Starts With A Bang

Comments of the Week #154: from Earth as seen from the Moon to the Universe at its birth

The cosmic microwave background appears very different to observers at different redshifts, because they're seeing it as it was earlier in time. Image credit: Earth: NASA/BlueEarth; Milky Way: ESO/S. Brunier; CMB: NASA/WMAP.

“What I find cool about being a banned author is this: I’m writing books that evoke a reaction, books that, if dropped in a lake, go down not with a whimper but a splash.” -Lauren Myracle

It’s been an interesting week unlike any other. Sure, we’ve had our usual slew of daily, fascinating articles here at Starts With A Bang, and like always, you’ve had a lot to say about them. Here’s everything that’s gone down:

We’ve also got a brand new episode of the Starts With A Bang podcast up: on why Pluto isn’t a planet anymore. Have a listen to it now!

But one of the more interesting developments we’ve had is a shift in how we run the comments section here. You are no longer free to be as big a jerk as you like to whomever you like. You can express your frustration, you can argue with people, you can tell them they’re wrong (and hopefully, why), and you can call out someone’s lies. But if you can’t do it while still being a respectful human being to them, you’ll lose your commenting privileges for a week. And that starts today: March 26th. All it will take is for me to notice it and enforce it. And feel free to point it out to me; I hate having to do it — because I expect adults to be able to act like adults — but apparently that is way too much to expect. So, babysitting it is.

And with that out of the way, let’s march straight into our comments of the week!

Electricity flowing through the human body. Image credit: Youngester of

From PJ on the passing of Mandozink: “Goodbye Mando. You are once again a part of the universe unfettered by humanity’s foibles.”

From eric on the same topic: “RIP Mando, and best wishes to his surviving family.”

And Sinisa Lazarek, saying goodbye: “If you were that which you thought off, then again you are never really dead, because the EM waves that made your thoughts are now forever traveling and will travel the vast expanses of Universe, until the end of time.”

The “you-ness” of existence is one of the most unique and precious things that we all have. Though we may be made of a huge number of fundamental particles — perhaps some 10^28 if you add them all up — it isn’t those particles that make us unique. For over our lifetimes, those particles enter, get incorporated into, and leave our bodies. Of all the atoms and molecules that make us up, none of them remain consistently in our bodies over our lifetimes; even our bones cycle through their calcium atoms on timescales of a few years. The only difference between a living and a non-living human is the electrical patterns that run through our brains and bodies, and for comfort, I would always turn to the conservation of energy.

In this illustration, one photon (purple) carries a million times the energy of another (yellow). Fermi data on two photons from a gamma-ray burst fail to show any travel delay, showing the speed of light’s constancy across energy. Image credit: NASA/Sonoma State University/Aurore Simonnet.

For energy can never be created nor destroyed, but only converted into other forms. And in addition to that, the impact we have on one another can never be undone; quantum interactions see to that. Forever, a state will have been altered by its interactions with anyone and anything that’s ever caused a shift in quantum states. We are all affected by our time together.

Rest in peace, MandoZink.

Graham’s hierarchy of how to argue. (Pyramid format.) Image credit: Paul Graham.

From jonathan on treating one another with respect: “This is one of the very best sites of the English-speaking internet for coverage of cosmology and other fields of science. It’s updated often, with great original content, responding quickly to items in the news as well as providing constant background posts, it’s well written, it’s reliable and authoritative, there’s a real voice to the articles and one senses a principled author behind it. So why is the comment section worse than the randomly selected youtube video? Why does it so quickly degenerate into the worst kind of childish, foul-mouthed lashing out?”

It only takes a few bad apples to spoil a bunch, and in the case of a comments section on a blog, only a few (or even one) foul-acting commenter. I would like to think it goes without saying that name-calling is off limits, and that people could just be decent to each other. Clearly, I have to enforce this, which I hate doing, because it means I have to spend my energy not on talking about the science I’m so excited about, but on playing “classroom manager” which is fairly soul-crushing to me.

But perhaps all it will take is a small amount of this until the bad actors get themselves banned entirely or shape up, and then we can go back to the comments section we all wish we had. That’s the goal, and I very much appreciate all of you chiming in.

Image credit: Global Warming Art by Robert A. Rohde.

From Denier on sea level rise: “The economic costs of ignoring climate change? Paltry. Even if the climate alarmists are on the nose with their numbers it pales in comparison their proposed changes could inflict on the economy. The most costly natural disaster in US History was Hurricane Katrina at ~$100 Billion dollars in damage. In the Great Depression, even after all the New Deal fixes, we were 27% below the GDP trend. There was a much larger initial GDP drop but for ease of math we’ll ignore that. Our GDP now is ~$17 Trillion. That would come to a loss of $4.6 Trillion dollars in yearly damage. We could get hit by 45 Katrina level disasters every year and the storm disasters would be cheaper. Not even Al Gore thinks we’re going to get hit with 45 Katrina storms next year. The cost comparison isn’t even close.”

Okay, then, what would you quantify as a cost-comparison between hurricane Katrina — which you gave a figure for — and the loss of all the inhabited, infrastructure-built land in our country that will be affected by sea level rise? How many feet of rise will it take for you to give an estimate? If we go the full 8 meters, how much of a loss would you quantify the loss of all of southern Florida, of much of the US’s shores, of all of Manhattan, of even the land just beside the rockies? You have shied away from quantifying the dollar value-cost of global warming, and yes, it’s not happening next year. But you are talking about your four-year-old’s future that you’re concerned with. What will the dollar value of our global inaction be, per year, 50 years from now? Or 75? or 200?

You know the phrase “a stitch in time saves nine?” Or “an ounce of prevention is worth a pound of cure?” This is one of the most extreme examples of exactly that… and it’s up to us to act now to avoid the largest disaster possible, because we are barreling towards it full steam ahead.

The first view with human eyes of the Earth rising over the limb of the Moon. Note how bright the Earth appears in comparison to the Moon. Image credit: NASA / Apollo 8.

From John on the full Earth as seen from the Moon: “More than an order of magnitude brighter that what we see!”

What’s pretty remarkable is that if you were on the near side of the Moon, you’d always have either the Earth or the Sun (or both) in your skies; it would never appear as dark as night here on Earth gets because of the Earth’s incredible brightness relative to the Moon. Yes, a factor of ~30-55 depending on cloud cover is impressive, but the fact that it would be continuous is something worth considering, too!

From Wow on how to not behave, in exemplary fashion: “Another moronic post from you, teabaggie. You have nothing to say and nothing to add but do so anyway, because you’re a retard.”

Honestly, that this was the follow-up comment you left to John’s previous comment is worthy of being banned all on its own. Why you would do this? I don’t know the internal issues you have that cause you to lash out like this, and I don’t know why you think it’s acceptable, and now that others have pointed it out, I don’t know why I’ve allowed it to go on for so long.

Knock it off, forever, and if that means you won’t have anything to say because you can’t say anything without an invective like this, your silence will be appreciated much more than this hateful drivel.

Image credit: NASA / Apollo 11.

From Peter on the dreams of being an astronaut: “I dream about this, to see the Earth from the lunar surface.”

I think that’s a wonderful dream. There are so many wonderful and wondrous sights to view here on Earth, but none are more foreign to our experience — and rare, from a human perspective — than to see Earth from the surface of another world. Only from the Moon would it appear as anything more than a point to our eyes, and yet, from that one location, it would appear as spectacular as your dreams allow. I love it here on this world, and this will always be my home. But to journey into space to take in the view, even once, would be a thrill of a lifetime unlike any other.

Taken in infrared light, the image shows the dense column and the surrounding greenish-coloured gas all but disappear. Only a faint outline of the pillar remains. By penetrating the wall of gas and dust, the infrared vision of the Wide Field Camera 3 (WFC3) reveals the infant star that is probably blasting the jet. Image credit: NASA, ESA and the Hubble SM4 ERO Team.

From PJ on ten pictures that showcase astronomy’s future: “Stunning ! Thanks, Ethan.”

You have to realize the most exciting thing for me in all of this is that the Universe isn’t really (or merely) what we see. The Universe as we see it — or visualize it — between the wavelengths of 400 and 700 nanometers is only reflective of a tiny portion of what’s out there. But if we can take a multiwavelength view, we can see it all: the plasma, gas, dust, stars, black holes and more, of all different temperatures and energies. It’s not an easy (or cheap) task, but the reward is a better understanding of our Universe. And so, so worth it.

Schematic representation of rotating disc galaxies in the distant Universe (R) and the present day (L). Image credit: ESO / L. Calcada.

From Patrice Ayme on how MOND could survive this changing-in-time: “If the ESO (European Southern Observatory) illustration turns out to be correct, how could MOND survive? MOND posits that gravity is stronger than the inverse square law. One assumes that this modification of gravity should not vary in time.”

The law (or modification) of gravity shouldn’t, presumably, change it time… but the distribution of matter can. There’s no reason why the outskirts of these galaxies can’t be poorer in not only stars but all types of normal matter at earlier times. In other words, rotation speed correlates with surface brightness in pretty much all galaxies, and the MOND advocates explain this change in the perceived law over time as a change in the density of normal matter over time.

If you come up with the right explanation, MOND proves very hard to kill from an evolutionary standpoint. Hopefully, as predictions become nailed down better, this will become indisputable and a much more stringent test.

The nebula of expelled matter created around Betelgeuse, which, for scale, is shown in the interior red circle. This structure, resembling flames emanating from the star, forms because the behemoth is shedding its material into space. Image credit: ESO / P. Kervella.

From Omega Centauri on a whole bunch of supernova questions: “So the current thinking is Antares has a smaller diameter than Betelguese?
Isn’t the core collapse triggered by the loss of thermal energy via neutrino emissions?
What color does a type-II supernova appear to be?”

Antares and Betelgeuse have significant uncertainties in their distances, and hence, their diameters. Within the errors, either one could be larger.

Core collapse is triggered by the end of nuclear fusion in the star’s core, where gravitation rapidly overcomes the insufficient radiation pressure. The loss of thermal energy via neutrino emissions helps sustain the reaction for more than an instant, and help it run away. It’s more of a help in sustaining the reaction, though, than in first triggering it.

And as for color? Like most of the stars visible to the naked eye, it will be quite white, covering the full gamut of the electromagnetic spectrum. A more complete analysis of color/temperature will hopefully be visible to us directly if it occurs in our lifetime, but those are the expectation.

The constellation of Orion, along with the great molecular cloud complex and including its brightest stars. Betelgeuse, the nearby, bright red supergiant (and supernova candidate), is at the lower left. Image credit: Rogelio Bernal Andreo.

From Wow on whether supernovae will emit gravitational waves: “Unlikely. The mass is still there and still roughly central, so there’s no dipole to radiate gravity waves. So all we’d get is whatever asymmetry happens in the blow up moving the CoG around and a delay to the effect so that we see the center of light move at the same time as the center of mass.”

Orion is a messy, star-filled constellation, but the stars themselves are not close enough to one another to cause the emission of gravitational waves with any sort of measurable frequencies, even at these close distances and even with future gravitational wave observatories. But if you’re aspherical for any reason — or if the physics of supernovae is different than what our models expect — there’s a chance. Supernova triggers are expected to be somewhat asymmetrical, but the level of asymmetry and hence the gravitational wave signal is expected to be weak.

Multiple neutrino events, reconstructed from separate neutrino detectors (akin to Super-Kamiokande, shown here), indicated a supernova’s occurrence before any optical signal ever occurred. Image credit: Super Kamiokande collaboration / Tomasz Barszczak.

Early models, in perhaps the 1990s, thought differently. As it is now, Betelgeuse is thought to be a single star with no companion that rotates quite slowly, and hence is quite spherical. The odds for gravitational waves don’t look good, but you never know what you might get for a transient signal. If the neutrinos arrive at a very particular time, we’ll have a timestamp to look for the gravitational wave signal as well… and that could be fascinating no matter what the outcome is!

The 2010 NASA mission timeline had James Webb launching in 2015. If that were the case, and if insufficient funding were not provided during two critical years, we would have collected over a year’s worth of data from it already. Image credit: NASA’s Astrophysics Division.

From eric on cutting basic science funding: “In addition to the issue that shutting down ongoing projects greatly increases the cost to (eventually) complete them, I worry about how big a hit there will be to basic science, and thus the long-term US ability to produce innovation and new products.”

This is absolutely a worry, and I would also like to highlight that this has been an ongoing problem since the Clinton years of the 1990s. The mandates that government research needs to address an aspect societal, industrial or commercial need in the near-term future has meant a dramatic reduction in long-term, potentially useless and fundamental research. This is something that should go beyond politics; Ronald Reagan approved the superconducting supercollider, Bush Sr. continued it, Clinton killed it. There’s more to the story than that, but yes, basic science has taken tremendous hits, and the hits just keep on coming. For the next four years, I expect them to come fast and furious, and it’s up to us all to fight to keep what we have and grow what we need.

A significant fraction of the scientists and engineers pictured here, in the 2016 installation of the final mirrors, were replacement hires for the originals who were laid off five to six years prior. Image credit: NASA.

From Frank on who’s to blame for anti-science sentiment in America: “I think popularity of anti-science today shows a failure of science education for a long time.”

I am a bit bewildered by this. If anti-science sentiment is so popular, why do you blame the largest pro-science force in this country — this underfunded, near-volunteer force that has to fight against all sorts of politics, ideology and misinformation — for not achieving total victory in a practically hopeless battle situation? That’s like blaming Poland for not stopping the Nazis in 1939, blaming the egg council for not stopping obesity, or blaming the EPA for not stopping the pollution of municipal water supplies. You can only stop what you have the power to stop. They should be lauded for the victories they achieved and the valiant fight they put up despite facing overwhelming odds. If you want to aid a good cause, don’t start by pointing fingers to how they haven’t managed to defeat all the enemies of science that exist.

Illustration of the density (scalar) and gravitational wave (tensor) fluctuations arising from the end of inflation. Image credit: National Science Foundation (NASA, JPL, Keck Foundation, Moore Foundation, related) – Funded BICEP2 Program.

From Carl on seeing the edge/beginning of the Universe: “No matter when or where, you can’t see / reach the “edge”. The speed of light creates the walls that forever box us in.”

That’s true… but you can see past any “light” if you look in gravitational waves. That will literally take you to the edge of the observable Universe, as those waves have moved at the speed of light, unimpeded since the end of inflation. I hope we can detect them in the next 20-or-so years, which we will if the tensor-to-scalar ratio is large enough.

How cosmic inflation gave rise to our observable Universe, which has evolved into stars and galaxies and other complex structure by the present. Image credit: E. Siegel, with images derived from ESA/Planck and the DoE/NASA/ NSF interagency task force on CMB research. From his book, Beyond The Galaxy.

And finally, from Jonathan on the beginning of the Universe: “Reaching back further into the inflationary phase, you say that somewhere between 10^-30 and 10^-35 seconds are “accessible” to us. In which sense is this period of time “accessible”, and how does the size of the universe* at the final instant of inflation depend on exactly how far back into the inflationary phase we can “access”?”

People want there to be a time “t=0” that they can identify as “the beginning” of the Universe, or whatever that means. We used to think that you could just take the expanding, cooling Universe and extrapolate back to a point of infinite density and temperatures, and bam: t=0, beginning of space and time, the birth of everything, etc. But inflation changes all of that.

Now, we have this exponentially expanding, empty space, and only its end where we are gives rise to the Big Bang as we know it. When I say “accessible,” what I mean is that the observable Universe — and the information that’s causally connected to us — all arises from that time period and none of the information from earlier can be obtained by us. That’s the end of it, and it’s all dependent on the energy scale of inflation, and hence the rapidity of inflation; that’s where the primary uncertainty lies.

Thanks for a good week, and let’s strive to make all the coming ones better ones!