Category Archives: Technology

Applied science and engineering

Data Fudging ?

In a galaxy far far away and long long ago in a remote place called Planet Houston I was teaching a general course on navigation. I was covering data adjustment, signal processing and navigation system calibration when one member of the class suggested that what I was teaching was “fudging the data”.

I asked a few questions and realized to my horror that several others in the class had clearly misunderstood the subject matter and agreed that data processing and standard data adjustment techniques were little more than sophisticated cheating techniques to get a desired result. Friedrich Carl Gauss  would turn in his grave.

The entire field of seismic exploration in the service of the search for oil rests on advanced data processing algorithms to extract meaningful information from vast amounts of extremely complex data. The view of some elements of my class was tantamount to believing the entire oil exploration business was built on a foundation of lies. By extension; they effectively believed that virtually all of scientific measurement and mathematics as applied to scientific data was little more than a farrago of chicanery and falsehoods. I was gob smacked.

Shit! What to do?

I decided right then and right there to add a little remedial math(s) to the navigation course because it seemed to me that my entire syllabus was a waste of time if its foundations were so badly undermined by misunderstandings and frightening mathematical ignorance.

I have seen many posts and articles recently that deny climate change and use seemingly legitimate arguments to do so. One of the most common is to show that supposedly conniving, cheating scientists have falsified temperature data in the interests of their hysterical and dishonest claims about climate change. This is the same mathematical and scientific ignorance exhibited by a few of my students several decades ago except that this time the future of the planet is at stake.

There isn’t space here to do a remedial maths or science course but perhaps a simple example might serve to illustrate the scientific necessity for measurement adjustments and data processing before using raw data to more closely determine scientific truths.

Imagine, if you will, a world wide project to determine the average height of five year old children around the world. All measurements are to be made with metal measurement tapes and the results sent to a central point for collation. Simple! What could possibly go wrong?

So all results are collected and the average height of 5 year old kids is calculated by adding all the heights and dividing by the number of kids. So far so good.

Then some curious social worker wonders if the average height of a 5 year old varies from one place to another. The results are recomputed for each geographical area and it turns out that there are variations. Why?

Some smart-arse scientist recognizes that since the measurements were made with metal tapes and all metal expands with increasing temperature, the kids measured in hot climates such as northern Australia would seem to be shorter than kids measured in the Arctic conditions of northern Canada.

Fortunately all height measurements were submitted with location and temperature data thus allowing the entire data set to be corrected for temperature variations.

Then some super nit picky awkward bugger asks “are all the steel tapes identical ?” The tapes are recalled and it transpires that one batch of measuring tapes were 2 mm short due to a manufacturing error. All measurements made with these tapes can be corrected by adding 2 mm to all heights.

Get the picture? All measurements and all data sets contain errors of one sort or another; offsets, biases, scaling errors, random noise and even mistakes. The art of measurement and the scientific use of measurements is to detect and eliminate those errors. Better results from older data can be obtained over time by applying better techniques and corrections for errors that might not have been known at the time of the original measurements.

So it is with measuring the heights of children and so it is with measuring global temperatures. Refining temperature data in the light of new knowledge is not fudging, it is good science.

Genius Not!

Look for the patterns
Look for the patterns

The key to most of these puzzles is to recognize that they are not equations and that they have very little to do with mathematics other than simple arithmetic.

Take the first so called “equation”; 7+3 does not equal 41021, but 7+3 does equal 10 and note that 10  appears within the string 41021.

Does this result hold for any of the other “equations”? Yes it does. The result of adding the two numbers on the left hand side is embedded within the string on the right hand side for all the “equations”.

Back to the first “equation”: 7-3 = 4, the difference between  the left side numbers appears as first number in the right hand string. This holds true for all the equations.

We are almost home: the product of the left hand numbers appears at the end of the right hand string in every case.

The right hand string is constructed by concatenating  the difference, the sum and the product of the two left hand numbers.

Test on the final equation.

17-8 = 9, 17+ 8 = 25, 17*8 = 136 giving us the string 925136

QED.

 

 

 

 

 

 

 

Newton’s Kids

NewtonsnKids

Newton’s cradle is an apparatus named in honor of Sir Isaac Newton.

The device comprises a series of suspended spheres and is used to demonstrate the laws of motion formulated by Newton.

I. Every object in a state of uniform rest or motion tends to remain in that state of rest or motion unless an external force is applied to it. This is the law of the conservation of momentum or because it is essentially Galileo’s concept of inertia it is often called simply the “Law of Inertia”.

II. The relationship between an object’s mass m, its acceleration a, and the applied force F is F = ma.

III. For every action there is an equal and opposite reaction.

When one sphere on the end is lifted and released, it strikes the next stationary sphere and imparting a force which is transmitted through the adjacent stationary spheres and causes the final sphere to swing.

When one sphere on the end is pulled back and released, it wants to keep moving and the stationary balls would like to remain motionless. The collision between the moving ball and the stationary balls results in a change in the forces acting upon all the balls in the system. [Click to see video of Giant Newton’s Cradle].

The moving ball has a certain amount of momentum (a tendency to remain in motion) and the stationary balls have a certain amount of inertia (a tendency to remain stationary). When the moving ball is stopped by the collision, its momentum is transferred to the first stationary ball in the line. The ball cannot move since it is sandwiched, so it transfers the momentum to the next stationary ball in line. This transfer of momentum continues until the momentum is given to the last ball in the line.

Because its movement is not blocked, when the last ball receives the momentum it continues on the path of the first ball. This process will repeat itself, going back and forth, until the energy of the system is lost to air resistance, friction, and vibrations and all the balls again come to rest.

The first law is seen to be satisfied by observing that the final ball swings to the same height (nearly) as the initial height of the first ball. The third law is demonstrated by noting that the first ball is stopped dead in its tracks. The second law can be used to calculate the forces involved since we can measure the mass of each ball and we know that the initial acceleration is from gravity.

[Click here fore some interesting variations on this theme]

Drone Strike

 

DroneOn an April evening this year, swarms of glowing spacecraft will begin a flight and hover over locations around the world.
Click here for original article.

The goal is maximum panic – and to cause an ‘apocalypse’ in the media. But the pilots of the eerie craft are not little grey men from Alpha Centauri – but UFO fans using drone aircraft.

At first I thought it funny, after all I love pranks. Then I thought a bit more and wondered “how hard would it be to replace the on-board camera with a gun or some explosive?” No trick at all. You can buy these things very cheaply in any hobbyist store and many toy stores.