“[W]hen I was younger, I was afraid of something that didn’t make a lot of sense. But now I’m not. I have nothing to worry about. It doesn’t matter.” -Maurice Sendak
Well, here in the USA we’re all still reeling from the loss of an hour for daylight savings time, and in the meantime, I’ve been reeling here at Starts With A Bang as I sift through your comments. Maybe there was something special about this week, but you weighed in with hundreds of comments on the following:
- Is this a hole in the Universe? (for Ask Ethan),
- Pluto’s color variations finally make sense (for Mostly Mute Monday),
- Science is not faith-based, no matter what the Wall Street Journal says,
- Could right-handed neutrinos solve the dark matter puzzle?,
- Gravitational waves will show the quantum nature of the Universe, and
- Could the LHC make an Earth-killing black hole?
This past week saw me give a public talk on the subject of how we discovered the Universe extended far beyond the galaxy, with a huge, 1-hour Q&A afterwards. Watch the whole thing here!
From Robert Nemiroff on the image, above: “Maybe NASA should have a site that explains images like this.”
This is the ultimate burn! Robert Nemiroff, for those of you who don’t know, is one of two people (along with Jerry Bonnell) who runs NASA’s astronomy picture of the day (APOD) site. Nemiroff has featured Barnard 68 no fewer than eight times, from 1999 through 2014. APOD is one of the longest-running sites in my bookmarks, and if you don’t check it out nearly daily, you’re missing out.
But aside from that, perhaps NASA should have a site out that debunks the non-scientific nonsense that many “science communication websites” are putting out. NASA? Are you there?
From See Noevo going way off-topic: “If the Big Bang is for real, shouldn’t there be an ever-expanding empty space where it happened? Kind of like this hole?”
No. If the Big Bang is for real (which it is), there should be an ever-expanding spacetime that contains matter and energy that’s roughly uniform on large enough scales, with imperfections and inhomogeneities that grow over time. Kind of like this Universe.
From Andromeda41, hating on the Big Bang: “I have been hearing the same generic explanation for. .50.years.ie I’ll ask it again. Start with the singularity. Now start inflation. Now refer back to my beginning. How much sense does it make to say there is no center to the universe.”
Why do you start with a singularity? All we observe is the last 10^-33 seconds (or so) of inflation. What happened prior to that? How long did inflation last? Forever? If not, what came before it? Was there a beginning to space and time (a singularity) or not?
Even if the answer to that last question is “yes,” that’s evidence for an origin, not a center. That’s evidence for all of space and all of time originating from a single point; because of the way mathematical maps work, that means that every point in the Universe can lay equal claim to being at the center. That’s how much sense it makes.
From CFT, misunderstanding and attacking when they should be learning, “Michael,
I couldn’t care less about where you work,
or how educated you think you are,
Your raisin bread analogy was utter dreck.”
No, the raisin bread analogy is absolutely brilliant. In fact, it’s one of not just Michael’s and mine but cosmologists’ all over the world favorites. If you want to conceive of space and how it expands, and how the galaxies within it have expanded since the hot Big Bang, there is no better analogy that I know of. If you want to talk about a different set of timescales, you need to be more specific. But since the end of inflation and the hot Big Bang, the raisin bread analogy is absolutely valid. In fact, if you listen to the video atop, you can hear me talk about it in the Q&A session!
From richard mitnick on image credits: “You credited ESO in [this] article but failed to tell us which ESO assets were used in this work. If assets of an astronomical organization are involved, they should be credited. As an ardent supporter of ESO, I would like to know which ESO assets were involved.”
I give the credit that ESO asks for on each ESO image that I used. If you want a link to the ESO website with the images, you can go here: https://www.eso.org/public/news/eso9934/. But if you want to support ESO, perhaps you should see how they credit themselves and ask to be credited worldwide. Then perhaps you can be ardent in being informed about ESO and their image policies, too.
From Denier on a hypothetical in cutting college funding: “In this case, a contraction of the money supply available to schools would cause administrators to lose their jobs, educators to lose their jobs, services to be cut, attendance to drop, and tuition prices to fall until a new equilibrium was reached.”
What’s interesting about the Finland example, where their flagship University had their funding cut by about 15%, is that many administrators lost their jobs, few educators lost their jobs, attendance didn’t drop and tuition prices didn’t change. In other words, that isn’t what happened. I offer the possibility that if you want to affect a different change — administrative cuts, increased professor autonomy and salary and cuts in the cost of tuition — student/faculty unions could create that change as well. That’s all.
From Axil on Pluto… no, just kidding, on Cold Fusion, what else?: “All this new observational evidence points to the existence of a billions of years long chemical production of nuclear heat in a cold environment. Cold fusion exists without any doubt. LENR’s proof of concept is establish without any doubt. It’s just a matter of finding how the production of cold nuclear energy works.”
So for five years now, Axil, you’ve been telling me about LENR and I’ve been asking you for a working device. “Any day,” you’ve been telling me. It’s been nearly 2,000 days. When will you be convinced — or will anything about this non-reproducible experimental suite of results ever convince you — that you’ve been taken in by a fraudster?
From Richard Enkgraf on science and faith: “Faith is a position which admits no conceivable alternative. People of faith tend to shape their conception of the universe (including scientific evidence) to fit their belief, instead of building up a view of the universe based upon objective evidence. Bertrand Russell defined faith as a belief which cannot be shaken by contrary evidence.”
More specifically, I’d like you to consider — particularly those of you who claim that science requires a faith as well — that there is a big difference between faith as a religion uses it and an assumption as science uses it. When you make a scientific assumption, you do absolutely everything you can to check it for self-consistency, and to look for any evidence that might run counter to your assumption. You might not be able to ever prove it, and you might be building a house of cards atop it if it’s an invalid assumption, but you have to assume something in order to get started.
Rest assured that if that assumption — any assumption — is ever forced to confront robust evidence that throws it into doubt, it will be the duty of any and all scientists to readdress and perhaps even throw out those assumptions. That fundamentally differs from faith.
From Nils-Erik Thorén on the assumptions that go into science: “Science rests on the axiom that there exists a world independent of any observers.”
Since the development of quantum mechanics, that is untrue. You can call it axioms, assumptions or faith, I suppose, but I’ve run across three common arguments that “science is faith, too!” in these comments. They are: that the Universe is logical (it doesn’t have to be), that the laws of nature are constant throughout space and time, and that our perceptions, measurements and observations of reality actually reflect reality.
The first one — that the Universe is logical — is not actually an assumption! The Universe could be completely illogical, where things happened uncaused all-of-a-sudden and phenomena were completely inexplicable all the time. Yet the Universe we observe is quite consistent with logic and every observation we’ve made is inconsistent with the “illogical” alternative. It has often been challenging to find the mathematical/logical formalism that describes the laws it obeys, but these laws seem to be logically self-consistent. If it were otherwise, we’d see otherwise.
The second one is not even something scientists always assume! The coupling strengths of the fundamental forces (three of them, anyway) are known to change with energy, and hence with time, since the Universe was more energetic in the past. What scientific observations and measurements tell us is that the laws of nature and the fundamental constants actually are constant in space and time to a very specific level of accuracy. But this, again, is not an assumption, but rather a conclusion. We may hypothesize that these laws and constant are completely invariable, but this is a hypothesis that is subject to scientific scrutiny and refinement; it is not an inherent assumption.
And the last one, I’ll concede, actually is an assumption: we assume that what we claim, perceive and measure as “reality” is actually real in some sense. The alternative to this is known as solipsism, and could be illustrated by René Descartes’ argument of the “brains in vats” scenario. So we can either assume that reality is real, and that we can learn something meaningful about the Universe, or we can assume that it is not, and that we can learn nothing meaningful about anything. So yes, all of science is predicated on the assumption that reality is, in some sense, real.
If that is what you call faith, then we all have (or don’t have) faith in that sense. But that is a far cry from what Emerson was arguing!
In fact, I believe lots of others express this same sentiment in their own words, such as those of Orion:
“Science doesn’t require faith, although it does require a priori. It simply makes statements regarding the world we apparently live it. It doesn’t state that the world actually exists. If this is all an elaborate simulation or some god toying with just one person, science seeks to describe the universe, real or imagined. Science, almost by definition, makes no claim about things outside the universe its trying to measure. It makes no claim about the supernatural — which by definition is outside the measurable, natural world. But, as such, the supernatural acts outside of the natural world and does not affect it. If it did affect the natural world, it wouldn’t be supernatural, it would be natural.”
I could have made the entire 133 (and counting) comment thread on this article all of our comments of the week, but there are other interesting topics to go onto as well!
From Denier on right-handed neutrinos: “The neutrino sector has always been curious and the article brings up 2 questions.
1 – We have already demonstrated an ability to detect neutrinos. What is it that causes the right-handers to escape the same traps that catch the left-handers?
2 – With electrons I know it is possible to change spin orientation via pulsed electron paramagnetic resonance. Would it be theoretically to do the same thing with a neutrino and watch it spontaneously gain a billion times its original mass?”
First off, both of these were answered very in-depth (and smartly, I might add) by Michael Kelsey, who states:
1) The detection problem is that right-handed neutrinos won’t interact via any known (i.e., observed and measured) interaction. Regular neutrinos interact via the “weak force”, that is, through the exchange of W+/- or Z0 boson (in the same way that electric charges interact through the exchange of photons). Those interactions _maximally_ violate parity — the W and Z only interact with left-handed leptons (neutrinos, electrons, muons, or tau leptons), not at all with right-handed leptons.
If right-handed (so-called “sterile”, because they don’t interact) neutrinos exist, then they are either primordial, or produced as particle-antiparticle pairs from some high-energy interaction.
2) No. Electrons can flip their spin electromagnetically because EM is parity symmetric (it operates identically on left- and right-handed charged particles). Neutrinos don’t interact electromagnetically, and thus can’t have their spins flipped that way (or any other way, since they only interact via a maximally parity-violating left-handed force, see above).
I’d like to expand a little more, if I may. In principle, there’s no reason that all neutrinos should be left-handed and all anti-neutrinos should be right-handed, particularly if they do have mass, and therefore can move non-relativistically. “Handedness” is normally defined for massless particles only, because they “spin” in a particular direction relative to their direction-of-motion. If you move at less than the speed of light, then you ought to be able to “boost” (via special relativity) and turn a left-handed particle into a right-handed one, simply by changing your reference frame. Yet we never see a right-handed neutrino or a left-handed antineutrino under any circumstances, so far. Weird, right?
So does that mean there are no right-handers? Does it mean that neutrinos are totally different than anything else we known of? (I mean, they are, but this is a new kind of weirdness.) The right-handed ones I’ve talked about are super-heavy — on the order of ~10^15 GeV or so — and may or may not exist in any appreciable abundance in the Universe. They may be unstable and have decayed away, or they may be stable with incredibly suppressed interaction cross-sections.
But even if you were able to flip the spin of a low-energy neutrino, you wouldn’t turn it into a heavier one. We’re talking about two fundamentally different particles now, with the broken GUT symmetry, when we speak of left-handed (light) and right-handed (ultra-heavy) neutrinos.
From Omega Centauri on gravitational waves from inflation: “BICEP came to grief because there was another source (IIRC polarized stuff in galactic mag fields), that mimicked the signal they were looking for. So it seems that more than just sensitivity of the equipment is required. You also have to be able to rule out more mundane causes for the signal.”
The big problem was that BICEP2 claimed to know the foregrounds from Planck before Planck released their maps of the galactic gas, dust and light polarization. They “cheated” to get their results out fast, and they got burned super bad. Yes, you have to rule out your systematics, but that means having to rely on the data that actually exists, not inferring it from a pre-release map. They blew it big-time, and hopefully that mistake will pave the way for all future polarization mapping experiments to not make a similar one.
And finally, from Elle H.C. on the LHC’s potential to make an Earth-destroying black hole: “This is somewhat misleading because those particles (Ultra-High Energy cosmic rays) that are so much greater are most likely iron nuclei that collide with other nuclei in the upper layers of our atmosphere. What is going is a whole collections of protons, that have roughly the same velocity as those in LHC, colliding with and other bunch of protons. This particle is thus not so much an elementary particle but a whole group. The impressive number of 100,000,000 greater is because of the large shower output; but when you zoom-in the one on one collisions are close to the same energy region as those at the LHC.”
No, they are not most likely iron nuclei; they are most likely protons, which make up 90%+ of all cosmic rays. In fact, the charge reconstruction on UHECRs show very few nuclei heavier than helium, so I don’t know why you’d assume iron to be the highest-frequency and highest-energy cosmic rays at all?
What’s even stranger is that the LHC is also proton-proton collisions, and if you did the center-of-mass transformation of an iron-56 nucleus and its collision with an atmospheric proton, you’d find that the energies from cosmic rays were still many orders of magnitude (about a factor of 100,000) larger in energy than the LHC’s maximum energies. So your statement is patently untrue.
Granted, my experience with this is that there is nothing I can logically say that will dissuade a fearful person who doesn’t understand the LHC from their fears, but logically, I am professionally telling you that there is not a risk to Earth, space, time or you or me from the LHC’s collisions. Fear or not as you like, but that’s on you, not on science.