As tech companies begin to weave AI into all their products and all of our lives, the architects of this revolutionary technology often can't predict or explain their systems' behavior.

💡 Why it matters: This may be the scariest aspect of today's AI boom — and it's common knowledge among AI's builders, though not widely understood by everyone else, Axios managing editor of technology Scott Rosenberg writes.

• "It is not at all clear — not even to the scientists and programmers who build them — how or why the generative language and image models work," Palantir CEO Alex Karp wrote recently in The New York Times.

Zoom out: For decades, we've used computer systems that, given the same input, provide the same output.

• Generative AI systems, by contrast, aim to spin out multiple possibilities from a single prompt.
• You can easily end up with different answers to the same question.

🧠 Between the lines: Four researchers published a paper Thursday showing that users can defeat "guardrails" meant to bar AI systems from, for instance, explaining "how to make a bomb."

• The major chatbots, like ChatGPT, Bing and Bard, won't answer that question when asked directly. But they'll go into great detail if you append some additional code to the prompt.

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Stunning stat: Former President Trump's PAC has spent $40.2 million on legal costs to defend himself and his associates in the first half of this year, The Washington Post reports.

• That's more than Save America — the PAC — raised in the second quarter of 2023 and brings the group's total spending on Trump's post-presidential legal woes to around $56 million.

🔭 Zoom out: The former president is facing multiple criminal investigations at the state and federal levels, and he has been indicted in Florida and Manhattan.

🔎 Zoom in: Costs are adding up as Save America, which mostly raises money through small-dollar donations from Trump supporters around the country, takes on the legal bills of almost anyone in the former president's orbit who has been pulled into the investigations, The Post notes.

The U.S. is looking for computer code that it believes China has hidden within power grids and communication systems to disrupt American military operations, The New York Times reports.

• The first signs of a Chinese malware campaign came when Microsoft detected unknown code in telecommunication systems in Guam in May, but the campaign appears to be more widespread than that, U.S. officials and industry experts told the Times.
• The discoveries have raised fears that Chinese hackers have embedded code into U.S. systems that could interfere with an American effort to respond to a Beijing-Taiwan confrontation.

🖼️ The big picture: "Chinese cyberoperations seem to have taken a turn. The latest intrusions are different from those in the past because disruption, not surveillance, appears to be the objective," per The Times.

• Read on.

Out-of-office messages have been on the rise, Axios' Hope King writes.

• More working adults took vacation days in the first six months of this year than in any other January-to-June stretch in over a decade, The Wall Street Journal reports from government data.

🔭 Zoom out: Americans typically leave vacation days on the table each year.

• 46% say they take less time off than is offered, per a recent Pew survey.

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Republican presidential candidates have started to notice that Sen. Tim Scott's non-combative style is resonating — and they’re zeroing in on him for more scrutiny.

Why it matters: Scott has largely stayed above the fray as many of his Republican rivals spar around him, Axios' Erin Doherty writes.

• But his recent momentum in polls is bringing him into the crossfire and will test his "happy warrior" strategy.

👀 The intrigue: A confidential campaign memo from the DeSantis campaign said it expects "Scott to receive appropriate scrutiny in the weeks ahead," NBC News reported.

🖼️ Zoom out: Scott has bolstered his positioning in the crowded Republican primary as an antidote to the battles between former President Trump and Florida Gov. Ron DeSantis.

• He has one of the highest favorability ratings in the Republican field, according to a recent Quinnipiac University poll.

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The cost of attending weddings is rising as destination nuptials surge in popularity, Axios' Sareen Habeshian reports.

🧮 By the numbers: The global destination wedding market grew from $21.31 billion in 2022 to $28.31 billion in 2023 — and it's expected to grow to $78.89 billion in 2027, per the 2023 Destination Wedding Global Market Report.

• Last year, 18% of couples hosted a destination wedding, according to a survey by The Knot.

🗺️ Mexico is the most popular location for international destination weddings this year, according to The Knot, followed by Europe, the Caribbean and Costa Rica.

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American swimmer Katie Ledecky won her 16th individual world championship gold medal in Japan yesterday, breaking the record previously held by Michael Phelps.

• It was also her sixth gold medal in the women's 800-meter freestyle. She's the first swimmer in history to win a single worlds event that many times — and she's done it consecutively, ESPN reports.

🥽 What to watch: Ledecky is the favorite to take home gold in the women's 800- and 1500-meter freestyle races at the Paris 2024 Olympics. She's already the most decorated female swimmer of all time with six individual Olympic golds.

The ruins of Emperor Nero's lost theater — referred to in ancient Roman texts, but never found — have been discovered under the garden of a future Four Seasons Hotel, steps from the Vatican.

• Why it matters: The findings provide a rare look at a stratum of Roman history from the Roman Empire through to the 15th century. Among the discoveries: 10th-century goblets and pottery pieces that are unusual because so little is known about this period in Rome, AP reports.

Archaeologists found marble columns and gold-leaf decorated plaster, leading them to conclude that Nero's Theater — referred to in texts by Pliny the Elder, an ancient Roman author and philosopher — was indeed there, just off the Tiber River.

• Previously only seven glass chalices from that era had been found. The excavations of this one site turned up seven more.

Archaeologists had excavated deep under the walled garden of the Palazzo della Rovere since 2020 as part of planned renovations on the frescoed Renaissance building,

• The palazzo takes up a city block along the broad Via della Conciliazione leading to St. Peter's Square.

🔮 What's next: The portable antiquities will be moved to a museum. The ruins of the theater will be covered again after all studies are completed.

• The hotel is expected to be open for the Vatican's Jubilee 2025, when 30 million people are expected to flock to Rome.

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