Neil F. Comins

University of Maine | UM · Department of Physics and Astronomy

Students come into our classrooms with many misconceptions about science in general and astronomy in particular (see numerous papers and references in Novak, 1993 and Pfundt & Duit 1993). These beliefs evolve from a variety of sources throughout childhood and adolescence (Comins, 1993a, 1993b, 1995). I have found that directly addressing these inco...

With the help of surveys and statistics, we tried to optimize the order in which we presented astronomy concepts. But students persisted in retaining wrong ideas about them.

This article reviews In Search of the True Universe: The Tools, Shaping, and Cost of Cosmological Thought. by Martin Harwit 410 pp. , 2013. Price $50 (hardcover) ISBN 978-1-107-04406-7.

The new edition captures the current state of our understanding of the cosmos, with new findings, new study help, and an expanded new media/supplements package centered on W.H. Freeman’s breakthrough online course space, LaunchPad.

Discovering the Universe confronts the challenges of the one-term astronomy course by heightening student curiosities about the cosmos, by using the context of astronomy to teach the process of science, and by highlighting common misconceptions and showing students how to think their way past them.With its signature combination of vivid writing and...

We investigate the effects an interacting galaxy, the 'intruder', has on the shape of a disk galaxy with the aim of determining the cause of integral shaped warps in the disk. Using N-body simulations, we investigate the ways in which an intruder causes a spiral galaxy to warp as a function of the angle of passage, relative speed, relative masses,...

Magnetic fields are pervasive and complex features of many stars. There are many gaps in our understanding of how stellar dynamos operate and how various stellar magnetic features relate to each other. In order to explore these issues, we are in the process of developing a 3D computer code that simulates the convection zone in partially convective...

The aim of this study is to develop a mathematical description of the perceived colors of stars as viewed from the surface of the Earth across a wide range of possible atmospheric conditions. These results are then to be compared to the colors of the stars as seen in space. In this paper we focus on the apparent color of the Sun as viewed from Eart...

My (Andrej Favia) Ph.D. thesis involves quantifying the "difficulty" of unlearning common astronomy misconceptions. I do this by applying factor analysis and Item Response Theory (IRT) to a retrospective inventory of when, or if, college students dispelled the misconceptions under consideration. Our inventory covers 235 misconceptions identified ov...

This is the first in a series of papers that analyze college student beliefs in realms where common astronomy misconceptions are prevalent. Data was collected through administration of an inventory distributed at the end of an introductory college astronomy course. In this paper, we present the basic mathematics of item response theory (IRT), and t...

Discovering the Essential Universe, Fifth Edition is one of the briefest texts available for the introductory astronomy course, while still providing the wide range of factual topics that are the hallmark of the text and are consistent with most course needs. Discovering the Essential Universe provides up-to-date explanations of core concepts in a...

In this first paper of a series on the formation and abundance of substellar mass dwarf black holes (DBHs), we present a heuristic for deducing the stability of non-rotating matter embedded in a medium against collapse and the formation of a black hole. We demonstrate the heuristic's accuracy for a family of spherical mass distributions whose stabi...

Discovering the Universe is the bestselling brief text for descriptive one-term astronomy courses (especially those with no mathematics prerequisites). Carried along by the book's vibrant main theme, "the process of scientific discovery," the Ninth Edition furthers the book’s legacy for presenting concepts clearly and accurately while providing all...

While most disk galaxies are observed to be warped, the mechanisms for the warping are not well understood. We explore warping caused by gravitational perturbations created by the passage of a distant galaxy (the 'intruder'). We propose that the intruder's effect on the disk galaxy can be explained in terms of pseudoforces that occur while the two...

“What if?” questions have always stimulated people to think in new ways. What if the Earth Had Two Moons leads us on a fascinating 10 world journey exploring what the Earth would be like if conditions in the universe were slightly different. The answer: Earth would be different, often in ways that would surprise us. The title chapter, for example,...

Students harbor misconceptions (deep-seated incorrect beliefs) about our astronomical environment. While some of these beliefs have their origins in faulty reasoning, many others come from external sources, including from teachers and even professional scientists believing and sharing misconceptions, and from media sources. I will relate a horror s...

Motivated by observations of disk galaxies with counterrotating stars, we have run two-dimensional, collisionless N-body simulations of disk galaxies with significant counterrotating components. For all our simulations the initial value of Toomre's stability parameter was Q = 1.1. The percentage of counterrotating particles ranges from 25% to 50%....

"Discovering the Essential Universe, Fourth Edition" (DEU 4e) is designed to help students overcome common misconceptions about astronomy. It provides up-to-date explanations of core concepts in a flexible and student-friendly text, supported by an impressive collection of multimedia resources developed by astronomy education researchers.

In summary, development and testing of a combined hydrodynamic and N-body code are now underway. The work here at Maine is necessarily on a small grid because of the limitations of the computers available. It is already clear that physically meaningful results will require much finer grids, more N-body particles (250,000 vs 5,000 now), faster throu...

Now renowned physicist and astronomer Neil F. Comins, Ph.D., has written a hands-on guide to outer space for potential tourists and armchair travelers. Bringing to life the hard science are the fictional log entries of an imaginary colleague from the future, astronaut Mack Richardson. Together they reveal the risks and challenges that await tourist...

The astronomy laboratory course at the University of Maine consists of weekly lessons in which students work in small groups on computer-based exercises. In this presentation, we discuss research involving a lesson on astronomical time-keeping, including sidereal time, Apparent Solar Time, and time zones. Four multiple-choice questions are administ...

Based on the most recent edition of Discovering the Universe (©2006), this text is the most concise, option for introductory astronomy courses.

Discovering the Universe is the bestselling brief text for descriptive one-term astronomy courses (especially those with no mathematics prerequisites).

http://digitalcommons.library.umaine.edu/fac_monographs/1177/thumbnail.jpg

Discovering the Universe is the best-selling brief text for descriptive one-term astronomy courses (especially those with no mathematics prerequisites). Carried along by the book's vibrant main theme--the process of scientific discovery--readers will encounter spectacular sights, landmark experiments, and recent discoveries, while learning to avoid...

This is an excerpt from Neil F. Comins' book titled Heavenly Errors. The author describes some common misconceptions about astronomy, many of which pertain to objects in our solar system. Evidence from recent space missions dispels the mistakes. The author is a professor of physics and astronomy at the University of Maine.

Discovering the Universe is the best-selling brief text for descriptive one-term astronomy courses (especially those with no mathematics prerequisites). Carried along by the book's vibrant main theme--the process of scientific discovery--readers will encounter spectacular sights, landmark experiments, and recent discoveries, while learning to avoid...

Black holes won't swallow Earth and they don't suck in everything for light-years around, but these misconceptions seem dull when compared with reality.

One of the great paradoxes of modern times is that the more scientists understand the natural world, the more we discover that our everyday beliefs about it are wrong. Astronomy, in particular, is one of the most misunderstood scientific disciplines. With the participation of thousands of undergraduate students, Neil F. Comins has identified and cl...

Nearly all elements essential for life were forged in the nuclear furnaces at the centers of stars and then scattered into interstellar space.

http://digitalcommons.library.umaine.edu/fac_monographs/1176/thumbnail.jpg

Students come into astronomy courses or courses with astronomy content believing a significant number of incorrect ideas about the cosmos. Without our addressing these beliefs, it is extremely difficult for students to permanently replace them with accurate information. In this paper I report on the impact of forcing students to address on paper th...

Observations of lopsided spiral galaxies motivated us to explore whether the rapid passage of a companion galaxy could cause them. We examine whether the center of mass of the visible matter becomes displaced from the center of mass of the dark halo during the intruder's passage, thereby causing an asymmetric response and asymmetric structure. Two...

Observations of lopsided spiral galaxies motivate us to study possible causes and several effects of such asymmetry using an N-body simulation. Our test galaxy particles are free to move while embedded in a fixed halo. The causal agent we explore is the rapid passage of a companion galaxy. We find that the center of mass of the disk becomes offset...

The deep seated nature of misconceptions often requires drastic measures if they are to be successfully replaced. In this paper I report on the effects of asking misconception-based questions in an introductory astronomy class and encouraging students to answer them in writing. The questions are used to verify student attendance. Students are requi...

The author treats the forming and decay of planetary rings, with images of Saturn's and Uranus' rings.

How can what-if questions become a catalyst for scientific discovery in the classroom? The author presents a sample scenario, some typical student responses, and a scientific analysis.

The development of massively parallel supercomputers provides a unique opportunity to advance the state of the art inN-body simulations. TheseN-body codes are of great importance for simulations in stellar dynamics and plasma physics. For systems with long-range forces, such as gravity or electromagnetic forces, it is important to increase the numb...

We have constructed N-body particle-mesh simulations of disk galaxies in which the relaxation times of the simulated disks (as measured by thermalization of the disk, i.e. increase in Toomre's Q parameter) is comparable to the actual relaxation time scale in actual disk galaxies (several tens of rotation periods). These simulations require 1M to 4M...

Starting in early childhood, everyone acquires ideas about astronomy that are incorrect. By the time students enter introductory astronomy courses in college, they often harbor hundreds of such misconceptions. Over the past three years I have been meeting with small groups of students who are taking introductory astronomy at the University of Maine...

We are continuing to develop multi-component simulations of disk galaxies. The present paper reports on the dynamics that occur in a two-dimensional, N-body system in which stars and giant molecular clouds are treated as collision-less and inelastically colliding particles, respectively. We present a systematic survey of the effects of the followin...

The development of massively parallel supercomputers provides a unique opportunity to advance the state of the art in N-body galaxy simulations. For systems with long range forces it is important to increase the number of particles to N >= 10(7) particles. Increasing the number of particles reduces the sensitivity to random fluctuations, which incr...

Although two dimensional N-body simulations of disk galaxies have been done for over thirty years, we feel that the interactions between various free parameters deserve further study. As a preliminary step in validating a computer code with collisionless particles representing star clusters, colliding particles representing giant molecular clouds,...

If intelligent life on Earth took 9 billion years to evolve, this life would see a larger Sun, a smaller Moon, and a more slowly expanding universe.

If Earth contained fewer metals, its gravity and magnetic field would be weaker and aurorae would grace the sky almost nightly.

Ocean tides, day and night, and the cycle of the seasons would be drastically different if Earth's rotation axis pointed along its orbit.

The distinctive system 3C 442, a source associated with two galaxies, NGC 7236/7237, is investigated with VLA at 6, 20, and 90 cm. The image of the radio source shows a mass of filaments and diffuse emission surrounding the two galaxies. The properties of this source are similar to a few other well-studied systems, all of which are associated with...

Star-formation activity is studied in three-dimensional stochastic self-propagating star formation (SSPSF) models of disk galaxies in order to determine the change in star formation rates associated with environmental interactions. These include the interactions between galaxies, the stripping of a galaxy by the intracluster medium, and gas enrichm...

Photoelectric UBV observations of 120 stars in the young open cluster Trumpler 37 are presented, primarily in the magnitude range 10.0 - 13.5. An analysis of the color-magnitude diagram of the cluster yields an age of 6.7 million yr and reveals the presence of a number of possible pre-main-sequence stars in the cluster.

The equilibrium and associated relaxation times in a stable, axisymmetric, constant Q disk of N-body particles are measured from the time rate of increase of Toomre's Q. The recent suggestion by White(1988) that two-body relaxation in two-dimensional simulations is not always negligible is tested and found to be a major cause of heating of the syst...

Results of N-body simulations of disc galaxies using a two-dimensional Cartesian N-body code are presented. Both trailing arm spirals (TAS) and leading arm spirals (LAS) were used with varieties of pitch angles and pattern speeds. LAS perturbations transferred their energy to TAS via swing amplification; TAS perturbations led to TAS arms. In both c...

Over 4.5 billion years ago a small region deep inside an enormous cloud of interstellar gas and dust, located in an outer spiral arm of the Milky Way, gradually contracted until it became gravitationally unstable. When the density in this region of the cloud became great enough to allow gravity to overcome all other forces acting on it, the region...

A three-dimensional, two gas-phase, stochastic self-propagating star formation model of galaxies is developed which allows gas to move from cell to cell, permanently removes some gas in the form of long-lived, low-mass stars, and follows the change in galactic chemistry at least as far as to track changes from primordial abundances of hydrogen and...

It is argued, following Stahler (1985), that in young galactic clusters both the suggested exponential increase in star-formation rates with time and the mass-age correlation are artifacts of incorrectly assigning pre-main-sequence ages to main-sequence stars. Quantitative arguments are presented for simultaneous formation of stars with different m...

A three-dimensional Stochastic Self-Propagating Star Formation (SSPSF) model of compact galaxies is presented. Two phases of gas, active and inactive, are present, and permanent depletion of gas in the form of long lived, low mass stars and remnants occurs. Similarly, global infall of gas from a galactic halo or through galactic cannibalism is perm...

The Kalnajs (1972, 1976) Omega models of global mass and velocity distributions are employed in the present two-dimensional N-body simulation, which allows for a spectrum of particle masses, stellar explosions, explosion remnant interactions with an interstellar medium, and the creation of new stars from the gas. Two sequences of runs using the Ome...

The behavior of stochastic self-propagating star formation (SSPSF) in three dimensions is examined in simulation for the first time, emphasizing the effect of the added dimension on the sensitivity of spiral structure to the probability of star formation. The model produces global equilibrium spiral structure over a much more restricted range of st...

Gerola, Seiden, and Schulman (1980) have recently presented the results of a two-dimensional stochastic self-propagating star formation (SSPSF) model for dwarf galaxies in an effort to relate dwarf blue galaxies with their red counterparts. They found that in sufficiently small galaxies SSPSF allows a normally red galaxy to become blue due to short...

The formation of spiral arms in disc galaxies is generally attributed to the effects of spiral density waves. These relatively small (i.e. 5 per cent) non-axisymmetric perturbations of the interstellar medium cause spiral arms highlighted by O and B type stars to be created. In this paper we examine another mechanism for spiral arm formation, the s...

This is the second of two papers on secular instabilities in rigidly rotating, stationary, axisymmetric, incompressible stars. The time scales of the instabilities caused by gravitational radiation reaction and viscosity in these stars are calculated using the equations derived in the preceding paper (Comins). These instabilities cause the star’s a...

This is the first of two papers on secular instabilities in rigidly rotating, axisymmetric, stationary incompressible stars. The equations which give the e-folding times of the instabilities caused by an important class of nonaxisymmetric perturbations of the stars are derived. The stars are modelled as Maclaurin spheroids. The instabilities are du...

Rotating ultracompact stars in general relativity can have an ergoregion (ER) in which all trajectories are dragged in the direction of the star's rotation. The existence of the ER leads to a classical instability to emission of scalar, electromagnetic and gravitational radiation from the star. In the present paper eigenfrequencies are calculated f...

An ergoregion (ER) is defined as a region around a collapsed rotating star where all particle and photon orbits are forced to corotate with the star. An approximate method for determining the existence and structure of an ER is presented which involves calculation of the structure of a nonrotating star and subsequent integration of the equation for...

The astronomy lab at the University of Maine consists of discrete weekly lessons in which students work in small groups. Individual pretests and post-tests accompany each lesson. The lesson studied here covers the topic of time, including sidereal time, Apparent Solar Time, and time zones. The pretest consists of four multiple-choice questions, whi...

Our two dimensional simulation of disk galaxies has five components: collisionless N-body particles representing star clusters; colliding N-body particles representing giant molecular clouds (GMCs); a gravitating hydrodynamic component simulating the intercloud medium; a dark-matter halo; and, a central black hole. Besides gravitational interaction...

Based on Discovering the Universe, this best-selling text is a shorter, less expensive option with streamlined presentation of topics. While maintaining the themes and approach to astronomy found in the longer text, Discovering the Essential Universe, 2e presents only the essential information for students' reference, enrichment, and review with mi...