![]() SANCHEZ: Say, two, three years, everybody was gone. The white people seemed to have left very quickly? But then.ĬHANG: But then she says most of those white families on this block started leaving. SANCHEZ: And then over here was a white family with kids and all (ph). And she says back when she first moved to Compton, almost everyone on her block was white. JUANITA SANCHEZ: There lived a white person with a son.ĬHANG: Juanita Sanchez (ph) has lived on this block since the late 1950s. His new next-door neighbor noticed the same thing. You know, you're a kid, you know?ĬHANG: Another thing he noticed - everyone moving in that day was Black, just like his own family. JOHNSON: And so I thought it was moving day for everybody - everybody just switch houses (laughter). For blocks and blocks, he sees people moving into houses. Johnson is just 5 years old, and he realizes his family isn't the only one moving into Compton that exact same day. ![]() I see moving vans, trucks and everything, all down the street. ROBERT JOHNSON: And I'm looking down the street. JONAKI MEHTA, BYLINE: There's this day that's been imprinted on Robert Johnson's mind for the past 60 years. It's a city just south of downtown LA that was in the midst of transforming from all white to majority Black. We're going to show you the forces responsible for this by visiting Compton in the 1960s. But the real estate market often values homes in majority-Black neighborhoods much less than comparable homes in white neighborhoods, robbing Black families of wealth and opportunities like financing a college education. For most Americans, the key to building intergenerational wealth is to own a home. Because of this very short wavelength, X-rays ca… Radiology, Radiology is a branch of medical science in which various forms of radiant energy are used to diagnose and treat disorders and diseases.As part of our series on American democracy called We Hold These Truths, we've been looking at property ownership in this country and the structural forces that have held back Black homebuyers. Thousands of experiments have since shown that light can exhibit both wave and particle behavior, a property called wave-particle duality.Īt the high-energy end of the electromagnetic spectrum, x rays provide a unique window on some of the hottest and most violent objec… X-ray Spectroscopy, X-ray fluorescence spectrometry An analytical method which can be used to determine the concentration of a wide range of chemical elements, using the… Arthur Holly Compton, Compton, Arthur HollyĪrthur Holly Compton, who shared the Nobel Prize in physics in 1927 for his discovery of the eff… X Ray, X-rays are electromagnetic waves, like light waves, but with a wavelength about 1,000 times smaller. Compton received the 1927 Nobel Prize in physics for his work. Compton ’s x ray scattering experiments provided additional evidence that light does exhibit particle like behavior. This photon model for light still needed further experimental confirmation. In 1905, Albert Einstein (1879 –1955) explained the photoelectric effect, the effect that causes solar cells to produce electricity, by assuming that light can occur in discrete particles called photons. The frequency of the x ray decreases as it loses energy to the electron. The energy and frequency of light and other electromagnetic radiation are related so that a lower frequency x-ray photon has a lower energy. The x ray loses energy and momentum to the electron as the electron begins to move. The x-ray photon scattering off an electron behaves similarly. It also loses some of its momentum and kinetic energy to the 8 ball as the 8 ball begins to move. When the cueball strikes the 8 ball, which was initially at rest, the cue ball is scattered at some angle. Only the cue ball and 8 ball are left on the table. The amount the frequency changes depends on the scattering angle, the angle that the x ray is deflected from its original path. Compton found the x rays that scattered off the electrons had a lower frequency (and longer wavelength) than they had before striking the electrons. Compton (1892 –1962) did experiments bouncing x rays off the electrons in graphite atoms. The Compton effect, sometimes called Compton scattering, occurs when an x ray collides with an electron.
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