MIT Science Reporter - "One Part in a Trillion" (1964) 

@Hopi Ng Shalom Chemicals mixed with light refracting But as spectacular as it is ,the question is, is the Illumina that's being emitted harmful to the environment? As chemicals from the rocket’s exhaust freeze and drift like clouds through the atmosphere, the sun shines through them as well. The light is refracted through these frozen chemicals at different wavelengths, creating the spectacular displays of color. Unfortunately what can cause something spectacular may not always be a healthy situation! And putting aside the conspiracy theories of chemtrails, but focusing on the Clear truth of the chemicals that are being emitted from these Rockets, these can be harmful! For instance Every time a rocket launches, it produces a plume of exhaust in its wake that leaves a mark on the environment. These plumes are filled with materials that can collect in the air over time, potentially altering the atmosphere in dangerous ways. It’s a phenomenon that’s not well-understood, and some scientists say we need to start studying these emissions now before the number of rocket launches increases significantly. Some rockets do produce heat-trapping greenhouse gases, like carbon dioxide, but those emissions are negligible, according to experts. “The rocket business could grow by a factor of 1,000 and the carbon dioxide and water vapor emissions would still be small compared to other industrial sources,” an engineer at the Aerospace Corporation who studies the effects of rockets on the atmosphere, tells The Verge. Instead, it’s tiny particles that are produced inside the trail that we need to watch out for, engineers say. Small pieces of soot and a chemical called alumina are created in the wakes of rocket launches. They then get injected into the stratosphere, the layer of Earth’s atmosphere that begins six miles up and ends around 32 miles high. Research shows that this material may build up in the stratosphere over time and slowly lead to the depletion of a layer of oxygen known as the ozone. The ozone acts like a big shield, protecting Earth against the Sun’s harmful ultraviolet radiation. However, the magnitude of this ozone depletion isn’t totally known, says engineers.

You said that twice.

John Fitch was famous internationally in his time, I would love to have met him. I saw many of his films ( not then videos ! ) while studying sciences in the 1960s here in the UK.

What. That is, not incongruous.

trillion, not billion.

Wait Homer? Working at a reactor?

Simpson also works in a reactor building.

Only because you wern't around in 1964.

No, it was likely pumps and other motorized equipment.

Why is that dangerous? Natural uranium isn't dangerous to handle. Even enriched to a pretty decent grade, it's still perfectly safe. The greatest risk to a uranium fuel pellet, for example, comes form someone touching it with bare hands; the oil and dirt from their skin would ruin the fuel. Radiation is so poorly understood (thanks in large part to the fossil fuel industry's scare campaigns).