Starts With A Bang

Comments of the Week #150: From space travel to cosmic superclusters

A large collection of many thousands of galaxies makes up our nearby neighborhood within 100,000,000 light years. It's dominated by the Virgo Cluster, but many other mass collections abound. Image credit: Wikimedia Commons user Andrew Z. Colvin.

“I didn’t even know there were stars to look at to not see. If you don’t know that they’re there, you don’t know that you’re missing them.” -Neil deGrasse Tyson, on light pollution

As with pretty much every week that goes by, we’ve had a slew of fantastic stories here at Starts With A Bang! There have also been events galore, including two public talks on gravitational waves and the controversy over the expanding Universe, and many upcoming events, including:

There’s been a ton of new science as well, including a brand new podcast on the first star in the Universe.

Treknology, my upcoming book, has been officially announced by Star Trek and is on sale for pre-order at Amazon. In addition to all that, we’ve had some amazing articles this past week. While there’s more to come, here’s what we put out into the world:

We’ve got a lot of comments that you’ve left here, so with no more ado, it’s onto our comments of the week!

Sending any particles through hundreds of kilometers of space should always result in the particles arriving no faster than a photon would. The OPERA collaboration famously observed a faster result a few years ago. Image credit: OPERA collaboration; T. Adam et al.

From John on relativistic neutrinos: “The phenomenon of neutrino oscillation implies neutrinos have a non-zero mass. Taking this as given, the speed of neutrinos should be slightly lower than the speed of light.
Is there any measurement showing, within the experiment’s margin of error, that neutrinos do travel slower than the speed of light? As a follow on question, where does the mass come from? When I learned of this particle, it was defined as having no mass.”

When we talk about the rest masses of the fundamental particles, they arise from the interaction of the Higgs field with the particles themselves. The strength of the interaction is determined by something called a Yukawa coupling, and that determines the particle’s mass. A stronger interaction means a higher mass. So the top quark and the Higgs boson have very strong couplings, and the electron has a weak one. Somehow, the neutrino has a coupling that’s over 1,000,000 times weaker than the electron.

Particle masses, with the bizarre low-mass neutrinos. Image credit: Gordon Kane, Scientific American, May 2003.

The mass is so low that the only neutrinos we’ve ever detected have so much kinetic energy relative to their masses that their speeds appear to be indistinguishable from the speed of light. We expect that they’ll move slightly slower, but even from supernovae a million light years away, the “delay” in a neutrino compared to the speed of light will be less than a single second, and neutrinos themselves are emitted over a period of 10-15 seconds in such an event. Until we can detect the low-energy neutrinos arising from the Big Bang directly, rather than the indirect method we use today, we don’t have any prospects for measuring neutrino speeds departing from the speed of light.

Book cover for my new book: Treknology. Image credit: Voyageur Press / Quarto Publishing Group.

From Art Glick on Treknology: “My iPhone already does way more than Kirk’s tri-corder ever did. I defy someone to dispute this. Measure radiation? Diagnose disease? Analyze materials? It’s even a communicator, too! Kirk needed a separate communication device.”

Well, Bones’ tricorder did things your iPhone will never do. It’s true that many of the devices envisioned by Star Trek are not only real, the real-life application of them has far surpassed what Star Trek ever envisioned. Some technologies are on their way, others are just emerging, still others feel like they’re forever out of reach. You can laugh at the quaint ideas of Star Trek from 50 years ago, but how many of the things we envision today will still be pipe dreams in 50 years, and how many will be achieved and surpassed quite easily?

I don’t know, myself, which ones to bet on past the next decade. But there are a few I know to bet against…

The starship Enterprise at warp speeds. Image credit: Star Trek / CBS studios / Paramount Pictures.

From PJ on the same topic: “If the acceleration doesn’t get you, the beer & deceleration might stand a good chance.”

The problem of accelerating is a big one in Star Trek. There are no such things as inertial dampeners, and the reason is a pretty fundamental one that appears difficult to overcome: there’s no such thing as a gravitational conductor. With electromagnetism, you can configure charges — positive and negative — in such a way that fields can cancel out in a region of space. But with gravitation, you only have one type of charge, and can’t do the same thing no matter how you arrange them. Not every Treknology is going to become real, at least, not without introducing new physics from what we know to the Universe.

What a digital camera (top) and the human eye (bottom) sees from dark sky locations rating a 4, 6 and 9 on the Bortle scale, respectively. Image credit: Tony Flanders of Cloudy Nights, via

From eric on light pollution and the Bortle scale: “I live in the suburban eastern seaboard. This time of year we can see the constellation Orion and maybe 5-10 other stars on a good night, but that’s about it. I think that puts us at about a 8 on the scale?”

If you can only see about 20 stars, you are likely a 9 on the Bortle scale. A good test is the Big Dipper: if you can see all 7 stars, you’re probably an 8. If you lose the dimmest one — that connects the handle to the cup — you’re probably a 9. Megrez, the connector star, is a third-magnitude star, while all the others are second-magnitude. If you see fewer than six and/or can’t find the North Star, you’re not only a 9, you’re well above the 8/9 transition. Skies are getting rougher all over the eastern United States, with no signs of letting up. Incidentally, many places in the ocean are now terrible for stargazing as well; squid fisheries can be as bad as parts of Las Vegas for light pollution.

Messier 81 and 82, as seen through a telescope. Image credit: Graeme Coates, 2007.

From Omega Centauri on seeing galaxies: “From my house I never could find triangulum (with a 12inch Dob). Once I thought I found a slightly brighter patch of sky with the binocs, which was probably a detection? But, that was years back, its much worse now. Other than M-31 all galaxies are only tiny cores (the galactic nuclei tend to be bright enough). truly disappointing…..”

This is the problem with light pollution: for galaxies or nebulae, objects whose brightnesses aren’t concentrated into points but rather are extended, or smeared-out over the sky, the ground brightness can swamp anything that the natural sky produces quite easily. At my home college of Lewis & Clark, we have a huge (~24″) telescope in an observatory. With the light pollution we have, many Messier objects — the ~110 objects among the easiest to find — cannot be seen at all. But from a dark sky location just perhaps 50 miles away from Portland, I can easily make out both M81 and M82 with a pair of  binoculars.

They don’t look like much, but if you don’t see clouds without a pair of binoculars, then you see fuzzy, cloud-like objects that don’t move relative to the stars over seconds or minutes, you’ve probably found yourself a galaxy… or two!

Artificial lights strongly overlap with the concentrations of Earth’s population, showing the locations of light pollution. Image credit: Data courtesy Marc Imhoff of NASA GSFC and Christopher Elvidge of NOAA NGDC. Image by Craig Mayhew and Robert Simmon, NASA GSFC.

From Denier on light pollution: “Here’s a global map with a light pollution overlay:

That is a cool site, but one that I only recommend if you want your information 11 years out of date. There is a modern, zoomable light pollution atlas covering the entire world here:

What’s most incredible if you compare the two sites is that you can clearly identify many locations where light pollution has severely worsened from 2006 to 2016. It’s a quiet tragedy how we’ve lost our connection to the night skies, and yet it’s a relatively inexpensive fix if we only had the political and economic will to make that tiny investment.

Image credit: Berkeley Earth Surface Temperature project, via

From Denier on climate change: “I find interesting the dichotomy between how simulations are handled by real scientists versus how they are handled by climate “scientists”.”

You are way off base here. Your interpretation of what is happening is not reflective of the actual science in any way whatsoever.

  1. Climate scientists are real scientists.
  2. Climate scientists handle data in the exact way real scientists ought to.
  3. If you look at the full suite of the climate science literature, you can see this for yourself.
  4. When you take the raw data and calibrate it yourself and do the analysis yourself, you can reproduce this.
  5. Teams of climate skeptics have done exactly this — some even taking their own data from scratch — and have repeatedly reproduced what the climate science literature says.

If you want to see how well-or-poorly simulations and models match what we actually observe, I highly recommend this simple interactive well-constructed presentation from Bloomberg. Perhaps you can now give me a lesson in how to be good about admitting when you’re wrong?

This artist’s impression displays TRAPPIST-1 and its planets reflected in a surface. The potential for water on each of the worlds is also represented by the frost, water pools, and steam surrounding the scene. Image credit: NASA/R. Hurt/T. Pyle.

From Omega Centauri (and others) on the suitability of worlds around red dwarfs for habitability: “Between tidal locking, and the high stellar activity of red dwarfs, these planets may not contain favorable conditions. Didn’t Ethan largely rule out red dwarf systems as promising candidates for life a few months back?”

We make an implicit (erronous, IMO) assumption when it comes to life on alien worlds: the conditions must be like Earth in a great many ways. I have seen arguments that things need to be far enough from the galactic center, or they’d get too much cosmic radiation. That they need a gas giant just beyond the frost line, or asteroid collisions will be too many. That they need a large moon, or the axial tilt will vary too much. That they can’t be tidally locked; that they can’t have energetic, flaring suns; that they can’t be too low in density; etc.

These arguments are mostly garbage until we actually have more data, and most of them are demonstrably wrong. There are many who argue against red dwarfs as promising, but that’s only assuming all of the Earth-like conditions are necessary, which isn’t a great assumption. I will have more on this not this week, but next week.

The particles and forces of the Standard Model. Image credit: Contemporary Physics Education Project / DOE / NSF / LBNL, via

From jklsdjklsd (sic) on a question begging for a Yahoo answer: “Why photon doesn’t get submerged into Higs field…”

Because the Yukawa couplings of all massless particles to the Higgs field are identically zero.

An artistic rendition of Benjamin Franklin drawing electricity from the sky at the Philadelphia Museum of Art. Image credit: Benjamin West, c. 1816.

From CFT on science and politics: “But if you are going to make science a political entity, you are going to have to accept all that goes with it, namely, there will be ‘consensus’ driven science…”

Either you didn’t comprehend what I wrote, or I didn’t do a good job explaining myself over the many years I’ve been talking about this. There are certain truths about the Universe that are demonstrable. There are experiments you can perform, observations and measurements you can make, that will validate or invalidate scientific theories that seek to explain these. The article you link to is a contrarian piece, and contrarian pieces are allowed and even encouraged in science.

But they are not accepted without evidence. Science is a human endeavor, and so it is inherently subject to our human biases and failings. To pretend otherwise is just that: pretending. But consensus in science is only achieved when the evidence is so overwhelming that there are no outs. Ask 100 physicists for a consensus on the meaning/interpretation of quantum mechanics. Then ask for a consensus on the validity of general relativity. You’ll see a big, big difference, and that difference is illustrative of when there is an isn’t a scientific consensus.

A Franklin-style lightning rod in Germany. Image credit: Wikimedia Commons user Frank Vincentz.

From rork on Ben Franklin’s lightning rod: “Ben’s own Franklin rod in his house had a small gap, with a bell that would ring when there was enough charge in the sky. The gap was small enough so that lightening could bridge the gap. Evidence mostly from a letter to his wife explaining how to make it stop making noise.
A thing I find odd, is that how the kite and other experiments actually worked, and what they showed, was never explained to me in high school or university.”

I never knew the story about the rod-gap in his house because his wife wanted it to stop making noise. The second point you bring up is actually something I’m okay with: I don’t think it’s up to us to legislate a uniform education for everyone; I think having people know a variety of things and have different toolkits to solve problem is a very valuable thing. The one thing that should be an option is that you can always go and learn the “hows” or “whys” behind what you’re interested in. The opportunity should be there; taking it can require a bit of initiative.

Various models of inflation and what they predict for the scalar (x-axis) and tensor (y-axis) fluctuations from inflation. Image credit: Planck Collaboration: P. A. R. Ade et al., 2013, A&A preprint, with additional annotations by E. Siegel.

From Sinisa Lazarek on inflation: “Couple of things to note. Science doesn’t start or end at physics, let alone just HEP and inflation. So saying scientists care about sigma… is just as wrong as saying, all people in IT care only about shift registers.
Secondly, inflation (as much as a buzzword and nice hypothesis) is nothing more than that. An idea.. which is based in science but which isn’t tested, and which might never be tested. So going with inflation might not be correct, but since inflation is not accepted as fact as is hasn’t been scientifically tested.. you can’t really use that as a strawman”

I don’t really agree with your second part; inflation has made a number of predictions, and a great many of them have been verified. I’ve written about that multiple times — including in my book — but you can read about the most recent iteration of that online here, with information from 2016’s AAS meeting.

The Laniakea supercluster, containing the Milky Way (red dot), on the outskirts of the Virgo Cluster (large white collection near the Milky Way). Image credit: Tully, R. B., Courtois, H., Hoffman, Y & Pomarède, D. Nature 513, 71–73 (2014).

From Frank on what existing means: “I don’t think we can really say Cosmic superclusters do not actually exist. By looking at Laniakea in the image, it clearly has a structure/order. It just does not have “gravitationally bound” property that smaller clusters have.”

That’s true, but what you call that property of “gravitationally bound” is what defines something as a structure or not in cosmology. If you’re not bound, you’re not a structure. You’re an association instead. We are not part of the Virgo Cluster; quasars in the Huge-LQG are not bound together because the Huge-LQG isn’t a true structure; and the components of Laniakea are not “all part of this supercluster.” Because when these words like “superclusters” were coined, we didn’t know about dark energy. Now that we do, this idea is worse than meaningless; it’s incorrect. You can’t redefine your way out of that.

Image credit: © 2015 Shaper Helix — II Demo, via

And finally, from Anonymous coward on some fun math: “All polynomials, even those of degree higher than four, do have full solutions. The fundamental theorem of algebra sees to that. You must mean solutions in radicals, but there really is nothing special about radicals. More general functions known as Siegel modular functions (By the way, Ethan, do you have any relation to Carl Ludwig Siegel?) and hyperelliptic integrals have been developed to express the solutions to polynomial equations of arbitrarily high degree (Thomae’s formula).”

You’re not guaranteed real solutions, but you are guaranteed solutions mathematically. One of my favorite ways to illustrate the difference between physics and mathematics is to ask people what the square root of four is. They’ll usually say two, and I’ll ask them if they’re sure. They’ll often pause after that, because they think I’m trying to trick them. And I am. Because it’s plus or minus two, right? So which one is the answer to my question? Which one is my square root of four? In mathematics, they both are. But in physics, we only have one Universe, and one solution, and only one of them is going to be right. Mathematics won’t give you the answer; you need to apply something about the physical Universe to find which one is our solution.

And as far as I go, it is very unlikely I’m related to any of the other Siegels you know. My great grandfather, Jake, immigrated to the United States about 100-110 years ago. Back in Russia/Poland, he was Jake Pechenik. (Or maybe Pochenik, or maybe even Pieczenik; my uncle would probably know.) He took the name Siegel when the military came looking for a Pechenik to draft, and then left the country and came to America through Ellis Island. So I am a Siegel, but I don’t come from a long line of Siegels. No relation to Carl, Irving, Joel or even Bugsy. But despite that, we’ve got a great week on tap for you coming up on Starts With A Bang, and I’ll see you back here tomorrow to kick it all off!