241543903 (a.k.a “Heads in Freezers”) is a numerical keyword associated with a photo meme that involves people taking pictures with their heads in the freezer & sharing them online. By tagging a series of image files with a cryptic number, a high level of search engine optimization can be easily achieved. As a result, typing “241543903” into image search engines like Google Images successfully yields pages after pages of pictures showing people’s heads in freezers.
In 2009, David Horvitz started the “Heads in Freezers” meme. Participants took photos of their heads in freezers, tagged them with “241543903” and uploaded them to social media sites like Tumblr.

“The Lockheed Martin X-33 is an unmanned, sub-scale technology demonstrator suborbital spaceplane developed in the 1990s under the U.S. government-funded Space Launch Initiative program”. – Wikipedia

Photo: An Artist's Rendering Shows How Nasa's X-33 Technology Demonstrator, A Cost-Cutting Fully Reusable Single-Stage-To-Orbit Space Vehicle, Will Look Upon Completion. The 67 Foot-Long, 278,600 Pound, Twin Engine Space Vehicle, Capable Of Reaching Speeds In Excess Of Mach 15, Will Lead To The Construction Of A 127 Foot-Long, 2,186,000 Pound Version With Seven Engines And A 50,000 Pound Payload Capacity Called The “Venturestar”. (Photo By Nasa/Getty Images)

Mahmoud El Komy, a 26-year-old Egyptian mechatronics engineer, stands beside Cira 3, a remote-controlled robot that runs tests on suspected coronavirus disease (COVID-19) patients, to limit the human exposure to the virus, amid a second wave of infections in Tanta, Egypt, November 18, 2020. (Photo by Mohamed Abd El Ghany/Reuters)

This dyed straw is grown in Ban Dong Saen Suk, Sakon Nakhon province, Thailand on September 28, 2021. Sarawut Intharap, 38, an engineer who capture the image, said: “The straw is entwined together to make mats used for sleeping and eating and they are sold at around £2.50 (3.40 USD) a mat at the local market”. (Photo by Sarawut Intarob/Solent News)

Advanced Space Suit Engineer at NASA Kristine Davis wears the xEMU prototype space suit for the next astronaut to the moon by 2024, during its presentation at NASA headquarters in Washington, U.S., October 15, 2019. (Photo by Carlos Jasso/Reuters)

The AMECA robot from the manufacturer Engineered Arts is in the Deutsches Museum Nuremberg (Future Museum), Bavaria on May 3, 2022. AMECA is a humanoid robot that will be presented to the general public for the first time in Europe as part of the Blue Night on May 7, 2022 in Nuremberg. (Photo by Daniel Karmann/dpa/Alamy Live News)

Madras Engineers Group (MEG) soldiers perform “Kalaripayattu”, a traditional martial art from Kerala, during celebrations for the India's 74th Republic Day in Bengaluru on January 26, 2023. (Photo by Manjunath Kiran/AFP Photo)

Dunnottar Castleis a ruined medieval fortress located upon a rocky headland on the north-east coast of Scotland, about 3 kilometres (1.9 mi) south of Stonehaven. The surviving buildings are largely of the 15th and 16th centuries, but the site is believed to have been fortified in the Early Middle Ages. Dunnottar has played a prominent role in the history of Scotland through to the 18th-century Jacobite risings because of its strategic location and the strength of its situation. Dunnottar is best known as the place where the Honours of Scotland, the Scottish crown jewels, were hidden from Oliver Cromwell's invading army in the 17th century. The property of the Keiths from the 14th century, and the seat of the Earl Marischal, Dunnottar declined after the last Earl forfeited his titles by taking part in the Jacobite rebellion of 1715. The castle was restored in the 20th century and is now open to the public.