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Sunday, September 22, 2019

Understanding Movie Physics: Armageddon


Armageddon. The end of the world. Humanity's execution by meteor. That is what would have happened in the movie if Bruce Willis' character, Harry Stamper, and his team had not drilled a hole in the meteor, threw a nuke inside it, and blew it up. To be brutally honest however, that plan would have ultimately failed and humanity would have perished...even NASA has confirmed that the nuke idea used in movie would fail. Luckily enough, in reality, NASA has contingency plans in place that actually will protect the Earth from asteroids. 

Last year, the White House Office of Science and Technology released a plan called the "National Near-Earth Object Preparedness Strategy and Action Plan". The document describes 5 goals NASA is going to take over the next decade to deal with any asteroid threat. None of which requiring a drilling team - or even an a regular astronaut for that matter- to go into space and forgo the threat.

It will be to much to go into the specifics of the specifics of the objectives that are laid out in the 18 paged plan, but it will be good to provide a basic overview:

  • Objective 1: Improve Surveying Methods and Technology 
    • In a sense, find areas to improve existing survey telescopes and provide those using them with new training to make them proficient in the use of the new technology in order to upgrade NASA's process of detecting, tracking, and analyzing asteroids that may pose a threat to the Earth. These improvements will help "reduce current levels of uncertainty and aid in more accurate modeling and more effective decision-making," as described by the document.



Image result for asteroid survey telescopes
  • Objective 2: Estimation of Probability Improvement
    • After improving the tracking and basic analyzing of an asteroids, NASA wants to work on upgrading the process of putting all that information together to get the most accurate prediction possible of when and where on the Earth a possible asteroid could impact the Earth. With this information, more "emergency-handling" qualified agencies like the Federal Emergency Management Agency (FEMA) can come up with the best way to approach the situation when dealing with an incoming asteroid.
  • Objective 3: Deflection Ideas

    • Once as much possible information and estimations have been made, NASA is tasked inventing new technologies and methods that will help remove the threat of an incoming asteroid, primarily by moving it out of the way. One such method is the idea of a Near-Earth Reconnaissance mission in which a satellite or spacecraft would move in the direction of the oncoming object and in some way move it out of line with the Earth and neutralize the threat (this is where the new technologies I mentioned before will be needed).
    • NASA plans on testing its Double Asteroid Redirection Test (DART) in 2022 when it encounters the asteroid Didymos in 2022. The plan for this is to launch the DART probe in 2021 and by some time 2022 have the probe crash in the asteroid at 21,600 mph and study the effects and determine how much force is needed to move an asteroid that could potentially hit Earth out of its orbit.
                                            
  • Objective  4: Improve International Teamwork
    • This goal aims to reach a high enough global cooperation under the guidance of the United States in order to properly prepare the rest of the world of an asteroid strike and the aftermath of one should deflection attempts fail.
    • To help achieve this goal, NASA's Planetary Defense Coordination Office is constantly in talks with the United Nations in order to decide what a global response to an asteroid strike should look like. 
  • Objective 5: The Job of the United States
    • The final objective tasks the US government and all its appropriate agencies with developing a plan in the event of an actual, potentially devastating asteroid threat and a plan for a possible aftermath as well.
    • NASA's job would mainly be enacting NEO impact plans in hopes of deflecting the asteroid and FEMA would work to notify anyone who would be threatened by the asteroid and would send out emergency responders to help with a recovery process if its needed.

Wednesday, September 18, 2019

Understanding Movie Physics: Eraser



Arnold Schwarzenegger. Action scenes. Rail guns. Inaccurate physics. All of these factors contribute to the thrill that is the movie Eraser. However, it's that last factor, inaccurate physics, that tends to bug many of this movie's viewers. Especially the physics that violate the law of the conservation of momentum.


The scene posted below, like many of the other's seen throughout of the movie, show a human, often either Arnold's character or one of the enemy thugs, firing a weapon called a rail gun. In the movie, a rail gun is explained to be a gun that uses electromagnetic energy to fire a lightweight aluminum bullet at almost the speed of light, and it is here that we discover the inaccuracy of these scenes.


Eraser Scene:

https://youtu.be/IDC-tIQpJ_0 

Whenever one of the speeding rounds hits a human body, that individual is most often sent flying across whatever environment they are in , but the shooter is always left unaffected and in the same position as they were before. This is the violation of the law of  conservation of moment as previously mentioned, which states "In the absence of external forces interacting upon an object or a system of objects, the total momentum will not change". This basically states that the momentum before and after the collision must be the same. Therefore the shooter must face a negative 
recoil velocity that sends them flying backwards that is equivalent to the positive velocity of the bullet being shot forward in order for the momentum's of each object to cancel each other out and get a total momentum value of zero that was present before the collision. Another approach is that neither the shooter or the one shot face any kind of momentum that would send them flying and instead don't get sent flying like before.

Due to the complete disregard of the law of conservation of momentum, I am rating this movie with an RP (retch physics) rating.