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Is College Bull****? I think it is.

Jimbo07 said:
Just... wow...
:(
Originally Posted by M.S. in Microbiology
I was thinking about Einstein's equation which says that the energy in matter is equal to its mass time the velocity of light squared. It occurred to me that he would have had something if he hadn't squared the velocity of light, because nothing can move at velocity squared.
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Stupid Einstein. He was so close to an insight... :p
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How does one square velocity anyway? There must be some trick to vector multiplication I am not aware of.
 
hgc said:
How does one square velocity anyway? There must be some trick to vector multiplication I am not aware of.
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Actualy you do it all the time, think of how you determine the magnitude and that this is realy the square of the magnitude(more or less). You are either looking at a component velocity or the total magnitude either way squareing them is normal procedure.
 
ponderingturtle said:
Actualy you do it all the time, think of how you determine the magnitude and that this is realy the square of the magnitude(more or less). You are either looking at a component velocity or the total magnitude either way squareing them is normal procedure.
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Thanks. Squaring magnitude is something I understand, or we can even talk about vector cross products. But then Einstein's famous equation squares the speed of light anyway.
 
hgc said:
Thanks. Squaring magnitude is something I understand, or we can even talk about vector cross products. But then Einstein's famous equation squares the speed of light anyway.
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The point is that you are not getting a vector as a product. You are sometimes sqauring the X component of velocity to figure out how various velocities add to gether and such, but never really getting a vector result from it.

That is one of the reasons why mv makes no sense as energy, it is a vector, while 1/2mv^2 is a scaler.

I tried to tell him that of course mv is concerved as well as that is momentum which while not the same thing as energy, is also concerved. He was absolutly conviced I was wrong and could not do math, well that showed my that biology does not require much of a math basis.
 
Hey, ponderingturtle and hgc!

You didn't go to college or anything, did you?
 
Katana said:
Hey, ponderingturtle and hgc!

You didn't go to college or anything, did you?
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College hell this is something highschoolers should learn. This is basic high school physics something that he should have taken before he decided it was all wrong.

But techinicaly my physics degree is not quite complete.
 
ponderingturtle said:
College hell this is something highschoolers should learn. This is basic high school physics something that he should have taken before he decided it was all wrong.

But techinicaly my physics degree is not quite complete.
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pt, I don't recall path integrals from high school. This is necessary to see how to get from F=ma to Kinetic Energy. That is, start with Force (all the way back to Newton) show work, W, as the integral of that force over a given path. Solving gives our old friend (mv2)/2. Discuss the equivalency of work and energy... or summat. :cool:

If not, you have to take all the formulas as a given, n'est-ce-pas?
 
Jimbo07 said:
pt, I don't recall path integrals from high school. This is necessary to see how to get from F=ma to Kinetic Energy. That is, start with Force (all the way back to Newton) show work, W, as the integral of that force over a given path. Solving gives our old friend (mv2)/2. Discuss the equivalency of work and energy... or summat. :cool:

If not, you have to take all the formulas as a given, n'est-ce-pas?
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No, I was thinking about constant acceleration and falling as being a easly way to get from F=ma to ke=1/2 mv^2.

You just say that Potential energy is Weight*Hieght and you accelerate at G, and use the simple constant acceleration equations to solve the problem.

There are lots of ways to get kinetic energy, and some of them can be worked out easily in high school.
 
If this person accepts height*mass as a accurate formula for gravametric potential energy, it would be easy to demonstrate that one has to launch a mass with four times the velocity to obtain twice the height instead of with only twice the velocity.

Aaron
 
HeavyAaron said:
If this person accepts height*mass as a accurate formula for gravametric potential energy, it would be easy to demonstrate that one has to launch a mass with four times the velocity to obtain twice the height instead of with only twice the velocity.

Aaron
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Yes but you have to break through the thick walls surrounding him being a total crank. Of course he is wrong in easy and proveable ways, but you are not going to get him to listen
 
drkitten said:
Wolfram and Hart might want to hire me to work as a lawyer without my having gone to law school. In California, Virginia, Washington, and a few other jurisdictions, they could hire me and train me themselves for a couple of years, after which I can take the Bar exam and start practicing law for them. (Granted, Wolfram and Hart would probably be fools to want to go this way and pay "training wages" instead of hiring a fully-qualified J.D., but there's no law that says senior partners can't be fools.)
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W&H's senior partners may be evil, but they're not stupid. They've been in the business for a long time.
 
Snide said:
You are clearly a hypocrite because you can't even spell "impediment." And don't give me any cr@p about it being a typo!! ;)
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Fixed, Mister Hippocr@p. :D Who let Norm Crosby into the room, anyway? *belch*

DR
 
ponderingturtle said:
No, I was thinking about constant acceleration and falling as being a easly way to get from F=ma to ke=1/2 mv^2.

You just say that Potential energy is Weight*Hieght and you accelerate at G, and use the simple constant acceleration equations to solve the problem.

There are lots of ways to get kinetic energy, and some of them can be worked out easily in high school.
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I've never tried, but I think it would be hard to teach Kinetic Energy, starting from force, not using derivatives and integrals, and not assuming a definition for either Kinetic or Potential energy.

This was this bungle-head's problem. He seems to have randomly assumed that you can define momentum to be energy just by stating so.

Newton 1 is inertia.

Newton 2 is F=ma.

Force = time derivative of momentum, d(mv/dt) = m(dv/dt) and work/energy = integral of force along a path or int(m(dv/dt)ds). That is, F=ma is the relationship through which a change in momentum impacts (requires) a change in energy. Potential energy is actually a special case. F=ma holds, and m1v1=m2v2 hold, regardless of your source of potential.

You can certainly state in high school that KE2 - KE1 = PE2 - PE1, but you have said nothing really about why KE and PE are the way they are. High school may deal with the 'whats' of mechanics, but not the 'hows' of physics... unless I'm completely wrong about highschool, or not thinking about mechanics properly.

(Jimbo waits for correction... :o )
 
EBU said:
A fairly useless addition to the discussion about whether it is possible to practice law without having gone to law school.


http://www.lawschoolbible.com/
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California's bar exam is notoriously difficult, even for a bar exam; the usual explanation for this is that they want to make it extra hard for people who haven't gone to law school to be admitted to practice law. I wouldn't be surprised if the other states that allow the "reading the law" method take similar precautions. Having taken the New York bar, I think that any reasonably intelligent person who took a standard bar review course and studied very diligently could probably pass it, if not on the first try then certainly on the second or third. But passing the bar exam is not in itself a guarantee that one is fit to practice law; it's more like a final quality-control mechanism that works best if the person already has a substantial legal education. I imagine that the few states that still have the reading the law option do so as a holdover from the days of 19th-century apprenticeships, but I can't conceive of how working as a legal assistant could reasonably prepare anyone to practice law without further training.
 
Jimbo07 said:
I've never tried, but I think it would be hard to teach Kinetic Energy, starting from force, not using derivatives and integrals, and not assuming a definition for either Kinetic or Potential energy.
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Starting from force, but I was ignoreing force and starting from potential energy. Yes you do need to decide that potential energy is Weight*Height, but that is pretty easy to show that it is a linear relationship.

You have to assume something, and that is a pretty easy thing to test(and oddly something the person cited accepts).

This was this bungle-head's problem. He seems to have randomly assumed that you can define momentum to be energy just by stating so.

Newton 1 is inertia.

Newton 2 is F=ma.

Force = time derivative of momentum, d(mv/dt) = m(dv/dt) and work/energy = integral of force along a path or int(m(dv/dt)ds). That is, F=ma is the relationship through which a change in momentum impacts (requires) a change in energy. Potential energy is actually a special case. F=ma holds, and m1v1=m2v2 hold, regardless of your source of potential.
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You should note that is it the sum of all m1v1=sum of all m2v2, any individual can change. Just like the sum of all the energy has to be the same at the begining and the end, regardless of it being mechanical, chemical, potential nor what have you.

You can certainly state in high school that KE2 - KE1 = PE2 - PE1, but you have said nothing really about why KE and PE are the way they are. High school may deal with the 'whats' of mechanics, but not the 'hows' of physics... unless I'm completely wrong about highschool, or not thinking about mechanics properly.

(Jimbo waits for correction... :o )
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College does not nessacarily make it more fundamental than high school at least for intro classes. Looking at it all as differential equations was not 100 level physics in my college but 300.

The point still stands that all you need is high school physics to show the inconsistencies and errrors in the web page in question.
 
ponderingturtle said:
You should note that is it the sum of all m1v1=sum of all m2v2, any individual can change.
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I suppose you're also going to say that I should be bolding where appropriate for vectors and subscripting my indices. :p

College does not nessacarily make it more fundamental than high school at least for intro classes. Looking at it all as differential equations was not 100 level physics in my college but 300.
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I'm hoping this year to get a job marking (or as a lab assistant) for some of the general 100 level courses. This will help remind me what and how it is taught. We also have 100 level classes for non-physics majors, 100 level classes for physics majors and the spread of mechanics/electrical/modern classes for eng. phys majors. :D

The point still stands that all you need is high school physics to show the inconsistencies and errrors in the web page in question.
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Inconsistencies yes. I'm not sure that you could demonstrate a mathematical meaning for these things taking the form that they have. I put to you that they wouldn't typically introduce even velocities and accelerations as being time derivatives of position. You just have to accept:

x(t) = x0 + v0t + (1/2)at2
 
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