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Momentumous

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  1. Momentumous
    I've mention in a previous post how poorly magic and physics mix. That being said, there are many variations on how magic works depending on what fiction you're referring to. In most fictions I've seen, practicing magic tends to simply require a lot of mental focus and memorizing a few words. This concept is entirely impossible in the real world if the fundamental laws of physics hold true. Energy can't be created or destroyed, simply changed. Magic tends to make things move with no physical cause, thus making it impossible.
    Some fictions, however, take a more plausible route. I've read a few books where in fact it takes just as much energy to do something with magic as it would to get up and do it yourself--thus making the only major convenience of magic that you can do things faster. In this theory, you could attempt to do something with magic and end up essentially committing suicide because you tried to do something that you simply don't have enough strength to do.
    By far this is the most plausible theory I've ever heard. For one it doesn't mess quite so much with our laws of physics. Energy created by your body is still being used to make something happen, thus energy is still conserved. This means that essentially the magic wielder is using their mind to direct energy in less-than-conventional ways.
    True, it's still pretty far-fetched. Maybe I'm a hopeless romantic, but I'd still like to think it's possible. As it stands, humans on average only use 10% of their brain for sitting and thinking, who knows what'd be possible if we could find a way to have constant access to the other 90%, no matter what the activity!
  2. Momentumous
    Of all the tv shows we watch, each and every one retains varying levels of accuracy with respect to physics. Here's my personal reflection on the accuracy of some shows I watch:

    The Big Bang Theory:
    The big bang theory is a hilarious comedy relating to the lives of social awkward phsyicists. We don't have any problems with someone leaping too far out of a window or something blowing up when it shouldn't because... well that stuff doesn't happen in the big bang theory. Noteably, however, is all the physics they talk about. The directors of the show truly put a lot of research into making sure things are accurate. Every single equation you see on white boards in the background are real, and everything they talk about (though I doubt the actors actually do them) are real physics concepts and researches. Funny, and realistic? I think yes!

    Myth Busters:
    This one is pretty obvious. The whole concept of the show is to use phsyics to disprove or prove common place misconceptions or wives tales. In fact the whole concept of the show is kind of how I'm currently treating all the shows being reviewed. I approve.

    Merlin:
    Merlin is a show in a magical world about (you guessed it) Merlin, a warlock who is destined to protect the King Arthur. Considering the magical nature of the world they live in, it's hard to say what is or isn't accurate. Physics and magic are concepts that don't mix well. Particularly since magic often seems to create and destroy matter and energy without putting any effort into it--which goes against the most basic and fundamental concepts of physics. So it's truly hard to judge the accuracy of a show like Merlin. But if we disregard the impossibility of magic and still look at the physics, Merlin is actually pretty plausible. It's not too hard to keep it physics-ly plausible, it's pretty easy to stay accurate when you're only worrying about things that can happen in the medieval ages. Overall, with disregard to magic, Merlin gets my approval!
  3. Momentumous

    Bending a bullet?

    By Momentumous,

    Yes, this has indefinitely been proven impossible, but just how impossible?

    Google appears to have failed me for actual statistics on the infamous gun used in Wanted for the curved bullet, so lets just say this pistol has a muzzle velocity of 250 m/s (810 ft/s). Lets also say the barrel length is 5". So the bullet sits at rest with a velocity of 0 to 250 m/s over 5". That means in .000508 seconds (v=(x/t)=> x/v=t) the bullet got to the end of the barrel. Which also means it had an acceleration of about 500000 m/s^2 (a=(v/t)).

    With this in mind, note that you'd also have to have IMPECCABLE timing so that you change the motion of the muzzle JUST as the bullet is about to leave, nicking the bullet and therefore affecting its direction. So if you're so lucky as to have the timing down, you'd have .000508 seconds to move the muzzle.

    I don't know about you, but when I jerk my hand as fast as possible, I can still SEE the movement, it'd take some sort of crazy robot that can accelerate faster than 500000 m/s^2 to even hope to curve a bullet.
    Plausible? With modern technology, maybe, but certainly not by hand.

    (please note I know very little about guns from prior knowledge, these are theoretical values deduced from numbers I found online with some sort of frequency).
  4. Momentumous

    Spiderman's webs

    By Momentumous,

    Aside from the snazzy suit, you know who you're looking at is Spiderman as soon as stick webbing starts shooting from his hands.

    So if Spiderman does manage to shoot web through his spandexy-body-suit, this webbing must be seriously strong. For one, it can be shot through the air quick enough to go in relatively straight lines, and then miraculously latch on to some sort of object, and THEN can hold all of Spiderman's bulk!

    Spiderman is a hero, so he's probably around 5'10 and weighs 160 pounds (comprised mostly of muscle of course). This means that this webbing can can hold at LEAST 711.5 Newtons.

    But no, it can hold more than that!
    In one of the Spiderman movies, Spidey shoots out some webbing to catch a falling bus Presuming this is a smaller school bus, empty it weighs around 10,000 pounds. Considering the mixed crowd, its hard to say how much the people weigh, but lets say there were 50 people (comfortable seating) of each 100 pounds. That's another 5000 pounds, making the weight of the bus 15,000 pounds. So this webbing can actually hold up to a force of at LEAST 66678.22 N. That's pretty tough stuff!

    Oh, and spiderman can break it with a flick of his wrist. No big deal.
  6. Momentumous

    The Bumble Bee

    By Momentumous,

    I've always just kind of assumed nature optimized the way all things are formed for what they're designed to do. Apparently, however, this is not the case.

    Though it's a myth that bumble bees shouldn't be able to fly with their rather small wings and rather large body, the way in which they do fly is incredibly inefficient. Essentially they move around the air through sheer brute force. Not only are their wings unsynchronized, but the way in which they flap i makes it impossible for air flow to aid the bee in traveling through the air more easily.
    Its huge thorax combined with the high energy necture diet allow for the necessary force to create thrust with such tiny wings for such a heavy body. It's speculated that this brute-force method was developed so that bumble bees can maneuver through the air more easily, sacrificing overall flying efficiency, or as a result of the already wide body of the bee.
    More on this can be found at: http://www.sciencedaily.com/releases/2009/05/090507194511.htm
  7. Momentumous
    Now, don't get me wrong, I truly appreciate the genius of this handsome devil's creation, and honestly I'm not too educated in all the details. However, part of what makes fiction so great is being able to imagine it being feasible ..and that's not so easy when you have even a basic understanding of physics. Honestly, every experience I've had watching a superman movie starts of fantastic, and then gets interrupted by some obnoxious little inconceivable detail that drives me insane and ruins the rest of the movie.

    For one, at least in the movies I've seen, Superman gets his strength because he's from a planet with a much higher gravitational constant. Nice physics-y touch. So this means even as a baby, to be able to move at all he's got some sort of much stronger muscle. With the structure of the human body considered, I really don't see how this is feasible without these muscles being pretty darn heavy. How do his adopted parents just pick him up like it's nothing? Baby or not this kid's gotta be heavy! But then, there's the fantasy factor, I suppose there might be some new biological thing going on there.

    So what about flying. Is this magic, or just an extension of his strength? I can't really argue against magic, and I honestly don't know what the intention there is, but there's no way it's an extension of super-human strength. I can see immense leaps that are so huge that perhaps they mimic flying, but he wouldn't be able to bend his path and what-not simply by will of mind.
    What's more, how does the guy leave the ground without a mark half the time? I mean, the force to leap as high in the air as fast as he does would be pretty darn significant! Sure, he slams in the ground for dramatic effect all the time, but I think his take off would have a little more bravado as well. I mean, think about it. One second he's on the ground and couple seconds later he's hundreds of feet in the air? I'd say that'd put a crack in any concrete...

    And what about catching the tumbling damsel in distress! This is the man of steel we're talking about here; and a super macho man at that! So a macho-man without superhuman strength tends to have pretty dense muscles... meaning the harder you hit him the more it hurts you as well. Superman is indestructable to an extent, so I'm certainly not going to argue that catching someone would do him any damage, but what about the person he's catching?! Someone falling stories and stories down (in many cases easily hitting terminal velocity), and he just swoops in and catches them feet from their imminent death. If you ask me, they should have just met death again in a new manner. For one, that's not NEARLY enough time for a sufficient impulse to be even close to feasibly safe. You'd take all of the person's momentum and jerk them in a completely new direction almost instantaneously... that's a death by broken everything I'd say. Furthermore, if the change in direction didn't kill you, you were caught by two steely arms. At that kind of speed, that'd break quite a few bones by my judgment... so death by broken everything x 2!

    I could go on, really, but the more I write the more annoying they get. I suppose it's time to let the classic rest. Maybe the new superman movies won't be so flawed!
  8. Momentumous

    Physics of skiing!

    By Momentumous,

    Yesterday I went skiing for the first time (and no, I did NOT look that cool). And somehow as I was going down the slopes (very VERY slowly with lots of falling involved), I realized there's a LOT more physics going on that one would think initially.
    For one, there's a LOT of friction problems. Obviously the goal of most skiers is minimal friction, and therefore go faster! However that was NOT my goal, considering speed led to panic which lead to crazy turns which lead to the unavoidable fall. So my goal was to maximize friction.
    The easiest way to do this is to make a wedge and to turn a lot--go across the slope at small angles rather than straight down. This helps for obvious reasons; with the wedge, the edge of your skiis dig into the snow more, causing more friction and removing some of the slick, waxed surface area from the low-friction snow. The turns are a little more complicated, considering you can go QUITE fast if you do them a certain way. However in a sense the concept of using turns to go slow is simple; the ground you cover when you go down a slope in wide turns is less than if you were to go straight down. Energy is expended on turning, and friction is increased by going more sideways (using more of the edge of the ski than the waxed bottom) rather than going strait down.

    There's a lot more physics involved when you look at moguls, jumps, and even the design of the skis themselves. However, considering I've only gone once, I'm going to leave an analysis of that up to the experts.



    Friendly ski tip to beginners: NEVER fall backwards downhill on your skis if you can avoid it, you will NOT stop going down the slope
  9. Momentumous
    With a little digging, I was able to figure out how transitions lenses really work on this website:
    http://en-us.transitions.com/Why-Transitions/The-Technology/Photocromic-tech/

    To sum it up, within the lenses are photochromic molecules. These molecules react to UV rays and actually change their structure when exposed, which is what causes the lens to darken.

    And some fundamentals of weather still play into effect. When it's hot, the lenses react more quickly because the heat allows molecules to move faster, which in turn means the photochromic molecules can change their shape more quickly. The reverse is also true for the cold, since molecules move more slowly in cold tempurtures, the lenses will react more slowly in cold temperatures as well.
  10. Momentumous
    For some of us, taking the lovely AP-C Physics course was simply to have that shiny passing grade to rub in the face of colleges and use to squeeze out some money from them--a "hey look I'm s-m-r-t!" badge if you will. Nearly everyone in the class thought about it economically when considering taking it; taking it in highschool is FAR cheaper than in college, and allows more focus on new materials, maybe it'll draw some scholarships, help get a job ect. But physics goes beyond that. Here's a list of some majors requiring a noteworthy amount of physics:

    Acoustics
    Aeronautical Engineer
    Agricultural Engineer
    Air Traffic Controller
    Airline Pilot
    Archaeologist
    Architect
    Astronomer
    Audio Engineer
    Broadcasting
    Cartographer
    Chartered Surveyor
    Civil Engineer
    Climatologist
    Clinical Scientist
    Computing
    Designer
    Doctor
    Electrical Engineer
    Energy
    Engineering
    Environment
    Environmental Scientist
    Forensic Scientist
    Gas Engineer
    Geologist
    Health Services
    Journalist
    Laboratory Technician
    Marine Engineering
    Mathematician
    Mechanical Engineer
    Medical Physicist
    Meteorologist
    Naval Architect
    Naval Career
    Nuclear Scientist
    Oceanographer
    Operational Research
    Patent Agent
    Patent Examiner
    Pharmacist
    Radiation Protection
    Radiographer
    Scientific Officer (Government)
    Space and Remote Sensing
    Teacher
    Transport
    Water Management

    And here's a list of some of the best paying careers:

    1. Doctors/surgeons
    2. Orthodontists/dentists
    3. Cheif executive officer
    4. Petroleum engineer
    5. Lawyer
    6. Architectural and engineer manigers
    7. Natural science manager
    8. Marketing manager
    9. Computer info. systems manager
    10. Industrial-organizational psychologist
    11. Financial manager
    12. Airline pilots, co-pilots and flight engineers
    13. Sales manager
    14. Air traffic controller
    15. Pharmacist

    Note the frequent overlaps? That's because physics is essential in a world of technological dependency and progression. So not only will physics save you money now, but it could very potentially make you plenty in the future!
  11. Momentumous
    Physics plays a huge roll in skiing--and yes, I've posted about such before, but a 3 day ski trip really struck some new physics relations home.

    Revelation one:
    When turning, bending the knees into the turn, and standing up out of the turn actually makes the turn far more efficent and more fun. Part of the efficiency is simply Newton's law--every reaction has an equal and opposite reaction. By bending, you're thus using your body weight to turn more forcefully with the aid of the shape and design of the ski. Depending on the circumstances of your turn, bending your knees can also flex the skis themselves partially, making them pop back to their normal shape and thus aiding the turn.

    Revelation two:
    Too much wax is a bad thing. After every ski trip good ski care mandates that you wax your skis. This is to help mildly smooth out any small scrapes and to thus make the flat surface smoother, thus creating less friction. However, too much wax can have the opposite effect seeing as wax is...well, sticky, and has a far higher coefficient of friction than the actual material skis are made out of. So if you don't want your skis to catch in snow so much, make sure you wiped off the wax well.

    Revelation three:
    Using the edges is a good idea. Beginners often learn to ski in wedge form, which means they use the outside edge of both skis and basically just plow through the snow. Though this works, its working completely against the design of the ski and isn't exactly efficient. If you ski in parallel thus using an outside and inside edge of the ski, the sharp part cuts into the snow in the curved shape of the ski. This in fact means that (thanks to physics!) using edges allows the skis to do half the work for you! And lets be frank, less work in one slope means more slopes to come! Efficiency is our friend
  12. Momentumous
    I've been pondering this for a while and be it because I haven't really looked at equations nor truly tried applying equations in creative ways, I've stumbled across a relationship I can't seem to figure out (maybe someone could answer it with a blog? {I'm such a nice person}).

    So I have a volvo s60, and for its size, its a pretty hefty car. Being so massive, my dad has often preached what a splendid winter car it is, as its weight increases friction and thus provides better traction in bad weather.
    However a car of a greater mass has greater momentum, which should make it harder to stop the car once it's in motion.
    So I suppose my question is, is there a way to relate momentum's impact on velocity to frictional impact on velocity when referring to an object of constant mass? Theoretically if the two are somehow related, wouldn't there be an optimum mass for maximizing traction while minimizing momentum?
  13. Momentumous
    Does anyone else feel it too? End of the year syndrome... it's kinda like senioritis, except anyone can get it. Essentially what it means is a complete and total lack of motivation to do anything whatsoever. I don't know about you, but it's hitting me hard right now, with 5 days left of school and numerous projects not yet completed.
    So lets remind ourselves why we like physics, shall we?

    http://www.youtube.com/watch?v=_3Zf1f3-JYs

    Because physics is everywhere, and it can be funny!
    But most importantly, because it tells us how much peter griffin weighs.
  14. Momentumous
    1) The course is HARD-- and it doesn't get easier as you go along. The longer you wait, the harder it gets, and the more you'll have to do.

    2) Deterrence-- as this challenging work gets harder and harder, you're going to be less and less inclined to do it. Think about it, I'd be far more proactive about climbing a 5 foot cliff than a 100 foot cliff, if you do it in chunks it won't seem so bad.

    3) Imagination-block-- if you have ANYTHING creative to do (like blog posts for example), you're going to have to be full of ideas. If you have to sit there and think of 10 different things to talk about in one day rather than over 10 weeks, it's going to be a LOT harder to think of something.

    4) Cognitive function-- when a body is tired or stressed out, decreased cognitive function (you're ability to think at optimum levels) is a common side effect. Like I said, this course is HARD, you're going to want all the cognitive function you can get!

    5) The test date isn't changing-- due dates are the procrastinators worst enemy; and trust me, they don't move because you have a tradgic illness called procrastination. The AP exam is set and in May, regardless of whether you try to cram the stuff in the day before or months before.

    6) Memory retention-- repetition is your friend when you're trying to memorize something. If you don't leave yourself enough time to practice and repeat everything you need to memorize (and there's a LOT of that in any physics class), you're just not going to remember it. And it's pretty common knowledge you're not really going to remember what you crammed an hour ago--you're going to remember what you've practiced so many times it seems stupid to not remember.

    7) You work better in pieces-- alright maybe not literally in pieces, but work in small chunks is a good thing! By taking things in small portions, deterence lowers and cognitive function is at a higher level (wooo big words!) making it optimum to work as the work comes rather than saving it until right before it's due.

    8) The teacher knows what they're doing-- meaning if they give you lots of time to do something, it's PROBABLY because you actually need it. You can never really tell how long something is actually going to take you until you start it--which means you could pretty much s.o.l. if you save something till last minute

    9) Spontaneous fun--let's be real, NO ONE ever makes plans to do fun things anymore. Don't you want to be able to be spontaneous?! No one wants to say "No, I can't go {insert beloved task} because I have physics to do." Get it over with and open up time to enjoy a little spontenaity

    10) Because I said so; no better reason than that
  15. Momentumous

    Ice skating!

    By Momentumous,

    Ice skating has a lot of obvious physics involved.

    For one, you could easily look at the centripital motion invovled when a figure skater spins. Conservation of angular momentum plays a huge roll in how they control the speed of their spins, but we've all heard that before.

    There's physics involved in the very fundamental movement of iceskates. When you iceskate, you put a lot of pressure on a very small, thin surface area. This force, as well as the friction between the blade and the ice, actually causes the ice just beneath the skate to melt. So in actuality, you're not ice skating--you're water skating. This is why ice skating leaves tracks behind you; because you melted the ice in divets where you're skates were. The friction is also why you can glide to a stop pretty easily-- since there's enough friction to melt the ice, there's plenty of friction to slow the skates to a stop. If you didn't keep propeling yourself and adding force into the equation, you'd never go anywhere.
    Friction plays a HUGE roll in control during the winter!
  16. Momentumous

    My internship!

    By Momentumous,

    I can't believe I didn't think of this as a subject earlier, I did LOTS of physics in my astronomical imaging internship!

    Okay, well, in reality I more looked at images and programs and readings, I didn't actually DO the physics, but there's a lot of physics behind what I did.

    My internship was focused on assisting with research around the stellar phase called planetary nebula. This is a post-red-giant phase of smaller stars. The majority of the gases within the star have been burned up or converted through fusion to different elements. In the planetary nebula phase, the outer layers of the star are now composed of ionized gasses, and the core becomes visible. Planetary nebula come in many different shapes, and the theories behind why they form some of the more obscure shapes is still hotly debated, though it is widely agree that interstellar winds create the basic shapes.

    I asked one day what an interstellar wind actually was, and received a lecture that resulted in this whiteboard:


    [ATTACH=CONFIG]529[/ATTACH]

    Mind you, many things have been erased and written over on this board to explain, and the lecture took at LEAST an hour as well as numerous pages of notes. So I will not be explaining interstellar winds, mostly because its a lengthy explanation and marginally because I don't remember most of it.

    The most relevant physics to what I was doing had to do with the ionized gases that surround the planetary nebula. As both basic chemistry and physics teaches us, excited atoms emit light. The gas surrounding the stars in the planetary nebular phase indeed emit a LOT of light, though often times this light is not emitted in the visible spectrum nor even in only one spectra. The emitted light comes in various wavelengths and therefore on various areas of the spectrum (visible, infrared, ultraviolet ect).

    To capture images of the emitted light with the most possible information, there are various telescopes and sattelites that take images on different levels of the spectrum (ie Galex sattelite takes xray images). Different spectral images are also useful because different levels of the spectrum correspond to different heats, which help astronomers figure out what is going on in the stars. With all of this in mind, astronomers can use wavelengths to figure out distances, numerous spectral images to deduce shapes, and emissions to figure out the temperature of things happening in space.

    Knowing that different things are emitted in numerous levels of the spectrum, my job was usually to gather images from different wavelengths to either see if there was any emission to begin with or to compare emissions we already knew were there. Physics plays a HUGE part in asrtronomy, since we have to use what we know to figure out things that we can do nothing more than observe from a great distance away. You can't exactly take a sample of a nebular gas (even if you found a way to handle the temperatures), so we have to use our knowledge of physics to figure out the mysteries of space.

    (the attached images are xray farthest left, and 3 different infrared wavelengths next to that)
    [ATTACH=CONFIG]525[/ATTACH][ATTACH=CONFIG]526[/ATTACH][ATTACH=CONFIG]527[/ATTACH][ATTACH=CONFIG]528[/ATTACH]

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