The 100 Stars within 20 light years

A sphere centered on the Sun with a radius of just under (actually almost exactly) 20 light years has 100 stars in it. (Source: RECONS (Research Consortium on Nearby Stars). ---Unfortunately, this data includes some brown dwarfs and Red subdwarfs, which complicates things, because these things are not stars, really, and, worse, there are probably lots more of them than this data shows, but the essential points are correct anyway).

• The brightest star, type A, is Sirius, Alpha Canis Majoris. 8.58 ly distant.
• The second brightest is Procyon, Alpha Canis Minoris. Type F-5, just edging off the main sequence. 11.4 ly distant.
• The third brightest is Altair, Alpha Aquilae. Type A7, 16.7 ly.
• The fourth brightest star is THE SUN. Type G main sequence star.
• The fifth brightest is Alpha Centauri A, 4.37 ly distant. Main sequence type G2, similar to the Sun but a bit older.
  

So our star is in the 96th percentile. Not exactly the "garden variety" we're told about in popular treatments. Stars like the Sun are common, but not nearly as common as dimmer stars.

Of the remaining  95 stars, there are no F dwarfs. (stars of the next brighter class relative to the Sun). (Only Procyon, see above). Stars in this class are also relatively common. We have two A dwarfs (Sirius and Altair) and one F dwarf (Procyon) in our actual Sun-centered population. Probably more typically it would be two or three F type in 100, probably on average there should only be one A dwarf. The very bright classes O and B are only found in star forming regions (because they don't live very long), and are exceedingly rare compared to these other classes. Which is why they're often referred to as giants and supergiants.

Among the remaining 95, then there are five more G dwarfs (same class as the Sun), all quite a bit dimmer than the Sun (in addition to Alpha Centauri A and the Sun, above, so 7 total, including the Sun). (Tau Ceti, Sigma Draconis, Eta Cassiopiae A, 82 Eridani, and Delta Pavonis).

There are 17 K dwarfs. (Next dimmer class). These include Alpha Centauri B, Epsilon Eridani, 61 Cygni A & B, Epsilon Indi A, AX Microscopii, Omicron-2 Eridani, 70 Ophiuchi A & B, Eta Cassiopiae B, and 36 Ophiuchi A, B & C, plus several stars that only have catalog numbers. When you get to 20 light years or so, the mid-to late-K dwarfs are very inconspicuous in the sky.

That leaves 78 stars. Of these 78, (skipping the most numerous category), seven are White Dwarfs, which are stars which were once bright G or brighter stars but which have ended their lives as burnt out little white stars, no longer undergoing nuclear fusion in their cores. These include Sirius-B and Procyon-B; and van Maanen's star. The rest just have catalog numbers. All white dwarfs are very inconspicuous. Sirius at 8+ ly is far and away the brightest star in Earth's sky, but its white dwarf companion, besides being drowned out by close proximity to Sirius, would not be a naked eye star in its own right even if Sirius A weren't there... despite being one of the six or seven nearest stars to the Sun.

That leaves 71. Of those, another 7 are T-dwarfs, or methane dwarfs, better known as brown dwarfs. These are failed stars that never did undergo nucleosynthesis. These stars, if they are stars at all, are practically invisible, almost no matter how close they are. The only ones with 'names' are Epsilon Indi B & C, and the only reason they have those designations is that they're in the Epsilon Indi system (although A is a relatively dim star in its own right; see above). [In fact, as noted, it's likely that there are even more of these, so if you count them as stars, the percentiles are off but the meaning is clear. There may well be over 100 more of these. If you don't count them as stars, you could extrapolate percentiles but just multiplying by ~108%].

So, disregarding the brown dwarf issue, we're left with 63. The majority. A landslide in a presidential election.

All 63 of the remaining stars are red dwarfs. Class M.*  Red dwarfs are little stars that burn hydrogen to helium, slowly and steadily, produce on average just a percent to a few percent of the light of the Sun, and live up to a trillion years without evolving off the "main sequence" (so we're told... the Universe is only 13.7 billion years old, so you have to believe the theory).

Over half of the individual stars in this population are in multiple systems, which translates, if you think about it, to something less than half of the systems being multiple. (If you have two systems, one single and one binary, 2/3 of the stars are in the binary system).

There's every reason to believe in disk populations in typical spiral galaxies, these proportions ought not to be too far from the norm.

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To me, the takeaway is confirmation of something I already knew, which is that most stars are red dwarfs, and the brighter stars become increasingly rarer, more or less in direct proportion to increase in their mass, which directly correlates to increasing brightness, with minor adjustments for age and composition.

The Sun is a relatively bright star, not a typical star.

But on the other hand, there is a selection effect when you look at the night sky. Very very bright stars are SO MUCH brighter than dimmer stars that they dominate the night sky in visible light. MOST of the naked eye stars are exceptionally bright and very rare stars. Whereas, in the actual population, most of the stars are very dim dwarfs. And if you count the bodies that never really started shining with thermonuclear energy, there are even more of them. They're everywhere.

For  the future of humanity, the brown dwarfs are less interesting, because it's hard to imagine how future Homo stellaviator (Man the Starfarer) will be interested in systems that only contain them. These stars, if they even are stars, glow only with the heat of their own collapse and are so cool they don't really emit enough light to drive photosynthesis or solar power generation. It's hard to see how it would be worth the cost and time to travel to such systems.

The abundance and energetics of thermonuclear fusion core Red Dwarfs, though, may be another story. If we someday literally cross the great voids of space in person, these are what's out there in huge numbers, and they are engines of energy production, like the Sun but smaller and weaker, and their systems are already known to typically have planets and probably other material in abundance. I'm enough of a dreamer to think of all that as real estate.
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*(One is Class L, a special class of even lower temperature Red Dwarfs, which may also be under-represented even in this population study of the very nearest stars because they're so dim some are being missed. But this particular star is probably in thermonuclear fusion. The dimmer L's should be classed with the Ts. Look up spectral class T and L on Wikipedia if interested in this subject).

Are we living in a Young Universe? Some further thoughts on the Fermi Paradox

[Updated]. This post is a follow up to a post I put on here almost three years ago to the day. Here. 

What if the answer to the Fermi Paradox is simply that, contrary to what we like to think, the Universe is yet young, and no (or very few) Elder Races have yet appeared? 

Here is a (perhaps) plausible scenario. Items noted with ♠ are, to my understanding, "generally accepted as true," although perhaps not widely known. 

♠ The Sun is more than one third the age of the Universe, and is significantly (not to say greatly) anomalous, in the direction of having a higher proportion of elements beyond Helium in the Periodic table (higher metallicity) than is typical for stars of its age. (Some stars older than the Sun have even higher metallicities, such as Alpha Centauri (7 b.y. old, somewhat higher metallicity), but we're talking averages here). Typical 5 billion year old stars in the Galactic Disk formed from the moderately enriched Galactic medium of the time, and are consequently less metal rich than typical stars forming today. (It's also true that star formation has tapered well off, but it may be that of all the life bearing worlds that ever form, a high proportion will be from the later-formed stars, for this reason, and the point below). (How stars form plays a role here; there are at least hints that the Sun formed in a cluster where a chain reaction of supernovas had enriched the medium; this is not unusual, and was probably more common in the past than now, but is not typical). 

♠ Metallicity is thought to be positively correlated with the likelihood of the evolution of life; in the sense that planets forming in systems where the protostellar neblua was initially metal-poor, (the ubiquitous and only gradually diminishing condition of the general population of Stars in the early universe), would not yield the materials necessary to form rocky watery worlds like Earth and the marvelously complex chemical/energetic systems we refer to as "life."

♠  [New from original version of this post] It's perhaps worth noting that when these facts are generalized, i.e., we are talking about "stars of the Galactic Disk" as opposed to "the Sun," the basic facts will apply, more or less, with no great degree of variation, to all spiral galaxies everywhere in the Universe, since they're all more or less similarly formed, and all are roughly the same age, having resulted from an evolutionary process instigated by the Big Bang itself. Other types of galaxies may not have sunlike stars at all, for reasons I won't go into here, but there are such a vast number of galaxies essentially similar to the Milky Way in the wider universe that it really doesn't make any difference for purposes of this discussion. Also, the fact that the Milky Way is a "barred spiral" as opposed to other types of spiral galaxies doesn't appear to make any difference; the populations of disk stars in all galaxies with dust-containing disk regions are all essentially similar. Moreover, it's an accepted principle that all parts of the universe are much like all other parts, so it's generally accepted as true that this will be the case everywhere in the universe, even in regions beyond the "time horizon," i.e., beyond the border of where the universe is theoretically observable (the horizon's distance in light years equal to the age of the universe in years; adjusted for recessional velocities from the expansion of the universe itself. Most of the universe is beyond this horizon). 

From these generally recognized facts, let's posit this: the Earth is a pioneer among worlds. Having formed in an unusually metal rich system, in a typical spiral galaxy at an early age, its complex biosphere is likely to be more typical of those found in star systems that formed later (which will only later come to resemble ours), or which are yet to form, than those that began the process of evolution at approximately the same time as the Solar System. 

Now, of course, in the vastness of all of space, this same "pioneer world" phenomenon has probably occurred innumerable times (and sometimes much earlier than here, no doubt), but let's just posit that it is an explanation for something we might begin to suspect, which is that advanced living worlds are currently rather, or possibly even extremely, rare. This says nothing about their likely future prevalence, which, by this reasoning, could be very much greater than it is now. 

Now, another posit: the evolution of intelligent life on Earth took 5 billion years or so from the origin of the Solar System. Maybe this is typical. Maybe it's an extra-long time. But, from information available to us, we don't know: maybe, on other hand, it's remarkably fortuitous, and atypically efficient and quick. Maybe life sometimes or even usually goes its merry way and does not evolve into beings that use thought as a competitive adaptation to ensure their survival; or that, on average, such evolution usuallytakes longer than it did on Earth. These are not known; we have no real way to evaluate any of these possibilities. Remember that it took complex (i.e., multicellular) life over 4 billion years to emerge on Earth, and it took a further 550 million years before technologically adept creatures (us) evolved (please don't plead for the Whales and Dolphins... they may be smarter than us but they're not building spaceships or intergalactic radios anytime soon). So most of the history of Earth, which, again, is over 1/3 the entire history of the universe, saw life but no "intelligence." So the latter is not necessarily implied, at all, by the former. (Stephen Jay Gould, in reasoning that I found unconvincing, hypothesized in his book Wonderful Life that if you could "play the tape" of evolution over again, given the same starting conditions, it was spectacularly unlikely that intelligent beings would evolve again. I thought, and still think, his rationale was hopelessly parochial, and failed to take into account the power of convergence. Nonetheless, the fact that for hundreds of millions of years there was no intelligent life surely indicates that the chances of its evolution are not 100%). 

So, here's what I think may be happening. Supercivilizations are possible. They may already exist, in some corners of the Vast Universe (although probably not real near here, since we see no signs of their amazingly stupefying technology, which we would, presumably, if they were mucking about on our doorstep). We may evolve into one of these, ourselves, eventually. What that will look like, we can hardly guess. But the Young Universe has yet to produce Supercivilized Elder Races in abundance. Most living worlds, even those which have chanced to evolve intelligent beings, are, in fact, isolates, like ours. 

Someday, that may all change, as the universe matures. 

But in the meantime, this is why, at least for now, we appear to be, and effectively are, "alone."

On Social Security

I've previously made my views on Social Security very clear.  So it will be no surprise that I am glad that the Administration has apparently withdrawn its offer of a few weeks ago to include a change in how the COLAs are calculated ("Chained CPI"), which amounts to nothing more or less than a long term stealth benefit cut to a program that should be increased, not cut. Were that terribly dumb idea actually put into effect, Social Security, which is the primary income for more than 70% of retirees, would gradually cease to do its most essential job, which is to keep the elderly out of poverty. I am totally intransigent on this point: if Democrats agree to this, they will have betrayed their constituency and forfeited any claim to being the party of Progressives.

Now, it also appears that the payroll tax holiday will not be extended. And here, I hope, my view is consistent. I also applaud that outcome. Along with Bernie Sanders, I and many other Progressives were deeply suspicious of the idea of using a payroll tax cut as a stimulus measure in the first place.

The key to Social Security is that it is and always has been self-funded. (This also true, but not entirely true, of Medicare, but let's keep the focus on Social Security). Taxes are paid into the Trust Fund, which uses the funds, including past surpluses, to pay benefits. The tax is regressive, in that it is levied essentially only on wages and salaries, and only up to a certain level. There is no maximum benefit, per se,  but there is, effectively, because you only receive benefits based on the amount of income that was taxed, and that's capped, currently at $110,000. Of course, the General Fund has always, in effect, borrowed the surplus, but this is not, as many people seem to think, commingling. It is actual debt, in the form of US Securities, whose full faith and credit is a critical factor in the financial health of America. So that the idea that Social Security is a house of cards because it only has a bunch of IOUs is a pernicious and frankly profoundly stupid canard: if politicians were to allow the debt to the Trust Fund to be defaulted upon, it would be indistinguishable from defaulting on our national debt to China or other creditors. And it would amount to theft from the American people themselves. All of which is why I repeat Ronald Reagan's comment whenever this subject comes up: Social Security has nothing to do with the deficit. 

Not only that, but the very idea that Social Security is even a problem right now is ridiculous. Under current projections, it is solvent to 2033 (used to be 2037, but there was that not-too well-advised payroll tax holiday... possible only because Social Security was, in fact, so fiscally healthy). Any insurance or pension system that could show it was solvent with current income and surplus to 2033 would be declared solid gold and would have no competition.

So right wingers and ill informed Democrats who crow about how Social Security is "unsustainable" and "going broke" just don't know what they're talking about. Or they're deliberately lying, which I suspect is often the case.

Since the long term health of Social Security is important, however, I am glad to see that payroll taxes, which are its funding source, are going to go back to their statutory intended level after the first of the year. We do need stimulus, no doubt about it, but this is bad policy. 1) Tax cuts are relatively ineffective as stimulus, as any rational economist will tell you; and 2) if a program's long term viability is a policy issue, cutting its funding makes no sense.

So then, you may ask, what should we "do about" Social Security. (So glad you asked).

The most obvious fault of Social Security is that it is a social insurance system funded by taxes, but that those taxes are not progressive. We need to make a decision as a society that we are going to provide a buffer against poverty for all our citizens, and continue the guaranteed income to all payees that makes the whole system popular. (After all, if it were just welfare, it would be SSI, which we already have, for the indigent elderly and disabled, thanks in part to that notorious liberal, Richard Nixon, but that's another issue). Having committed ourselves to Social Security as a benefit system more or less in its current form, we need to enhance the way in which its paid for. I actually think that Roosevelt's plan to fund it separately from general tax revenues was pure genius. Americans hate income tax but they by and large don't resent paying for Social Security (or Medicare). But there are some improvements that could be made. Here's my idea:

The portion that employers pay should remain essentially the same, except for two major changes. First, the cap on wages and salaries subject to tax should be lifted. Not raised. Removed. All compensation should be subject to the tax. (Benefits would remain capped, based on current levels, and the difference would fund the surplus necessary to keep the program solvent forever, which this scheme would accomplish). The other big change would be that no form of deferred income should be exempt from either income tax or payroll taxes.should be exempt from either income tax or payroll taxes. (Stock options, in-kind perks, fancy schemes to treat income as dividends or carried interest, etc. -- all of which should be addressed in more comprehensive tax reform anyway). If it's compensation, it's taxed. Period.

Now, the portion of Social Security (and, incidentally, Medicare) taxes paid by the employee should be handled a bit differently. I would like to see the same lifting of the cap on income subject to tax, and the same application to all compensation. But for incomes up to $110,000, I would like to see tiered rates, so that those who are earning less than a defined "middle class threshold" income should pay at a lower marginal rate, while keeping benefits the same. This is a recognition that there is  a component to the program that comprises social welfare. Again, I'm proposing that the benefit system be capped, but that all compensation be taxed. For compensation above a certain level, perhaps $75,000, the payroll tax rate would go to maximum, and stay there above the present cap. The system would be adjusted so that current levels of income to the trust fund would be generated from the taxes on compensation below some level, say $150,000, and taxes on compensation above that level would pay for a trust fund surplus, to keep the program solvent forever. 

To WH: don't back down on Hagel nom

 This is my e-mail to the White House contact site today.

Never thought I'd be writing to the White House urging them to stand behind a Republican (potential) cabinet nominee, but the Right Wing attacks on Chuck Hagel should be resisted resolutely. Hagel is as honest and straightforward as they come in politics, and his position on reasoned restraint towards Israel's Right Wing government, and a rational and cool review of America's relations with Iran, are EXACTLY what is needed right now. Assuming Hagel is in fact the president's choice, he should not back down. 

This opinion is a reflection of the comments of Colonel Lawrence Wilkerson on Ian Masters's show on Sunday, the 23rd. See ianmasters.com .

Too late for Grand Bargain/Great Betrayal, plenty of options for can kicking

I often disagree with Matthew Yglesias, but in this instance, I think he's got it just about exactly right. 

Apart from the relatively brief likely effect of Market nervousness from now until after the 1st, I think the way things have turned out in these negotiations is actually better for the prospects for long term benefit to the American people than if some deal had been struck this month. 

I fully expect that the Bush tax cuts for the under $250K income cohort will be extended or made permanent, and some version of can kicking will occur, but the fact that the idiotic plan to permanently cut Social Security under the so-called chained-CPI scheme, or other ill-advised cuts to essential services, will not be occurring, is a very definite plus. We in the reasoned liberal community can try like hell to sound the voice of reason and keep these terrible ideas from resurfacing, while lobbying for more revenue from progressive tax reforms, including a modest financial speculation tax, reform to increase tax rates on capital gains, dividends, and carried interest (possibly with a floor to protect middle class investors), real reform (i.e., elimination) of overseas tax havens, elimination of corporate and Agribusiness welfare, restoration of substantial estate tax, and a lifting or raising of the cap on income subject to payroll taxes. If anything like the bulk of these could be enacted sometime in the next decade, we could easily put this country on the road to quite sustainable fiscal health, and maintain the essential services which are an obligation of the government to its people, based on years of regressive taxes to pay for them, every bit as much as its bonds and securities are obligations to the investors who've purchased them. 

The Price of Civilization

Jeffrey Sachs of the Earth Institute (Columbia University) laid it out really well in an interview Thursday with Ian Masters (ianmasters.com). Allow me to very briefly summarize, with a bit of my own panegyric thrown in for good measure:  

The current budget negotiations are a case of both parties toying around the edges of a much more fundamental problem, which is that, in thrall to a destructive Right Wing ideology, this country is no longer paying the price of civilization. Our infrastructure is crumbling, we are not investing in the energy resources of the future or the social systems and services (education, preventive health options, housing for aged and poor, transportation, etc.)... that would be necessary for us to have the kind of robust democratic civilization we once strove for. Obama and the Republicans are arguing about a revenue rise of 0.7% of GDP vs. 1% of GDP when what we really need is to increase revenues substantially to pay this price. And hysterical concern over debt, when the world clamors to buy our debt and money is practically free, is beyond stupid right now. 

Major corporations and rich people are avoiding all social responsibility. They ensconce their money in foreign tax havens, and live in a privatized world, while the country as a whole has lagged far behind other developed countries in these essential government functions.

Rich people have essentially all the power, over both parties, and until the people demand that government start paying attention to the needs of the many, not just the few, we will have an oligarchy and a society in decline, resembling ever more and more a third world country: with a wealthy elite and a rapidly declining standard of living for everyone else. Eventually, America’s ability to carry on the technological innovation and cost of being a superpower will also collapse, if we don’t go back to forcing everyone with means to pay a fair share of the price of civilization, and for those with the most means to pay the largest share. This is how it works; and nothing else will work. Period. 

President Obama has failed to lead. He has the right rhetoric, but he tries to accomplish policy goals through backroom negotiations, not by taking the case to the people and asking them to make the policymakers do it, which is how these kinds of reforms (both Roosevelts, Kennedy, Johnson), have been accomplished in the past. If he doesn’t change course soon, things will continue to get worse, and the proposals being discussed now will actually make matters worse than just letting the stupidly named “fiscal cliff” happen, which would at least bring in Clinton era revenues for a while. Of course, there are much better ways to do it (such as really eliminate tax havens and subsidies to oil, tax media companies for use of airwaves, impose a transaction tax on speculation, bust up big banks, raise top marginal tax rates a lot, increase payroll tax cap, impose carbon tax, convert the ACA to single payer, restore estate tax and some excise taxes… in other words make those who have benefited most from the American economic system pay the real costs of maintaining it). But none of this can be made to happen by negotiating with people who hate the very idea of commonweal, and whose goal is only to protect the narrow, selfish interests of plutocrats. Only sweeping leadership… a broad and emotionally charged appeal to the masses to force change; in other words what people were hoping for when they voted for Obama in the first place… would have any chance of achieving what we must do.

We can’t give up, even if this president will not or cannot do what is needed. We have to work to elect people who understand what we’re up against, and make them do it. There is no other way.