Prime numbers are divisible only by themselves and 1. This free online game designed by a British mathematician helps sharpen your mental math skills by seeing how many prime numbers you can correctly identify in 60 seconds -- but that means clicking "no" on all those tricky non-primes like 87 (which might look prime but is 3x29) that also pop up. isthisprime.com/game/
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Just days ago, with the Tokyo Olympics underway, the site of the original Olympic games, Olympia, Greece, was evacuated due to wildfires. Intense wildfires are also raging across multiple locations in Turkey, Italy, and elsewhere around the Mediterranean. In fact, over the last two weeks all of the countries shown in red on this map have experienced serious wildfires, many of which are still burning.
Modern navies depend on cutting-edge technologies to detect threats. But what happens when those technologies are being spoofed? This article from Wired looks at one recently discovered ploy:
“According to analysis conducted by conservation technology nonprofit SkyTruth and Global Fishing Watch, over 100 warships from at least 14 European countries, Russia, and the US appear to have had their locations faked, sometimes for days at a time, since August 2020. Some of these tracks show the warships approaching foreign naval bases or intruding into disputed waters, activities that could escalate tension in hot spots like the Black Sea and the Baltic. Only a few of these fake tracks have previously been reported, and all share characteristics that suggest a common perpetrator. "By international law, all but the smallest commercial ships have to install AIS transponders. Using GPS data, these devices broadcast their identity, position, course, and speed to other ships in the area every few seconds, helping to keep crowded waterways safe. … Over 20 types of AIS message exist—some for supertankers, others for pleasure boaters—and each contains multiple data fields covering everything from navigational information to arcane communication settings. By closely comparing fields that are usually invisible to sailors, [maritime data analyst Bjorn] Bergman eventually found subtle differences between the fakes and the genuine data. He then used that pattern to write a query for a global historical database of AIS messages—and was shocked by the results. "His search found nearly a hundred sets of messages from multiple AIS data providers, going back as far as last September and spanning thousands of miles. More worrying still, the ships affected were almost exclusively military vessels from European and NATO countries, including at least two US nuclear submarines. … One suspect track, not previously reported, shows the US guided missile destroyer USS Roosevelt steaming 4 kilometers into Russian territorial waters around Kaliningrad last November, a maneuver that would have been recklessly provocative if real. … In recent months, the faking activity appeared in the Black Sea for the first time. In June someone faked the AIS tracks of the UK destroyer HMS Defender and the Dutch frigate HNLMS Evertsen to show a direct approach to the Russian naval base at Sevastopol, near occupied Crimea—even while webcams showed them at dock in Odessa. And on July 2, Bergman’s query turned up another apparently fake incursion into Russian-claimed waters off Crimea, this time supposedly by the UK patrol vessel HMS Trent, accompanied by an Italian frigate and a Bulgarian corvette. … "Bergman is not making public the exact pattern that distinguishes the fake AIS messages, for fear that the attacker or attackers might modify them to be less detectable.” www.wired.com/story/fake-warships-ais-signals-russia-crimea Occasionally one reads that climate change may benefit countries like Russia by delivering a longer growing season. However, this article from Geographical (UK) about the Russian Republic of Kalmykia, makes clear the issue is far more complex than that, especially as drought spreads on the steppe. geographical.co.uk/places/deserts/item/4101-the-republic-of-kalmykia-sits-at-the-forefront-of-global-climate-change-as-the-desert-encroaches
There's still plenty of time this summer and fall to get outside and explore. This article from Outside magazine highlights what editors have decided to be the best campground in each U.S. state. The article features trail maps in addition to photos. www.outsideonline.com/adventure-travel/destinations/north-america/the-best-campground-in-every-state/
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