Comments of the Week #60: from the entire Universe to sexism in science

“I do not think, sir, you have any right to command me, merely because you are older than I, or because you have seen more of the world than I have; your claim to superiority depends on the use you have made of your time and experience.” -Charlotte Brontë

Our exploration of the Universe, near and far, continues here on Starts With A Bang, as we've looked at the entire Universe, our local corner of it, dark matter and even the most human of issues. Make sure you catch up on anything you missed, including:

In addition to these, I had two new pieces appear over at Forbes that give us a deep glimpse into our Universe as well:

As always, you didn't disappoint with all you've had to say, so let's dive into your Comments of the Week!

Image credit: Christopher Vitale of Networkologies and the Pratt Institute. Image credit: Christopher Vitale of Networkologies and the Pratt Institute.

First, a comment from Erik Martino Hansen: "How space can be perfectly flat and at the time of the big bang have had a finite size. [...]It is possible to be flat and finite in size without some kind of edge?"

It is very, very much possible to be perfectly flat and have a finite size. Think of -- if you like two dimensions -- a flat sheet of paper. You can imagine the paper extending in all directions infinitely, or you can imagine just a finite sheet of it; so long as our observable Universe is smaller than the true size, we'd never know the difference. Think now, if you want it to be flat, finite and edgeless, what could you do? Well, if you "rolled up" one dimension to make a cylinder, and then "rolled up" the other to connect in a donut/torus-like shape, you'd have a flat, edgeless Universe.

Image credit: Wikimedia Commons user LucasVB. Image credit: Wikimedia Commons user LucasVB.

I'm not the first nor the only person to point this out; an additional great answer came from our diligent, particle physicist commenter Michael Kelsey, who added:

We don’t know whether “space” (the larger system of which our whole observable universe is a part) is finite or infinite. We don’t know whether it has an edge, or is a closed, unbounded surface. The inflationary hypothesis is close to your option (1): The expansion rate was so fast that an initially tiny patch could grow immensely in a very short time. The consequence is that our observations correspond to a tiny patch of that tiny patch, so we don’t know about what’s “outside.”

We do know (observationally) that our observable universe, currently 46 billion light years in radius, is at least five times larger than that (if it were smaller, there would be observable features in the CMB). We know that it is not a closed flat surface (like a torus), because we do not have observations of repeated structures in the CMB (that is, we aren’t seeing “all the way around” the Universe multiple times).

The only thing I'll add to this is that the latest SDSS observations of baryon acoustic oscillations have placed the curvature constraints to be so tight that, so long as the Universe isn't topologically closed, the radius of curvature (either positive or negative) is constrained to be at least fifty times as large as the portion of the Universe presently observable to us. (As of January, 2015.)

Image credit: NASA/WMAP Science Team. Image credit: NASA/WMAP Science Team.

From Tjd on the shape of the Universe: "[This article] finally cleared up the shape of the universe for me. Great article got me thinking. We may never know the true shape because of the limitation of light."

This is factually accurate. As more and more time goes by, we can see farther and farther back into the Universe's past, and to greater and greater cosmic distances. But the Universe's expansion is accelerating! So even though -- as time goes on -- we're seeing out to greater distances in the Universe than ever before, we're never going to see arbitrarily far, and learn whether the Universe has a "true shape" that's different from perfectly flat.

Unless there's some great, cosmic conspiracy afoot, it's very likely that the Universe we see will forever be indistinguishable from flat on the largest, global scales.

Image credit: Steve Price, of The Friends Star, via flickr at Image credit: Steve Price, of The Friends Star, via flickr at….

From This story is limp as fuck on the LEGO friends star: "This is the werdist thing i have ever seen, and im 11 so yea!"

Stick around, kid. It gets a lot werder from here. I have a feeling you're gonna like it.

Image credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration; Acknowledgment: R. Fesen (Dartmouth College) and J. Long (ESA/Hubble). Image credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration; Acknowledgment: R. Fesen (Dartmouth College) and J. Long (ESA/Hubble).

From Omega Centauri on our galaxy's most recent supernova: "I would place high odds, that there have been other “invisible” [M]ilky [W]ay supernovas since then. Cas A was easy to detect because it was nearby and radionoisey, and not behind the inner regions of the galaxy, where the dust is much thicker. In fact there have probably been several."

This is actually an outstanding bet, Omega. When you look around at our galaxy, it's true, the galactic plane obscures practically everything (in the optical) with its copious amounts of dust. But it's that very same region -- replete with gas and dust -- which is where the vast majority of new stars and star clusters form. We took a look at that not too long ago on a previous Mostly Mute Monday.

Image credit: NASA/JPL-Caltech/ESA/CXC/STScI, via Image credit: NASA/JPL-Caltech/ESA/CXC/STScI, via

If the dust weren't there, you'd imagine we'd be able to see these newborn stars crackling away, and when they run out of fuel, we'd be able to see their spectacular fireworks shows. For a long time, technology was simply incapable of detecting these. While the Cas A supernova remnant was first found in the radio in the 1940s, there's more likely a more recent one: Supernova Remnant G1.9+0.3, near the galactic center itself.

Image credit: NASA/CXC/NCSU/K.Borkowski et al. Image credit: NASA/CXC/NCSU/K.Borkowski et al.

The image above, taken from 11 days' worth of Chandra data, is of a supernova remnant so young it was thought to have occurred only in the late 1800s. It was first observed by the Very Large Array of radio telescopes in the 1980s, but by time Chandra observed it again in the 2000s, it had increased in size by ~15%, indicative of an age of less than 150 years!

Now, there's too much we don't know about this object for certain to be completely sure that this is what we think it is, but it's very likely. Considering that Milky Way-sized galaxies typically display one-to-four supernovae per century, we may have had even more since then. Time -- and better observations -- will be the only way to tell.

Image credit: NASA, ESA, Z. Levay and R. van der Marel (STScI), T. Hallas and A. Mellinger. Image credit: NASA, ESA, Z. Levay and R. van der Marel (STScI), T. Hallas and A. Mellinger.

From eric on the science of the local group: "The series of artistic renderings showing the merger of Andromeda and the Milky way are interesting, but it leaves me wondering a couple things.
1. Is this really accurate (in terms of how the sky would look at various points in our future)?
2. Will the Milky Way merge with any of the smaller galaxies in our local group before we merge with Andromeda?
3. If so, what would those mergers look like? Equally spectacular? After all, the other objects in the local group may be small compared to Andromeda, but they’re still galaxies."

So there are three separate questions here, and I'll do my best to take them all on. First off, no, this isn't really accurate, in the sense that Earth will continue to move, stars will live-and-die (and move relative to us), new, bright ones will appear and disappear, and the individual details of what we see are not able to be represented accurately. The overall gist of what we're illustrating is right, but the individual details are most likely grossly incorrect.

Image credit: R. Jay GaBany of Cosmotography, via Image credit: R. Jay GaBany of Cosmotography, via

For your second and third questions, there are many, many small, dwarf galaxies that are merging with us all the time. While we say that there are a few larger ones in our local group: Andromeda, the Milky Way, Triangulum, and the Large Magellanic Cloud, the reality is that there are 50+ discovered dwarf galaxies, and probably many more still undiscovered. Most of them will eventually merge with either us or Andromeda, and some of them are merging with us right now.

In particular the Canis Major Dwarf and the Sagittarius Dwarf Galaxy are both in the process of merging with ours, similar to how a small galaxy is merging and being ripped apart, tidally, by NGC 5907, above. These things are anything but spectacular to an interior observer, and are incredibly difficult to detect at all; they will not change the size, shape, structure or night sky of hardly anyone in our galaxy.

My advice? Wait for the big one. It's only a major merger -- where major is defined by having a galaxy of at least a third the mass of the one you're in -- that will really disrupt the structure of your galaxy, and have a chance to turn a spiral galaxy into an elliptical. The only galaxy in our local group that meets that criterion is Andromeda; everything else, even the Triangulum galaxy, is minuscule (less than 10% of our mass) compared to us.
Image credit: ESO/L. Calçada. Image credit: ESO/L. Calçada.

From Soegeng Wibowo on dark matter: "Can dark matter have antigravity?"

And the answer from commenter Wow: "No."

People misuse the term "antigravity" all the time, using it to refer to any sort of repulsive force. Electromagnetism is not antigravity; radioactive decay is not antigravity; buoyancy is not antigravity; even dark energy is not antigravity. An anti-gravitational force would be something that acted just like the gravitational force, except with the opposite sign, as though something had negative mass (or energy).

As far as we can tell, no such thing exists in the Universe, and there is no phenomenon that indicates such a thing exists.

Image credit: Ayodhya Ouditt/NPR, via UNC Charlotte at Image credit: Ayodhya Ouditt/NPR, via UNC Charlotte at….

And finally, there were many many many comments on this issue, but here's an excerpt of one by Denier, on the issue of sexism in science: "The motivation for the posting of this article was a set of comments made about the appearance of Amanda Peet. One of the comments was singled out for shaming was as follows:
Not the Amanda Peet you’re thinking of, I’m afraid.
This comment was in response to another poster who had conflated Amanda Peet the Physicist and Amanda Peet the Celebrity. For making this comment, this poster who had absolutely no history of making sexist comments and arguably didn’t even make one here, was tarred as a sexist in a subsequent post by Ethan.
While this massive overreaction in the noble effort to have all people treated as people seems to be harmless or even helpful, that view is naïve. Unfortunately there is no shortage of naïve people. The quick jump to outrage on display here is not uncommon."

I understand where you're coming from, here. What you're saying is:

  1. I didn't do anything wrong.
  2. I certainly didn't do anything sexist.
  3. I made a joke -- a quite funny joke -- about someone's name, that happens to be identical to another name.
  4. And because of this, I'm being wrongly accused, perhaps even convicted, of being a sexist, when I am not in any way.


Now, I don't know Amanda Peet personally, but I do know them professionally -- from their work -- and from their web presence, webpage and publications. Some of those things are not for me to share with you, but perhaps others are.

Image credit: Reuters. Image credit: Reuters.

This, above, is Amanda Peet, the actress. And this, below, is Amanda Peet, the physicist.

Image credit: screenshot from the perimeter institute live stream. Image credit: screenshot from the perimeter institute live stream.

So I want you to imagine that you're Amanda Peet, the string theorist. You're already a rarity: a woman in a heavily male-dominated field. You've got the same name as a famous, young, beautiful actress who's far more famous than you are, and if people weren't already judging you on your looks, speculating about your sexuality and gender identity (hint: they were), you just happened to get dealt a hand of cards that make that all the more likely.

Did you do anything wrong, Denier, by making that observation? Not in isolation, but you've got to realize that you are not in isolation. You are not the first person to make that joke, it is not a funny (or new) joke, and it's one that just serves as a reminder that no matter how professional someone is, if that person happens to be different in some way from what you expect them to be, that will be the first and perhaps foremost thing that person will be judged on.

We do have a problem in many STEM fields in particular that make it a discouraging (and sometimes an outright hostile) environment for people who aren't straight, white men to make careers out of. It isn't only STEM fields, of course, but that's where I work, that's what I experience, and that's the one thing I can stand up and say, "I want to make this a better work environment for everyone who wants to work in this environment."

So whether you're sexist or not isn't the issue. Whether you mean to discourage women or not isn't the issue. Whether you think someone should be strong enough to get hit with a freight train of unfairness and shrug it off isn't the issue. In short, it isn't about you at all, and I couldn't care less about what you feel you're being accused of, fairly or unfairly. It's about demanding that people be treated with respect as they would like to be respected.

You will mess up; I will mess up; all of us will mess up at some point. But when we do, the proper response is not, "I didn't do anything wrong," but to learn what we can do to not mess up again, and to create a better, safer, more inclusive environment for everyone who wants to be in it. That's not the case right now, and that very fact -- that the environment as it exists right now is harsher for women than men -- is why I say it's sexist, and that there is institutional sexism. Not that you're sexist, but that sexism exists, it has these effects, and that if we want this situation to get better, it's up to us all to do something positive about it.

You don't have to agree with me, in fact I suspect many of you won't, but that's my stance on it, and that's one of the things I'll keep fighting and advocating for.

So thanks for a great week, everyone, and I'll see you back here next week for more wonders, joys and stories of the Universe!


More like this

"Not even light can escape such hollowing, this huge mass in a small space. Even the Milky Way with its open arms is said to have a black hole at its heart." -Susan B.A. Somers-Willett Our Milky Way is home to us all. With its hundreds of billions of stars, massive spiral arms, dust lanes, and…
"Do you see the absurdity of what I am? I can't even express these things properly because I have to - I have to conceptualize complex ideas in this stupid limiting spoken language! But I know I want to reach out with something other than these prehensile paws! And feel the wind of a supernova…
"At the last dim horizon, we search among ghostly errors of observations for landmarks that are scarcely more substantial. The search will continue. The urge is older than history. It is not satisfied and it will not be oppressed." -Edwin Hubble It still boggles my mind that a scant 100 years ago,…
"I am undecided whether or not the Milky Way is but one of countless others all of which form an entire system. Perhaps the light from these infinitely distant galaxies is so faint that we cannot see them." -Johann Lambert When we look out at the Universe, our view is pretty consistently dominated…

"So I want you to imagine that you’re Amanda Peet, the string theorist. You’re already a rarity: "

So special treatment, then. But that flirting is special treatment too. Just unwelcome.

I would also refute your externalised internal monologue. My problems are

1) You've not shown it WAS sexist. Only in poor taste. You can point out the ACTION, but you should not make up the INTENT. Absent information in support.

2) You tar everyone with blame. It's EASY to blame others. Rather harder to think of GOOD reason for their actions.

3) Presupposed that the "problem" could be resolved by our action.

"You're being sexist" is a thoughtcrime, pure and simple.

But when we do, the proper response is not, “I didn’t do anything wrong,” but to learn what we can do to not mess up again, and to create a better, safer, more inclusive environment for everyone who wants to be in it.

It's ALSO not to go "I want to make this a better work environment for everyone who wants to work in this environment.”.

Seriously, your arguments defending yourself here are precisely the ones you're deriding others of.

Denier probably doesn't give a fig what you, or Amanda think of them. This is not accepted as excuse by you, though. It is FOR you, though.

"So whether you’re sexist or not isn’t the issue. "

So stop telling everyone about sexism of people in STEM, then.

Oh, you only say that in defence of an accusation against you. But if I were to say "Amanda is dumb", that would surely be an insult, right? But if I went and said "Amanda may be smart, but women in science are dumb", then surely THAT IS SEXIST, correct?

The line dropping from "hate crime", such as sexism and racism to "insult", such as trolling or baiting, is whether you believe a group is guilty, not whether you think an individual is guilty.

If I hate someone, and that someone is a woman, this is not sexism.

If I hate women, then that is.

You may not agree with me, but your crusade really only achieves polarisation and hate.

Try and include all sexes and orientations. That means inclusivity has to include those you think are being sexist. Find out FIRST. Point out the offence and why. And stay away from calling it sexism, racism or any of the other bigotries until it's evidenced that there IS bigotry. Not just convenient to assume it.


This is going to be my last post on the sexism subject because obviously we are missing each other. Your bullet points are not even close to the mark.

To put it bluntly, you are the sexist in this. You are advocating that women should be treated differently from men. Comparing Amanda Peets isn't sexist. That the scientist and celebrity who share the same name happen to be women was simply chance. You used that happenstance to drag out the very ugly charge of sexism to use as a cudgel in your defense against an imagined attack on someone you viewed to be less than you.

If my life experiences were more focused on environments with a concentration of young not-yet-cynical-enough-for-their-own-good women, or I worked in a field that as dominated by older males, I might still think as you do. That isn't the case and I am trying to help you learn from my past mistakes.

By blowing this up the way you have, you have not done string theorist Amanda Peet any favors. Previously it was 4 tiny arguably non-sexist comments in some thread few will ever read because the presentation being blogged about wasn't that great.

Now we have multiple posts with much more sensational content, pictures contrasting the actress and sting theorist, and statements about looks, sexuality, and gender identity all by your hand. Your defensive of her, regardless of your motivations, did far more damage than good to Amanda Peet the individual. If you recognize it or not, you also did damage to the larger cause of women being treated on an equal footing to men.

You are a teacher and an undisputed expert in your field. Compared to you and many others on this board, I know practically nothing of theoretical physics, but I know a thing or two beyond that. I am telling you to put the shovel down and step out of the hole. In this case it might be of benefit for you to take off the mantle of instructor and listen.

Perhaps he can't put down the cudgel as he has crossed the Rubicon and can't go back else the leftist in academia will crush dissent.
Large parts of academia has been taken over by the progressive movement and that movement does not tolerate dissent.
SEE: Professor John McAdams is being stripped of tenure by Marquette University for writing a blog post that administrators characterize as inaccurate and irresponsible.…

So now because of the speech police on college campuses everywhere, these instructors probably out of fear, err on the side of paycheck and career instead of freedom of expression.

On the flip side it could be a nice published social resume piece boost that could be used to deflect future criticisms as well. Sort of an insurance policy that would ease employers or business partners concerns of lawsuits.
That whole Ellen Pao v. Kleiner Perkins lawsuit that just went down has the tech world abuzz with the sexism meme.

By Ragtag Media (not verified) on 16 May 2015 #permalink

OMG!!! Ethan, You Just Got Owned On Outrageous Acts of Science
Women were fine with comments about their breast.. To Funny
And Why The Heck Not?
See the Start 16:20 mark

Rack, Mellon's, ect.. Women like to be appreciated for what they have.. haha

Disclaimer: I Am A Breast Man

By Ragtag Media (not verified) on 16 May 2015 #permalink

Ethan, you rock! Keep fighting the good fight, and posting mind blowing science blogs! And hopefully this one positive charge has more weight than those negative ones, and tips the scales away...

By Carriesavagevt (not verified) on 17 May 2015 #permalink

Just face the facts and don't evade. Your comment was in poor taste and probably sexist too. It does not mean you are a bad person, it just means that you fucked up. Nobody is reaching for pitchforks.

By Lotharloo (not verified) on 17 May 2015 #permalink

Thanks for answering my question. Though I am disappointed to think there will be no visually spectacular galaxy-mergings prior to the Andromeda one. I guess the question was always academic given the time scales involved, but it still would've been neat if future humans could've looked up and seen some giant globular cluster or dwarf galaxy filling much of the sky.

"Your comment was in poor taste and probably sexist too. "

Can a *comment* *be* sexist? It has no opinion on gender.

a) Yes, it was in poor taste.

b) That isn't proof of sexism

and because of b, please refrain from assigning internal monologue. Get more proof.

Can a *comment* *be* sexist?

Yes, *comments* can be sexist. The word is both adjective and noun; the adjective can apply to writing, speech, art, music, whatever. As a general rule of thumb, if you have ask whether written comments can even in principle be sexist in order to defend a comment, you're probably in the wrong and the answer is probably "this one is."

"Yes, *comments* can be sexist."

(ˈsɛk sɪst)

1. pertaining to, involving, or fostering sexism: sexist advertising.


Pertaining, well, this is neutral, surely. Talking about it is pertaining, but that doesn't make Ethan's commentary sexist in the commonly understood meaning, correct?

Involving, same thing.


No, I'd say not. But I could see an argument for it. It really does require that someone want to be for it. So it's again another presumption.

If I make mother-in-law jokes a la Les Dawson, it's not sexist, despite being, if it came from, for example, Bernard Manning, sexist.


The intent of the comment.

My problems here are that the intent is being inferred, then judgement passed.

And worse, questioning the judgement is seen as being part of the "criminal" just "convicted".

"As a general rule of thumb..."

No. That would be a crap rule of thumb, I'm afraid. As a rule of thumb, if you have to use your own inquiry when someone else makes the claim and you ponder its application as "proof" of the validity of the accusation, the accusation is unsupported.

Like the difference between an unsolicited compliment and a solicited one.

Or an unforced confession and coerced testimony.

Post Scriptum:

I also get this definition:

Adj.1.sexist - discriminatory on the basis of sex (usually said of men's attitude toward women)

Which definitely doesn't apply to the words, just your reaction to them.