English, history: AD vs CE

Tutoring English, conventions are important. The tutor brings up one he was curious about.

As far as I can determine, timewise, the two acronyms AD and CE have the same meaning. However, their literal meanings are different:

AD anno domini: year of our lord

CE: common era

The reason CE might be used is to avoid religious connection to a given topic.




Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Chemistry: groups IB and IIB

Tutoring chemistry, the periodic table is important. The tutor mentions a peculiarity of it.

The transition metals are the elements in the middle of the periodic table, starting the fourth row from the top. Their first element is scandium (Sc).

On some periodic tables, you’ll notice that scandium (Sc, 21) is under group IIIB, then follows titanium (Ti, 22) under IVB, and so on. However, if you continue across, you’ll notice that copper (Cu, 29) is under IB, then zinc (Zn, 30) is under IIB. Why do IB and IIB appear at the right side, while IIIB appears at the left?

Beginning with scandium, the 3d subshell is being filled, but 4s, in the shell above, already is. Scandium is 3d14s2. At nickel (Ni, 28), the 3d subshell has 8 electrons, the 4s, 2. However, at copper (Cu, 29), the 3d subshell gains two electrons to reach 3d10, while 4s drops to 4s1. Zinc has 3d104s2. Perhaps it’s the refilling of the outer s subshell that defines IB and IIB at the right side of the transition metals.

In the next period, silver (Ag, 47) has 5s1, while cadmium (Cd, 48) has 5s2. However, the filling of 4d happened back at palladium (Pd, 46).

One more period down, gold (Au, 79) has 6s1, while mercury (Hg, 80) has 6s2.


Mortimer, Charles E. Chemistry, 6th ed. Belmont: Wadsworth, 1986.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Statistics: how often can something “better” be expected to perform better?

Tutoring statistics, you might imagine everyday situations. The tutor brings up one.

Let’s imagine we have two mile runners. Runner 1, called R1, has mean time 4:45, with standard deviation 10s; R2 has mean time 5:00 with standard deviation 12s.

In any given race, give the probability R1 will beat R2.


First, we convert the mile times to seconds: R1’s mean is 285s, while R2’s is 300.

The expected difference between R2 and R1’s time is 300-285=15.

We can’t add standard deviations, but rather variances: 10^2 + 12^2 = 244. The standard deviation of the difference is then 244^0.5 = 15.6.

The standardized statistic is z = (x-15)/15.6. We wonder p(x>0), which means p(z>-0.96). From the z-table, the answer is 0.8315.

So, R1 should beat R2 about 83% of the time.


Harnett, Donald L. and James L. Murphy. Statistical Analysis for Business and Economics. Don Mills: Addison-Wesley, 1993.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Lifestyle: food wrap: wax paper vs aluminum foil

More lifestyle self-tutoring: the tutor makes a preliminary comparison between wax paper and aluminum foil.

We’ve always used wax paper to wrap sandwiches, but a couple of weeks back we ran out. The only alternative on hand was aluminum foil, so I used it.

Aluminum foil I find easier to work with than wax paper, since it has a stronger memory. After wrapping the sandwiches I wondered if I could always just use aluminum foil from then on.

Apparently, aluminum foil and wax paper can be gotten for around the same price. So, if you like aluminum foil better for wrapping your sandwiches, it’s a viable alternative to wax paper.




Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Astrology: what is the Sagittarian temperament?

Tutoring, you meet so many new people. The tutor shares some facts he discovered about Sagittarians, whose time in the calendar is now.

Birth November 22 to December 21 indicates Sagittarius. I’ve recently met a few, and also realized that a few people I already know are Sagittarians. If astrology is to be believed, what might we expect about them?

According to astrology, Sagittarians are wanderers, both in body and in mind. They love to travel and they love to philosophize. They love to be happy and can be intolerant of people or routines that might inhibit their free spirit.

Sagittarians may have the weakness of overextending themselves, since they want to enjoy as much of life as they can. They can lack the patience to be tactful.

(A tendency to be too honest can perhaps be witnessed in people of other signs, as well.)




Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Lifestyle: do you have to proof yeast?

More lifestyle self-tutoring: the tutor wonders whether you need to proof yeast.

When I started making bread, the first kind of yeast I used was active dry yeast. I was under the impression you need to proof yeast, so did so each time.

Proofing, from my point of view, means putting the yeast in warm water with the sugar. Next, you wait until the yeast starts to change. When it starts to puff at the surface, it’s “proofed”.

I thought yeast needs to be proofed so that it will be properly active from the very start of the bread making process. However, I read today that proofing the yeast is just done to assure it’s alive. If it indeed is, then it will work fine (to make bread) without being proofed.

Proofing the yeast became part of the bread making process, for me; I’m sure I’ll continue doing it, even with fresh yeast.




Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Handyman role: hinge measurements

Taking on the handyman role leads to self-tutoring: the tutor shares a discovery about hinge sizing.

At possibly around 20 years old, little things on a house can need replacing. Such was the case with the spring hinge on the door between the garage and the shoe room.

I sized the hinge, then went to the hardware store to seek a replacement. I knew I needed a 4″ hinge. However, the measurements on one package said 4″ by 4″ by 1/4″, while the other said 4″ by 4″ by 5/8″.

The measurement at the end, 1/4″ or 5/8″, stumped me. I couldn’t recognize anything that could be that measurement. Furthermore, I feared choosing the wrong one – whatever that measurement might mean – would turn out problematic.

My conclusion is that 1/4″ or 5/8″ means the radius that the mounting plate corners are rounded. I measured the rounded corners of the one to replace; they indeed have radius 5/8″. I bought the 4″ by 4″ by 5/8″ replacement spring hinge, and successfully installed it.

Looking at the spring hinges, I was imagining their functionality, so didn’t think, at first, about their decorative features.


Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Lifestyle, nutrition, health: Fibre battle: apple vs orange

More lifestyle self-tutoring: the tutor researches which fruit – apple or orange – has more fibre.

Just before bed I tend to eat fruits and/or vegetables if I haven’t had enough during the day. One reason to eat fruits/vegetables is for fibre.

I’ve been wondering which fruit has more fibre – apple, or orange?

Apparently, they are dead equal, both averaging 2.4g fibre per 100g.

Oranges can be much easier to eat, though, especially when you’re not hungry but need to consume your daily allotment of produce.




Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Medical technology: is CT scan the same as CAT scan?

Curiosity has led to self-tutoring: the tutor discusses the two terms CT scan and CAT scan.

CT scan and CAT scan have the same meaning. CAT scan is the older term.

CT stands computerized tomography, whereas CAT stands for computerized axial tomography.

Tomography: a method to produce pictures of internal body structures. Tomography acquires information from many cross-sectional scans.

Computerized tomography conveys the idea that, once the cross-sectional scans have been taken, a computer program is used to produce an image from their data.

In the phrase computerized axial tomography, the word axial refers to the idea that the cross-sectional scans are taken by revolution around a common axis (axis=line). Specifically, a scan is taken around the patient, then another a short distance along, and so on.




Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Lifestyle: how to cook pasta

Yet more lifestyle self-tutoring shared by the tutor, who wondered yesterday if he was cooking pasta correctly.

When I was a kid, someone told me to add oil to the water when cooking pasta. My wife, however, says not to.

Apparently, my wife was right. (When is it else-wise?) Here are some tips I picked up, yesterday, from my research about cooking pasta:

  1. Don’t add oil to the water.
  2. Don’t put in the pasta until the water is boiling fiercely.
  3. Add salt when the water starts to boil.
  4. Cook the pasta in a big pot, with abundant water. (My wife says so as well.)
  5. Don’t rinse the pasta after it’s cooked.



Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.