Sunday, November 24, 2013

Electric Comets: Failures of the Electric Comet Model

With the recent hubub over comets, provided by some Sun-grazers in the news (ISON, Pan-STARS, etc. NASA Comet ISON Observing Campaign) I realized that I did not really have any well-established write-up on the claims about comets made by Electric Universe (EU) supporters.  I discovered that I had actually addressed some of these claims a number of times, but always as a part of other claims.  So I thought I'd take a quick break from my winter hiatus to assemble some of these into a single post.

Recently, a reader pointed me to some claims being made by the ThunderBolts project in some of their YouTube videos.  Most of them are recycled old stuff that keeps getting repeated on a variety of forums.

Periodically, the Electric Universe supporters repeat their claims that comets, like the stars, glow predominantly due to a cathode discharge-type interaction with the Sun.  They seem to tie this claim back to some work by Kristian Birkeland but the notion predates Birkeland, and was explored by mainstream astronomers in the late 1800s and early 1900s when electromagnetism was placed on a unified mathematical foundation by Maxwell's Equations and was still the new and exciting force in physics.

Let's collect and update the responses to some of these claims from some earlier posts:
Many of the 'Electric comet' claims are being repeated all over the web, with very little critical examination.  Here I'll just examine a few.

EU Claim: The evidence suggests that comets are highly negatively charged with respect to the Sun. As they rush toward the Sun, the voltage increases until at some point the comet nucleus begins to discharge. Electrons are stripped from a few points on the comet surface where the electric field is strongest. These “spark discharges” finely machine rocky material from the surface to form a “cathode jet” of negatively charged dust together with surface matter that has been torn apart to release ionized atoms and molecules, including oxygen.  
Prediction #3: Electric Comets and the "Domino Effect"

Laboratory cathodes and anodes form part of a complete circuit.  Where is the return circuit between the Sun and the comet?  If we see the comet, why don't we see the return path of the particles?  In the lab, the return circuit corresponds to the wires connecting the discharge tube to the power source.  And just where is the battery or generator that keeps the system energized?  To maintain the potential between the Sun and the comet, the return circuit would have to be isolated or insulated as it is in a laboratory environments.  Otherwise the comet would quickly 'discharge' and stop glowing.

But even without a solar-system scale voltage, charged particle interactions can take place at the boundary of the comet material moving out and the solar wind moving in.  Orbiting spacecraft experience a range of interactions, from ultraviolet solar photons liberating charges from the satellite metal components (photoelectric effect) to charge redistribution on the spacecraft as an otherwise neutral plasma flows around the satellite and the electrons can diffuse more quickly into the wake behind the satellite, generating a small charge separation. 

This boundary interaction, similar to the Earth's magnetosphere and the heliospheric termination shock, is common when two different flows meet.  Even electrically neutral flows such as the wake of ships moving through water, or aircraft moving through the air, can form these boundary layers where more complex interactions can take place.

EU Claim: While moving between the orbits of Saturn and Uranus (14 times farther from the Sun than the Earth), Comet Halley experienced an outburst between the orbits of Saturn and Uranus that caused dust to stretch over some 300,000 km. At that distance from the Sun, the surface should be in deep freeze at –200 degrees C.  
Prediction #3: Electric Comets and the "Domino Effect"

Again, EU 'theorists' demonstrate incredible misunderstandings in thermodynamics and chemistry.  Strange oversight for a group that claims to be 'interdisciplinary'.

This is hardly a problem for the standard comet model where comets have large amounts of carbon dioxide.

Melting and boiling points are different in the low pressure of space. 

Most people are familiar with the fact that water boils at lower temperature at higher altitudes.  The lower the the pressure exterior to a surface, the easier it is for atoms to 'boil off' of the surface, creating a vapor around the object.  Many sensitive instruments launched into space must be allowed to 'outgas' for a time as volatiles trapped in metals and plastics under atmospheric pressure where the satellite was built will begin to escape from surfaces exposed to vacuum.   The lower the pressure, the lower the boiling point, for CO2.

While at atmospheric pressure, CO2 sublimates at -78.2C.  Drop the pressure and the sublimation point drops even further.  At about 1/760 atmospheric pressure, the sublimation point drops to -134.3C (Wikipedia: Carbon dioxide data page).  For those unfamiliar with chemistry, the boiling or sublimation point is defined as the temperature where the vapor pressure is equal to the ambient pressure.

In addition, the temperature at the surface of the comet is going to be WARMER than the cloud-tops of planets at the same distance due to the reflectivity of the comet nucleus.

Planets, whose atmospheres are more reflective (30% or higher), will have a lower cloud-top temperature than a comet nucleus at the same distance which has a much lower reflectivity (about 3%), and therefore absorbs more of the radiant heat it receives.  The temperature of the surface of a comet in sunlight will be higher than the cloud-tops of a more reflective planet at same distance.  Got a layer of snow on your asphalt driveway? Watch how fast it melts around the regions of exposed asphalt when the sun comes out compared to areas completely covered with snow.

EU Claim: "Their surfaces display sharp relief, not what one would expect from melting ice, " On Gravity-centric Cosmology and the Implications of a Universe Awash with Plasma
Section 2.11: Comets as dirty snowballs
by David B. Smith

Even years after the earlier claim noted above, EU theorists don't understand chemistry or thermodynamics.  Has Mr. Smith never observed melting snow and shapes that form due to non-uniform heating, melting and refreezing?  Perhaps Mr. Smith has only observed ice melting in his glass of tea?

I shoveled plenty of dirty snow for Snowmageddon & Snowpocalypse (wikipedia) and observed the many odd shapes formed as it melted and refroze with the day-night cycle.  It's funny that EU 'theorists' could convince others that this was a valid argument when there is so much real world experience with why they are wrong.   To paraphrase Sherlock Holmes to Watson: You have SEEN snow, but you have not OBSERVED snow. (Wikipedia: A Scandal in Bohemia)

The ambiguity between comets & asteroids has been known before Thornhill & Talbott
    •    Evolution of Comets Into Asteroids? (1971)
    •    Do comets evolve into asteroids - Evidence from physical studies (1982)
Some of these papers point out even earlier sources.

EU Claim: A direct confirmation of the electric connection came unwittingly from the Chandra X-ray Observatory on July 14, 2000.  At that time, the Chandra telescope viewed the comet Linear repeatedly over a 2-hour period, detecting unexpected X-rays from oxygen and nitrogen ions in the coma of the comet. The capture of electrons from the negatively charged comet by positively charged hydrogen ions in the solar wind is, of course, nothing else than an electric discharge, nature’s highly efficient means of X-ray production.  Prediction #3: Electric Comets and the "Domino Effect"

All of these recombination process happen due to relative motions of atoms, electrons and ions, regardless of how the particles are accelerated.  They are in no way evidences for any solar-system scale giant voltage drops of a million volts or more across planetary distances.

Electric Universe supporters now rely on a very ambiguous use of term 'discharge'.  EU basically wants to call anything that involves the motion of charges as a 'discharge', a definition so broad as to be technically useless.  If moving charges is all that is required, chemical reactions, which alter electron orbital configurations, could also be called a 'discharge' process.

In spite of EU claims of 'success' for their model, it still seems to take an non-EU person to figure out which specific process.  Here's the atomic process that move electrons around that professional astronomers, and REAL plasma physicists, must be familiar with: 
I suppose since alpha and beta decay as well as many nuclear reactions involve emission and absorption of charged particles, Electric Universe supporters can call that a 'discharge' as well!  Perhaps they'll quietly start calling nuclear reactions in the cores of stars as discharge processes and use that to claim the sun is electrically-powered!

EU Claim:  "that there would be a double 'flash' consisting of a powerful electric discharge event prior to a very large impact event which would be more explosive than expected, and that radio communication would be interrupted." 
Section 2.11: Comets as dirty snowballs
by David B. Smith

I've yet to find the original reference of the double flash before the impact AND a radio interruption with this impact event.  The only place I can find this is on Electric Universe sites.

Let's see, the spacecraft cameras saw the comet nucleus clearly.  The comet nucleus reflects only about 3-4% of the light falling on it, about as dark as a lump of charcoal, and it is being observed against a dark sky slightly brighter due to reflection from the cometary dust material.  So it's pretty clear that the camera was adjusted for low-light conditions, much like night-vision goggles.  Under those conditions, highly reflective material ejected from the impact point will be really bright, probably more than enough to saturate the camera.  Of course it was bright.

Any electrical arc sufficient to light up the region between the comet and spacecraft would have been more than enough to fry the spacecraft electronics, probably with no chance of recovery. 

But we have measured electric fields in the solar wind and in the vicinity of comets.  Solar wind models combined with spacecraft models enable satellite designers to estimate spacecraft charging as they move through plasmas.  Because discharges can kill the satellite electronics, knowledge of these conditions is vital to success of the missions.

Consider these values from the Giacobini-Zinner encounter, which measured +1 volts near the comet vs. +6 volts in the solar wind.  This was LOWER than the expected +10 volts (Dynamic PIC-simulations of charging phenomena related to the ice-spacecraft in both cometary and solar wind environments).  Considering these are voltages on the scale of batteries you can buy at the corner market, how could this be a "powerful electric discharge"?

After the impact of the probe with the comet nucleus, only a relatively weak x-ray enhancement was detected, so this also makes claims the impact produced an electric discharge as suspect.  The additional X-ray emissions were delayed and consistent with charge exchange between the solar wind and outgassed simple molecules.
    •    Chandra observations of Comet 9P/Tempel 1 during the Deep Impact campaign
    •    Swift X-Ray Telescope Observations of the Deep Impact Collision

Here's some additional summaries of what was learned in these comet flybys and impactors.  From NASA: Deep Impact (EPOXI):
  1. First determination that a comet's surface layer (few to 10 meters or so) is very porous (greater than 75 percent empty space)
  2. First direct evidence showing chemical diversity of outgassing associated with different parts of the cometary nucleus
  3. Discovered that hyperactive comets (5-10 percent of all comets) are driven by carbon dioxide and that the observed excess water is from icy grains in the coma. The processes of hyperactive comets are very different from those in normal comets.
or  NASA Epoxi: Encounter with Comet Hartley 2:
"NASA's EPOXI mission found that Comet Hartley 2 is a hyperactive little comet, spewing out more water than most other comets its size."
So lots of CO2 and water found in comets, still in line with the standard model of these objects.
EU Claim: "A forbidden oxygen line was discovered in Comet Austin’s coma. “Forbidden lines” are spectral signatures that are not expected in space because here on Earth they are found only within strong electric fields." -- Wal Thornhill.
Comet Wild 2, January 6, 2004.

Where did Thornhill get bizarre mis-understanding about forbidden lines? 

Forbidden lines are created by metastable states in the atom, which have a lifetime much longer than the regular atomic states.  Under normal circumstances, these states get de-excited by collisions with other atoms before they have a chance to radiate a photon.  However, under extremely low pressures, the states will not be de-excited by collisions and will de-excite by emitting a photon at a frequency correspond to the 'forbidden line'.  Electric fields may be in the environment, but they are not required to form forbidden lines.

I suspect Thornhill may be confusing forbidden lines (Wikipedia) with the Stark Effect (Wikipedia) which also has a long history in astronomy.

In spite of repeated claims by Electric Universe supporters to the contrary, the "Dirty Snowball" comet model has been refined, with better details on the composition and structure, but it is far from dead.

Meanwhile Electric Universe supporters continue to echo their support for their model that has a radically different particle and field arrangement for this part of the solar system, while they have yet to provide any model that allows us to to make useful estimates of these quantities.  This modeling capability is vital for the safety of satellites and astronauts (see Challenges for Electric Universe 'Theorists'). 

Yet the standard model, which lacks the million-or more voltages claimed by the Electric Sun advocates, seems to do quite well for protecting our satellites and we continue to explore around the solar system using it (see ADS: An advanced physical model of cometary activity).

So Electric Universe claims continue to be completely useless for doing real spaceflight...

Sunday, November 3, 2013

Winter Hiatus - November-December 2013

It's that time of year again...

When holiday activities start impacting my available free time for writing and research needed to keep new topics for this blog.

I regard my best accomplishment of the past year to be the completion of the 'discordant redshifts' series.
Heavy research on this topic started during my hiatus last year when I found a copy of Arp's book at my favorite technical library.
Discordant redshift claims was one of the topics which I started exploring back when I first started actively examining pseudo-science issues in the late 1990s.  I'm glad I was finally able to complete this.

On Deck...

I'm registered to attend and present at the 223rd Meeting of the American Astronomical Society.  Part of my hiatus will be preparing this poster.

I've done load of reading as well as a number of mathematical demonstrations and plan to start the write-ups for this blog.