The document discusses why missiles fired from stealth fighters are difficult to evade. It explains that radar warning receivers and missile approach warning systems typically do not detect missile launches until it is too late to evade. Against stealth fighters like the F-22 and F-35, the target often does not detect the launching aircraft at all until the missile activates its radar seeker just prior to impact, giving the target no time to evade or deploy countermeasures. The element of surprise provided by stealth aircraft makes the missiles much more likely to hit their targets.
The document discusses why missiles fired from stealth fighters are difficult to evade. It explains that radar warning receivers and missile approach warning systems typically do not detect missile launches until it is too late to evade. Against stealth fighters like the F-22 and F-35, the target often does not detect the launching aircraft at all until the missile activates its radar seeker just prior to impact, giving the target no time to evade or deploy countermeasures. The element of surprise provided by stealth aircraft makes the missiles much more likely to hit their targets.
SpaceX is developing a new kind of space station called Starship that will be the world's first commercial space station. Starship will be a large self-sustaining city in space capable of hosting up to 10,000 people and will be operational by 2030. The space station will be built using SpaceX's next-generation Starship rocket and will serve both government and private astronauts and tourists.
The Perseverance rover successfully deployed NASA's Ingenuity helicopter onto the surface of Mars. Ingenuity survived its first night on Mars after being dropped off by Perseverance. The $85 million helicopter will attempt the first powered, controlled flight on another planet in the coming weeks, with the flight pre-programmed due to delays in signal transmission between Earth and Mars.
The South Atlantic Anomaly is an area of weakening magnetic field stretching from South America to Africa that has been intensifying over the last 200 years, which could signal an impending reversal of Earth's magnetic field. Geophysicists are examining archaeological artifacts to understand changes in our planet's magnetic field over the past 3,000 years. Climate change and accelerated melting of glaciers and ice since the 1990s has caused Earth's magnetic poles to drift more rapidly toward 26 degrees east at a rate of about 3.3 millimeters per year as more water moves onto land.
The document discusses drones and their use for stockpile measurement. It explains that having a lower ground sampling distance (GSD) allows for more accurate measurement of a stockpile's surface area, which reduces differences between real and measured volumes. It also provides links to lists of the best indoor drones and a Twitter post.
This document discusses computer science and information technology topics including operating systems, computer hardware components, single board computers, audio synthesis techniques, engineering simulation software, diagramming software, decision tree software, and how augmented and virtual reality can help reduce skills gaps in manufacturing. It provides an overview of key concepts and tools related to information technology and computer science.
This study examined antibody prevalence in the Brazilian cities of Manaus and Sao Paulo following COVID-19 outbreaks. In Manaus, the study estimated that between 44-66% of the population was infected by July, with infection rates reaching the herd immunity threshold in late April. In Sao Paulo, antibody prevalence was estimated at 29% by October, with a slower rise and fall of cases and deaths compared to Manaus. Both cities had high total COVID-19 mortality rates despite different infection rates, likely due to higher infection fatality rates in Sao Paulo.