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  1. Justin- I had no idea that the tidal waves on Miller's planet were fixed waves, I did not even know that fixed waves could actually be possible in that sense (as stupid as that might sound). That is really cool (and kind of freaky). Jake- The idea of watching a live feed from Miller's planet is definitely something I would never have thought of, very cool! I think the idea of time dilation, as you described and applied it here, is pretty neat and a little bit scary. I can't imagine watching a live feed moving that slow! Nate- I actually was wondering about how Cooper could have gotten out of the black hole, thanks for the explanation! Very interesting ideas!
  2. One of the physics concepts I picked up in Interstellar was the physics was the idea of a 5th dimension. I did some research and very quickly realized that I had opened the Pandora's box that is quantum physics. Simply put: I was lost. So I asked my physicist brother for some help and ended up getting a ten minute crash course in the dimensions. Here's what I got. To gain the perspective of another spacial dimension: When you hit a 2-dimensional drum set, which is in "flatland," you have to hit it from our third dimension, one in which the drum head would never perceive. Likewise, you can't smack a spherical drum unless you're smacking it from the fourth dimension; we are in the third. Matthew McConaughey (Cooper) was essentially doing the dot product between himself and the rest of space-time (everything, the universe?) when he interacted with Murphy's room from inside the tesseract (5th dimension). If anyone cares to help me out and explain this whole 5th dimension thing a little more, it would be appreciated. Moving on, I was also curious about the equation that Dr. Brand and Murphy are trying to solve on Earth. The premise of this equation was to enable humans to understand and control gravity, but how could that even be possible? For the most part, since this within the realm of theoretical physics, this was left up to speculation. However, I did find it interesting to note a one of the ideas that I found, since it made the most sense to me. So the basic idea was that Murphy and Brand were trying to unify the concepts of gravity and Newton's laws with theories of quantum mechanics and the dimensions. Murphy and Brand were trying to use the fifth dimension to learn about and control gravity in the third dimension. The idea, as physicist Kip Thorne suggests in his book The Science of Interstellar, is that Murphy was able to locally reset Newton's gravitational constant (G), in effect shutting off Earth's gravity so small rockets could launch the space stations into space and toward Saturn. The Earth, obviously, would not make it. Since most of this is theoretical, as a lot quantum physics is, there are bound to be discrepancies with existing theories. It happens to be one of those concepts that is still open to discussion and frequently debated about.
  3. It's everybody's favorite physics problem: the elevator! One does not learn mechanics without encountering the elevator problem (as far as I know). This is an interesting, sort of different take on it though. http://www.cbs.com/shows/scorpion/video/46616DDC-D143-4956-909B-9B31759797B6/scorpion-i-love-machines/ I'll be honest, the first I saw this I had no idea why Walter and Toby were tying their belts to the elevator bars. But it all makes sense about 5 seconds later when a rather...well....happy Happy stopped the elevator very suddenly. The belts looped around their arms and the elevator bars keep the duo from a painful collision with the ceiling of the elevator, a fate their captors cannot avoid. By why do they slam into the top of the elevator when its acceleration is downward, why don't they hit the ground instead? Let's start with what we know about elevators. So this is pretty nifty! We are looking at the "accelerating downward" one. What we know is that while the elevator accelerates downward, the net force on the person is actually upward. This occurs due to the support force of the cable holding the total weight of the person and the elevator. We know from this that the net force (F=ma) on the person is total support force minus the force of gravity on the system. Therefore the net force on the person is less than their actual weight (thus the idea of weighing less in a downward accelerating elevator). What does this have to do with our problem from the episode? Well, we know from looking at this that person doesn't actually float (as much as I'd like that to happen) when the elevator moves down, but the contact force between the person and the floor of the elevator has lessened since the normal/net force on the person is less. Now we bring in the idea of inertia. The human body, in this case will want to stay at rest with in the elevator, so we are not seeing the people accelerate upward but rather the their bodies attempting to stay in place the elevator floor "falls out" from under them (so to speak). Their bodies will attempt to remain still as the elevator moves downward in short bursts and thus they are thrown into the ceiling. Well, Walter and Toby aren't, they have their belts. Although, I do wonder how they did not break an arm or something. Anyways, that's all I've got to say, so thanks for reading!
  4. Drones! Yes, the flying machines with four propellers that are all too popular these days surfaced in an episode of Scorpion. I thought this might be a cool opportunity to examine the physics of how drones fly. We never get a good look at the drone in the episode, but I do know that its suppose to look like a bird (Sylvester calls it "Bird-Droney"). However, for the sake of this post, I'm going to the discuss the quad-rotor model of a drone (recreational drones). They usually look something like this: When it comes to the physics of how these things fly, we turn to our good friend Newton and his laws. Guess which law? Yeah, the second one. In case anyone forgot (though I trust you all know this one by now) F=ma. The other fundamental concepts in place here are that velocity (v) is equal position (x) over time (t) or v= dx/dt [in other words velocity is the derivative of position with respect to time] and that, similarly, acceleration (a) is equal to dv/dt [or the derivative of velocity with respect to time/ velocity over time]. First of all, the flight is- for the most part and not accounting for weather and other variables- stable because the force generated by the rotation each of the propellers (which lifts the drone) is coming from four equally space out sources. So now that we know we can lift the drone, how do change it's speed? Here's where Newton comes in. Given F=ma, a=dv/dt, and that m (mass) is constant, the only way to change acceleration and thus velocity, is to vary the force. To vary the force, the propellers have to rotate faster to generate a greater lift force. Since v=dx/dt as well, if vary force and thereby vary velocity, we also change the position (x). There's also the idea that acceleration is the second derivative of position (x) and so from F=ma, varying force also changes the position in that way too. If add a force in the opposite direction, for example, we reduce the acceleration and eventually stop or turn the drone. This my fairly basic interpretation of some of the research I found. If you want some more information check out this place: http://www.rcgroups.com/forums/showpost.php?p=15973405&postcount=69 Also, the Scorpion episode can be found here: https://www.youtube.com/watch?v=nSzIK2RD4QU (the quality is wierd, but its the only one I can find. The drone is referenced multiple times so you'll stumble upon it eventually!) That's all I've got, thanks for reading!
  5. The throwing saga continues! This post is all about shot put (the one that looks like throwing a cannonball), my other event. In this a event, throwers compete to see who can launch a weighted metal ball (8 lbs for girls, 12 lbs for guys) the farthest distance. This fairly basic projectile motion, but a lot of people struggle with it. So, here goes: Actually, I lied. This is slightly more complex projectile motion since, as the diagram shows, the release point in a height (h) off of the ground (not on the ground) which changes out equations quite a bit. However, we know the equation of a projectile in free flight: So this is very helpful. Now, we want to figure out the angle the will create the maximum distance. A basic knowledge of physics and/or trig will tell us 45 degrees should be the optimum angle of projection. Any higher or shorter and the distance begins to shrink. The following data certainly agrees with that assertion: If the optimum is around 45 degrees and we know this, why is it so hard for us to throw an 8 lb ball a good distance. A lot of throwers have the issue of completely removing the angle of projection altogether. In doing so, they release straightforward and the distance travelled by the shot is dramatically decreased. The lack of angle is due mostly to the inability of arm muscles to support a shot put (although that means they're holding it wrong). So what does shot put actually look like? Ok, not that fast, but you get the idea. For more info, check out Http://www.people.brunel.ac.uk/~spstnpl/BiomechanicsAthletics/shotput.htm (this where I got the data and the diagrams!) That's all I've got! Thanks for checking this out!
  6. Hello again! As you might have guessed this post is not about a TV Show (though I could probably find a movie or show that involves what I'm going to talk about). I actually want to talk about the physics behind throwing a discus. The discus throw is one of the events I compete in with the school track team, so in honor of our first meet yesterday I decided to do a blog post on it. A "disc" or discus looks like this: The larger radii are for men while the smaller, lighter discus are for women. First things first: how does one throw a disc? The most important part of throwing a disc is releasing it in a way that creates back spin. The spinning motion stabilizes the discus in flight. The faster the disc spins as it leaves the hand of the thrower, the greater the angular momentum and the more stable the flight. This keeps the disc from wobbling and tilting on its axis as it flies, helping to maintain lift which prolongs flight time. This is called gyroscopic stability. The goal of this sport- of course- is to throw the farthest so the longer the flight time, the better. I can't find a good image to show you, but the disc is shaped similarly to the wings of an airplane. Due to this shape, the disc gains lift due to increasing wind speed, helping the disc to travel further in windy conditions. That does not mean that wind is necessarily good for a discus throwing, in fact the even is cancelled (at least at the high school level) in high winds. The discs are affected by wind speed and direction (the greater lift comes from the speed of the air moving around the disc) and they're very light (1 kg for a girls disc) and thus strong winds in any direction to the right or left of movement of the disc can push it off course a rather large and scary distance, which can injure spectators or runners on the track. This happened at a meet last year, luckily our runner out ran the falling disc and she never noticed until after her race that the disc had nearly hit her. Interestingly though, a headwind- a wind directly opposing the disc- can actual add up to 25 ft of distance (as opposed to wind in the direction of the disc's movement. This has to due with the combination of aerodynamic lift and gyroscopic stability. So, that's a quick, basic look at the discus throw. There are tons of cool videos and explanations online that get even more in depth into how the sport looks, in case you want to learn more. If you're wondering about the title, I've had one too many people say something like "Oh, you mean you throw it like a Frisbee right?". No, I do not throw it like a Frisbee. That would not be safe. That's all I have. Thank you for taking the time to read this!
  7. Let's talk about Ferraris. At the beginning of this episode Walter is given a Ferrari, which he immediately and excitedly points out can drive at speeds of at least 190 mph (some models can go as fast 214 mph). As one can imagine, this could turn out poorly. And turn out poorly it did. By the end of the episode and rage-filled Walter manages to send the vehicle- with him inside of course- over the side of a cliff. I will say, before I get into the physics of the crash, that the physics this time are actually pretty good (shockingly). (the link should take you to the point in the video you need to see, if not skip to about 2:40) Alright, so the cause of the crash was the car's inability to make the turn without sliding out, going at the speed it was going (FAST). Given the fact the Walter said it out loud at the beginning, one can assume that car is moving at 190 mph (someone that mad and that reckless isn't going out for a leisurely drive). There is also the tell tale noises of the brake being pressed hard, meaning that he is making sharp, fast turns around the corners of the road and he isn't slowing down much to do so. The braking force is essentially a frictional force, the kinetic friction created between the road and tires of a car when the tires are forced to stop moving. The turn is important when driving at speeds as ridiculously fast (for a car) as 190 mph. The quick change in direction aids the breaking force, creating more friction as the tires turn 90 degrees on the road to make the turn. Turning and braking was Walter's best shot, even though it failed him. The issue comes from the fact the probability of slipping out, where the tires lose their tread and the car slides out to side, is much greater when preforming braking turns. However, had Walter tried to stop the car without turning, he'd have nose-dived over the cliff. If his initial speed (V) was 190 mph than stopping distance (d), using the equation d= (V2)/(2ug) , the car would need about 1677 ft or 511 m to come to a stop. He had about 50 feet. So, he did the best he could given the situation, from a physical standpoint braking into the turn had much greater chance of stopping the car than just braking. Of course, what kind of genius takes a Ferrari up into the Hollywood Hills and drives 190 mph, in the first place? So, there you have it, the basic reasoning behind Walter's actions as the car was crashing and why, ultimately, the car crashed like it did. Thanks for reading!
  8. So I've realized that with all the posts I've done on Doctor Who, I never actually looked at the theory behind how the T.A.R.D.I.S. can actually travel through time. There have actually been studies into how a time-travelling space might work in this universe and the findings have led physicists to believe it is theoretically possible for a T.A.R.D.I.S. to exist and to function as it does on the show in our universe. The research paper is called Traversable Achronal Retrograde Domains In Spacetime (see what they did there?) and it was written by a pair of physicists named Ben Tippet and David Tsang. Tippet and Tsang proposed a spacetime geometry in which retrograde time travel, travelling back and forth along one's own timeline, is possible. A spacetime geometry is when spacetime- the fabric of the universe (where everything has happened, happens, and will happen in the future)- is arranged in a certain pattern. This is a fairly complex topic; however to put it simply, space exists of three dimensions (X,Y,Z) and time creates a fourth dimension. There are many theories as to how this spacetime geometry might be structured- the most famous being the Euclidean and Minkowski space. In order for retrograde time travel to be possible, spacetime geometry must be structured in a way such that the time dimension curves around and back in on itself. This spacetime structure- called closed timelike curve or CTC- would theoretically allow one to hop from their current space and time to another space and time (i.e. the idea of the "time votex"- basically a wormhole- that the T.A.R.D.I.S. flies through). Essentially the T.A.R.D.I.S. would create its own sort of bubble containing a closed timelike curve, which it would use to travel through time and space. So that's essentially what the universe would have to look like for the T.A.R.D.I.S. to exist. Given the vastness of the universe and how long it has and will exist, there actually is a possible these conditions already exist somewhere and that a race like the Timelords already exists out there too. So that's about it, thanks for taking the time to read this. If you're interesting in learn more you can find Traversal Achronal Retrograde Domains In Timespace by Tippet and Tsang or you can check The Blue Box White Paper, which takes a more basic approach to the concept; both of these papers should be online if you search for the title.
  9. Thanks? I can split it into two posts if that would make it better.
  10. Yes, I'm adding another show! The other day I was watching a newer episode of the Big Bang Theory when I realized that there could be some good things to talk about in this show. After a bit a research, I was definitely right about that. So let's start here: So, Sheldon- a super smart astrophysicist- is trying to teach Penny- an average human with no knowledge of physics- about some basic physics concepts. One such concept is Newton's equations for gravity and gravitational force, or Newton's Law for Universal Gravitation. I should start this by saying that he his referring objects falling a vacuum, not in regular space. The equation he writes on the board is Fg=(GMm)/(r2), where G= universal gravitation constant (6.67x10-11), M=mass of the planet, m=mass of the object, and r=radius of orbit. We also know from Newton's Second Law that Fg=ma, where m=mass of the object and a=acceleration of the object. Setting those equal to one another, since both are equation to Fg, yields the following. (GMm)/(r2)= ma => a=(GM)/(r2) => a=g But wait, there's more! Another known concept is that g= (GM)/(r2), where g is the acceleration due to gravity on a given planet (usually Earth). So lets add that above (see the bold letters). Once he works this out, Sheldon asks Penny what this means we know. For one, it means that the object is accelerating towards the planet's center of gravity (downward) since it is being acted on by the force of the planets gravitational field. It also means that the object is accelerating due to the force of gravity of the planet it is on or above and that this acceleration is uninterrupted. If a=g exactly there are no other forces on the object as it accelerates. An force in the upward direction (opposite the acceleration) would slow down (decrease) the acceleration of the object and added downward force would increase. Therefore if a=g, there is no other forces besides the force of gravity acting on the object. This can happen because the object is considered to falling in vacuum, which means that mass and size don't affect acceleration, there are no other forces acting on the object and thus a=g is possible. Ok! So there's some pretty neat, albeit basic, uses for some of Sir Isaac Newton's laws. Other than that, enjoy the rest of the clip (its quite funny) and thanks for reading!
  11. I really thought it would not get worse than a man standing on the wing of an accelerating plane, but I was wrong. In this episode, the team is trying to protect a witness from a gang that is trying to kill her and so obviously we have some high speed chases and what not. Well, according to the show, an RV travelling at 100 mph (~44.7 m/s) can make an almost 90-degree turn without crashing, tipping over, or slowing down at all. So, I'm going to use this blog post to prove them wrong. The first link here will explain the situation, the second is the RV making the turn. http://www.cbs.com/shows/scorpion/video/E016991B-C97D-A543-09C9-6C695ADFD0E8/scorpion-out-of-control/ (Skip to about 3:00 for the important part) http://www.cbs.com/shows/scorpion/video/E7AADC42-A805-EB93-4905-6C695ADF9080/scorpion-near-death-experience/ I'm actually going to talk about the fact that Happy and Walter were able to use longboards to roll under the RV while it was in motion first and it'll set me up for the discussion about the RV making that turn. These are some big longboards, so lets say all together one board weighs 8 pounds (~3.63 kg). A mass of 3.63 kg accelerated at about 44.7 m/s2 (given that board was not moving until it was set on pavement, at which point it travelled at the same speed at the RV it was tied too) creates a force (using F=ma) over about 162.3 N. Obviously I ignored friction, so there is room for error here. Now we add the average weight of a woman- about 140 lb (~63.5 kg)- bringing the total weight of the board with Happy on it up to about 67.13 kg. Thus, the force created increases to about 3000.7 N (~674.6 lb) and Toby should never have been able to hold the rope after this point. Quite honestly, they must have tied the other end to something very strong and/or heavy otherwise the rope would never have held and Happy would have roll off on her own. Interestingly, it is possible for her to step on the to the board once it is moving at the same speed as the RV, which also why she can move herself underneath the RV. Since she is moving the same speed as the board (because she was moving that speed inside the RV) it is like walking around inside the RV. Its the principle of inertia, her mass is moving at the same speed and thus is not displaced when she takes the step. Here is gets impossible again: she lets go and is able to roll all the way to the back of the RV and climb through the window. There should not be any slack in the rope, otherwise she would have to hold the force generated by her weight on her own, and she was barely holding on to the bottom of the car. Plus there is no way anyone could hold 674.6 lb for more than a few seconds. Anyways, you're probably wondering what all this has to do with the RV turning. Here's the kicker: Walter was still under the RV when it made the turn. Disregarding the fact that the RV never should have made the turn, Walter should have been thrown of the edge anyway. Once again, we are talking about inertia. The average male weighs 180 lb (~81.6 kg), so the force even greater for him (approximately 3809.78 N or 856.47 lb). Now I don't know anything about the rope besides that it is relatively thin (maybe 1 inch in diameter maximum) and braided very small if at all. It most likely would not be able to hold that force since the mass of Walter and the board would try to keep moving forward (an object in motion stays in motion) while the RV turned. With huge weight and force of the RV moving in a completely different direction than Walter on the longboard, the rope probably should have broke and Walter should have been flung over the cliff. Finally, I've gotten to the RV making the turn. Okay so here's the thing, that RV was travelling at 100 mph at least and Paige (the one driving) showed no signs of breaking Plus, there is no way the RV could have slowed from 100 mph to a speed slow enough to make that turn (probably a speed more like 30 mph given the sharpness of that turn) in the few seconds Paige had to slow down that car. So, without breaks, a RV that is most likely 13,000 to 30,000 pounds and 30 to 40 feet in overall length is expected to make an almost 90-degree turn WITHOUT falling over. In reality, all of the weight in the RV would have been pushed to the outside while it made that turn and the RV would have tipped to the left and fallen on its side. Not to mention the fact that the an RV of that length would need to take the turn even slower in order to fit around the sharp curve, which is even more reason for RV to never have made the turn in the first place. Ok, long rant over. I'm sorry about the length, but there was alot to talk about with this one. Anyways thanks for reading! OH! By the way, new favorite quote from Scorpion:
  12. As I mentioned in the previous post, here is part II: the wildfire. Honestly, I just wanted to know if it is even physically possible for that many slow-moving people to out run a spreading wildfire, especially in high winds. Here's a short clip from the episode showing the spreading fire: http://www.cbs.com/shows/scorpion/video/45699904-3F02-8272-59C1-482673FE0BEF/scorpion-fire-is-getting-close/ So the first thing I noticed was that Sylvester (the man who was on his own dragging that other guy) was walking pretty much the entire time and he started at the epicenter of the fire. The other group stood still for probably 10-15 minutes deciding how to get across the ravine. However, the group started on the outskirts of the fire in the first place so they had more time escape. So really, the question I'm trying to answer is could Sylvester (and the injured man he had to drag) possibly out run the fire? The average maximum speed of a wildfire varies from 9 mph to 12.5 mph (16 km/h to 20 km/h). The average human can run at speeds of up 15 mph for short periods of time, which would mean that Sylvester could have outrun the fire that way, if it was a normal wildfire. However, there are multiple reasons why this becomes impossible. For one the added weight of the man Sylvester has to pull creates a force in the opposite direction of his movement, slowing him down. Also, the heavy wind- at least 50 knots (~57.5 mph)- accelerates the wildfire's spreading speed meaning this wildfire could be moving significantly faster than most humans could run period. So then how did Sylvester and his friend survive? He takes advantage the titanium door that they been using as sled for the man he was pulling. Titanium is- as Sylvester points out- a low conductor of heat. This mean that when the fire rolls over them the heat is not absorb well and thus does not hurt them. As for the metal of the pipe they are in, I'm not sure what it is but one can imagine we are to assume that it too is a low conductor of heat. Anyways, that concludes my exploration of this episode. Thanks for reading!
  13. Ok so I know its been a while, but I'm back! This episode is about the Scorpion Team trying to save a group of lost hikers and getting caught in a wildfire in the process. http://www.cbs.com/shows/scorpion/video/60C5E5EA-F07C-9BE2-1635-482673FE41E0/scorpion-we-re-going-to-die/ I'll start here, with the falling helicopter. Helicopters fly through the use of propellers. As the propellers are rotated at increasing speeds , the air flowing over them generates lift. Because the the propellers rely on ability to create air flow to maintain this lift, high wind speeds create dangerous flying conditions. There are multiple types of wind that create issues for pilots. Headwind, wind that flows opposite to the path of the helicopter's motion, slams into the helicopter’s nose and slows it down. On the other hand, a tailwind generates force in the same direction raising the helicopter's speed. Just like headwind, crosswinds that blow across the path are also equally dangerous to the helicopter. Ok, now back to the show: First of all, I thought he was suppose to aim away from the trees? Anyways, given that helicopters average in weight from 1,000 to 10,000 pounds, lets go on the low end and say this one is 1,000 pounds. If each of the men in the plane average 180 pounds and each woman averages 140 (these are the approximate average weights for adult males and females), that's an extra 1,000 pounds. So that means we have at least 2,000 pounds (~8896.4 N) of weight falling from at least 500 feet, the amount of force this would generate on impact would most likely kill at least one of them, if not all of them. Luckily, the helicopter propellers try to maintain flight as it falls, meaning the helicopter doesn't fall straight down. The angle of the fall reduces the speed at which the helicopter hits the ground- or the trees in this case. I suppose this might be why the tree branches did not break when the helicopter landed on them. The helicopter did eventually fall, a few moments later after the team had barely escaped. Ok well that's all for now. I might have to make a second post about this episode, since I never got to the wildfire part. Thanks for reading!
  14. Ok, so today is my midterm and I've been studying and looking over my notes and everything and I think I'm about ready. The test is going to be an actual AP Mechanics exam I guess, so I've done a few practice ones and such to get ready for it. I'm hoping that I can get at least a 4 on this thing. This going to be a short post for now but I plan to update this later after the exam so I can complain talk about it. I guess that's all I have to say for now. Wish me luck! OK, that's one exam down! I think the multiple choice was a little rough (and by rough I mean there some questions that I completely guessed on because I had no clue) BUT I think the free response went better. There was a question on certain topic I hadn't studied (it was air resistance) so now I know what to study next time. Turns out I knew a lot more than I thought I did about mechanics! All in all, great learning experience! Thanks for stopping by!
  15. Hello again! This one I had to talk about because there is just so much wrong with the beginning that I don't even know where to start. Scratch that, yes I do. Let's start with the Doctor falling out of a spaceship exploding in orbit, that seems like a good place to me. I'm not sure if the Doctor has special lungs that don't need air (pretty sure that is not the case) but he survived for like 5 minutes hurtling towards Earth in space with no atmosphere. Than he reaches out into space and tries to swim to a nearby space suit. Both left the exploding space ship with the same velocity and since there is nothing in space for the Doctor to use to accelerate himself forward (there is even air so he should have died really) he never should have reached it at all but he does. Up until this point, the show isn't doing to well with physics. But this time he actually makes a crater! If you remember one of early posts about how the TARDIS does not make an impact when it strikes the Earth then you'll know this is an improvement by them. They actually showed that the force of an object strike the Earth from that far up in space would be enough to dent the surface of the planet. Realistically though, he would still be dead- space suit or not. There is no way that the space suit he got on could have reduced the force of his impact enough (or at all) to cause it not to shatter every bone in his body. In fact, shouldn't he have burnt up in atmosphere? The resistance of the atmosphere against the Doctor should have caused him to catch fire like a rocket re-entering Earth's atmosphere. Maybe this is morbid but the fact remains the same, he should have died like three times. But this is a show so they cannot kill a main character for the sake of physics. Or maybe this is just time lord stuff that we humans could never understand. The writers on this show have a great excuse. Anyways, as always thanks for stopping by!
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