Astronomy Without A Telescope – Say No To Mass Extinction

35 Replies to “Astronomy Without A Telescope – Say No To Mass Extinction”

1. It’ll be fine, it’ll be fine…

   Just call Bruce Willis (Or Chuck Norris – better yet, send them both).

2. Extinction of earthlings… Bah Humbug!

   Who knows. It might actually be a good thing, and may produce something better. (It might help fix that climate change too…)

   Now. Where’s my proton pill? The Eagles are getting a bit restless!

3. We humans are doing an excellent job of engineering a mass extinction already. We are adulterating the chemical make up of the biosphere. A chemical change was likely the thing which brought about the Permian and KT extinctions.

   LC

4. Yeah. It is called the Anthropocene Epoch – and it is coming faster than we think!

5. This isn’t something that would keep me up at nights, considering that the risk is very remote.

   First, on this terrible bad part of the article:

   you have probably heard that there are hints of a certain periodicity in mass extinction events,

   Yes, and it is an urban myth. Or if not, if it is actually still considered in the astronomical community, it should be worked on to be eventually classified as one. I.e. to be disregarded. I’ve commented on this before: “the fabled myth”.

   The reasons are the following.

   1. The initial paper of Raup and late Sepkoski is an exercise in bad model fitting. As they can’t use regular Fourier analysis due to the uneven time axis they _construct series that fits the time scale_. In effect looking for regularity by making it up.

   And they only test the result for noise, not against more data. Further, they test this to p < 0.01, not p <. 0001.

   There are more and serious problems with their "peek" definitions, see below.

   I believe a lot of criticism has been leveled on this model. Here too, see below.

   2. Modern larger data sets using modern Fourier and correlation analysis shows that any periodicity is due to bad analysis.

   This is what I said over on Astroengine on these 2 points last year:

   “Now I’m confused.

   Assuming we want observations of extinction rates to be a basis for a physics hypothesis, wouldn’t we want to have the usual significance for new observations, say P < 0.0001 or so? Yet the Raup & Sepkoski paper that Iorio references are satisfied with P < 0.01.

   That may be good enough for biology as regards historical observations, but it doesn't seem to measure up to physics criteria in astronomy.

   there may be a mechanism for the regularity of comet impacts on Earth, thus causing the statistical regularity of extinctions. Once again, this is a hypothetical argument, but it is based on good science and historical evidence.

   Is it really good science? I can find papers that speak of a long debate and includes current data [Alroy 2008]:

   The hypothesis that mass extinctions show an ≈ 26-Myr cycle of periodicity (6) has arguably been the most debated hypothesis by paleontologists over the last quarter century. A host of potential mechanisms for periodicity have been offered, such as impacts driven by astrophysical factors (6) or the lag time needed either to accumulate species vulnerable to mass extinction (48) or to build networks of ecological interactions that can collapse if even slightly perturbed (29).
   Qualitatively, it is hard to discern some of the extinction rate peaks that should fall in the periodic pattern (13). Quantitatively, extinction rates in the Fossil Record 2 family data (3) and Sepkoski’s family and genus data (1, 2) are not correlated with themselves at any time lag (49), which is a necessary condition for periodicity to hold. That said, analyses of origination rates in all three datasets (49, 50) suggest short-term autocorrelation. However, the current dataset shows no autocorrelation in either kind of rate (Fig. S1), and a standard spectral analysis (Fig. S2) also suggests purely random variation through the time series (i.e., white noise). [My bold.]

   Alroy suggests that the variation over a modern dataset is consistent with white noise. The low significance in the original paper combined with low fossil data coverage can perhaps explain the discrepancy between correlations found in older data and this modern result. (It could also be a problem that the fossils are AFAIU used to define stratigraphic staging, and the stratigraphic staging is used to analyze the fossil data against.)

   [I don’t want to be too flippant, but I quickly scanned Raup & Sepkoski paper, and found two large problems IMHO. First, after they use a Fourier transform to detect any variations in extinction rates, they use a subjective filter to model data with, “extinction peaks”. These are “a peak being any point flanked by lower points”.

   A model Fourier spectra with a peak around twice the average stratigraphic stages suggested by such a data model, or 12 My, is coincident with the peak they use (and as a method runs up against aliasing problems). Without any further analysis to discern if that is all there is in their signal model they should exclude this peak as suggesting “extinction peaks” (instead of any periodicity consistent with the data).

   Second, I believe they should have seen this if they had used a no signal reference to check their analysis against – but they did not.

   I don’t suggest that these methodical problems is why the signal disappeared with modern data sets, the initial low significance combined with low fossil data coverage and staging issues suggested above could be enough, but it wouldn’t have helped.]”

   Check Alroy’s paper, it looks good to me.

   3. There is only firm support of one mass extinction as caused by an impactor. Peter Schulte et al paper “The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous-Paleogene Boundary” is prettyd definitive. It also tells us that the reason the impact was so harmful was the unlucky hit in “carbonate- and sulfate-rich target rocks” cuased “the release of climatically sensitive gases” that “could have caused catastrophic environmental effects such as extended darkness, global cooling, and
   acid rain (7–9). These effects provide an array of potential mechanisms for the ecologically diverse but selective abrupt extinctions (Fig. 1) (10–13).”

   This is then likely a rare and modern event due to sedimentary rock formation. Remaining mass extinctions are likely then from other causes.

   Second, (eys there is a second even after all of that :-D), even if there is another extinction impactor life will continue. Or at least if Abramov and Mojzsis models of microbial habitability in Hadean LHB predict the correct outcome: “there is no plausible situation in which the habitable zone was fully sterilized on Earth” since cells multiply and migrate faster than sterilizing impacts can keep up.

6. Is that Epimetheus? and what is it doing way out there near Earth? =P

7. At this moment we are not doing a good job for our planet, but when enough research is done and some cheap energy solution becomes possible and nano-technology get better, We might be able to reverse the pollution because we can then clean the air and water again. Food and meat could be grown in big tanks without need of killing animals.

   The tricky is finding the money to do the necesary research. If we can get to the Moon in 10 years back then, And invent the atomic bomb in record time, then we surely can also create some cheap energy source like nuclear fusion.

8. No need to worry about problems on that time scale human kind will be lucky to see the start of the next century

9. The passing of Gliese 710 may induce Oort cloud objects to enter the inner solar system, which could of course result in an impact. However this is not something of immediate concern. Even concerns over modest 10-100 meter asteroid impacts are not something which keeps me up at night.

   It does appear that our species is some sort of terminator species which is changing the characteristics of the biosphere, and increasing the entropy of the planet. This could be called the anthropocene; a period where a particular species of life increased the entropy of the biosphere until that entropy reaches some maximum or equilibrium point. It is the case the biosphere is an open thermodynamic system, but the time periods or cycles at which free energy restores the system occur on a much larger time scale than the time frames of our activities. So our impact on the planet is approximately that of a closed thermodynamic system, which approaches equilibrium. EQUILIBRIUM = DEATH, and that appears to be what we are approaching.

   The first question is how long this process will take. Will be reach this final state in 50 years or 200 years? That is what we do not know very well. We are clearly reaching certain resource and energy limits, which will place unpleasant constraints on our economic system in the next few decades. The ultimate limit we face is where we run out of environment, or equivalently damage the life support system we depend upon for biological existence. The next question is whether this ecological collapse exterminates our species utterly, or whether this places Homo sapiens into some longer term (10-100 thousand year) bottleneck which could be our next crucible of evolutionary change. The final question is if we do survive some bottleneck whether there will emerge a Homo sapiens 2.0 species which might emerge once again to develop something we might call civilizations.

   LC

10. @ Lawrence B. Crowell:

    That wouldn’t keep me up at night either. Also in this case it is nothing unique, since there are many reasons to believe that specific species have changed the Earth irreversibly before (the catastrophic oxygenation event due to photosynthesizing cyanobacteria). Life itself has irreversibly changed Earth to the worse – current conditions would likely not lead to a new abiogenesis if life disappeared.

    On the physics, I have serious problems with what you are claiming.

    First, entropy isn’t part of what makes a thermodynamic equilibrium. It is AFAIU approaching a local maximum when a system approaches thermodynamic equilibrium.

    Second, it is life that increases entropy production locally by making more energy levels available. It has to be, or it wouldn’t exist as a process. Whatever we do that harm life we could in sum decrease entropy locally.

    Now, since Earth is at best a steady state system (well, not really, but close enough here), entropy isn’t in any way characterizing it. Landauer shows this.

    I doubt there is any way that you can observe entropy and its production, and conclude if a system approaches equilibrium. The reverse seems to be the case.

    Now the former (observing entropy) doesn’t seem to be what you are actually claiming, but an unfortunate overlay on said claim. You are claiming that we are approaching a closed system, by not having free energy natural processes that restores the system on the appropriate time scale.

    Fine if true, but what does that mean exactly? It is usually claimed that since we aren’t treating Earth like a steady state system but using up fossil sources, having an even more open system, we are in trouble. In that process we are making free energy available on a large scale.

    The problem, it seems to me, is that we may run out of free energy resources before we have time to find new ones and/or make the current usage effective enough to not run out. This is then not a problem of free energy processes replenish current resources fast enough, but if they historically have put down enough resources for us to use meanwhile we develop a sustainable resource economy for Earth.

    One of the suggestions for such an economy is to utilize space resources. That would take us even further from any putative equilibrium.

11. Btw, it hits me that if we start to utilize space resources we are no longer discussing free energy potentials (which applies to reversible processes of constant pressure and temperature in closed systems). We would then have to look at the grand potential which applies for open systems and irreversible processes.

12. Torbjorn Larsson OM said: First, entropy isn’t part of what makes a thermodynamic equilibrium. It is AFAIU approaching a local maximum when a system approaches thermodynamic equilibrium.

    Hmmm, the last sentence is basically what I said.

    The Earth is an open thermodynamic system so characterizing a thermodynamic state is difficult. However, if our activities are rapid compared to the replenishment rate of the open cycle the system approximates a closed thermodynamic system. So

    dF = dU – TdS – mu dN

    approximately holds. We are using the free energy stores on the planet, and we are changing the chemical make up of the environment, so there is an entropy due to a general chemical potential mu.

    From a biological perspective the extinction of species is the loss of genetic information. The erasure of information results in entropy as the Shannon-Khinchin formula

    S = k*n log(n).

    The ultimate problem is not so much energy and resources. We are approaching peak output issues, but we can manage that. We should be able to recycle materials and transition to renewable energy sources. We can also power down some and we can shift to a different type of economy than the current hyper-consumerist system we have. Of course that will be difficult, and there are clearly resistances to anything of this sort, but it is possible, even workable. Indeed, I argue it will in the long run be desirable, for we humans have a proclivity to go crazy when given ever greater power — physical and political power alike. The ultimate problem is running out of environment. Issues such as global warming and other environmental problems point to some problem in the future where our life support system collapses out from under us. Curiously there is a growing upsurge in hydrogen sulfide producing bacteria in estuary and coastal ecosystems, and these are now known features with the Permian and KT extinctions. Chemical change in the environment is ongoing, and we may change things in ways which collapses the global ecosystem or mega-biome, we depend on. This could be an extinction period, maybe a mass extinction comparable to KT. The question is whether we will survive it.

    LC

13. Rising to the challenge of not “if” but “when” seems pretty straight forward in that we absolutely MUST find faster ways to get around our solar system to intercept and deal with possible collision hazards… Nip it in the BUD!

    I must applaud NASA’s recent industry seed funding for advanced rocket propulsion systems!

    Also of interest are the Russian nuclear powered rocket engine and/or a modified NERVA U.S. engine.

    And then there’s the possibility of using directed electromagnetic pulse generators to accelerate rocket engine exhaust plasma’s…

14. Lawrence B. Crowell:

    It does appear that our species is some sort of terminator species which is changing the characteristics of the biosphere, and increasing the entropy of the planet.

    You mean we’ll end up like this?

15. I agree, economics as we know it will have to be changed to something more efficient. Enconomics is like a pyramide scheme It stops when we reach the bottom.

    Recycling materials is a good option but not the way we recycle now. We actually need to develop bacteria or nanotechnology to extract the elements back. For example iron from rust, carbon from CO2. Interesting is that if we have bacteria that can extract carbon from CO2 we can use that as a source for carbon based materials. Cars could be built out of the harvested carbon instead of iron.

    The key element is very cheap energy. And I am not talking about wind mills and solar panels since they will also have an impact on the environment. I actually talk about generating very cheap energy the way we do not know yet. Nuclear fusion could be one possibility.

16. Nuclear fusion is the lofty goal. It might happen sometime this century. I do think there are huge gains with wind and solar energy. Graphene printed on a thin substrate, such as a silocone or plastic sheet, could provide solar energy at the cost of pennies per square meter of the stuff. Die based solar panels already cost a fraction of standard hard silicon cells.

    It is possible the Ponzi-pyramid scheme began over 5000 years ago. it might even be argued it started when our Australopithecine ancestors took themselves off the menu (throwing rocks at offending leopards etc) and began to put more on their menu some 3 million years ago.

    The question is whether we can figure out the foundations of the universe before the pyramid scheme implodes.

    LC

17. Hey, space enthusiasts, you should read again through your comments!

    I’m not completely serious, but … the first reason for the destinction of mankind will be *your* runaway negativism 😉

18. Surely the Interwebz will save us!

19. It’s a little bit worrying to think that we have the technology to create this and yet we’ve invested more money into sci-fi doomsday films than we have doomsday prevention. The odds of us getting hit by a Near Earth Object of doomsday calibre are slim at best in our life-time but let’s think about preventing those smaller chunks of rock and ice which like to hit us every 100 years or so, I for one wouldn’t want to see millions of people perish when prevention exists. Good luck searching for those Near Earth Objects it’ll one day save many, many lives. Astronomers ARE as important as doctors. Getting hit again is not a question of IF but more of when.

20. The whole universe is a thermodyamic system. BFD.

    Thermodynamic equillibrium isn’t a control of one thing, there are many things which must be controlled, (by definition, the Earth will never be in thermodynamic equillibrium) and whenever thermal dynamic equillibrium does occur it cannot be maintained over any great period of time… see the final law of thermodynamics (real entropy).
    ..and speaking of thermodynamic entropy… can we get a set activist definition; since every left wing crazy organization on this planet cannot agree on it, (dont give me the scientific def… I know it) and in my view really abuse the term, since it isn’t something I don’t think anyone can truly fathom

    Extinction is not the loss of genetic information/code… since we have been able to extract genetic information/code from extinct animals/plants.

    …can I get a DUH!?

    …for most everything else I agree with Torbjorn

21. As I mentioned above.. there’s stuff going on that is just below the surface that P. Obama is privy to and the GP is unaware. Check this out: http://nextbigfuture.com/2010/03/dense-plasma-focus-dpf-fusion-systems.html

22. Thanks for all comments… but do I detect a degree of impact denial?

    I found a old reference on the odds of dying here: http://www.livescience.com/environment/050106_odds_of_dying.html
    which puts death by asteroid somewhere between dog attack and fireworks – and about on par with tsunamis.

    I’m not sure if this analysis adequately deals with the chances of one big one killing the species – but it does show the calculated risk declines as surveillance improves.

    Cheers – S

23. I am not sure how one can estimate the probability of death by asteroid impact. So far there are no known casualties of such. So it is difficult to know how to get a Bayesian prior estimate. Tsunamis are somewhat computable. in 2004 250,000 people died in one, which is might be used to give a prior 3.85e-5. This is close to the Livescience probability. Evidently the joint probabilities are close to unity, or a P(A|B) ~ 1/2.

    LC

24. For someone who tosses out a lot of mathematical formulas, you don’t seem to know much about math itself.

    You don’t have to have a history of something happenening to figure out probability or risk.

    In fact, in many instances using history can throw off figures because people attempt to use common sense and/or experience instead of sticking to the numbers.

    For instance… I tossed a coin up into the air 9 times… all 9 times it came up heads. If I toss it up a 10th time, what are the odds it will come up tails? The answer… 50/50, 1:2, etc. Just as it was the first time the coin was tossed, the 3rd time it was tossed, the 4th time it was tossed…etc.

25. Ok.. math lessons aside. Can someone please explain to me how it’s possible to calculate the possibility of something happening without knowing something about the history or frequency of such events?

    At this point, I almost don’t care what you say… unless you consider the frequency of asteroids colliding with the earth then your numbers are not real… there might be math that gives you that number without that data but it’s more or less made up at that point isn’t it??

26. p.s. that wasn’t meant to sound condescending… just incredulous!! I have been looking into calculating probabilities and I still don’t see how you get away from making a WAG about an event at some point if you don’t know anything about it…

    I understand the coin toss example however it just seems to me as if the frequency can’t be 50/50 if you keep getting “Heads”. If you know the frequency is 50/50 how was this calculated without some knowledge of the events histories. The example is 100% “Heads” if taken on it’s own??

27. @ Aodhhan: For a simple system such as a coin toss elementary frequentist arguments may be applied. For more complex problems one can only use a Bayesian prior probability in the Bayes rule. The Bayesian prior is not the same as a simple coin toss set of probabilities one can compute in an elementary way.

    LC

28. I hadn’t known Aodhhan was a fan of the Russell Crow film “A Beautiful Mind” and John Nash’s ideas on game theory.

    Thanks for the maths lesson, little buddy!

29. Interesting LBC.
    So set up the Bayes rule calculation you would use for a 15km asteroid striking the Earth; using 63 as the number of near Earth asteroids which meet this condition, and lets say we know 8 similar asteroids have already struck Earth. Remember.. using Bayes, the goal is to solve for the form: P(Ak | B). Good luck.

    The thing is, Bayes uses conditional probability. Meaning, you must have a history. Although, this can be used to be accurate when you have a lot of events in a short amount of time. It isn’t so accurate when there are only a few events scattered over a long amount of time. Also, one or two events can really skew the results when you have fewer events. Its like taking the average of (3, 4, 6, 2, 77, 3, 91).

    SBC…go eat another pudding pop and sit down. It’s for individuals like you, that many educators use simple and well known examples….because eventually it may just sink in. 🙂

30. If you read further on up this is exactly my point. For a Bayesian prior you need data, or history if you call it that. We have a serious paucity of such with respect to computing the probability of death by asteroid impacts.

    LC

31. Aodhhan said;

    “For someone who tosses out a lot of mathematical formulas, you don’t seem to know much about math itself.”

    Kind of rude don’t you think, little buddy?

    Even if you have a point – why bother to listen?

    Very first thing about teaching is respect for others. Guess you must have missed your first class the, eh little buddy?

32. SBC… first of all.. you’re the one who chimed in with disrespect, and if this is the best you have… you’re just a waste of any educators time.

33. LBC…Why bring it up then? Especially if you can’t do anything but explain something beyond what someone can lookup.

34. I brought it up as a question about how the estimate about expectation of death by asteroid was arrived at. Maybe not everyone who reads here is familiar with Bayesian statistics.

    LC

35. @ Aodhhan
    You seem just a little more bitter lately.
    Needless attacks on others just shows your insecurities and makes you look like a bully.
    I did read Lawrence B. Crowell opinions, and I get his point. The ‘probability’ issues you and he raise and the maths behind it are frankly irrelevant and fairly trivial.
    It is a blog site and not some very formal scientific debate after all!

    You need to grow up a bit, methinks!

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