First my apologies for the delay, I have been working 10 hour shifts and then pretty much been going straight to bed.

The math version is also coming it's just been a lot of work (especially as the census was that people wanted to the equations displayed right).

The math diary will be out Friday or sooner.

Now then let us jump into the world of Newtonian Physics, also known as Classical Physics.

First a confession of sorts, the past diaries have all been about Newtonian Physics and yet I never introduce Newton's Laws (which are the foundation of this branch of physics).

I did this intentionally because first it was how I was introduced to physics. Also because I wanted people to see that a limited and yet useful understanding of physics can be achieved with absolutely no understanding of Newton's Laws.

Now then, I introduce to everyone the basis for Newtonian Physics and frankly the genesis of physics itself (and no that is not hyperbole).

1. A body at rest stays at rest and a body in motion stays in motion; unless acted upon by an external force
1. Observed from an inertial reference frame, the net force on a particle is equal to the time rate of change of its linear momentum: F = d(mv)/dt

3)Whenever a particle A exerts a force on another particle B, B simultaneously exerts a force on A with the same magnitude in the opposite direction.

Now I have tried to somewhat simplify the laws but no worries I am going to devout time to explain and talk about each.

1) A body at rest stays at rest and a body in motion stays in motion; unless acted on by an external force.

The first law of Newtonian Physics is often simply referred to as the law of inertia. Inertia though is also a property of matter and can be observed in 2 distinct ways as noted above.

The first display of inertia is that an object that is not moving stays that way unless it is acted upon by an external force.

This should be intuitive, we see it all the time and yet it is profound. If this was not the case then the world as we understand it would just not be possible.

The second display of inertia is that an object in motion stays in motion.

This probably is not as intuitive as for example a hockey puck struck by a hockey stick does not carry on forever. Nor does a car coast indefinitely. And yet such examples are deceptively complex. See you have to account for the sum total of the forces and there is more then just one force to account for. In fact what is missing is friction which simply stated (for now, I'll devout an entire future diary to friction) is resistance to motion.

Thus your car encounters friction (caused by the wheels among other things) and slows down.

I want to briefly talk about the power of inertia and to do so I want to draw upon  Star Trek. In Star Trek the heroes (and villains) travel around at faster then light speed. Now I do not want to get into the physics of that, instead I want to talk about what is known in that universe as 'inertial dampeners'. The physics of which (to date) do not exist, but what would happen if such technology did not exist?

Quite simply when the ship accelerated past the speed of light it would crush every bone in the body of any aboard the ship. And that's just the obvious effect. It would also cause anything not bolted down to rip though the ship.

Inertia is one of the most important concepts in physics. While it is not the only important thing in Newtonian Physics it's effects are felt profoundly (and in actuality much of the complications to Newtonian Physics are in fact trying to account for inertia).

2) Observed from an inertial reference frame, the net force on a particle is equal to the time rate of change of its linear momentum: F = d(mv)/dt

This is often simplified to force is equal to mass times acceleration (F = m * a).

Those familiar with derivatives should almost immediately see where that equation comes from. To those that do not, I will simply assert that the derivative of velocity with respect to time (dv / dt) is acceleration. And that as mass is a constant one can not take the derivative with respect to time of it.

Unlike the first law there is little to explain as this is effectively just an equation. And there is little verbal description I can give about this law. Rather I think it more effective to see it used in practice. As such I want to devout at least the next diary to exploring the implications of the 2nd law and how it is used to solve Classical Mechanics.

3)Whenever a particle A exerts a force on another particle B, B simultaneously exerts a force on A with the same magnitude in the opposite direction.

This is perhaps my favorite of the 3 laws (I will confess that some of that is because unlike the 1st law there is no complication due to full consideration of the law. Or because unlike the 2nd it is not a mathematical construct but rather a concept.)

This also might be the most well known aspect of Newtonian Physics.

Basically when a force is exerted upon an object that object also exerts an equal and opposite force.

For example you know why a punch hurts a person's hand? Because the force of that punch is directed back at the hand and the puncher.

Or for example if you were to take a rubber disk, place it on a frictionless surface and then slide a second rubber disk straight the first disk. There would be a collision and the first rubber disk would move forward at a set speed and the second rubber disk would be moving backwards at the same speed.

For those reading this that use guns, the 3rd law is why you feel recoil.

Well that's all I have for now, I will remain around to answer questions. I hoped people enjoyed this and that it made sense. On Friday as I said I will publish  the math aspect of ballistic motion. After that on Saturday I will move back to the math light aspect and explore some examples of using the 2nd law to solve mechanics as well as highlight how using the concepts presented in the 1st and 3rd laws are useful for solving mechanics. Then on Tuesday I will move back to math oriented approach and mathematically prove the 2nd law.

#### Tags

EMAIL TO A FRIEND X
You must add at least one tag to this diary before publishing it.

Add keywords that describe this diary. Separate multiple keywords with commas.
Tagging tips - Search For Tags - Browse For Tags

?

More Tagging tips:

A tag is a way to search for this diary. If someone is searching for "Barack Obama," is this a diary they'd be trying to find?

Use a person's full name, without any title. Senator Obama may become President Obama, and Michelle Obama might run for office.

If your diary covers an election or elected official, use election tags, which are generally the state abbreviation followed by the office. CA-01 is the first district House seat. CA-Sen covers both senate races. NY-GOV covers the New York governor's race.

Tags do not compound: that is, "education reform" is a completely different tag from "education". A tag like "reform" alone is probably not meaningful.

Consider if one or more of these tags fits your diary: Civil Rights, Community, Congress, Culture, Economy, Education, Elections, Energy, Environment, Health Care, International, Labor, Law, Media, Meta, National Security, Science, Transportation, or White House. If your diary is specific to a state, consider adding the state (California, Texas, etc). Keep in mind, though, that there are many wonderful and important diaries that don't fit in any of these tags. Don't worry if yours doesn't.

You can add a private note to this diary when hotlisting it:
Are you sure you want to remove this diary from your hotlist?
Are you sure you want to remove your recommendation? You can only recommend a diary once, so you will not be able to re-recommend it afterwards.
Rescue this diary, and add a note:
Are you sure you want to remove this diary from Rescue?
Choose where to republish this diary. The diary will be added to the queue for that group. Publish it from the queue to make it appear.

You must be a member of a group to use this feature.

Add a quick update to your diary without changing the diary itself:
Are you sure you want to remove this diary?
 Unpublish Diary (The diary will be removed from the site and returned to your drafts for further editing.) Delete Diary (The diary will be removed.)
Are you sure you want to save these changes to the published diary?

#### Comment Preferences

• ##### tip jar(10+ / 0-)

now some humor

thoughts? comments? I plan to address each law as it's own diary eventually but I wanted to give a general over view of Newtonian Physics

Why aren't you more like Gandhi? Why aren't I?

• ##### omg that is my (2+ / 0-)
Recommended by:
drache, cee4

pootie too, just like her!!

We must practice `pessimism of the intellect, optimism of the will.' Antonio Gramsci

[ Parent ]

• ##### I just should not have basically named(1+ / 0-)
Recommended by:
MarkInSanFran

my cat 'ghost' or 'darkness', he's not evil but he's very very sneaky even with 4 bells on him.

Why aren't you more like Gandhi? Why aren't I?

[ Parent ]

• ##### The ship never exceeds the speed of light(2+ / 0-)
Recommended by:
drache, cee4

It uses magical means to warp space and time so that it can get around the laws of physics. That is a useful convenience to study human behavior under a wide range of hypothetical conditions.

"It's the planet, stupid."

• ##### it still instantly accelerates(2+ / 0-)
Recommended by:
MarkInSanFran, cee4

to speeds that would crush a human body.

As you can not completely warp space time so that one end touches the other.

Though even throwing that out, accelerating to .5 c (half the speed of light) would be just as disastrous.

Even if you take issue with the specifics, look to the larger point.

Why aren't you more like Gandhi? Why aren't I?

[ Parent ]

• ##### Yes, we can only take so many g's(2+ / 0-)
Recommended by:
MarkInSanFran, drache

Science fiction uses conventions to achieve other insights than pure science.

"It's the planet, stupid."

[ Parent ]

• ##### it was just an example (2+ / 0-)
Recommended by:
MarkInSanFran, FishOutofWater

I could have just have easily pointed out the forces we feel when we turn a car are a result of inertia.

No need to search deeper then that.

Why aren't you more like Gandhi? Why aren't I?

[ Parent ]

• ##### I really like good science fiction(1+ / 0-)
Recommended by:
drache

but I know that it's usually not about science. It's about human societies, human behavior and case studies of what to do in odd situations.

FWIW, did you know that Willard F. (Bill) Libby and Isaac Asimov disliked each other immensely? Scientists and sci fi writers have their conflicts.

"It's the planet, stupid."

[ Parent ]

• ##### true enough(2+ / 0-)
Recommended by:
MarkInSanFran, FishOutofWater

I never have really understood that though as good sci fi inspires science and science inspires sci fi.

To me though it's just that while the social commentary is fascinating and while I was hand waving a bit with the 'physics' of moving past the speed of light, the basic point is valid and it's valid precisely because of inertia.

Why aren't you more like Gandhi? Why aren't I?

[ Parent ]

• ##### Ya canno change the laws of physics, Jim (nt)(2+ / 0-)
Recommended by:
happy camper, drache

Who said that?

"If religion is the opiate of the masses, then fundamentalism is the amphetamine." Miz Vittitow

[ Parent ]

• ##### cool I will definitely look into them(1+ / 0-)
Recommended by:
MarkInSanFran

I was considering writing my own java applets but frankly I did not want to spend that much time on a diary.

This is a great alternative thank you again.

Why aren't you more like Gandhi? Why aren't I?

[ Parent ]

• ##### These Too(1+ / 0-)
Recommended by:
drache

"I call on all governments to join with the United States ...in...prosecuting all acts of torture." GW Bush

[ Parent ]

• ##### 3rd paragraph from bottom-collision not collusion(2+ / 0-)
Recommended by:
MarkInSanFran, drache

True for collisions where no energy is dissipated in deformation of the colliding bodies.

"It's the planet, stupid."

• ##### lol(2+ / 0-)
Recommended by:
MarkInSanFran, FishOutofWater

I knew someone would bring this up and yes I am purposefully not bringing up the types of collisions but I did describe an elastic collision (hence why I said rubber).

Why aren't you more like Gandhi? Why aren't I?

[ Parent ]

• ##### So essentially, yr saying(2+ / 0-)
Recommended by:
drache, cee4

A body at rest stays at rest and a body in motion stays in motion; unless acted upon by an external force

Michael Jackson will not rise again on his own?*

"If religion is the opiate of the masses, then fundamentalism is the amphetamine." Miz Vittitow

• ##### Summer reading recommendation(4+ / 0-)
Recommended by:
MarkInSanFran, roses, drache, cee4

While it's written for students, I've yet to find an adult who wasn't entranced by Joy Hakim's The Story of Science books.

Volume II, Newton at the Center, tells the story of Renaissance science, while Volume III, Einstein Adds a New Dimension, takes the reader from Newton to Dark Matter.

I've taught physics for multiple decades, and understand more about the methods of modern physics from these books than I ever did before (and no, I am not involved or paid by these folks! Sold by Smithsonian.)

Quidquid latine dictum sit, altum viditur.

• ##### I will look into them(2+ / 0-)
Recommended by:
MarkInSanFran, cee4

I already hold my Bachelor's in physics but one can never learn too much.

Why aren't you more like Gandhi? Why aren't I?

[ Parent ]

• ##### "Faster than the speed of light"(1+ / 0-)
Recommended by:
cee4

This is a marvellous book by Imperial College physicist João Magueijo describing how he came up with his Variable Speed of Light theory that explains a number of Cosmological Problems.  The physics is presented for a general audience and is very intuitive.

Even more entertaining than the physics are the author's descriptions of his challenge of getting acceptance of a totally new theory in the "real" world of academic physics.

Feynman himself was a good example of what he advocated -- a fuck-everyone-else-I'll-do-my-own-thing-and-don't-care-about-what-you-think kind of scientist.  He has become an icon of U.S. science, and yet the prosaic reality is entirely different: It's a world in which young people are encouraged to work en masse on the same mainstream problems, without the balls to move away from the madding crowd.  As with scientific red tape, my feeling is that if you're going to do science in this way, you might as well go and work in a bank.

Big Joe Helton: "I pay Plenty."
Chico Marx: "Well, then we're Plenty Tough."

[ Parent ]

• ##### Second Law in words(1+ / 0-)
Recommended by:
drache

Force is the only thing that can change an object's momentum. If an object's momentum is constant (i.e. dp/dt=0), then there is no (net) force acting on it.

There is nothing so practical as a good theory—Kurt Lewin

• ##### I don't think the law of inertia is intutitive at(1+ / 0-)
Recommended by:
drache

all .... if it was intuitive, the ancients would have thought of it, and so would children.  In fact, it's deeply counter intuitive, because (at least near the Earth) there's a force that's always acting (several, really, but we need worry about only one) and it's invisible, and that's gravity.  And there's another force stopping things from moving, and that's friction (even with the air).

Intuitively, everything tends to fall towards the Earth unless something stops it, and things tend to slow down unless something is pushing.

• ##### I think there is some confusion(1+ / 0-)
Recommended by:
plf515

I meant (and mean) the first aspect of the law of inertia is intuitive.

Namely that objects at rest stay at rest.

I do agree the second part is not as intuitive because often the forces acting on an object are not obvious.

Why aren't you more like Gandhi? Why aren't I?

[ Parent ]

• ##### I don't even think the first part is intuitive.(1+ / 0-)
Recommended by:
drache

Things, by their nature, only stay at rest in certain limited circumstances: When they are placed on a reasonably flat surface, with "reasonably" some combination of flatness and friction.

Aristotle's physics is more intuitive than Newton's.

• ##### fair enough nt(1+ / 0-)
Recommended by:
plf515