Ceiling Lights | Incandescent | CFL | LED

Our home has many can-light ceiling fixtures. We replaced the original incandescent bulbs with CFL in many of them and noticed some cost savings on our electric bill for several years. More recently we added some LED style.

Bulb costs, duration of use, and total cost of use are some of the quantities tabulated in the chart below from wikipedia. I don’t know how recent are the values. But, they illustrate the cost savings with LED. With LED costs coming down, the savings is improving.

The main problem with an incandescent bulb is that about 75% of the energy needed to operate it is wasted as heat energy to the surroundings. Only about 25% goes toward making light energy. The CFL and LED bulbs convert a much greater fraction of their operating energy into light energy. As a result, they need less electrical energy to produce the same light output as an incandescent.


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Nuclear Options | Dialogue & Planning Needed

This post is a follow-up to one from a week ago. See below the line break for the original.

Thanks to comments by readers, there are three resources to promote which discuss the need for careful, considered dialogue and planning with regard to our nation’s domestic and military nuclear capacity. Readers shoreacres and Jim Wheeler discussed two resources by Thomas Nichols. The third resource is a recent NOVA program about the nuclear option.

First, what if we could rebuild our nuclear weapon forces from scratch? How should it be done?

Second, read the preface and introduction to the Nichols book No Use: Nuclear Weapons and U.S. National Security

Third, the NOVA program Nuclear Option is available for viewing until 8 Feb 2017.

All three urge bi-partisan discussion by all interested parties. One of the reasons hinges on the need for safety and security in our world today. The other reason hinges on the need for a viable solution to the challenges of climate change and global warming.

I believe nuclear energy should play a role in our future. To not examine the ideas and technologies formed in the 50s, 60s, and 70s which brought us to our current position is foolhardy. The world has changed very much since then.

Nuclear Weapons | Do Accidents Happen?

Have there been nuclear weapon accidents or incidents? Yes, there have been many. We are lucky to not have detonations or major spills of radioactive material. An accident near Damascus Arkansas on 18 Sep 1980 illustrates how a simple event can cause a situation of monumental potential for disaster.

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Exercise | Power Generated

We use our Body-Solid home gym regularly. My workout takes about 20 minutes with pauses between routines. Today. I didn’t pause. Workout time was 15 minutes, or 900 seconds.


A principle of physics I taught about involved work, energy, and power. I wondered how much work was done lifting the weights during my workout. Each routine raised the weight different amounts. Units used are Newtons of force and meters of distance. 1 N-m = 1 Joule of work.

Work done = Newtons x distance x number of reps


Total work done was the sum of the separate routines equal to 20,900 Joules.

Average power generated, or work per second, equals 23 Joules/sec, or 23 Watts.

Metabolic Equivalent

If I just sit around and do nothing, my body utilizes energy at a rate of about 81 Joules/sec, or 81 Watts. It is calculated from the Metabolic Equivalent expression of 1.162 Watts/kg. I multiplied my 70 kg x 1.162 Watts/kg to get 81 Watts.

Other physical activities are scaled with reference to this figure. For example, earlier I went for a walk at a brisk pace of 3.4 mph for about 30 minutes. According to the tables, energy was utilized by my body at a rate 3.6 times the metabolic equivalent, or 81 x 3.6 = 292 Watts. Bicycle racers can generate 500 Watts for hours at a time. If a level of 746 Watts is reached, it is also known as one horsepower.

You can look up many activities at the Compendium of Physical Activites. They include things like bicycling, dancing, sexual activity, lawn mowing, etc. Each is rated with a Metabolic Equivalent score. Take your body mass in kg x 1.162 x the score in the activity.

Melanie said “Be sure to provide a link to your post about mowing the lawn.” Thank you, dear.

El Niño | Likely To Be Strong In 2014

UPDATE: May 26, 2014 | For those of you interested in keeping informed about climate issues, the agency NOAA offers Climate.gov. I suggest that you bookmark the site and visit it regularly. One of their offerings is called the ENSO Blog. It addresses specific concerns about El Niño. On May 19, 2014, four days after this post of mine, the ENSO Blog published an excellent summary of the potential global and regional effects of a strong El Niño this year. I invite you to read it in conjunction with this post of mine.

On May 8, 2014, scientists at the Climate Prediction Center of the National Weather Service (NWS) announced there was a 65% likelihood of a strong El Niño event this summer/fall. There is still uncertainty when and exactly how strong. Indications are that it may rival the significant El Niño of 1997. This image compares the sea height for the regions of the equatorial Pacific on the same date in 1997 and 2014. Warmer than normal sea water moves east toward South America. The warmer waters cause expansion and higher than normal sea heights along the equatorial zone. Both are markers for the onset of El Niño.

NASA JPL | Marit Jentoft-Nilsen, Robert Simmon. Michael Carlowicz

What Happened in 1997?

It was one of the strongest El Niño events observed. Extreme weather affected several continents. One of the warmest and wettest winters on record took place in North America. California and Florida were both strongly affected. Strong rainstorms and flooding occurred in Peru, Mexico, and other parts of Central and South America. Severe droughts struck Indonesia and parts of Asia.

Will the same weather events happen to those areas this year? That cannot be predicted with certainty. Past history does show an increased tendency toward these abnormal events. None of the climate models predict a La Niña, while 16 of 20 models predict El Niño will occur this year. According to climatologist Bill Patzert of NASA’s JPL, who has studied El Niño for twenty years:

“If El Niño returns, the American West and Southwest could see major relief next winter from the long-lasting, punishing drought. Further, the very frigid winter in the upper tier of the U.S this past winter could do a flip to mild next winter.”

Tell me more about El Niño.