simple minded understanding of graphs, when the scale is labeled 7 9 11 13 15… with equidistant spaces +2, it’s ‘linear’! If the same graph is labeled 10^7 10^9 10^{11} 10^{13} [Hz]…, that’s logarithmic with a factor x100 between each :wink:
It’s worse than that: They (incorrectly) believe that only carbon can generate the Planck spectrum! So for them, the CMB must be generated by carbon. Iron can also generate a Planck spectrum (stove top burner), and so can tungsten in a light bulb. Also, under some conditions, liquids, gases and plasmas can generate a blackbody spectrum.
We can’t use this process of elimination to find the source of the CMB.
Not quite, the paper states: “The cosmic background (CB) radiation, encompassing the sum of emission from all sources outside our own Milky Way galaxy across the entire electromagnetic spectrum”
This is better said as “The CMB is much more powerful than all sources outside the Milky Way.”
@RedshiftDrift Basically you hold two contradictory positions. The first is that the spectrum of the extragalactic Cosmos is continuous and well described by the subject graph. That is also assumed by the authors of the graph and by me when I did the calculation that gives a 1 trillion minimum radiance for the spectrum of the Cosmos.
Your second position is: >The CMB is much more powerful than all sources outside the Milky Way.
If the first position is true, the second is false and vice versa. They could both be false but they can’t both be true. Some attempt to reconcile your self-contradictory views would be appreciated.
Bud, you’ve got a screw loose here! The y-axis on Louis’s chart is actually linear. 5.0E-8 doubled is 1.0E-7, tripled is the next tick, quadrupled is the one after that, and so on. The spacing is perfectly linear.
Also, I’d suggest setting aside the Hill, R., Masui, K.W., Scott, D. chart for a moment, and looking at the chart under the line: “After that, I divided each point by the frequency to get the specific intensity, basically undoing what the authors had done to the data.” If you calculate the area under the curve for whatever frequency band you’re interested in, that’s the total power in that band.
A lot of this confusion would vanish if you just explained, in straightforward terms, why you’re so committed to the idea that the CGB must be more powerful than the CMB, regardless of what the charts actually show.
Louis, just to clarify what I meant earlier: since the y-axis is linear and the x-axis is logarithmic of the physical quantity, wouldn’t that be considered a lin-log plot?
As for the carbon discussion, what’s actually wrong with carbon as a possibility? Or iron, tungsten, and other heavier elements? Those are all ejected by dying stars. Couldn’t carbon, iron, tungsten, and other metals exist outside the Milky Way, and carbon and those metals naturally be heated to 2.7 K? Just to be clear, though, I’m not arguing for DemystifySci’s “CMB is the oceans” idea. I don’t buy that explanation either.
@ericcosmos Well Eric I’ve been wondering if you were an actual mathematician who wandered over into the physics department and you were just getting your bearings but what you have demonstrated is that you’re just a garden variety mathematicist. Mathematicists as a general rule are not good at physics and, surprisingly enough, not very good at math either:
The y-axis is not linear at all. It is quasi-linear over the E-7 scale because the .5E-7 labeled intervals have a constant value. When the E-6 scale is reached the same intervals will be labeled .5E-6 and each regular interval will have a 10x greater value than the E-7 scale intervals. The y-axis is nonlinear above 1.0E-7 and just irregular obfuscatory nonsense below. Logarithmic scales are in powers of ten. You and @RedshiftDrift need to take a remedial course on the difference between linear and logarithmic scales.
The confusion is all yours. I have repeatedly stated the fact, and it is a fact, that if you assume the the spectrum of the CBR is continuous as the graph’s authors and @RedshiftDrift drift assume then a straightforward and quite standard calculation says that the minimum total radiance ($W m^{-2} sr^{-1}$) of the CBR dwarfs the power of the CMB. You don’t understand that because you do not seem to understand basic physics, basic math and obviously not logarithmic scales.
Bud, another screw fell out! This isn’t complicated. The y-axis is linear: 0, 5.0E-8, 1.0E-7, 1.5E-7, 2.0E-7, 2.5E-7, 3.0E-7, 3.5E-7. Those are evenly spaced intervals. Eventually it would reach 10E-7 or 1E-6, and then after that would be 10.5E-7 or 1.05E-6.
You then wrote, “the 0.5E-7 labeled intervals have a constant value.” Yes. That’s what linear means. You’re literally describing a linear scale while insisting it isn’t one.
Bud, people keep trying to help you put the screws back in, but they don’t seem to stay put for very long.
That’s way to cherry pick a quote dude:
Here’s the complete statement:
So I can’t decide whether you’re being deliberately disingenuous or it’s just that the complete thought is too hard for you to process. Given your overall performance since your arrival, I’m leaning towards the latter.
And BTW you are the only person I’ve ever encountered at ACG who produces such ridiculous arguments - a non-linear axis is linear because one section of it is linear? Sure, anything you say Eric.
Déjà vu in a discussion with Sahil Gupta. >So I can’t decide whether you’re being deliberately disingenuous or it’s just that the complete thought is too hard for you to process. Given your overall performance since your arrival, I’m leaning towards the latter.
I find this one and previous remarks in your discussion with Eric close to personal attacks. It is certainly not up to you to throw doubt on the competence of someone else in this group. As a participant in this discussion, I would like to rise a red flag, but can’t find anything appropriate. So instead, Bud, please show some restraint and read ACG’s code of conduct, especially the first few lines:
@budrap00 .
Let’s start with the good news. You are a fervent opponent of mathematicism. The word is an invention of yours and you should be praised for it. The bad news is that you think that you are the only one who is fighting against mathematics overruling modern physics. No Bud, you are NOT the only one. (Almost) everybody here knows that I (HanDeBruijn) have a strong bias towards mathematical formulations. Does that make me a mathematicist? If you think so, then read at the top of my personal webpage this mantra:
A little bit of Physics would be NO Idleness in Mathematics.
I have been fighting against your mathematicism since I was a student, more than 50 years ago. I am not complaining about the fact that this has made any career in academia impossible for me. But I have learned one thing. If you want to combat them successfully, then you have to understand exactly what they are doing, even if you find that - let’s say: too much effort. Maybe the following references are helpful. In order of increasing difficulty. Just trying, to my own defense as well.
Notes. My presence at the Mathematics (Stack Exchange) forum has not been without risk. What do you expect? Sabine Hossenfelder too is infamous for her condemnations of contemporary physics bullshit.
Han, Since you are a practitioner of the dubious not to mention aggressively dishonest argumentative technique of selectively quoting someone in order to misrepresent their views, I understand your concern. You obviously don’t like it when that type of disreputable behavior gets called out - apparently it hurts your delicate feelings.
Criticizing a dishonest argument for being dishonest is not a personal attack. Criticizing a nonsensical argument for being nonsensical does not constitute a personal attack. “Bud, you’ve got a screw loose here”, now that’s a personal attack. I’m not offended by it given the source but your peculiarly nuanced take that criticizing a dishonest argument is a personal attack is, shall we say in your case, a little self-serving.
The issues here have nothing to do with matters of opinion but matters of fact. As an American politician once remarked, everyone is entitled to their own set of opinions but not to their own set of facts. It is unfair to disparage opinions but it is not unfair to disparage deliberate misrepresentation of the facts. If you find it offensive when I point out a misrepresentation of the facts (a non-linear scale is linear), I don’t particularly care.
My English is better than your Dutch 😁
No argument there.
@HanDeBruijn I know you are not a mathematicist and I don’t believe I ever said you were. I am also aware that we actually have similar views in many ways. That said I would never presume to tell you what you think:
If I were a sensitive soul like you I might take that as a personal attack. As it is I could not care less about such a stupid remark. Note, this is not a personal attack. I did not say you are stupid, just that your comment was - you quite obviously don’t know what I think and probably don’t care. If you actually wanted to know you could have done the polite and civilized thing - ask me.
Anyone else think it’s kind of funny that Bud’s first question was, “Am I screwing up the analysis or…?”
@ericcosmos Why do you think that’s funny?
There’s nothing wrong with carbon as a possibility for generating the CMB. What’s wrong is DemystifySci’s position that only solid carbon can generate blackbody radiation.
A closer examination of the data shows that these metals, in the form of atoms or ions, is in the few 1000K. Dust itself (a solid) is colder, perhaps reaching the low temperatures of 2.7 K in between galaxies. But to emit a blackbody spectrum the medium must also be opaque. Astrophysicists pretend to know the amount of dust present in the IGM, but I can’t confirm their numbers. It is unlikely however that there is enough absorption by dust to produce a blackbody spectrum. We know that because we see objects at a large distances emitting at these wavelengths.
@HanDeBruijn your red flag has been seen. But many other posts also deserve a red flag.
It seems I’m the only one left, out of three moderators, who is still reading this stuff. So: cut it out everyone.
@budrap00, here’s some guidance in addition to the code of conduct:
This is a scientific forum, the opinion of politicians is not welcome here.
That’s not what you are doing. Instead, you are rejecting languages you can’t read.
If someone writes $A = \oint_L f(s) {\rm d}s$, you reject it as mathematicism because it’s above your pay grade. But being illiterate in the language of calculus doesn’t mean that other people who can read it are wrong. This is not a matter of fact, it’s a convention.
If someone shows a logarithmic and a linear scale
you reject it as being disingenuous because you can’t read graphs. But being illiterate in the representation of graphs doesn’t mean that other people who can read them are wrong. This is not a matter of fact, it’s a convention.
If I say “traduire”, but Han says “vertalen”, it’s not a sign of obfuscatory nonsense. Being illiterate in other languages doesn’t mean that the people who use them are wrong. This is not a matter of fact, it’s a convention.
What people answered here is that “you are screwing up the analysis” because you can’t read the graph. It’s not a math issue, it’s not the data. In addition, numerical examples and various representations of the graph are given, with the hope that it would help. But despite these many ways to represent the same physics, you still are screwing up the analysis because you can’t read those graphs.
Now that you’ve “brushed up your physics”, it’s time to brush up on a few more languages if you want to continue discussing the physics.
To everyone: when no progress is made because communication is impossible, it’s time to stop sending replies.
The question has been answered, this discussion is closed.
Anything to change the subject right Louis. I didn’t label your graph lin-lin, you did, demonstrating that it is you who has trouble reading graphs and understanding the difference between linear and logarithmic scales. It’s of a piece though with your difficulties with standard physics like claiming that you had an interferometer sensitive to $10^{-15}meters$ - because the laser frequency was $10^{15}Hz$.
The next time you go to label a graph you should first refer to this page. And try to think before you write - thinking is the hard part.