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# Pushing back against the ‘WTF happened in 1971’ thesis

It’s easy to lose perspective at how good things are now despite all the negativity in the news and the chronic dysfunction of the political class. Conditions for the professional class are better than ever compared to probably any time in US history for wealth creation, both in terms of high wages and the ability to invest said wages in rapidly appreciating assets.

In the 80s and 90s although the stock market and economy boomed, inflation was high, and mortgage rates were significantly higher than today. Moreover, the wage premium for professionals was not as high as it is today, and this even holds after accounting for student loan debt. Adjusted for inflation, doctors and specialists have seen enormous gains over the past 3+ decades.

From 2000-2010 real asset returns were poor despite low inflation.

The 70s had the worst of everything: poor asset returns, high inflation, stagnation.

I think the era of sub-3.5% 30-year mortgages has been one of the biggest tailwinds for the creation of personal wealth ever. And then second, the rise of the consumer information technology sector.

This stands in contrast to the ‘wtf happened in 1971’ thesis , which posits that the world has gotten worse since 1971. The evidence suggests that things are way better now in terms of inflation-adjusted wealth accumulation than probably at any time in US history.

Wages may have lagged productivity, but this does not take into account everything else: the distribution of wages and very high wages for many jobs, the inherent impreciseness and difficulty of measuring inflation, the utility derived from wages which can be considered deflationary, other forms of compensation such as employer healthcare and 401k matching, higher asset returns, and a bunch of other things.

A common argument is that since the 70s Americans are working too much, too long, or that Americans are underpaid relative to productivity. But such arguments ignore the utility one derives from work, such as the ability to invest one’s wages in rapidly appreciating assets. Making $100 from labor becomes more attractive if it can be invested in an asset that quickly turns it into$200, effectively doubling one’s wages, which goes against the 1971 ‘stagnant wages’ argument.

Stock market returns over the past decade, from 2010-2020, adjusted for inflation, were among the strongest ever, second to only the 1950s and only a tad weaker than the 90s:

So far, for 2021, the S&P 500 is on track to repeat this performance.

Thus working long hours is more attractive, as the financial payoff is so great both in terms of wages but also by investing one’s income in rapidly appreciating assets such as stocks and real estate (the post-2009 bull market is the biggest and longest ever). Consequently, there are many people on Reddit and Hacker News on popular subs such as /r/personalfinance , r/investing, /r/financialindependence, /r/wallstreetbets (a lot of gambling, yes, but also many rich people who have 6-figures to play with) and /r/fatfire who have amassed considerable wealth by late 20 or 30s. Putting in long hours in your 20s and 30s to have a massive nest egg that will last you the rest of your life by your 40s seems like a good trade-off.

What about healthcare? Although costs have surged in recent decades, Americans enjoy a high level of care (such as among the highest rates of survival for cancer of developed countries), and at the individual level pay little of the cost (the high sticker price is almost always negotiated much lower by patients and insurance companies). [However I think the opacity and inefficiency of the US healthcare system is a major problem though.] Half of Americans have employer-sponsored healthcare. Europeans pay more for their healthcare despite it being ‘free’ , due to higher taxes. Same for college tuition, in which few Americans actually pay the high sticker price, but the college wage premium has continued to surge.. This means college grads are still getting a good deal (even in the humanities) even if college is more expensive than ever.


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formula for arc length.

Today in a variational principles lecture we were shown the following:

If we have two points on the plane, namely, $$(x_1,y_1)$$ and $$(x_2,y_2)$$ and we have a curve $$y(x)$$ s.t. $$y(x_1)=y_1$$ and $$y(x_2)=y_2$$ then we can calculate the length of the curve by considering the arc length of the curve at a point $$s(x)$$ with $$s(x_1)=0$$.

We calculate the length of the curve by the integral:

$$\int_{x_1}^{x_2}{\sqrt{1+(y'(x))^2}}dx$$

This result comes from considering small changes in $$x$$ and $$y$$ resulting in small changes in $$s$$.

Specifically, we look at $$ds^2=dx^2+dy^2$$. We were told this is because the curve can be approximated by a line when looked at closely. Is there a more rigorous justification to this or is it that simple?

• Look into the idea of a homeomorphism, that may help – JacobCheverie May 2 at 18:15
• Anything specifically, or homeomorphisms in general? – Sam.S May 2 at 18:18
• Wikipedia explains the justification for the definition of arc length for a curve $f : [a,b]\to\mathbb R^2$. For your case, the curve is $f(x) = (x, y(x))$. – Rahul May 2 at 18:19
• I'm not sure if it'll even apply because I am not an expert, but in general, homeomorphisms rigorously treat the idea of a space deforming to another. It just made me think of your curve "deforming" to a line at a small enough scale. – JacobCheverie May 2 at 18:20

The "rigor" comes from the fact that we literally define the arc length to be the (infinite) sum of the small straight line segments that "make up" the arbitrary arc.

It is very much like integrals. The concept of "area of an arbitrary region" itself doesn't have much meaning. So we do three things: 1) We define the area of a rectangle (our basic region). 2) We "cover" the region with infinitesimally small rectangles and sum their areas. 3) We call that number (result of the sum) the area of the arbitrary region.

Same goes for the arc length. 1) We define the length of a straight line segment (using the Pythagorean theorem). 2) We approximate/cover the arbitrary arc with infinitesimally small line segments. 3) We add the lengths of the small lines segments together and call the result, the length of the arc.

I think it is based on Pythagorean theorem and at any point on a curve, the slope at it is given by $$\frac{dy}{dx}$$. Let $$ds$$ be the length of a small arc on that point. So, it can be approximated to a small line. Thus we have, $$dx$$ as the base, $$dy$$ as the height and $$ds$$ as the hypotenuse.
So, $$(ds)^2 = (dx)^2 + (dy)^2$$
• We can use the limiting value that for small $\theta$, $sin\theta \approx \theta$. Now $sin\theta$ is the ratio of two lengths,( e.g. consider $\frac{height}{hypotenuse}$) and $\theta$ is the ratio of of arc length and radius. So if we take the height of a small triangle equal to the radius of a small arc of circle having a small angle, we can approximately consider the hypotenuse as the length of the arc – Ak19 May 2 at 18:24

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# (1+2 pts) Fcr end (h) helow, censicler the eqquation: ( 1d - dy=0 ( Eetetmine whether the equation exacl .Find

###### Question:

(1+2 pts) Fcr end (h) helow, censicler the eqquation: ( 1d - dy=0 ( Eetetmine whether the equation exacl . Find the genezal xoluticn of (443

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# A&C and Elsevier

Top

Older: v1

Back in 2012, Bob Mann and I pushed ahead with setting up Astronomy and Computing (A&C) as a journal for the astronomical computing community. We ended up getting Elsevier to publish the journal, with a hybrid access model. This overlapped with the ‘Elsevier boycott’. Below is my brief recollection of why we went ahead by this route. It's not intended to persuade anyone else that we were right or wrong (though I don't feel at all bad about it), or change anyone's mind, but instead to record that it wasn't a thoughtless decision.

I also don't plan to engage with the whole argument about (different colours of) open access or with various publishers' various wickednesses, nor really engage other than tangentially with the whole sorry serials crisis. I will dreamily recall, though, my confidently asserting that traditional journal publishers were clearly on the very point of collapse, and would definitely be gone before, say, 2000. Ho hum.

## Prehistory

Bob and I organised a ‘birds of a feather’ session about ‘astroinformatics’ publication at the 2010 ADASS, described in the proceedings and on ArXiv (1103.1982). The problem, in a nutshell, was that people in this community were increasingly expected to publish in journals rather than semi-formal conference papers, but that the main astronomy journals were disinclined to publish primarily software articles, and the outlets we did use (eg PASP) didn't have the publication statistics we felt we needed. That conference paper describes our fairly informal survey of half-a-dozen journals, where we sent abstracts of a range of representative ADASS papers and asked ‘would you desk-reject this paper?’ (answer, most of the time: ‘yes’).

The mood was broadly in favour of new publication outlets and new publication types (eg ‘what worked’ articles), but stuck to the ‘let's publish more in PASP’ line mostly, I think, as a result of a strong conservative streak in astro computing. We also talked about open journals on that occasion, but the feeling in the room was strongly sceptical of the operational feasibility of relying on volunteer effort. We would very possibly have got a different conclusion from a similar BoF at a different conference, but ADASS is a pretty established conference in this circle, so probably a plausible indicator of community sentiment. It's probably relevant that a good chunk of the participants at ADASS are science operations folk, worrying about questions like ‘can we commit to this design/schema/format/SLA for the next 20 years?’

A year on, the hinted flood of PASP papers hadn't materialised. We took three things from this, and from other conversations at the time:

• (i) the ‘astroinformatics’ community still needed an outlet, or something else to create a defining narrative;

• (ii) this ‘colonise PASP’ route was still possible, but would require some impressive social engineering; and

• (iii) the community was (is?) conservative enough that an annotations journal, or a wiki journal, or a crowd-reviewing journal, or any of the other properly imaginative journal ideas, would be a very hard sell.

So this seemed to leave us needing a traditional-looking journal – any innovation in this line wasn't going to be in publication methods.

## Platform?

Our first instinct, of course, was to set up an open-access journal, using suitably open-source journal management software. Exercising heroic self-restraint, we decided against writing such software ourselves, and from a heart-to-heart with a colleague who'd gone down this route learned that:

• such journal publishing software did exist, unsurprisingly (I think it was the then-current version of OJS that we were talking about), and
• it was free as in speech (hooray), but
• running it was not free as in beer (ah...).

I remember the figure of half an FTE of effort to keep the journal working. I can't remember if that was paid effort – and thus money that would have to be raised – or an estimate of the effort gifted to the project from the day-job, but in either case it was a soberingly large number.

### Costs

In a way, it shouldn't have been a surprise. As everyone knows, who hasn't organised a conference, running a conference consists of nothing more than booking a room and putting up a web page. As everyone knows who has run a conference, there's a teensy bit more to it than that, involving a silly quantity of effort which it's almost impossible to account for afterwards. I think it's the same with publishing.

A couple of years after these events, I was talking to an editor at a (successful, cost-covering) academic press, who said that the cost price of scientific journal publishing was well north of £150 per paper. How much?! It seems that DOIs, feeds to Scopus and the like, ORCID integration, and all of the other tedious-but-fiddly back-office IT does add up alarmingly, that authors will not write sane LaTeX, that there's no APC revenue from rejected articles, and ten minutes later I'm whimpering slightly, trying to dig my shoulderblades out of the wall, and deciding that bitching about authors' bad LaTeX is a more fun direction for the conversation (yes, $\section{\gamma}$ will indeed get you bold maths, but no, I agree that's probably not great for long-term archivability please put down that bottle). But just as I'm unable to pin down, in retrospect, just what bit of being local conference chair will give you a nervous breakdown, I still can't put my finger on what specific bits of the journal publishing workflow are so irreducibly costly. They just... are.

There's an discussion of the economics of journal publishing in a Nature article from 2013 (10.1038/495426a). That's presumably at least a little out of date, but it can be handily summarised as: it's complicated.

Another data point comes from the Journal of Open Source Software, who have published a blog post describing both their actual costs (negligible), and an estimate of what their costs would be if they weren't relying on grants, volunteer effort, and effectively donated services. That estimates a cost per paper between $100 and$1300, depending almost entirely on whether or not, and how much, you pay editors. They keep costs down by requiring authors to produce camera-ready copy, by doing no copy-editing, and not paying editors; A&C, for completeness, provides post-acceptance copy editing and english-language editing, and pays editors (since you ask, above minimum wage iff you're time-efficient) but not reviewers. There are various positions one can take on the question of ‘editor compensation’.

Even without too much detail about the costs, the problem was that neither Bob nor I particularly wanted to run a journal, in the sense of operations rather than editing. We both had enough experience with the relevant sort of operations to know that the available quantum of giggles would be exhausted pretty promptly, and enough experience with academia to know that the associated glory (while of course undying) would set no heather alight, and the associated professional merit, though non-trivial, would be modest. Running a journal is an important job which we're all glad to praise someone else for doing.

But then, shortly after we published our thoughts about this, it happened that an Elsevier publisher approached us, having heard about our ruminations through the usual academic gossip networks, and said ‘I couldn't help noticing your paper...’. ‘But, the boycott...’. ‘And...?’ So on to the next phase.

## Is this, then, a Good Thing?

Without a publisher to take a commercial interest in this, I doubt the journal would have appeared. Perhaps a free (speech and beer) model could be found for this, but neither of us came up with anything that sounded plausible, and in any case we'd already formed the impression, as I mentioned above, that the community wanted something that looked respectable in a rather old-fashioned way. We hadn't decided ‘commercial or bust’, and I don't recall us shopping the proposal around, but if Elsevier hadn't turned up, I'm not optimistic that the project wouldn't have ended up in the bucket of life's ‘maybes’.

### Elsevier

And Elsevier? Yes, they're a commercial publisher whose goal is to make money out of this sort of activity. Unlike many publishers through the ages, they currently seem rather good at the profit-making bit. I am reminded of PTerry's description of ‘Mr Goatberger', who, in publishing Nanny Ogg's dubious recipe book,

dreamed the dream of all those who publish books, which was to have so much gold in your pockets that you would have to employ two people just to hold your trousers up.

And you may recall that Gutenberg's bible project went over budget by a factor of several, whereupon he fell out with his venture capitalist/publisher, went bankrupt, and had to take his technology elsewhere (is this a cautionary tale about the vagaries of print, or just a reminder that nothing ever changes?).

### Profit-making

Is profit-making wicked? For some social necessities – firefighters, healthcare, clean air, the drains and their associated ecosystems – yes, I think it probably is. For luxuries, not so much. Now, ‘knowledge’ in the abstract clearly is a social necessity (and I'm willing to be quite bang-on-the-table dogmatic about that); but for any particular instance of that knowledge – a journal on astronomical computing, to pick an example at random – I'm slightly less certain. There's a spectrum of ways of making a profit, some of which are more benign than others: if I found myself in Mr Goatberger's career (ideally sharing his problems with pockets), I'm confident I'd sleep happily at night.

### The publication process

Is this the best way of organising all this? No, surely it really cannot be – there's got to be a less deranged way of getting text from academic writers to readers. The chain of payments from funders to institutions to authors, from multiple institutions and haggling consortia to publishers to printers and editors, and non-payments from publishers to referees/authors, is so far from the maximally efficient linear value chain that enthusiasts for capitalism insist must necessarily emerge if only the market can be free enough, that it's easy to feel that someone (possibly the enthusiasts) is being mocked.

Whether or not the current setup is justifiable or not, the problem is that it feels like someone's being rooked, so everyone involved ends up cross and shouty.

I should mention that Plan S is a Thing (it's a Thing which I currently have zero coherent opinions about).

For what it's worth, there is at least one possible alternative, that has the twin virtues of actually existing stably, and being describable without sounding like a gibbering idiot. That is SCOAP3. Here, a consortium of funders of HEP science have negotiated an agreement with a consortium of journal publishers – crucially including the three or four key HEP journals – so that the funders will give the publishers a large wodge of money, after which the communities can both publish in those journals for free, and read the contents for free. This cuts out the reluctant middlemen, means libraries don't have to haggle separately with journals and feel permanently but non-specifically diddled, means academics don't have to feel that they're taking part in some obscure not-quite-fraud they neither deeply care about nor want to understand, and means publishers get a secure contract to get money for the fiddly layout, editing, and archiving work they've made their own.

What I don't know is how astronomy would get there from here.

SCOAP3 works for HEP because (a) there's a small number of ‘key’ journals that have to be dragged into the consortium; and (b), crudely, HEP has CERN, which has a role to play in catalysing that community's haggling of multi-year funding and planning. It would be harder work in astronomy. But it gets the material out there, avoids authors having to think much about publication and, as a system, doesn't look permanently on the verge of rapid unscheduled disassembly. Which is good.

Norman, 2019 June 1

Updated 2019 June 9: Added a couple of further details and links


text:
Highlighted
Level 3: Gumshoe

## NBN Connection

I am connecting to the NBN. I already have a smart modem. Why do I need to connect another smart modem? Can't I use the existing?


text:
main-content

## Über dieses Buch

Abstract semilinear functional differential equations arise from many biological, chemical, and physical systems which are characterized by both spatial and temporal variables and exhibit various spatio-temporal patterns. The aim of this book is to provide an introduction of the qualitative theory and applications of these equations from the dynamical systems point of view. The required prerequisites for that book are at a level of a graduate student. The style of presentation will be appealing to people trained and interested in qualitative theory of ordinary and functional differential equations.

## Inhaltsverzeichnis

### Introduction

Abstract
The purpose of this introduction is twofold: to present some examples of abstract semilinear functional differential equations and to describe the organization of the book.
Jianhong Wu

### 1. Preliminaries

Abstract
The purpose of this chapter is to collect some background materials required throughout this book. These materials include semigroup theory, Sobolev spaces, and elliptic operators. We will only state results and leave the details to the references listed in the bibliographical notes.
Jianhong Wu

### 2. Existence and Compactness of Solution Semiflows

Abstract
The purpose of this chapter is to establish the existence and compactness of solution semiflows defined by a class of semilinear functional differential equations. We will start with the case where the linear operator generates a C 0-semigroup of bounded linear operators and the nonlinear term satisfies a global Lipschitz condition. We will then indicate how to relax this global Lipschitz condition by imposing compactness on the linear semigroup. In the final section, we will derive a class of semilinear functional differential equations of neutral type from a continuous array of coupled lossless transmission lines and we will obtain the basic existence-uniqueness result for such a class of equations.
Jianhong Wu

### 3. Generators and Decomposition of State Spaces for Linear Systems

Abstract
The purpose of this chapter is to study the strongly continuous semiflow of bounded operators defined by abstract linear functional differential equations. Of main interest are the infinitesimal generators, their spectral properties, the distribution of characteristic values, the decomposition of state spaces according to characteristic values, and the computation of center subspaces. These results will be applied in later chapters to establish stable, unstable, and center manifold theory as well as the Hopf bifurcation theory for nonlinear systems.
Jianhong Wu

### 4. Nonhomogeneous Systems and Linearized Stability

Abstract
This chapter deals with linear nonhomogeneous systems and linearized stability.
Jianhong Wu

### 5. Invariant Manifolds of Nonlinear Systems

Abstract
The goal of this chapter is to prove various invariant manifold theorems and to demonstrate their applications to the study of saddle-point property and finite dimensional reduction near centers.
Jianhong Wu

### 6. Hopf Bifurcations

Abstract
In this chapter, we develop a Hopf bifurcation theory for similinear functional differential equations.
Jianhong Wu

### 7. Small and Large Diffusivity

Abstract
The central subject of this chapter is the effect of small/large diffusivity on the asymptotic behaviors of solutions to reaction diffusion equations with delay.
Jianhong Wu

### 8. Invariance, Comparison, and Upper and Lower Solutions

Abstract
This chapter establishes invariance and various inequalities for solutions of abstract integral equations with delay.
Jianhong Wu

### 9. Convergence, Monotonicity, and Contracting Rectangles

Abstract
This chapter establishes various results on monotonicity, convergence, and stability for reaction diffusion equations with delay subject to Neumann boundary conditions.
Jianhong Wu

### 10. Dispativeness, Exponential Growth, and Invariance Principles

Abstract
The first part of this chapter is devoted to the scalar equation
$$\frac{{\partial u\left( {x,t} \right)}}{{\partial t}} = \mu \Delta u\left( {x,t} \right) + f\left( {u\left( {x,t} \right),u\left( {x,t - r} \right)} \right),\quad t > 0,x \in \Omega \subset {\mathbb{R}^N}$$
motivated by Hutchinson’s population model. In Section 10.1, a reduction technique due to Luckhaus will be introduced and applied to establish the point dispativeness of the solution semiflow. It will be shown that, under a negative feedback condition on f, the solution semiflow is point dissipative in one space dimension for arbitrary delay and diffusion coefficients. In higher space dimensions, the point dispativeness still holds provided either the delay is small or the diffusion coefficient is large. But this dispativeness fails to hold if the diffusion coefficient is small and the delay is large. Indeed, as will be proved in Section 10.3, unbounded (exponentially growing) solutions exist in the case of large delay and small diffusion. This indicates that for small value of the diffusion coefficient, spatial heterogeneities no longer stay bounded for large t; rather, small irregularities in the initial distribution tend to grow larger and larger during the time evolution. Section 10.2 will be devoted to a convergence result for the above scalar equation by employing a naturally motivated Liapunov function. The second part of this chapter will develop a general invariance principle of Liapunov-Razumikhin type and its application.
Jianhong Wu

### 11. Traveling Wave Solutions

Abstract
This chapter deals with the existence of wave solutions in a system where spatial diffusion and temporal delay play a crucial role in determining the system’s spatio-temporal patterns and dynamics.
Jianhong Wu

### Backmatter

Weitere Informationen


text:
# [OS X TeX] Writing an Underscore in LateX

David Watson dewatson at me.com
Thu Jul 28 17:56:05 CEST 2011

The underscores in your PDF show up just fine for me.

On Jul 28, 2011, at 10:43 AM, Ishe Chinyoka wrote:

> Hi,
>
> Thanks for your help. Actually, for interest sake, I am using MacTex 2011 on Snow Leopard with Voiceover as the screen reader. What is strange is that when I run Plastex to convert the source Tex file to HTML, the underscores are there, but in the PDF file, they are not there.
> <test.tex><test.pdf>
> Anyway, find attached a sample of my test TeX source file and a sample output PDF.
>
> Thanks once again,
>
> Ishe
>
>
>
> On 28 Jul,2011, at 4:10 PM, Herbert Schulz wrote:
>
>>
>> On Jul 28, 2011, at 8:51 AM, Ishe Chinyoka wrote:
>>
>>> Hi,
>>>
>>> Thanks Klaus. I just tried that and the file was typeset, but here is another strange problem: I see no underscores in the final PDF document. I even tried to wrap these in the \verb|word_to_wra| and this worked. But now the issue is with items that are part of the description list environment like this:
>>>
>>> \begin{description}
>>> \item[word\_to\_wrap]
>>> \end}description}
>>>
>>> The underscores are stripped and I get
>>>
>>> Word to wrap
>>>
>>>
>>> Is there a way to put a word in the \verb|| wrap in a list item? If this were possible, I would try it. For example, can I do this:
>>>
>>> \item[\verb|word_to_wrap|]
>>>
>>> Thanks once again,
>>>
>>> Ishe
>>
>> Howdy,
>>
>> Works fine here. Could create a minimal but compilable example where it doesn't work so we can see exactly what is happening?
>>
>> Good Luck,
>>
>> Herb Schulz
>> (herbs at wideopenwest dot com)
>>
>>
>>
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>
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text:
# What was Seifert's contribution to the Seifert-van Kampen theorem?

The Seifert-van Kampen theorem is the classical theorem of algebraic topology that the fundamental group functor $\pi_1$ preserves pushouts; more often than not this is referred to simply as the van Kampen theorem, with no Seifert attached. Curious as to why, I tried looking up the history of the theorem, and (in the few sources at my immediate disposal) could only find mention of van Kampen; the wikipedia page of Herbert Seifert doesn't even mention the theorem.

So my question is: Why does the theorem bear Seifert's name?

-
Seifert's name is attached to many things already, so it's less distinctive. If we called it Seifert's theorem we'd always have to say something like "Seifert's fundamental group theorem". But saying Van Kampen is easier, since we don't need to worry people will misunderstand what theorem we're referring to. –  Ryan Budney May 9 at 12:32

According to Jahrbuch der Mathematik this theorem is in:

• Seifert, H. Konstruktion dreidimensionaler geschlossener Räume. (German) JFM 57.0723.01 Berichte Leipzig 83, 26-66. Technische Hochschule Dresden, Diss (1931).

See the (long) review in zbMATH by Erika Pannwitz. The relevant sentence is:

• (Die erforderlichen Hilfsmittel werden in § 2 und 3 der Arbeit zusammengestellt; § 3 enthält insbesondere Aussagen über die Fundamentalgruppe eines Komplexes, der aus zwei Komplexen mit zusammenhängendem Durchschnitt zusammengesetzt ist.)

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The paper Gramain, A. Le th\'eor`eme de van Kampen. Cah. Top. G\'eom. Diff. Cat. 33 (1992) 237--251, gives some more history. Actually van Kampen's paper is quite difficult to follow, and the matter was clarified by Crowell to the modern version. It seemed to me in 1965 that there was an anomaly that this theorem did not calculate the fundamental group of the circle, THE basic example in algebraic topology. This led to the use of groupoids in this area. See the discussion at mathoverflow.net/questions/40945/… –  Ronnie Brown May 9 at 9:58
@Ronnie: The paper of Gramain looks very informative. I seems that Seifert treated only the case of 2 sub complexes of a simplicial complex with connected (from the review I cited above) intersection. –  Peter Michor May 9 at 11:16
Wrt the paper by Seifert, that is also my understanding. The proof by Crowell is modern in that it goes by verifying the universal property; this proof generalises easily to the many base point case, i.e. non connected spaces, so dealing with many not unusual examples, including of course the circle; the proof also extends, with new ideas, to higher dimensions (see our EMS Tract vol 15, 2011, "Nonabelian algebraic topology"). –  Ronnie Brown May 9 at 14:17