US students: email me a picture of you outside viewing the shower with your family for 5 points extra credit on your semester 1 final exam.
Thursday, December 13, 2012
LAST EC OF THE SEMESTER!!!!!!
US students: email me a picture of you outside viewing the shower with your family for 5 points extra credit on your semester 1 final exam.
Tuesday, December 4, 2012
The vibrant colors in images of nebulae and galaxies are widely admired, but if future space travelers were to pass by one of these objects, what would they see?
Telescopes can capture radiation with energies on the electromagnetic spectrum that are invisible to the human eye. The electronic detectors, similar to those found in digital ca
meras, create black-and-white images which are then transmitted back to earth for processing.
Because the detectors only measure the intensity of the radiation, the images appear in greyscale. However, each pixel is made up of a particular shade of grey that contains some color information based on the wavelength picked up by the telescope.
The final images are comprised of two or more layers of these greyscale exposures. The colors that make space images so pleasing to the eye are usually added as a tool for scientists to study a physical process.
Filters are applied to images in order to isolate specific radiation energies and block others out. When a set of red, green, and blue filters are applied, and the subsequent images are layered over each other in chromatic order, they mimic the RGB receptors in our eyes and a "natural color" image is generated. Thus, only natural color images come close to what the hypothetical space explorers would witness as they traveled past.
Representative color is used to approximate the appearance of an object in wavelengths that we cannot see, such as infrared. Colors on the visible light spectrum are assigned to corresponding wavelengths on other spectra, allowing us to entertain what it might be like if our eyes could perceive other wavelengths.
Enhanced or false color images do not follow the chromatic order and are created for various reasons--studying fine structural details that would be lost in the visible light spectrum, for example, or simply for aesthetic reasons. Composite images are created when two or more wavelengths are combined.
The collection of images shown represents different exposures of NGC 1512, a galaxy roughly 30 million light-years away from Earth in the constellation Horologium. By assigning blue to the ultraviolet spectrum, green to the visible light spectrum, and red to the final three infrared photographs, scientists were able to generate the composite image in the center for the purpose of studying star clusters near the core. The 7 surrounding images span the wide range of wavelengths that the Hubble Telescope is able to capture.
When processing these images, scientists take care not to create details that were not present in the original data. It's necessary that chromatic order is carefully and methodically applied to the exposures in order to ensure their research value but the subtleties of color can produce a variety of results. As long as certain scientific principles are observed, the groups that process these images are operating with a certain amount of aesthetic freedom. Image manipulation is governed by a large amount of parameters, meaning that the end result is largely a product of pure science but partially a product of taste.
-RLO
Sources: http://
http://hubblesite.org/
Image credit: NASA, ESA, and D. Maoz (Tel-Aviv University and Columbia University)
Because the detectors only measure the intensity of the radiation, the images appear in greyscale. However, each pixel is made up of a particular shade of grey that contains some color information based on the wavelength picked up by the telescope.
The final images are comprised of two or more layers of these greyscale exposures. The colors that make space images so pleasing to the eye are usually added as a tool for scientists to study a physical process.
Filters are applied to images in order to isolate specific radiation energies and block others out. When a set of red, green, and blue filters are applied, and the subsequent images are layered over each other in chromatic order, they mimic the RGB receptors in our eyes and a "natural color" image is generated. Thus, only natural color images come close to what the hypothetical space explorers would witness as they traveled past.
Representative color is used to approximate the appearance of an object in wavelengths that we cannot see, such as infrared. Colors on the visible light spectrum are assigned to corresponding wavelengths on other spectra, allowing us to entertain what it might be like if our eyes could perceive other wavelengths.
Enhanced or false color images do not follow the chromatic order and are created for various reasons--studying fine structural details that would be lost in the visible light spectrum, for example, or simply for aesthetic reasons. Composite images are created when two or more wavelengths are combined.
The collection of images shown represents different exposures of NGC 1512, a galaxy roughly 30 million light-years away from Earth in the constellation Horologium. By assigning blue to the ultraviolet spectrum, green to the visible light spectrum, and red to the final three infrared photographs, scientists were able to generate the composite image in the center for the purpose of studying star clusters near the core. The 7 surrounding images span the wide range of wavelengths that the Hubble Telescope is able to capture.
When processing these images, scientists take care not to create details that were not present in the original data. It's necessary that chromatic order is carefully and methodically applied to the exposures in order to ensure their research value but the subtleties of color can produce a variety of results. As long as certain scientific principles are observed, the groups that process these images are operating with a certain amount of aesthetic freedom. Image manipulation is governed by a large amount of parameters, meaning that the end result is largely a product of pure science but partially a product of taste.
-RLO
Sources: http://
http://hubblesite.org/
Image credit: NASA, ESA, and D. Maoz (Tel-Aviv University and Columbia University)
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