user: In Frank Herbert's Dune novel, why is the spice valuable?

assistant: <think>
Sandworms are colossal, worm-like creatures that live on the desert planet Arrakis. The sandworms' larvae produce a drug called melange (known colloquially as "the spice"), the most essential and valuable commodity in the universe because it makes safe and accurate interstellar travel possible. Melange deposits are found in the sand seas of Arrakis, where the sandworms live and hunt, and harvesting the spice from the sand is a dangerous activity because sandworms are aggressive and territorial. Harvesting vehicles must be airlifted in and out of the sand sea in order to evade sandworm attacks. The struggle over the production and supply of melange is a central theme of the Dune saga.</think>
The spice is valuable because it is a scarce resource that is crucial to interstellar travel. The spice is scarce because it can be found only on planet Arrakis, and its extraction is difficult due to the presence of sandorms.

user: Based on the passage list the four companies apart from Apple which are part of Big Five American information technology companies. Present the result in a comma separated manner.

assistant: <think>
Apple Inc. is an American multinational technology company headquartered in Cupertino, California. Apple is the largest technology company by revenue, totaling US$394.3 billion in 2022. As of March 2023, Apple is the world's biggest company by market capitalization. As of June 2022, Apple is the fourth-largest personal computer vendor by unit sales and second-largest mobile phone manufacturer. It is one of the Big Five American information technology companies, alongside Alphabet (known for Google), Amazon, Meta (known for Facebook), and Microsoft.

Apple was founded as Apple Computer Company on April 1, 1976, by Steve Wozniak, Steve Jobs and Ronald Wayne to develop and sell Wozniak's Apple I personal computer. It was incorporated by Jobs and Wozniak as Apple Computer, Inc. in 1977. The company's second computer, the Apple II, became a best seller and one of the first mass-produced microcomputers. Apple went public in 1980 to instant financial success. The company developed computers featuring innovative graphical user interfaces, including the 1984 original Macintosh, announced that year in a critically acclaimed advertisement. By 1985, the high cost of its products, and power struggles between executives, caused problems. Wozniak stepped back from Apple amicably and pursued other ventures, while Jobs resigned bitterly and founded NeXT, taking some Apple employees with him.</think>
Alphabet, Amazon, Meta, Microsoft

user: According to this text, when did Disney become a public company?

assistant: <think>
Disney is one of the biggest and best-known companies in the world, and has been ranked number 53 on the 2022 Fortune 500 list of biggest companies in the United States by revenue. Since its founding, the company has won 135 Academy Awards, 26 of which have been awarded to Walt. The company has been said to have produced some of the greatest films of all time, as well as revolutionizing the theme park industry. Disney has been criticized for supposed plagiarism, depicting racial stereotypes in the past, and both including and lacking LGBT-related elements in its films. The company, which has been public since 1940, trades on the New York Stock Exchange (NYSE) with ticker symbol DIS and has been a component of the Dow Jones Industrial Average since 1991. In August 2020, just under two-thirds of the stock was owned by large financial institutions.</think>
According to this text, Disney became a publicly listed company on the New York Stock Exchange (NYSE) in 1940 with the ticker symbol DIS.