5.3 Power

This is the third week of Module 5 in the Navy Basic Electricity and Electronics series. This module is on the relationships between current, voltage, and resistance. The first two sections were:

5.1 Voltage, Resistance, and Current
5.2 Ohm's Law Formula

1. "Power is the rate of doing work" (66), the amount of work done by the electricity (in this case) in a given time. We might express this relationship with the formula:

P = W/T

Another way to put it is to say that electrical power is the rate of converting electrical energy into some other form of energy (e.g., heat).

2. Electrical power is measured in watts (watts having the symbol w). A 100 watt bulb burns brighter, has less resistance, and dissipates more power than a 60 watt bulb.

3. Power equals voltage times current P = EI .

• If we substitute in E = IR from the previous lesson, we get P = I²R .
• We can also do a little algebra and come up with P = E²/R
• You use different versions of the relationships depending on what information is given.

*4. Read at your own risk. Another tidbit in this section is that the amount of heat produced by a resistor is the power times the amount of time or I²RT . If you think of the original formula P = W/T, this formula suggests that work relates in some way to the heat given off.

The section doesn't really explain what work is when it comes to electricity. I guess that is something for a later module. In terms of mechanical energy, work is the force times the distance. I am not remembering exactly how that plays out with electricity, but I seem to remember that the same unit of work is used, the joule.

Wise Serpents, Harmless Doves

There's a certain situation that always brings to mind the verse, "Be wise as serpents, harmless as doves" (Matt. 10:16). It's usually a situation where a person who is committed to be good is engaged with the powers of evil in the world. If I dare to quote a certain character from science fiction, "Spock, I've found that evil usually triumphs [over good] unless good is very, very careful."

I heard another proverb once from Keith Drury, "Don't wrestle with a pig. You both get dirty but the pig likes it." I think of the Parable of the Unjust Steward.  A Christian in the halls of money and power is in a surreal world, an Alice in Wonderland.

The pacifists among us would say not to engage the worldly powers on their own terms. They would say that the person who dabbles in the world to try to do good inevitably infects themselves and cannot retreat.  You start trying to bomb just the terrorists but you end up blowing away a whole country because they're all your enemy.  Sinestro tries to harness the yellow energy of fear to fight evil but ends up evil instead.

I've never been able to go the whole way with pacifism or absolutism on these sorts of things. The Nazis are at your door looking for the Jews hiding in your attic and you lie even though you would rather not.  So what of that rich and powerful member of the congregation to whom you have to give attention even though in God's eyes he or she is no more valuable than anyone else?

It's an age old story. Does Jimmy Stewart take the job at the bank or stick with the building and loan?  In the movies, the most virtuous decision often prevails.  In real life, it often doesn't. Is it "no compromise or die"?  "Better dead than red"?

It's a quote about the circus of life--be wise as a serpent because the world is a surreal, strange place that will just as soon chew you up and spit you out. Be careful with power. Be constantly on your guard. Guard yourself when you get a little of it.  Be harmless as doves. Constantly check your true motives.  If you find yourself with venom in your hands, be careful who it gets on.

Watch out for Power 3

... continued from Wednesday.
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Jesus addressed a specific context in Galilee, although the Gospel of Matthew presumably wanted its audience to see this teaching as applying to them as well. However, we at least have to ask the extent to which Jesus' teaching on non-violent conformity was local or timeless and universal. What exactly might Jesus say--or Paul for that matter--if he were addressing a democratic society or one where the state at least seemed less evil? This is the difficult task we face together of working out faith in a world that is much different in many respects than that of Jesus, and we have to "test the spirits" carefully when people like me make suggestions.

The first thought that occurs to me is that Jesus would probably tell us to be very, very careful when we try to wade into the world of politics and power. You've heard the saying, "Power corrupts, and absolute power corrupts absolutely."  It's not in the Bible, but it fits the sense we get in the gospels that the vast majority of the humans in power in the story--except for Jesus--are morally questionable. The high priest, Pilate, the Jewish leaders, they are not the ones to model oneself after.

Sure, there are some with power who are true seekers.  Nicodemus, Joseph of Arimathea, the centurion, they are the exceptions. But in general, "it it is easier for a camel to go through the eye of a needle than for someone who is rich to enter the kingdom of God" (Matt. 19:24), where wealth is a form of power.

Christians believe that although Christ had all power, he "emptied himself" of that status and willingly took on the form of a servant (Phil. 2:6-7). Paul says that we are to serve each other this way as believers.  And we should not too quickly dismiss Jesus' instructions to the rich young man when he told him to "Go, sell everything you have and give to the poor" (Mark 10:21). How easy it is for us to slough off this statement as just something for this one man, while obsessing on more peculiar statements like "Women should remain silent in the churches" (1 Cor. 14:34). Jesus' trajectory away from money and possessions was completely consistent throughout his ministry. [1]

Yet we do see individuals with significant resources and possessions in Scripture. While we need to linger longer on the warnings of Jesus and the New Testament against wealth, it is true that this trajectory is not absolute. Those with power can do good in this world and in the kingdom. God can use a pagan king like Cyrus to accomplish his will (Isa. 45:1). There is a time for the Christian statesman and the Christian patron.

I think of the curious statement Jesus makes in Matthew 10:16 to be "shrewd as snakes and as innocent as doves." A snake has power. Surely that's why we fear them so much, especially in places where the primary snake is a rattlesnake, a cobra, or a black mamba.  The dove has no thought of harming others. It hardly has any sense of its own danger.

The two images together are striking, to have the power to harm but to be harmless. Surely this is Jesus' philosophy of power. There is a rare person who can have immense power and yet use it for good. We may all think we would be the exception. The ambitious Christian will no doubt gladly smile, raise his or her right hand and say, "Yes, yes, I seek power only to do good." But it will not be true in the vast majority of cases...

[1] By contrast, numerous women ministered in the early church from Priscilla, who led the way in discipling Apollos (Acts 18:26), to Phoebe, who was a deacon (Rom. 16:1), to Junia, who was an apostle (Rom. 16:7).