news sciences: Comments of the Week #71: From the Universe’s age to the science of the CMB [Starts With A Bang]

“The specific moral is that within the standard model the [cosmic microwave background] temperature is a key parameter in fixing the thermal and dynamical history of the Universe. The measurement of this parameter made physical cosmology much more definite, and the detection of the radiation made the Big Bang cosmology a good deal more credible.” -P.J.E. Peebles

The Universe is never going to run out of wonders for us to discover and explore at a deep level, from fundamental truths to how the Universe assembles all its structures. Here at Starts With A Bang, we covered just a slice of it:

How do we know the age of the Universe? (for Ask Ethan),
The living bridges of India (for our Weekend Diversion),
The galaxy’s fireworks (for Mostly Mute Monday),
Einstein, Edison, and an aptitude for genius (a historical romp by Paul Halpern),
How does the Universe change in a year?,
and The science of the cosmic microwave background (for Throwback Thursday).

There was also a fun piece about the non-native element Technetium over at Forbes:

A Periodic Table Surprise: The One Element In Stars That Isn’t On Earth.

Plus, payments went through, and we did hit our second milestone goal on our Patreon, where voting on which book chapter we should release to supporters is underway. Want in? (Yes, you do!) Then join and donate today. That said, it’s on to our Comments of the Week!

Image credit: Greg Kochanski, Ian Dell’Antonio, and Tony Tyson (Bell Labs), of the reconstructed mass in a large galaxy cluster.

From Denier on my own skepticism: “Is there something you want to tell us? This is a safe place and we all support you, even @Wow. If you are having a crisis of confidence in Dark Matter it is great and beautiful and completely natural. Don’t worry about what anybody else thinks. The people who really care about you just want to see you happy in your own cosmological understanding.”

There are a ton of independent lines of evidence supporting the existence of dark matter. I go over them all the time — including just last week — and so do others. But for all of it, there are still gaps in our understanding of dark matter. Why does the standard cold dark matter picture fail to reproduce the correct details for the Universe on small (sub-galaxy) scales? Why does MOND work so well for individual galaxies? Why have we not found a WIMP, an axion, a magnetic monopole or a heavy, stable, right-handed neutrino? Why do all our dark matter searches come up empty?

Image credit: Mirabolfathi, Nader arXiv:1308.0044 [astro-ph.IM], via http://ift.tt/1Mh44G5.

These are real issues with the paradigm of dark matter. But they do not lead me to the conclusion that dark matter doesn’t exist, although there are a small minority of scientists who think these obstacles are too great and throw dark matter out.

But if we’re being honest about scientific skepticism, we should all have a set of criteria in our heads that — if they are met — will lead us to change our mind about any scientific theory, from the speculative (string theory) to the accepted (dark matter) to the “known” (Newtonian gravity). I mean, if you woke up tomorrow and saw the Moon moving from north-to-south across the sky, wouldn’t that change your mind about Newton?

It should.

Image credit: E. Siegel.

From EpiPete on my table: “Excel? Really? I’m disappointed! ”

My SuperMongo license expired a number of years ago, but this was surprisingly easy to generate in… OpenOffice! (In your face, Microsoft Office.)

Image credit: Léopold Lambert of http://ift.tt/1UgFyWH.

From RagTag Media on this fun picture (I presume): “Those Ewoks, are awesome bridge builders.”

The Ewoks have nothing on the residents of Meghalaya, India. I mean, I see why it reminds you of Bright Tree Village on Endor, but let’s take a look at those bridges again.

Image credit: Star Wars: Return of the Jedi, Lucasfilm, George Lucas, Bright Tree Village, used without permission. :P

The trees are awesome, the forest is awesome, and the engineering is awesome. But that wood is dead. It’s still pretty cool, but I think this has one-upped even the imagination of the Star Wars Universe. (Or galaxy far, far away.)

Image credit: Screenshot from Latinoshealth.com.

From eric on Einstein, Edison and “intelligence” of sorts: “[A]bout a quarter of all the power generated that runs through those lines in the US, and a much larger fraction in Europe, comes from the nuclear science field that Einstein helped push forward. Because it wasn’t just relativity he explained/discovered, it was Brownian motion (which was an early direct proof of atomic theory), the photoelectric effect, and mass-energy equivalency. The latter is used by every nuclear physics, nuclear engineering, and nuclear chemistry student in the world, every day, when calculating nuclear reaction dynamics and power outputs.”

This is not only true, it’s kind of a pet peeve of mine. Not because Einstein’s E=mc^2 doesn’t underlie all of nuclear fusion and fission (it does), and not even because Einstein’s contributions to the practical world — even if they weren’t foreseeable in the 1900s and 1910s — often go largely unrecognized. It’s because the entire fields of nuclear science, nuclear physics, nuclear medicine, and nuclear anything still inspire that feeling of terror in people: that not in my backyard (NIMBY) terror.

Image credit: Business Korea, via http://ift.tt/1c4aO2v.

If we cared about the carbon content of the environment, we would’ve switched from coal, gas and oil to nuclear by now.

If we cared about human lives, health and safety, we would’ve switched from coal, gas and oil to nuclear by now.

If we cared about reducing spills, air pollution and water pollution, we would’ve switched from coal, gas and oil to nuclear by now.

But humans are notoriously bad at assessing risks, and so we’ve stuck with these dinosaur fuels (see what I did there, ha ha?) despite unlocking the secrets of the atom. The reality is, we could have a Fukushima-type disaster every year and it would still be better for humanity and Earth overall than what normally happens just from using coal, gas and oil. If only science mattered more than fear when it came to crafting policy.

But I digress.

Image credit: Thomas Edison with his famed light bulb; public domain image.

From LdB on Edison, GE, Westinghouse and Tesla: “I agree Tesla had more to do with modern electrical system and more influence on where we are today but the kicker was his idea of how it all worked was ultimately wrong. Proof that sometimes a wrong answer will get you a really long way.”

There are different degrees of wrong, and they mean very different things for science depending on how wrong you are (or aren’t). For example, it’s wrong to say the Earth is flat, but it’s also wrong to say the Earth is a sphere. In reality, the Earth is an oblate spheroid, with perturbations to that based on complex geophysics and outside gravitational and tidal effects.

Image credit: National Geodetic Survey, via http://ift.tt/1HxfuNR.

But saying “the Earth is flat” and “the Earth is a sphere” are not equally wrong. In fact, being wrong in an almost-right way will often get you a lot farther than being right for the wrong reason. That latter case often involves making multiple mistakes that only give you the right answer because the two mistakes work to cancel each other out in that one particular case. If you try to apply that reasoning or approach to other problems, it can lead to immediate disaster.

To circle back to the very first comment this week, that is exactly what you encounter when you run across MOND-enthusiasts talking about “how they predicted the second peak of the CMB before dark matter proponents did.” What they omit is that they failed to predict the third, fourth, fifth, sixth and seventh, which dark matter grabs in a self-consistent way with all the other data. We’re right to doubt something when the evidence conflicts with our predictions, but when a superior suite of evidence comes in, that’s what we should be basing our evaluations on.

Image credit: Over The Top.

We all make mistakes, but it won’t happen again.

From PJ on the changing Universe year-to-year: “‘May the next year be the one where we collectively come together and reach for those greatest distances as one.’
With all the petty bickering going on within this blog, that could be a harder task than not. “

You’d never know it from the way I write my blog or communicate with the world, but privately, I’m actually a very sarcastic person. (Maybe it was growing up in the 80s/90s in and around New York City?) But when it comes to science, you’ve got to realize that this is something that is for everyone. Science is the enterprise, process and body of knowledge of all we’ve ever learned about the Universe, and how we’ve come to know it. And that’s for everyone.

Image credit: J. NASA and Jeff Hester (Arizona State University).

Whether you believe in things that are unprovable or not, whether you have biases in one direction or another (or none at all, somehow), regardless of your politics or your ideology, the wonders, joys, and knowledge that we’ve acquired about what the Universe is and how it works — and maybe even what it means — is for everyone.

And I think everyone who comes here values that, even if they don’t necessarily agree on anything else. And that’s okay! I’m happy to contribute even if it’s only in that small, single way.

Image credit: NASA, ESA, the GOODS Team and M. Giavalisco (STScI).

From Gerhard on the aging of the Universe: “I wasn’t aware of the fact that at some critical distance galaxies recede from us faster than light. The thing about the slowing rotation of the earth seems instead to be well known, at least to me.”

That was very big of you, Gerhard, to throw in the “at least to me” part. All of the facts that I presented are well-enough known and accepted that the overwhelming majority of scientists who work on these problems agree that this is what is happening right now. The slowing of the Earth’s rotation has been known since shortly after the time of Newton, though, while the recession of distant galaxies faster-than-light was only first realized in 1998, and only well-quantified for about a decade. It takes a while for the public to accept changes to their world-view. But I have hope that, in time and with continued exposure, they’ll come around on even more fronts.

Image credit: Planck Collaboration: P. A. R. Ade et al., 2013, A&A Preprint.

And finally, from Lloyd Hargrove on the science of the CMB: “How do these mapping results differ from what we should detect from such devices if we may assume what they detect is derived at microwave bandwidth from the net vacuum energy of (approaching) infinite electromagnetic sources degrading across (approaching) infinite space?”

The best part about coming up with an alternative theory (like this one) is that if there are sources degrading (or producing radiation over time), it will offer quantitative predictions that are different from the currently accepted theory. In this particular case, the two differences would be a non-thermal (i.e., non-blackbody) spectrum for the relic radiation, and a change in relic radiation temperature that scaled differently than the expected (1 + z) relationship with increasing redshift.

Image credit: P. Noterdaeme, P. Petitjean, R. Srianand, C. Ledoux and S. López, (2011). Astronomy & Astrophysics, 526, L7.

But these measurements are pretty robust! They are consistent with the cosmic, Big Bang origin of the CMB and not with the other alternatives. Not only are they inconsistent with the alternative Lloyd presented, but with Tired Light, Steady-State, Plasma Universe, Milne Cosmology, and all other known alternatives. We can keep trying all we like, but until there’s an alternative that reproduces the full suite of successes inherent in the standard cosmological models, it’s not worth taking seriously.

And that’s all for this week! See you back here next week for more wonders, joys, and stories about the Universe.

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