How does potassium 40 dating work
The argon-argon dating method can provide more precise absolute dates for many geologic events, ranging from volcanic eruptions and earthquakes to the extinction of the dinosaurs and many other creatures at the end of the Cretaceous period and the beginning of the Tertiary period.Scientists at the University of California, Berkeley, and the Berkeley Geochronology Center have pinpointed the date of the dinosaurs' extinction more precisely than ever thanks to refinements to a common technique for dating rocks and fossils.
For more details on purple-fleshed and orange-fleshed sweet potatoes, please see our Description section below.Sweet potatoes are not always orange-fleshed on the inside but can also be a spectacular purple color.Sometimes it's impossible to tell from the skin of sweet potato just how rich in purple tones its inside will be.The product of this reaction can be predicted, once again, by assuming that mass and charge are conserved. They rapidly lose their kinetic energy as they pass through matter.As soon as they come to rest, they combine with an electron to form two -ray photons in a matter-antimatter annihilation reaction.-decay are often obtained in an excited state.Electron capture leads to a decrease of one in the charge on the nucleus.
The energy given off in this reaction is carried by an x-ray photon, which is represented by the symbol hv, where h is Planck's constant and v is the frequency of the x-ray.
“If I were asked which is the most destructive of all diseases I should unhesitatingly reply, it is that which for some years has been raging with impunity …
What contagion does thus invade the whole body, so much resist medical art, becomes inoculated so readily, and so cruelly tortures the patient ?  In 1495 an epidemic of a new and terrible disease broke out among the soldiers of Charles VIII of France when he invaded Naples in the first of the Italian Wars, and its subsequent impact on the peoples of Europe was devastating – this was syphilis, or grande verole, the “great pox”.
Orange-fleshed sweet potatoes may be one of nature's unsurpassed sources of beta-carotene.
Several recent studies have shown the superior ability of sweet potatoes to raise our blood levels of vitamin A.
Although it didn’t have the horrendous mortality of the bubonic plague, its symptoms were painful and repulsive – the appearance of genital sores, followed by foul abscesses and ulcers over the rest of the body and severe pains.