An Orchid and its X-ray

The Science

X-rays are one way in medicine and other fields that we can look at the internal structure of objects, including the human body. X-rays are also used in medicine to illustrate both health and disease.

The artwork is an x-ray of an orchid flower that I took with a faxitron at the Centre for Forensic Sciences in Toronto.  This is a small x-ray machine shaped like a microwave oven, most often used for samples from a mammogram biopsy, or in our specific case autopsy specimens.

X-rays images convey pictorially the density of objects. For example, the stem of the orchid, the crucial support of the flower, is the densest part and is white on X-ray, as the X-rays have been absorbed and do not pass through the stem to expose the X-ray film or digital receptor in this case. Similarly, in medical X-rays, the calcium in bones of the human skeletal system is the densest substance in the body and is also white on X-rays.  The softer tissues of the body and the flower are intermediate density and can be considered essentially the density of water.  More X-rays pass through these and give a darker, more exposed part of the image.

Plants and animals, including humans, are thought to have evolved from a common eukaryotic ancestor 2 billion years ago.  Evolution over the intervening millennia has acted on these organisms very differently to allow adaptation to their individual environments, however, many organisms are faced with similar challenges, such as maintaining an upright orientation despite gravity.  The similarities of the structure of the human skeletal system and the plant stem and their prominent density when seen on X-rays prompted me to create an X-ray of an orchid flower to complement my poem on X-rays in this issue of Consilience related to structure.

The art accompanies the poem, Electrons to Images. It gives an artful, concrete representation of the appearance of an orchid flower and an its X-ray appearance. X-rays respond to density. The stem is the densest part of the orchid flower and is white on X-ray, as the X-rays have been absorbed and do not pass through to expose the X-ray film (or digital receptor in this case). X-rays are one way in medicine and other fields that we can look at the internal structure of objects, including the human body.