Tag Archives: astronomy

THEORY VERSUS PRACTICE IN SCIENTIFIC RESEARCH! 

 

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.

 

GO BACK TO HOME PAGE    OR    SCROLL UP TO MENU UNDER THE WEBSITE TITLE

 

 

THE NEW JAMES WEBB SPACE TELESCOPE: BIG SCIENCE REQUIRES BIG MONEY AND BIG TIME, BUT SHOULD PRODUCE BIG RESULTS! 

 

The new Webb telescope will be a big eye in the sky! (http://dr-monsrs.net)
The new Webb telescope will be a big eye in the sky!  (http://dr-monsrs.net)

 

NASA (National Aeronautics and Space Administration) and its many partners now are building a giant new space telescope, with launch scheduled for October, 2018 (see: “James Webb Space Telescope” at the NASA website).  The construction phase of the Webb space telescope involves efforts by over 1,000 special workers in 14 nations, a total cost of 80 billion dollars, and, many industrial and academic organizations.  This huge science project is being conducted during about 10 years of time; it involves use of new technologies and building several special new research instruments.  Once the complex assembly is completed and fully tested, it will be transported by ship to the rocket launch site in South America, where it will be sent far into space.  This new mission for science will provide important new research data for astronomy, astrophysics, and space science; its research results will go far beyond the amazing images and data obtained by the orbiting Hubble space telescope launched in 1990.

What is the Webb space telescope [1-3]? 

The new space telescope will be as large as a moving van and will be placed into a specific region of space located about one million miles away from Earth.  It contains small rockets to provide for final adjustment of its position.  Data collected from its newly constructed high-tech mirror systems provide very high sensitivity, increased optical resolution, and longer wavelength coverage.  This space instrument is specialized to detect and measure near- and mid-infrared wavelengths, since those come from the  oldest stars.  Data will be transmitted back to the Webb Science and Operations Center at the  NASA Space Telescope Science Institute in Baltimore, Maryland, for analysis and distribution to research scientists and groups.  The new Webb space telescope is planned to operate in the cold vacuum of space for 5-10 years, starting in 2018.

What will the new space telescope do for scientific research [1-3]? 

At present, the Webb mission has 4 goals: (1) search for the first galaxies or luminous objects formed after the Big Bang, (2) determine how galaxies evolved from their formation until now, (3) observe the formation of stars and their planetary systems, and (4) examine the physical and chemical properties of extraterrestrial planetary systems, including investigations of their potential for life.  The Webb extends the capabilities of the Hubble space telescope by having much better detection sensitivity (10-100x), optical resolution, and telescopic spectroscopy.  By being able to look out to the far edges of the universe, the Webb can view and measure the very oldest stars and galaxies.

What are the chief worries about the new space telescope [1-3]? 

As with any very complex and multiyear building project, unforeseen problems can arise later.  The Hubble space telescope had an unanticipated problem that fortunately was able to be nicely repaired by visiting astronauts.  Since the new Webb telescope will be much further away from Earth than is Hubble, it will be impossible for astronauts to fix problems.  Thus, the preflight testing must be much more rigorous and extensive.  However, it is never certain that everything will work and last exactly as expected; extremely unusual events could occur (e.g., collision with a large meteorite, very high bursts of different radiations from our Sun, malfunction of communication systems, etc.) and might be beyond the capabilities of adjustments during its operation in space.

Many people will ask a very natural question, “Why do we humans need a new space telescope?”.  Technical answers that it will give results beyond those provided by the Hubble space telescope, will have a hollow ring to non-scientists asking this question.  A better answer is that all of us, whether scientists or ordinary people, deserve to have extended knowledge and understanding about our universe; dramatic new data provided by the Webb space telescope will do just that.

Will the new findings of this space telescope justify its immense cost [1-3]? 

This huge research project raises an interesting general question about scientific research.  Although the 80 billion dollar budget for the Webb is cut back from the initial plans, just about everyone must admit that this cost figure is gigantic.  It is reasonable to expect that the research by space scientists using data from the Webb will produce significant advances in understanding the formation and evolution of the oldest stars in our universe, the life cycles of stars, the environmental composition of different exoplanets, and possibilities for living systems on planets circling other stars.

Although accepting that answer, some scientists will ask the logical question, “How many research grants of ordinary cost and size could be made with the same 80 billion dollars?”.  Their follow-up question will be, “What would be the value of the new research results collected by all those numerous small projects?”.  Clearly, such questions are simply the latest in the ongoing controversy about the value of Big Science versus Small Science.  Answers cannot be provided at present because so much is unknown or theoretical.

Where can good information be found about the new Webb space telescope?  

There is an abundance of information available about the design, construction, and objectives of the Webb space telescope!  For starters, see websites about the Webb by NASA , the Canadian Space Agency , and, the European Space Agency .  These have loads of information, diagrams, videos, and the latest news about this giant research project; they are designed to be suitable and understandable for adults, students, teachers, children, and parents, as well as for scientists.

You also even can sign-up with NASA to receive e-mail newsletters with the latest updates for the Webb space research project !

For those curious about the efforts of all the numerous engineers,  scientists, and technologists working with this space project, I recommend the truly outstanding article by Daniel Clery, “The Next Big Eye”, within the February 19, 2016, issue of the journal, Science.  This well-illustrated piece includes a very good discussion about how these individuals are subject to increasingly large pressures as the assembly and testing advances.

Concluding remarks! 

The work of designing, fabricating, assembly, and testing the different components used for the Webb space telescope is an utterly fascinating story showing what humans are capable of doing!  After the final assembly is completed, its testing under conditions of space while still here on Earth also will be a wondrous story.  Much credit must go to the managers who coordinate all the different small and large groups working on this complex assembly project at diverse locations; they must ensure that everything fits together and functions reliably just as planned.  The Webb mission should produce much exciting new understanding about our Sun, our universe, and conditions on the planets of other stars!

 

[1]  “Explore James Webb New Space Telescope” is available on the internet at:  http://www.jwst.nasa.gov .

[2]  “FAQ: General Questions About Webb” is available on the internet at:  http://www.jwst.nasa.gov/faq.html .

[3]  “Webb Telescope Science Themes” is available on the internet at:  http://www.jwst.nasa.gov/science.html .

 

GO BACK TO HOME PAGE    OR    SCROLL UP TO MENU UNDER THE WEBSITE TITLE