Numerous books have been written about the Manhattan Project, so I won’t even attempt an outline here, but below are the main Wikipedia articles for your reference:

• Manhattan Project
• Trinity
• Atomic bombings of Hiroshima and Nagasaki
• Debate over the atomic bombings of Hiroshima and Nagasaki
• Surrender of Japan

Read these and some of the links on these pages and you’ll know a lot about the bombs, their development, why they were used, etc. Below are a few of the facts that were new to me or that I find particularly interesting. I’m sure there were more, but I didn’t take notes.

One of the things that makes the Manhattan Project so interesting is that these scientists took a completely theoretical idea and made a working weapon in less than four years (12/1941 – 8/1945). Granted, they did have virtually limitless resources and some of the brightest minds of their time.

In my opinion, the single most interesting person involved in the project was Robert Oppenheimer, the scientific director. He famously lost his security clearance in 1954 for having ties to Communism. History has cleared his name regarding any spying. It is now known that the KGB tried to recruit him numerous times, but they were always turned down.

The project actually produced two different types of nuclear weapons: one based on Uranium-235 and another on Plutonium-239. The element Plutonium had only been discovered in February, 1941.

The Uranium-235 was produced in Oak Ridge, Tennessee. The site was picked, in part, due to the availability of cheap hydroelectric power from TVA. At one time, the site used over a sixth of the electrical power produced in the United States. Due to security concerns, the Governor of Tennessee did not know Oak Ridge existed for some time, even though it would soon become the fifth largest city in Tennessee. Perhaps unsurprisingly, the area of the Oak Ridge complex where the Uranium was enriched is now an EPA Superfund site.

Copper was in short supply during World War II, so Oak Ridge was loaned 14,700 tons  of coinage silver (currently worth $7.3 billion) from the US Treasury to create massive electromagnetic coils. Approximately 99.965% of it was returned to the Treasury after the war.

Due to the small amount of Uranium-235 available and the confidence of the scientists, a test was never carried out using the Uranium design. They didn’t know for certain it would work until it was dropped on Hiroshima. As an engineer, I’m astounded that they pulled this off in such a short time with no final test.

On July 16th, 1945, a Plutonium weapon was tested at the White Sands Proving Ground in New Mexico. The test was code-named Trinity. The explosion was heard 200 miles away. The Army put out a press release explaining that a remote ammunitions magazine had exploded. Near the explosion, the sand was turned to a light green, radioactive glass that came to be called Trinitite.

In the brainstorming stage of target selection, Kyoto was a favorite. Supposedly Kyoto was taken off the list by Secretary of War Henry Stimson who had honeymooned there.

On July 26th, 1945, the Potsdam Declaration was released, in which the Allies requested an unconditional surrender from Japan. It promised “prompt and utter destruction” if they did not surrender. The Japanese did not respond.

On August 6th, 1945, three B-29s left Tinian headed toward Hiroshima by way of Iwo Jima, a six hour flight. They were picked up by the Japanese on radar, and the alert was initially raised, but after determining there were only three planes, the air raid sirens were turned off. The Japanese had previously decided not to intercept small formations with fighters to conserve fuel and planes, which is what happened on August 6th. When the planes arrived at Hiroshima it was clear. Had it been cloudy, they would have diverted to Kokura.

“Little Boy” was dropped from the Enola Gay at 8:15 local time. It detonated 1900 feet above the city, as designed. Approximately 70,000 people (~30% of Hiroshima’s population) died immediately. It is estimated that up to a total of 200,000 people died by 1950 due to effects from the bomb.

On August 8th, the Soviet Union finally declared war on Japan and invaded Manchuria.  Japan had been hoping to avoid war with the Soviets. They still did not surrender.

On August 9th, Bockscar and its supporting B-29s headed for Kokura. They had orders to drop the bomb only if they could see their target. Weather scouting planes flying an hour ahead reported clear skies. Bockscar was delayed due to a supporting plane missing its rendezvous. By the time it arrived in Kokura, it was cloudy. They diverted to the secondary target, Nagasaki.

At 11:01 local time, “Fat Man,” a Plutonium bomb similar in design to the one tested previously, was dropped on Nagasaki. Between 40,000 and 70,000 people died immediately.

At this point the officials in Japan were still split on the issue of surrender. Early on August 10th the Emperor himself came out in favor surrender, as long as he could retain his power. The Allies continued to demand an unconditional surrender. Finally, on August 14th, the Emperor and his government agreed. The was an unsuccessful coup d’état by elements of the military that did not want to surrender.

The US planned to have another nuclear weapon ready by August 17th, and it would have most likely been used had Japan not surrendered.

There is, of course, a debate about whether or not nuclear weapons should have been used on Japan. I have my opinion. I encourage you read up on the facts and develop your own.

If you know of any related, interesting facts that I missed, please post them in the comments.

Currently, the plan is to retire the space shuttles in 2010. Orion isn’t scheduled to be ready until 2014. However, there are various proposals out there to extend the life of the space shuttle program and/or speed up the development of Orion.

While that is mostly bad news, the good news is that every increase in the price of electricity makes solar power that much more viable. So, between the price of its “competition” going up and technology bringing the dollar/watt ratio down, solar will be viable before we know it.

And that’s a good thing, because solar is cool. With solar, you aren’t paying a monthly bill to a utility company, you’re paying off a capital expense that increases the value of your home or business. And regardless of your position on global warming, I think we can all agree that the less junk in the atmosphere, the better.

Unfortunately I don’t have any hard numbers to crunch on this, but all signs point to solar power becoming viable in the relatively near future.

Incidentally, TVA is an interesting experiment in American socialism. Take a moment to read up on it if you’re not familiar.

I had previously heard claims (on the local talk radio station) that gasoline with ethanol added gave you worse gas mileage than straight gasoline. I had never given it much thought, but the vandalism made me curious.

The most definitive numbers I could find were in a report from the American Petroleum Institute (page 9). The API is a trade association for the US oil industry, so, if anything, you would expect their numbers to err on the negative side. The report cites a small study using 2001-2003 model year cars and light trucks that shows a 1.4% fuel economy penalty when using fuel with 10% ethanol, the most common mixture. They cite another study using older cars (1989 models) that shows a 2.6% fuel economy penalty.

Let’s use the number for more recent cars: 1.4%. That means if your car gets 25 mpg with regular gasoline, it’ll get 24.65 mpg with 10% ethanol. That doesn’t sound like a big difference, but if regular gasoline is being sold for $3.59 a gallon then gasoline with 10% ethanol would have to be $3.54 or cheaper to make up for the decrease in fuel efficiency. So, keep this in mind and buy your gas accordingly.

Of course, if the US taxpayer wasn’t subsidizing the production of ethanol then this wouldn’t be an issue, but I digress. That is, perhaps, a blog post for another day.