Physics Shows Instability in Antarctic Ice Shelf

Fig.1: Locations affected in West Antarctica and Wilkes Basin (from Physics Today)  Physics of melting and onset of shelf instability shown below:


One of the constant points of issue in the nonsensical climate change debate (which shouldn't exist at all) is the extent of melting and instability in the Antarctic. As I noted in previous blogs, the take by the denialists is usually off because they don't grasp the processes at work. See e.g.

http://brane-space.blogspot.com/2012/09/brainiac-goops-screw-it-up-again-on.html

Now, new research shows that West Antarctica's unstoppable ice shelf collapse has likely begun. (Physics Today, July, p. 10). First, a team led by Eric Rignot at UC-Irvine and NASA have documented accelerated glacial retreat in the red-shaded region of Fig. 1.. Most importantly, the researchers point out the lack of any geological features (e.g. bedrock 'bumps')  that might re-stabilize the ice. (One computer model shows a full scale collapse is likely to occur over the next several centuries, if not sooner.)

Meanwhile, a team led by Matthias Mengel and Anders Levermann at the Potsdam Institute for Climate Impact Research in Germany have shown that the larger, thicker ice sheet of East Antarctica may not be as stable as previously thought. They found that the region shaded in yellow (Fig. 1) is held in place by only a small volume of coastal ice that eventually could melt. Such loss would have catastrophic consequences for global sea level rise.

The fragility of the West Antarctic ice shelf can be traced to several factors which physics can shed light upon. These are illustrated in Fig. 2. First, as shown, the ice rests on a bed that lies below sea level. Second, note that the bed slopes backward, actually falling deeper below sea level farther inland. It is this confluence of conditions that gives rise to marine ice-sheet instability since currents of warmer water eat away at the ice from below. When the 'grounding line' (see Fig. 2) gets pushed back by warmer-than-usual water then the rate of melt discharge increases and the glacier retreats further.

Rignot and colleagues used 20 years of interferometric synthetic aperture radar (Insar) data to track the retreat of grounding lines in 4 West Antarctic glaciers, including the two shown in Fig. 1. Their data showed that for these two areas the grounding lines had retreated between 10 and 35 km over the 20 year time and the rates are now speeding up.

What if there was a total collapse of both ice sheets - for Western and Eastern Antarctica? How large would the effects be, respectively? In the first case, there is enough ice mass to raise sea levels by about 3m or 9.9 feet. In the second case, there is enough ice to raise sea levels by more than 50 m or 165 feet. Thus, in such an event most of the planet's lower lying regions would be under water, including Florida. While you wouldn't have the extreme phase depicted in 'Waterworld' you would have a world with a lot more land claimed by water - perhaps 40 percent more. The Earth's image from space would appear radically different from what we see now.

How precise are the models being used? As with most climate change modeling, or modeling any complex systems, there's always a tradeoff between the scope (or scale) and accuracy. If I increase my model's scope, say using data beyond the resolution level of instruments to detect solar granulation, then I lose accuracy in the process. 

For example, very early in his Ph.D. dissertation (p. 17), Jason Lisle concedes an inability to properly resolve granules via his MDI (Michelson Doppler Imaging) data, though he does make an appeal to local correlation tracking (LCT) as a kind of savior since it allows motions to be deduced from the images even when individual moving elements aren't well resolved. The question that arises, of course, is whether the product of such LCT manipulation is real, or to put it another way, an objective physical feature that is not associated with instrumental effects, distortions or errors.

Exacerbating this suspicion is Lisle's own admission (ibid.) that LCT "suffers from a number of artifacts".   Thus, the question emerged of whether Lisle really had enough signal to ascertain a "persistent N-S alignment" in solar supergranules,  taken as exhibiting a fundamental polarity preference.

In the case of the Antarctic glacier modeling, the researchers were faced with a choice of representing a glacier's flow along a single line, or simulating a whole ice sheet using a coarse-grained model. In the end, they used something in between, a "regional scale model that covered an entire basin but not the full ice sheet" according to one of the researchers. Of course, it definitely helps if one can use a construct or entity pertinent to some "midway" position that actually exists!

In the end, the constellation of models shows the Antarctic ice sheets, both for the Eastern and Western sectors, are under severe and constant stress from climate change-global warming. The portents and predictions are far from sanguine but meanwhile too many human politicos fiddle while the glaciers and ice sheets melt.

Sadly, it is our future generations that will have to pay the price.

See also:
http://www.salon.com/2014/08/06/climate_scientist_drops_the_f_bomb_after_startling_arctic_discovery/

Once Again: Jason Lisle is NO Astrophysicist

Pseudo-scientist Jason Lisle: His groupies still believe he's an "astrophysicist" - so cite him often to bolster their Biblical bollocks, 'creation science' and other baloney.

Let's clear the air once more that Jason Lisle, despite his attempted "resurrection"  by some deluded fundies, is NO astrophysicist. One cannot be an astrophysicist if he doesn't adhere to basic principles of astrophysics!  One really has to wonder what intellectually deformed sort of nitwit – who calls himself an “astrophysicist”- can forego all the major postulates and principles (NOT beliefs!) of physics and astrophysics and subscribe to patently obvious bunkum like a young Earth, "young Sun" or young cosmos.

In the case of Jason Lisle, he's reputed to be an astrophysicist based on one Ph.D. doctoral thesis in which – perhaps for the first time in his academic life - he came close to doing real science. But even that had numerous holes, e.g. http://brane-space.blogspot.com/2011/06/why-jason-lisle-is-wrong-in-his-solar.html                         

And: 

http://brane-space.blogspot.com/2011/07/jason-lisle-astrophysicist-dont-make-me.html
and  http://brane-space.blogspot.com/2011/07/jason-lisle-faux-astrophysicist.html


Among the powerful arguments I made to show Lisle’s young Earth-young Sun etc. claims are bollocks (and automatically disqualify him from being any "real astrophysicist") is the fact he  rejects nuclear fusion in the Sun as the primary energy source.  Any first year astrophysics student knows that given accepted-known  nuclear fusion reactions the time taken to steer a spectral class G star through the Main Sequence- goes on for millions of years. Thus Lisle adheres to nonsense (for a thousands of years old Sun)  that NO REAL astrophysicist would hold! For example, Lisle in one dvd on “The Young Sun” attempts to convince gullible fundies and other viewers that he can show the Sun is “young” so fits in with the Genesis fairy tale that the Sun can be no more than 6,000 years old (since in Genesis the Earth was made before the Sun, an impossibility anyway as I’ve shown in a number of blogs).

Lisle's claim, supposedly made by a "real" (sic) astrophysicist, is absolutely astounding in context (especially for a "Ph.D.") - given that it stands all of stellar evolution, astrophysics and thermodynamics, statistical mechanics on its head, especially nuclear fusion: the basis for the Sun's energy! These are things EVERY budding astrophysicist is taught in his first graduate course in stellar astrophysics or stellar evolution. Thus, there are differing nuclear cross sections for differing fusion reactions and also differing time scales.

More to the point, the same arguments that torpedo Lisle’s claims for a young Earth, young Sun also torpedo D. Russell Humphreys' (another make believe "astrophysicist), e.g.



 for a young Earth and young cosmos. The reason? To embrace such codswallop would require rejecting most of modern stellar physics predicated on nuclear fusion. A key quantity in obtaining these time scales is the energy liberated per (nuclear fusion) chain defined as:

W(r) = rE, or W = (rE)/ r


which is in ergs/gram for example. (I.e. the total ergs of stellar energy given off per gram of stellar matter available for reaction.)

 

E is found from specific nuclear fusion reactions, such as p + p -> D2 +e(+) +v, where two protons fuse to yield deuterium, a positron and a neutrino(v). The key quantity is r, defined as the reactions/cm³. Obviously, the greater this value the shorter the energy generation time scale and the smaller the value the longer it will take. It is defined (see, e.g. Astrophysical Concepts, p. 331), by Martin Harwitt:
 

r = B (r)²  X1X2/ T^1.5 * exp^-3[2π^4e^4mH (Z1²)(Z2²)A'/ h^2kT]^1/3

 

where B is a proportionality constant, r is the density, h is Planck's constant (e.g. h = 6.62 x 10^-27  erg-sec), k is Boltzmann's constant = 1.38 x 10^-16 erg/K), T is absolute temperature of the reaction, i.e. in K deg, and X1 and X2 are the concentrations associated with atomic numbers Z1, Z2 while A' is the reduced atomic mass, i.e. A' = (A1 A2)/ (A1 + A2).

 Then working out 'r' for the proton-proton fusion cycle one can (after a lot of work) obtain the time scales for each chain part and the energy yielded for each, viz. (cf. Harwit, op. cit., p. 336):


p + p -> D2 +e(+) +v (1.44 MeV, Time = 14 x 10⁹   yrs.)

 

D2 + p -> He3 + y(gamma ray) [5.49 MeV, time = 6 secs)

He3 + He3 -> He4 + 2H1 [12.85 MeV, Time - 6 million years]

 

Note that the last branch of the cycle already takes 6 million years, i.e. for each fusion to furnish 12.85 Mev (millions of electron volts of energy, were 1 eV = 1.6 x 10^-19   J). Thus, this cycle alone takes almost 1,000 times longer than Lisle's time of 6,000 years, as the supposed maximum age of the Sun.
 

The only mildly problematical time frame in the p-p cycle is for the initial fusion, which yields 14 billion years or about three times the age of the current Sun. Thus, at face value, this translates into only about one fusion every 14 billion years for the first branch of the proton-proton reaction. While that is extremely long, the Sun fortunately has a vast number of protons available in its core, so that – at a temperature of 10 million Celsius, enough can fuse to initiate helium production and energy given off. Moreover, the key "catalyst" speeding the reaction time up is the phenomenon of "quantum tunneling" whereby a lower energy particle can surmount a higher energy barrier (what we call the "Coulomb barrier") by virtue of its wave-like properties.
 

To fix ideas, let us say a particle (say proton) of kinetic energy K, must overcome a barrier of energy V ("barrier potential"), via the process of "tunnelling". Consider a deBroglie wave of wavelength l_D =  h/p  or l_D =  h/ mv  where l_D is the de Broglie wavelength) arising from (p+) of form: U(x) ~ sin(kx) where x is the linear dimension along displacement and k, the wave number vector (k= 2π/ l_D).

 

 

Now, though the associated energy K < V (the barrier "height"), the wavefunction is non-zero within the barrier, e.g.

U(x_b)~ exp(-cx)

So, sketching axes for this:

E
!
!---------V------
!   *p
!
!
!------!-------------> x

 

with the potential (Coulomb) "barrier" at height V, for which we visualize the particle p(*) on the left side having "tunneled" over to the right side where it may have wave function, U(x) ~sin (kx + φ), where φ denotes a phase angle.  Note that if the barrier is not too much higher than the incident energy, and if the mass is small, then tunneling is significant.

Note also that the penetration of the barrier is a direct result of the wave nature of matter! In effect, this wave nature - which is uniquely quantum mechanical in origin- allows a higher energy barrier to be penetrated by a lower energy particle, something totally without parallel in classical, Newtonian physics.

In other words, without the benefit of quantum tunneling, the first reaction time in the p-p cycle would be inordinately long and have to be disallowed as unphysical.
 

Beyond this we know the photon diffusion time (the time to make it from the edge of the solar core to the Sun's surface or photosphere) is calculated to be nearly 1 million years. This takes into account all the changed random directions the released photons undergo as a result of absorption and re-emission by particles along the way out. No core photon makes it directly through, but instead undergoes millions of interactions en route resulting in collisions. Again, 1 million years for a photon's diffusion time belies Lisle's young Sun argument! It also belies Humphreys' own young Earth- young cosmos claims. (Since even the brightest O and B spectral class stars have lifetimes on the Main Sequence, much longer than this photon diffusion time)
 

In the case of  Jason Lisle, here’s another conundrum for his assorted worshippers to ponder: Lisle himself contradicts his 'Young Sun' assertion in his Ph.D.! (Introduction). Therein he concedes to the above dynamics for nuclear fusion occurring in the Sun! So one is forced to ask if he really believes that or if he LIED in his dissertation? If he lied then his Ph.D. isn’t worth an ounce of doggie lickspittle I don’t care which institution awarded it.

 

Let’s now return to Humphreys.  Let us grant, according to assorted online Wiki entries, that he is a physicist at the Institute for Creation Research (ICR), like Duane Gish. He is best known for his creationist views and his attempts to reconcile reality with the notions of young Earth creationism. As in the case of Lisle  before him, this reconciliation process entails standing long confirmed physics and astrophysics on its head, and dreaming up improbable assumptions to make the reconciliation work.  It would be roughly analogous to me using an array of misplaced physics and whacky assumptions to show an elephant could be suspended from a string and the spring’s tension would support it.

While one of Humphreys favorite sayings (cited on many fundie blogs)  is evidently that scientists –astrophysicists don’t have their own evidence but just  “believe what other scientists believe” we must take care to point out he is certainly not in the same league as many pseudoscientists.  Indeed, he appears to have far more truly scientific distinctions than Lisle.   For example, his biography at Creation Ministries International lists many commendable achievements and awards, but none of his awards appear related to his young Earth-cosmos research.

This shows two things: 1) The discontinuity in awards discloses the actual scientific establishment places no value on creationism or any of its offshoot “theories” including young cosmos, and 2) Though Humphreys cites these mainstream awards for his ICR bona fides, he technically rejects their basis since he rejects the science behind them!

This is important to note because it elicits the question of why he’d cite any mainstream awards at all. If it is to show his professional scientific acumen or capabilities then it’s mostly useless because by embracing young Earth, young cosmos bollocks he’s squandered all his scientific capital. So the awards only show a once prominent physicist who has now “gone off the rails” and in many ways has lost all credibility. In many respects this parallels what happened to the once great Nobel-winning chemist Linus Pauling who tried to parlay his many scientific awards into credibility for his whackadoodle megadose vitamin C conjectures. It didn’t work. People saw through it and concluded that a once great scientist had either become senile or that he betrayed his background to enter a fringe field.

Sadly, both Jason Lisle and  D. Russell Humphreys will continue to attract their respective, assorted acolytes and groupies - mainly anti-science fundagelicals - because the Bible isn't enough for the backward, uneducated  fundie  populace to confer gravitas on their religious bunkum. No, they all (or mostly) understand they need the patina of science - or at least scientific -sounding names, terms,  jabberwocky etc. to confer some scintilla of objective authority on their bollocks beliefs. Because that is what they are. Pure belies, based on no evidence, and no repeatable observations.

As I've noted many times before, the biggest indicator that what they're doing isn't science is the absence of any falsification tests. That is, testing their hypotheses, i.e. Young Sun, with the aim to falsify it. This is totally beyond them, but until they do it - as opposed to invoking the backward baggage of cherry-picked pseudo-scientists, they simply confirm they are all about promoting religious beliefs - not any scientific theories.