Motor Daddy's Ridiculous Box

[rpenner]

What is the problem that MotorDaddy is seeing anyway?

Motor Daddy doesn't like the concept that I don't need to know my absolute velocity to do physics just as precisely as someone who is doing physics in a different state of motion than myself. This is one of the essential concepts behind the theory of special relativity which explicitly states that all inertial coordinate systems (systems of coordinates where inertial motion is described motion with a constant velocity vector) are all equivalent to physics. The implication of special relativity being an accurate model of the behavior of reality implies that there can be no absolute agreement on spatial or temporal measurements -- but what can be agreed upon is only invariants of "Minkowski space-time".

For the specific diagram, with T=0, A = B = 1 light second and $$v = \sqrt{\frac{69}{169}} c$$, special relativity says there is an equally valid coordinate system where the cuboid box is not in motion (the rest frame of the box) but in that rest frame the lengths of the sides of the box along the X direction are longer than those in other directions by a factor of 1.3, so the cuboid box is not a cube in its rest frame. It is unclear how Motor Daddy expected to refute special relativity with this diagram since since he never even admitted another coordinate system could exist he does no comparisons and so has little hope of making a case for a contradiction.

 

[dumbest man on earth]

Well, like I said I can use math to figure out how long I would be driving, but apparently you would not have any idea how long it would take.:shrug:

Strange Thread - to say the least!

As has been pointed out by you previously, origin :

Math is a way to describe the universe and can be used to predict future outcomes.

Can Math accurately predict any and all possible impediments to your drive on the expressway? i.e., mechanical breakdowns - interactions with other drivers - traffic jams - weather conditions - emergencies - or possibly even neglecting to "fill-up" with gasoline prior to beginning the journey, and consequently "running out of gas" during the journey?

Math is Math - you can use it to "Model" Reality - you can use it to "Predict" Reality - it is not however "Actual" Reality. Ergo: if the "Model" or "Predicted Outcome" fails to match the "Actual" Reality - it is not the "Actual" Reality that is in error or wrong - it is the Math.

 

[Uncle Pythagoras]

Motor Daddy doesn't like the concept that I don't need to know my absolute velocity to do physics just as precisely as someone who is doing physics in a different state of motion than myself. This is one of the essential concepts behind the theory of special relativity which explicitly states that all inertial coordinate systems (systems of coordinates where inertial motion is described motion with a constant velocity vector) are all equivalent to physics. The implication of special relativity being an accurate model of the behavior of reality implies that there can be no absolute agreement on spatial or temporal measurements -- but what can be agreed upon is only invariants of "Minkowski space-time".

For the specific diagram, with T=0, A = B = 1 light second and $$v = \sqrt{\frac{69}{169}} c$$, special relativity says there is an equally valid coordinate system where the cuboid box is not in motion (the rest frame of the box) but in that rest frame the lengths of the sides of the box along the X direction are longer than those in other directions by a factor of 1.3, so the cuboid box is not a cube in its rest frame. It is unclear how Motor Daddy expected to refute special relativity with this diagram since since he never even admitted another coordinate system could exist he does no comparisons and so has little hope of making a case for a contradiction.

Oh I see. But Einstein's physics are wrong anyway. It is just too hard to use the real physics. There is no time, and no flat space. There are fields that are almost impossible to calculate. You can simulate them, but like my computer now, you don't get maths, just the physics for your entertainment.

I depends on what you want to know. Do you want to know how the Universe works, or do you want to have some working mathematics? My version is more Darwinian, and I just want to know the physics. You could write a program that would build the Universe, but it would be just like a movie of the physics. But with a few clever tricks it would build itself like a fractal. And that's all I wanted to know about.

 

[brucep]

Oh I see. But Einstein's physics are wrong anyway. It is just too hard to use the real physics. There is no time, and no flat space. There are fields that are almost impossible to calculate. You can simulate them, but like my computer now, you don't get maths, just the physics for your entertainment.

I depends on what you want to know. Do you want to know how the Universe works, or do you want to have some working mathematics? My version is more Darwinian, and I just want to know the physics. You could write a program that would build the Universe, but it would be just like a movie of the physics. But with a few clever tricks it would build itself like a fractal. And that's all I wanted to know about.

Your version is undoubtedly nonsense.

 

[brucep]

Math is very good at describing reality. Science is about making precision predictions of the behavior of reality and "precision" means agreement within small numerical tolerances.
Math is not predicated on reality. Physics is about creating the best model of reality, and certain mathematical models of reality have shown to be spectacularly precise at predicting all observed phenomena within their applicable domain. The success of math in the field of physics is the topic of this 1960 essay by Eugene Wigner "The Unreasonable Effectiveness of Mathematics in the Natural Sciences."
This is a peculiar position to take from the author of

​

where "this" is a diagram which has been marked up with a lot of numerical quantities.



Math is all about the consequence of certain rules, reality appears to be governed by rules, so to the extent that reality follows logically consistent rules then if we guess those rules correctly math will allow us to predict the behavior of reality. As a practical matter it has been the historical case (over 350 years) that guessing the rules wrongly can still lead to very good predictions where for most of the time only precision experiments or examination of extreme events can demonstrate that rules of reality and the wrong rules of the model that we implemented do not lead to identical outcomes. This is why Newtonian Universal Gravitation was so successful to the extent of allowing travel to the moon. Nevertheless we now know of phenomena in reality which are good at showing that UG is not precise at describing the behavior of reality and we have replaced UG with Einstein's General Relativity for that reason.

It is only in the comparison of math predictions with precision observations of reality that one can know if one is using appropriate math to describe reality.

Euclidean 2-D geometry follows certain rules that apply approximately (within certain tolerances) to small plowed fields and to flat blackboards and pieces of paper. But the surface of the Earth deviates from the assumptions of Euclidean 2-D geometry at some scales in ways that are both irregular (grains of dirt, ridges in a field, hills and valleys) and regular (curvature of the Earth). So Euclidean 2-D geometry has limited applicability to modeling reality. But within the applicable domain it is a very precise model of the geometry of reality.

Very informative. Folks who have a problem understanding the role of mathematics in describing natural phenomena should read rpenner. The voice of reason. Thanks for writing it down in your most amicable logical way.

 

[origin]

Can Math accurately predict any and all possible impediments to your drive on the expressway? i.e., mechanical breakdowns - interactions with other drivers - traffic jams - weather conditions - emergencies - or possibly even neglecting to "fill-up" with gasoline prior to beginning the journey, and consequently "running out of gas" during the journey?

No.

Math is Math - you can use it to "Model" Reality - you can use it to "Predict" Reality - it is not however "Actual" Reality. Ergo: if the "Model" or "Predicted Outcome" fails to match the "Actual" Reality - it is not the "Actual" Reality that is in error or wrong - it is the Math.

Gee, no kidding.

 

[billvon]

I depends on what you want to know. Do you want to know how the Universe works, or do you want to have some working mathematics? My version is more Darwinian, . . ..

You put ten mathematicians and a knife in a room, and you use the paradigms of whoever survives?

 

[Motor Daddy]

Math is very good at describing reality.

Really? Can you explain mathematically what gravity is, and how it works? What is the acceleration of gravity, anyway, rpenner, do you know? According to you, if a ball is on the earth, not moving compared to the earth, what is the acceleration rate?

 

[origin]

Really? Can you explain mathematically what gravity is, and how it works? What is the acceleration of gravity, anyway, rpenner, do you know? According to you, if a ball is on the earth, not moving compared to the earth, what is the acceleration rate?

Newton came up with a swell mathematical description over 300 years ago that works like a champ under most conditions. Here it is:

$$F = G\frac{m_1m_2}{r^2}$$

 

[rpenner]

Really?

I said describing reality. And the rest of the post makes it clear I was talking about measuring and predicting with precision phenomena.
Making a claim of the identity of X (meta-physics) is distinct from describing X (physics).

 

[Russ_Watters]

If .999...=1, then you can't ever drive 1 mile, you are always trying to get past the 0.999... marker, but suffer infinite miserable failure.

Zeno's Paradox was bad math even when first proposed 2500 years ago. Now it exists only as a silly illustration of how ignorant the ancients were.

Not our fault you don't understand math.

 

[Uncle Pythagoras]

Newton came up with a swell mathematical description over 300 years ago that works like a champ under most conditions. Here it is:

$$F = G\frac{m_1m_2}{r^2}$$

Yes he did come up with that sum, but it is still wrong anyway. I don't want to throw the thread off topic...

http://www.sciforums.com/showthread.php?140972-It-would-be-nice-to-fix-the-maths-in-science&p=3166481#post3166481

 

[paddoboy]

Yes he did come up with that sum, but it is still wrong anyway. I don't want to throw the thread off topic...

http://www.sciforums.com/showthread.php?140972-It-would-be-nice-to-fix-the-maths-in-science&p=3166481#post3166481

No, it is not wrong.....That's why the link you gave pushing that crap, is in pseudoscience.

 

[Uncle Pythagoras]

No, it is not wrong.....That's why the link you gave pushing that crap, is in pseudoscience.

It is wrong. I put it in pseudoscience to keep you happy. My version as tubes allows a spin force to throw matter out of black holes sideways, which is a Galaxy made from mini tubes. That is the correct picture.

 

[paddoboy]

It is wrong. I put it in pseudoscience to keep you happy. My version as tubes allows a spin force to throw matter out of black holes sideways.

No, it's pure solid, 100% unadulterated rubbish.....and is where it should be

 

[rpenner]

In a certain rest frame, we have a right cuboid box moving in the +x direction with velocity v. As measured in the rest frame the box has one axis aligned with the x axis and of length A and the other axes aligned with the Y and Z axes and of identical length B. At one point the center of the box coincides with the center of our coordinate system and a flash of light is emitted and bounces off a mirror at the leading edge of the box and returns to the center of the box. Also it hits a detector at the center of one of the faces parallel to the direction of the movement.

Question 1. Describe all events in the rest frame if the event where the center of the box coincides with the center of coordinate system is labeled as (T, 0, 0, 0).

Event O -- The light leaves the center of the cub[oid]

$$ O = (T, 0, 0, 0)$$​

Event D -- the light hits the detector in the center of a face parallel to the direction of movement. ...

$$ D = \left(T + \frac{B}{2} \times \frac{1}{\sqrt{c^2 - v^2}} , \quad \frac{B}{2} \times \frac{v}{\sqrt{c^2 - v^2}}, \quad 0, \quad \frac{B}{2} \right)$$​

Event M -- the light bounces off the mirror in the leading direction ...

$$M= \left(T + \frac{A}{2} \times \frac{1}{c - v} , \quad \frac{A}{2} \times \frac{c}{c - v}, \quad 0, \quad 0 \right)$$​

Event R -- the bounced light returns to the center of the moving cub[oid] ...

$$R = \left(T + \frac{c A}{c^2 - v^2} , \quad \frac{c A v}{c^2 - v^2}, \quad 0, \quad 0 \right)$$​

Motor Daddy's exact example is with T = 0, A = B = 1 light-second, $$v = \frac{\sqrt{69}}{13} c = \sqrt{\frac{69}{169}} c \approx 0.6390 c \approx 191.6 \, \textrm{Mm} / \textrm{s}$$. So:

$$ O = (0, 0, 0, 0)
D = \left( \frac{13}{20} \, \textrm{s} , \quad \frac{\sqrt{69}}{20} \, c \cdot \textrm{s}, \quad 0, \quad \frac{1}{2} \, c \cdot \textrm{s} \right) \approx \left( 0.6500 \, \textrm{s} , \quad 0.4153 \, c \cdot \textrm{s}, \quad 0, \quad 0.5000 \, c \cdot \textrm{s} \right) \approx \left( 194.9 \, \textrm{Mm} / c , \quad 124.5 \, \textrm{Mm}, \quad 0, \quad 149.9 \, \textrm{Mm} \right)
M = \left( \frac{ 13 (13+\sqrt{69}) }{200} \, \textrm{s} , \quad \frac{ 13 (13+\sqrt{69}) }{200} \, c \cdot \textrm{s}, \quad 0, \quad 0 \right) \approx \left( 1.385 \, \textrm{s} , \quad 1.385 \, c \cdot \textrm{s}, \quad 0, \quad 0 \right) \approx \left( \quad 415.2 \, \textrm{Mm} / c , \quad 415.2 \, \textrm{Mm}, \quad 0, \quad 0 \right)
R = \left(\frac{169}{100} \, \textrm{s} , \quad \frac{13 \sqrt{69}}{100} \, c \cdot \textrm{s}, \quad 0, \quad 0 \right) \approx \left( 1.690 \, \textrm{s} , \quad 1.080 \, c \cdot \textrm{s}, \quad 0, \quad 0 \right) \approx \left( 506.6 \, \textrm{Mm}/c , \quad 323.7 \, \textrm{Mm}, \quad 0, \quad 0 \right)
$$​

The theory of special relativity says the relations between these events have a geometry.

Question 2. What are all the geometric constraints (according to the theory of special relativity) on these four events.

Because of the nature of a geometry, the physics of a particular configuration of matter does not depend on the choice of coordinates (among applicable options) used to describe it.
Question 3. What then is the description of the same cuboid and the same events (according to the theory of special relativity) in the inertial coordinate system where the cube is motionless, the cube's center resides at the center of the coordinate system and the X, Y and Z axes are parallel to the same sides of the cuboid as before.

In a certain rest frame, we have a right cuboid box at rest. As measured in the rest frame the box has one axis aligned with the x axis and of length A' and the other axes aligned with the Y and Z axes and of identical length B'. The center of the box coincides with the center of our coordinate system. At one point a flash of light is emitted and bounces off a mirror at the center of the +x face of the box and returns to the center of the box. Also it hits a detector at the center of one of the faces parallel to the direction of the movement.

Here $$A' = \frac{A}{\sqrt{1 - \frac{v^2}{c^2}}} = \gamma A$$ and $$B' = B$$.

Event O -- The light leaves the center of the cuboid

$$ O = (T', 0, 0, 0)$$​

Event D -- the light hits the detector in the center of a face parallel to the X axis. ...

$$ D = \left(T' + \frac{B'}{2c} , \quad 0, \quad 0, \quad \frac{B'}{2} \right)$$​

Event M -- the light bounces off the mirror in the center of the +X face ...

$$M= \left(T' + \frac{A'}{2c} , \quad \frac{A'}{2} , \quad 0, \quad 0 \right)$$​

Event R -- the bounced light returns to the center of the cuboid ...

$$R = \left(T' + \frac{A'}{c} , \quad 0, \quad 0, \quad 0 \right)$$​

Which is a simple description and obviously obeys the speed of light constraints. Likewise, for Motor Daddy's exact example is with T = 0, A = B = 1 light-second, $$v = \frac{\sqrt{69}}{13} c $$ we have in the rest frame T' = 0 (by choice), A' = $$\frac{13}{10}$$ light-seconds, B' = 1 light-second, v' = 0.

$$ O = (0, 0, 0, 0)
D = \left(\frac{1}{2} \, \textrm{s} , \quad 0, \quad 0, \quad \frac{1}{2} \, c \cdot \textrm{s} \right)
M= \left(\frac{13}{20} \, \textrm{s} , \quad \frac{13}{20} \, c \cdot \textrm{s}, \quad 0, \quad 0 \right)
R = \left(\frac{13}{10} \, \textrm{s}, \quad 0, \quad 0, \quad 0 \right)$$​

which may be derived directly by application of the Lorentz transform between the coordinates.

 

[James R]

Here's just one of the many posts where I attempted to explain what is wrong with Motor Daddy's box to him:

Relativity of Simulaneity

That was 3 years ago. He's made no progress since then (and made none at that time, either).

Which all goes to show that this kind of thing:

What's it called when someone does this and nobody responds to the posts, but continues to call BS, and they have no idea what I'm saying, or what they're talking about? Insanity?


...oh, by the way, I'm f'n stupid, so it took me f'n hours! to make that, and nobody gave a damn!

is disingenuous.

 

[James R]

Moderator note: Complaints that are better suited to the "report" button, or to the Site Feedback or Open Government forums, have been moved to a separate thread:

Undefined's many complaints.