Tag Archives: theories in science



Quotation by Yogi Berra, star catcher for the New York Yankees baseball team; also attributed to several other persons! (http://dr-monsrs.net)
Quotation by Yogi Berra, star catcher for the New York Yankees baseball team; also attributed to several other persons! (http://dr-monsrs.net)


Theories play a big role in science!  I recently presented a short introduction for beginners about science theories (see “Towards Understanding Theoretical Research in  Science!” ).  Here, we will look at some current research developments in Astronomy that illustrate examples of theories within space research.

A brief background for beginners on the science of Astronomy! 

Knowledge in ancient times about our planet, Earth, our Moon, our Sun, and the stars came from direct observations with the naked eyes.  The early development of telescopes, photography, and other ways to record positions of celestial objects permitted measurements to be made; that was the real start of astronomy as part of physical science.

Astronomy today has the tools and technology to examine everything from the other planets circling our Sun, to distant galaxies and energy emissions in outer space.  Modern research in astronomy has been expanded by the development of space science with its explorations using robotic labs sent on distant travels, space telescopes and new large terrestrial telescopes, and, numerous advanced spectroscopes.  These tools and methods gather quantitative data that go far beyond what could be done by researchers only a few decades ago.  The new availability of direct measurements means that theories in astronomy now can be tested against real data.

Do exoplanets exist!

Humans have long wondered if we are alone, or if there are other planets with life somewhere out in the universe.  A theory that exoplanets (i.e., planets circling other stars) do exist is mirrored by a theory that there are no others!   The validity of any theory must be tested by evidence from research results.  Due to their limited size and great distance away from Earth, exoplanets cannot yet be directly imaged by any terrestrial telescopes; space telescopes should be able to do that, if exoplanets actually exist.  Instead of using light waves to form images, telescopes and radiotelescopes now can detect other wavelengths and types of radiation, and record spectra rather than images; much development in this research methodology has resulted in good confidence for interpretating spectroscopic data, although confirmation from adjunctive results always also is sought. Recent discoveries of hundreds of planets orbiting many other stars [e.g., 1] establishes validity of the theory that exoplanets do exist.

Proxima b is discovered! 

One exoplanet, Proxima b, has just been reported by an international team of scientists, after analyzing research data back to 2000 [1]!  It is slightly larger than Earth, and encircles our neighboring star, Proxima Centauri, with a periodicity of 11.2 days; its equilibrium temperature permits liquid water to be present.  There is much excitement in astronomy over this new research finding, because its relative closeness to Earth means that it will be a prime target for future fly-by missions.  A new article for general readers about the discovery of this exoplanet, written for CNN by Ashley Strickland [2], now is available (see: “Proxima b: Closest potentially habitable planet to our solar system found” ).

Does water exist on any exoplanet? 

Liquid water is a key component of all forms of life on Earth.  Any theory that life exists on exoplanets generally requires the presence of water there; this links one theory to another theory!  Space scientists are already defining the width of a zone around some stars as being habitable if its temperature range includes that required for liquid water to be present; however, such an estimation does not establish that water actually is present.  Much more direct research data is needed to be able to resolve this important question.

Does life exist on any exoplanets? 

The enormous distance of exoplanets from Earth makes any theory that life is present there extremely difficult to test.  The distant locations make it impractical to send scientists or robots out to any exoplanet via a spaceship.  Several innovative ideas for how to obtain direct images of exoplanets now are being developed and activated (e.g., see “Can Research Travel Out to the Stars?  Yuri Milner Says “Yes, Let’s Go!” ).  Advanced spectroscopy perhaps is the only currently available means to detect life forms on exoplanets, since direct imaging is not yet possible.

How to interpret images from exoplanets? 

Direct imaging of exoplanets is eagerly awaited!  All images in science must be interpreted, but the interpretation of future direct images from exoplanets is guaranteed to be a major controversy since images showing either creatures resembling those we all know on Earth, or something wildly different, will provoke vigorous doubts by other scientists and the public!  Life might exist that utilizes other means for energy mobilization, and does not need either water or oxygen; thus, exotic life forms imaged on exoplanets might not be recognizable as such!  Objective interpretation of those images might be nearly impossible!

Brief discussion! 

Nothing is written in stone, and everything can be questioned by scientists!  Theories are particularly useful in science as targets for new research experiments.  All theories must be evaluated on the basis of their ability to explain direct observations and measurements.  Theories can be proven or disproven by evidence from research results; valid theories have a predictive ability.  Even proven theories can be modified as more research data becomes available.  Speculative ideas and imaginative proposals differ from science theories because they are judged largely on the basis of popularity and subjective promise, rather than by direct evidence.

Concluding remarks! 

Theories in science always are controversial and hard to prove.  In space science, new research results now permit the validity of some theories to be tested directly.  These indeed are very exciting times for space scientists!


[1]  Anglada-Escudé, G., et al., August 25, 2016.  A terrestrial planet candidate in a temperate orbit around Proxima CentauriNature  536:437-440.

[2]  Strickland, A., for CNN, August 24, 2016.  Proxima b: Closest potentially habitable planet to our solar system found.  CNN – Health.







Theories and research results are both important for science! (http://dr-monsrs.net)
Theories and research results are both important for science! (http://dr-monsrs.net)


Despite the efforts of education and media, most people still do not know or understand much about science and scientific research.  The understanding I am referring to does not involve facts and figures so much as activities, aims, and rationales.  Research in theoretical science is particularly viewed and rejected as being a total waste of money and time.  Those mistaken viewpoints are largely due to an absence  of knowledge about the usefulness of theories in science.  This article tries to illuminate the value of theoretical research so you will understand how it plays an important role in the advancement of science.

Theories in science! 

Science wants to know more about everything!  Most research in biomedicine, chemistry, or physics deals with subjects and activities that can be examined directly or indirectly (e.g., animals or cells, polymers or monomers, and, minerals or atoms).  Theories in all branches of science deal with subjects that are not able to be examined directly or indirectly, but can be investigated at the level of what is known already, what could be possible, what can explain something that is not understood, what would happen if and when, and, how can some valid estimate be made for something that cannot be measured directly.  Theories in science basically use what is known to try to investigate or explain something that is unknown and unavailable for direct studies; their validity is judged on  the basis of evidence from research experiments.

Theory versus practice! 

Scientists usually are very specialized, but all can be divided into being either theorists or experimentalists.  The boundaries of this division can be changed with time, when more new knowledge by experimentalists is discovered.  A good example of this dynamic occurred recently when research probes and very special research instruments began to be sent far out into space (e.g., see:  “The New James Webb Space Telescope!” ); all of a sudden, astrophysicists working only at the level of theoretical physics had to confront their theories with real data!  Some of their theories about planets, stars, galaxies, and dark holes were validated, others had to be modified, and some were disproved.  Note that even established theories that are later shown to be invalid still had been helpful for temporarily filling gaps within scientific knowledge about outer space; by proving or disproving a theory, the newly acquired experimental data advances the scientific search for truth.

My own thesis advisor was an experimentalist in cell biology, and once told me that he had seen a certain senior professor walking along a walkway on campus with his head bent forward looking only down at the pavement.  That individual was a pioneering theoretical biologist who analyzed subjects with mathematics; anyone could readily imagine all kinds of equations bouncing around his head as he walked along!  My advisor said all that was very well so long as the theories agreed with practice (i.e., with direct experimental data).  I then asked him what he meant.  He answered that this theoretician had developed a mathematical study of eukaryotic cell division, and had come up with an extensive conclusion about how that activity operated, including that the entire process took place in 24.3 seconds; this number does not match actual direct observations with microscopy showing that it takes some hours!

What is the value of theories for science? 

Theories are good for science because they provide discrete points of study for new research, can give estimates where direct measurements cannot be made, and, help understand complex activities and relationships which are impossible to examine directly.  For science, theories are useful as targets for research questions and for designing new experiments.

Scientific theories are more than just fanciful ideas.  They are somewhat similar to large conclusions from direct research studies in that they: (1) always are subject to revision (i.e., due to new research results), (2) often last a long time, but some vanish when they are completely disproved, and, (3) stimulate new directions for experimental researchers to work on.

A classical example of the value of theories for science is the heliocentric theory of Copernicus, proposing that the Earth revolves around the Sun, unlike the older standard theory that the Sun circles around the Earth.  As time passed, more and more experimental research data provided evidence that the standard theory is wrong and the heliocentric theory is correct.  Many modern researchers in astronomy and space science now follow what has developed from the ancient theory of Copernicus.

Another good example is Darwin‘s theory of evolution.  That complex proposal cannot be directly examined today because the eons of time during which it operated are unavailable.  This extensive theory can explain very many observable details about similarities, differences, and specializations in animals, plants, microbes, and fossils.  The large amount of solid evidence from research for the validity of this classical theory does not prevent ongoing questions and criticisms from being raised.  That is good and is essential for science’s mission to find the truth based upon evidence from research results!

Concluding remarks! 

Everything can and should be questioned, even well-known theories, dogmas, or popular sacred cows!  Science always seeks to evaluate and test accepted conclusions, concepts, and theories when new research experiments make additional data available.  Theories and research in science are complementary, and both are very useful!