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🔗 Computer Security 🔗 Computer Security/Computing 🔗 Cryptography 🔗 Cryptography/Computer science

In computer security, a cold boot attack (or to a lesser extent, a platform reset attack) is a type of side channel attack in which an attacker with physical access to a computer performs a memory dump of a computer's random access memory by performing a hard reset of the target machine. Typically, cold boot attacks are used to retrieve encryption keys from a running operating system for malicious or criminal investigative reasons. The attack relies on the data remanence property of DRAM and SRAM to retrieve memory contents that remain readable in the seconds to minutes after power has been removed.

An attacker with physical access to a running computer typically executes a cold boot attack by cold-booting the machine and booting a lightweight operating system from a removable disk to dump the contents of pre-boot physical memory to a file. An attacker is then free to analyze the data dumped from memory to find sensitive data, such as the keys, using various forms of key finding attacks. Since cold boot attacks target random access memory, full disk encryption schemes, even with a trusted platform module installed are ineffective against this kind of attack. This is because the problem is fundamentally a hardware (insecure memory) and not a software issue. However, malicious access can be prevented by limiting physical access and using modern techniques to avoid storing sensitive data in random access memory.

🔗 Computing

In computing, an oops is a deviation from correct behavior of the Linux kernel, one that produces a certain error log. The better-known kernel panic condition results from many kinds of oops, but other instances of an oops event may allow continued operation with compromised reliability. The term does not stand for anything, other than that it is a simple mistake.

When the kernel detects a problem, it kills any offending processes and prints an oops message, which Linux kernel engineers can use in debugging the condition that created the oops and fixing the underlying programming error. After a system has experienced an oops, some internal resources may no longer be operational. Thus, even if the system appears to work correctly, undesirable side effects may have resulted from the active task being killed. A kernel oops often leads to a kernel panic when the system attempts to use resources that have been lost.

The official Linux kernel documentation regarding oops messages resides in the file Documentation/admin-guide/bug-hunting.rst of the kernel sources. Some logger configurations may affect the ability to collect oops messages. The kerneloops software can collect and submit kernel oopses to a repository such as the www.kerneloops.org website, which provides statistics and public access to reported oopses.

For a person not familiar with technical details of computers and operating systems, an oops message might look confusing. Unlike other operating systems such as Windows or macOS, Linux chooses to present details explaining the crash of the kernel rather than display a simplified, user-friendly message, such as the BSoD on Windows. A simplified crash screen has been proposed a few times, however currently none are in development.

🔗 Technology 🔗 Energy

A solar pond is a pool of saltwater which collects and stores solar thermal energy. The saltwater naturally forms a vertical salinity gradient also known as a "halocline", in which low-salinity water floats on top of high-salinity water. The layers of salt solutions increase in concentration (and therefore density) with depth. Below a certain depth, the solution has a uniformly high salt concentration.

🔗 Computing 🔗 Computing/Networking

Sorcerer's Apprentice Syndrome (SAS) is a network protocol flaw in the original versions of TFTP. It was named after Goethe's poem "Der Zauberlehrling" (popularized by the "Sorcerer's Apprentice" segment of the animated film Fantasia), because the details of its operation closely resemble the disaster that befalls the sorcerer's apprentice: the problem resulted in an ever-growing replication of every packet in the transfer.

The problem occurred because of a known failure mode of the internetwork which, through a mistake on the part of the TFTP protocol designers, was not taken into account when the protocol was designed; the failure mode interacted with several details of the mechanisms of TFTP to produce SAS.

🔗 Time

Solar time is a calculation of the passage of time based on the position of the Sun in the sky. The fundamental unit of solar time is the day. Two types of solar time are apparent solar time (sundial time) and mean solar time (clock time).

🔗 United States 🔗 Film 🔗 Library of Congress 🔗 Film/American cinema 🔗 United States/Film - American cinema 🔗 Film/Core

The Conversation is a 1974 American mystery thriller film written, produced and directed by Francis Ford Coppola and starring Gene Hackman with supporting roles by John Cazale, Allen Garfield, Cindy Williams, Frederic Forrest, Harrison Ford, Teri Garr and Robert Duvall.

The plot revolves around a surveillance expert and the moral dilemma he faces when his recordings reveal a potential murder. Coppola cited the 1966 film Blowup as a key influence. However, since the film was released to theaters just a few months before Richard Nixon resigned as President, he felt that audiences interpreted the film to be a reaction to the Watergate scandal. The Conversation has won critical acclaim and multiple accolades, including the Grand Prix du Festival International du Film, the highest honor at the 1974 Cannes Film Festival. It was nominated for three Academy Awards in 1974 and lost Best Picture to The Godfather Part II, another Francis Ford Coppola film. In 1995, it was selected for preservation in the National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant".

🔗 Architecture 🔗 Firearms 🔗 Metalworking

A shot tower is a tower designed for the production of small diameter shot balls by freefall of molten lead, which is then caught in a water basin. The shot is primarily used for projectiles in shotguns, and also for ballast, radiation shielding and other applications where small lead balls are useful.

🔗 Biography 🔗 Economics 🔗 Biography/science and academia 🔗 United Kingdom 🔗 Virginia 🔗 Chicago 🔗 Virginia/Albemarle County

Ronald Harry Coase (; 29 December 1910 – 2 September 2013) was a British economist and author. He was the Clifton R. Musser Professor of Economics at the University of Chicago Law School, where he arrived in 1964 and remained for the rest of his life. He received the Nobel Memorial Prize in Economic Sciences in 1991.

Coase, who believed economists should study real markets and not theoretical ones, established the case for the corporation as a means to pay the costs of operating a marketplace. Coase is best known for two articles in particular: "The Nature of the Firm" (1937), which introduces the concept of transaction costs to explain the nature and limits of firms; and "The Problem of Social Cost" (1960), which suggests that well-defined property rights could overcome the problems of externalities (see Coase theorem). Additionally, Coase's transaction costs approach is currently influential in modern organizational economics, where it was reintroduced by Oliver E. Williamson.

🔗 Animals

Tardigrades (), known colloquially as water bears or moss piglets, are a phylum of water-dwelling eight-legged segmented micro-animals. They were first described by the German zoologist Johann August Ephraim Goeze in 1773, who called them little water bears. In 1777, the Italian biologist Lazzaro Spallanzani named them Tardigrada, which means "slow steppers".

They have been found everywhere, from mountaintops to the deep sea and mud volcanoes, and from tropical rainforests to the Antarctic. Tardigrades are among the most resilient animals known, with individual species able to survive extreme conditions—such as exposure to extreme temperatures, extreme pressures (both high and low), air deprivation, radiation, dehydration, and starvation—that would quickly kill most other known forms of life. Tardigrades have survived exposure to outer space. About 1,300 known species form the phylum Tardigrada, a part of the superphylum Ecdysozoa. The earliest known true members of the group are known from Cretaceous amber in North America, but are essentially modern forms, and therefore likely have a significantly earlier origin, as they diverged from their closest relatives in the Cambrian, over 500 million years ago.

Tardigrades are usually about 0.5 mm (0.02 in) long when fully grown. They are short and plump, with four pairs of legs, each ending in claws (usually four to eight) or sucking disks. Tardigrades are prevalent in mosses and lichens and feed on plant cells, algae, and small invertebrates. When collected, they may be viewed under a low-power microscope, making them accessible to students and amateur scientists.