You are nearing the end of the school year and we know you are very busy. But don’t forget to check on the materials and supplies you need for next year. Contact us and we can help you organize your order to get the most for your science budget.
We are continuing the weekly discount specials. Watch your inbox for our “Weekly Special” offering items from our extensive selection of materials at great savings. A wonderful opportunity to obtain great science supplies at very low prices.
This Month’s Highlighted Products
Advanced Biological Binocular microscope with precision optics. For use by students or professionals. Model 215 has a Seidentopf head for comfortable viewing, ASC high contrast objectives, coaxial focusing, low drive mechanical stage and LED illumination with conveniently located intensity control. LED light rated up to 50,000 hours. More Info…
Now with detachable 8″ tablet, the BTW1-420TH offers the convenience and versatility of viewing a large picture at 10x magnification, then zooming continuously all the way to close-up detail at 40x magnification. Upright, unreversed 3-dimensional image remains in focus throughout zoom range. Optional eyepieces and auxiliary objectives expand magnification range and working distances. Trinocular port accepts video or SLR adapters (included). Features top light with directional beam, bottom light with cool, long-life fluorescent illumination. Like the Moticam X, this WiFi digital tablet transmits live images to iOS or Android devices. Use it as a conventional microscope or share live images with colleagues using WiFi tablets, wireless laptops, and HD-ready monitors/projectors through HDMI. Tablet includes preloaded Motic apps. More Info…
Science History Information
In 1978, Velcro, the hook-and-loop fastener patent expired, releasing the design to manufacture of imitations. It was developed by Swiss engineer Georges de Mestral, who noticed how thistle burrs clung to his clothing during a hike in the mountains. Using a microscope, he discovered their natural hook-like shape. From 1948, he worked with a local weaver from a textile plant to design a “locking tape.” The important discovery was accidental – that nylon, when sewn under ultraviolet light, formed industructable hooks. Velcro uses two tapes, one with stiff “hooks” like the burrs which clings to the second tape with soft “loops” like the fabric of his pants. The trademarked name Velcro comes from “vel” or velvet and “cro” from the French word crochet which means hook.
In 1953, the journal Nature published a paper with this date from Francis Crick and James Watson, titled Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid, in which they described a double helix structure for DNA. The diagram published with the caper was captioned, “The figure is purely diagrammatic. The two ribbons symbolize the phosphate-sugar chains, and the horizontal rods the pairs of bases holding the chains together. The vertical line marks the fibre axis.”
In 1938, Du Pont researcher Roy J. Plunkett and his technician Jack Rebok accidentally discovered the chemical compound polytetrafluoroethylene (PTFE), later marketed as Teflon. Plunkett was researching chemical reactions of the gas perfluoroethylene in order to synthesize new types of refrigerant gases. Rebok found an apparently defective cylinder of this gas, since no pressure was found when the valve was opened, even though the cylinder weight was the same as full cylinders. Rebok suggested sawing it open to investigate. Inside was a slippery white powder. Plunkett found it had unusual properties, a wonderful solid lubricant in powdered form, was chemically inert and had a very high melting point. He realized it was formed by an unexpected polymerization. It was patented on 4 Feb 1941.
In 1852, Edward Sabine announced that the 11 year sunspot cycle was “absolutely identical” with the geomagnetic cycle. Later, using a larger dataset, Rudolf Wolf confirmed this fact. Since Isaac Newton’s explanation of the effect of the sun’s gravity on earth, this was the first new phenomenon of the sun interacting with the earth. Thus began continuing studies of the solar-terrestrial activity. Sabine was an Irish geophysicist, astronomer, and explorer, who made extensive pendulum measurements to determine the shape of the earth, and established magnetic observatories to relate sunspot activity with disturbances in terrestrial magnetism. Sabine was knighted in 1869.
This Month’s Quote
In the Spring, I have counted 136 different kinds of weather inside of 24 hours. – Mark Twain