X-ray Diffraction Quotes (5 quotes)
As a scientist Miss [Rosalind] Franklin was distinguished by extreme clarity and perfection in everything she undertook. Her photographs are among the most beautiful X-ray photographs of any substance ever taken.
In his Obituary for Rosalind Franklin, Nature, 1958, 182, 154. As given in Andrew Brown, J.D. Bernal: The Sage of Science (2005), 359.
In describing a protein it is now common to distinguish the primary, secondary and tertiary structures. The primary structure is simply the order, or sequence, of the amino-acid residues along the polypeptide chains. This was first determined by Sanger using chemical techniques for the protein insulin, and has since been elucidated for a number of peptides and, in part, for one or two other small proteins. The secondary structure is the type of folding, coiling or puckering adopted by the polypeptide chain: the a-helix structure and the pleated sheet are examples. Secondary structure has been assigned in broad outline to a number of librous proteins such as silk, keratin and collagen; but we are ignorant of the nature of the secondary structure of any globular protein. True, there is suggestive evidence, though as yet no proof, that a-helices occur in globular proteins, to an extent which is difficult to gauge quantitatively in any particular case. The tertiary structure is the way in which the folded or coiled polypeptide chains are disposed to form the protein molecule as a three-dimensional object, in space. The chemical and physical properties of a protein cannot be fully interpreted until all three levels of structure are understood, for these properties depend on the spatial relationships between the amino-acids, and these in turn depend on the tertiary and secondary structures as much as on the primary. Only X-ray diffraction methods seem capable, even in principle, of unravelling the tertiary and secondary structures.
Co-author with G. Bodo, H. M. Dintzis, R. G. Parrish, H. Wyckoff, and D. C. Phillips
Co-author with G. Bodo, H. M. Dintzis, R. G. Parrish, H. Wyckoff, and D. C. Phillips
'A Three-Dimensional Model of the Myoglobin Molecule Obtained by X-ray Analysis', Nature (1958) 181, 662.
The examination of crystal structure, with the aid of X-rays has given us for the first time an insight into the actual arrangement of the atoms in solid bodies. The study of structure by means of a microscope is limited by the coarseness of the light which illuminates the object, for we can never hope to see details smaller than the wavelength of the light. By using X-rays with their very short wavelengths, this limit of minuteness has at one step been decreased ten thousand times, for the wavelength of the X-rays is of a smaller order than the dimensions of the atomic structure. We are actually looking into the interior of the molecule and the atom with this fine-grained form of light.
In Nobel Lecture (6 Sep 1922). Published in Nobel Lectures, Physics 1901-1921 (1967), 377-378; and on the nobelprize.org website.
There seems to be hardly any type of matter in the condition of a true solid which we cannot attempt to analyse by means of X-rays.
In Nobel Lecture (6 Sep 1922). Published in Nobel Lectures, Physics 1901-1921 (1967), 380; and on the nobelprize.org website.
While the biological properties of deoxypentose nucleic acid suggest a molecular structure containing great complexity, X-ray diffraction studies described here … show the basic molecular configuration has great simplicity. [Co-author with A.R. Stokes, H.R. Wilson. Thanks include to “… our colleagues R.E. Franklin, R.G. Gosling … for discussion.”]
From 'Molecular Structure of Deoxypentose Nucleic Acids', Nature (25 Apr 1953), 171, No. 4356, 738. (Note: in W.F. Bynum and Roy Porter (eds.), Oxford Dictionary of Scientific Quotations (2005), 226, this quote is listed under Rosalind Elsie Franklin and cited, incorrectly, as from “Rosalind Franklin and R. G. Gosling, 'Molecular Structures of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid', Nature, 1953, 171, 741.” However, the Franklin and Gosling article on p.741 is the second of two pages titled 'Molecular Configuration in Sodium Thymonucleate'.)
In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
(1987) -- 
