EdEarl

The short circuit essentially removes R3.

What confuses me is the current through I5, and whether R3 actually makes any difference to the total resistance of the circuit, because in my eyes it is as if it is bypassed by the wire carrying current I5.

Correct. There is a short circuit across R3.

I cannot afford most peer reviewed papers, but some reliable sources are available. Here are a few I believe are reliable.

http://nsidc.org/arcticseaicenews/

http://phys.org/news4906.html

http://www.nasa.gov/topics/earth/features/glacier-sea-rise.html

http://nrmsc.usgs.gov/research/climate_glaciers.htm

I didn't mean to imply government would not be involved, merely that business will shape laws.

Reinventing fire doesn't discuss all the things I have learned about climate change and related issues.

There is no doubt considerably more going on that I know about.

And, research will yield additional relevant information and advanced technology.

True, correlation is not causation, but without other proof, there is a 50% chance. Since we can create jobs and maintain or improve our economy at the same time we reduce anthropomorphic CO2, it is better to play it safe and reduce CO2. Subsequently, after CO2 reduction, we may better understand the effect of atmospheric CO2 and temperature.

Agreed. Our contribution may make life on this planet better. I have no problem with finding out, but until we do we should study not act.

It is obvious that burning fossil fuels puts CO2 in the atmosphere, and from ice cores that global temperature is linked closely to CO2 levels. Reducing CO2 levels is a worthy goal. However, IMO doing so will not destroy the economy; on the contrary, it is and will continue to revitalize the US economy because we will not be spending billions to buy foreign oil, and these industries will and are creating US jobs. I just read the a 500MW solar power plant in San Antonio, TX created 800 jobs and saved the local power company money compared to them continuing to use an existing coal power plant.

On the other hand, there are scenarios whereby the eliminating fossil fuels would be an economic disaster. But, industry will not do that, and they control enough governmental decisions I have no fear the economy will not get into trouble from the conversion.

On the other hand, doing nothing to control CO2 in the atmosphere would cause a disaster. Mountain glaciers around the world are disappearing. If they do, many of the worlds major rivers will be dry except when it rains, and millions or billions of people will die.

Eliminating CO2 is and will continue to be a balancing act. We need to grow economies and preserve critical natural resources at the same time. It is complicated and cannot be done immediately. Some people clamor for too much too soon, and others want to go too slow. I hope we progress fast enough but not too fast.

It is a contour map. In other words, many of the lines on the map indicate constant altitude along the line. Dotted parallel lines are probably a road or railroad. My eyes cannot make out all the detail. It is difficult to explain here, but sets of curved lines show hills or mountains and valleys, The river (blue) is in a valley and brown lines beside the river (e.g., left-bottom just above the bend) show a steep rise in altitude, because the brow lines are close together. A small loop in these lines shows the top of a hill (or a depression). The altitude is marked in numerals (e.g., 800) and there will be other altitude numbers on lines to show altitude increasing or decreasing from contour line to contour line. If you count ten lines between 800 and 700, then each line is 10 (feet/meters) difference in altitude from the others. Refer to the legend on the map.

As water flows down hill, you must determine which way is downhill.

I hope this helps. I apologize if my explanation is difficult to understand.

He is rather famous or notorious, depending on your point of view.

We really declined in advancements didn't we, If you think of all the great philosophers and inventors that were around in ancient and medieval times even compared to a few hundred years ago, In my opinion ; We seriously declined in intellect in some way. But recovered around 1900 onward.

Do you think this could be to do with Civilizations? As a civilizations grow so does the people's intellect?

Imagine what Plato and divinci could have done with today's technology?

 

Since there are more people on the world today, there are probably more people with the intellect equal to people like Plato and others from the past. Since evolution continues there may be people even more capable.

Nonetheless, the contribution to knowledge, art, music, and literature by historic figures is notable. We would not be where we are without them. We owe them honor and respect.

Climate changes. It always has. It always will. Pulling a human cause from the noise has not been done. Perhaps someday a human cause will be found but until that is done why kill the economy? There is enough human suffering now.

Yes, climate has always changed. We are a part of nature, and we contribute to the change. The only question, is how much we contribute, and whether our contribution is contrary to our needs or not.

Science cannot answer the metaphysical why, such as why is there a universe or why is there motion.

Science does answer the physical why as the Universe began with a big bang and everything was thrown into motion. Moreover, dark energy (whatever that is) pushes on the fabric of space time causing acceleration of distant things away from each other, and forces (such as gravity, electrostatic, weak and strong) suck pulling things toward each other. And, for some unknown reason photons move at the speed of light. I don't know if other things, such as neutrinos, move at the speed of light or not.

I do not remember the details, but two other kinds of energy affected the expansion of space-time, one caused inflation very early in the history of the universe, and another energy was dominant after inflation and before dark energy is dominant.

Tornadoes create terror and destruction. I have been lucky, not having been in one. I remember as a child having tornado drills in school. An a few years ago, a tornado came through my town, about a mile from me...a much smaller one. Nonetheless, it left a path of destruction.

Please accept my sympathy and hope that everyone injured makes a full recovery, including those who survived the ordeal without a scratch, but were terrified. And, I offer condolences to those who lost friends and family members.

Add a pressure sensor to indicate when something actually touched the target.

A webcam in or near the target can see the ball touch or enter the target. A computer program can monitor the camera and detect a score.

About 10,000 years ago, glaciers covered New York City, and many other places. This year, for the first time in recorded history, it was warm enough for the Greenland ice cap to melt enough for a thin layer of water to cover it everywhere. Glacier National Park is almost glacier free because they have been melting for a very long time. In fact, most mountain glaciers in the world are receding, in other words melting in the summer faster than they are being replenished in the winter. Permafrost in Alaska is melting, in other words it is no longer permafrost. The evidence for global warming is pervasive, and obvious. Yet, some people who live in parts of the world where there is no obvious evidence, deny the evidence exists.

Get up from your couch and visit somewhere like Tuvalu, the headwaters of the Ganges, Greenland, or Alaska and talk to people who are experiencing global warming. If such an experience does not convince you that global warming is real, then you will have convinced me that humanity is self destructive.

It may be possible to train yourself to hallucinate. The same neurons activate when we remember or think about something as when we experience it. We can improve our strength by thinking about exercising. Thus, reading a fantasy story must be similar to hallucinating. Reread the story until you memorize it. Replay the memory until it seems real...maybe.

My feeble brain is befuddled by the idea of infinity and gods. Just because I can consider whether a god or gods exist neither confirms nor denies their existence. Just because I can think of doubling an infinite set of integers, does not confirm that the set of infinite numbers actually doubled or not. Do alternate universes branch off from ours as we encounter alternatives in our lives. Do numbers only exist when someone thinks of them or do they always exist. How many angles can dance on the head of a pin?

Forgive my babble, I think I'll move on to a subject that is easier to resolve...maybe climate change.

Unusual: Steel (iron actually) wool burns (not the stainless steel stuff); rather, the kind that is gray and very fine.

There are open source arbitrary precision calculators that you may download and use for free. One for windows is at http://preccalc.sourceforge.net/

Sometimes I wonder if some people have a lemming gene that makes the suicidal or irrational during times in the face of prolonged stress.

The notion that there is some kind of "center of consciousness" sitting elsewhere in the brain, that is notified of decisions and the like "after the event", is suspect. More likely the reflex reaction contributes to the mental pattern that forms conscious awareness at the same time as it directs the muscle response (reflexes use "voluntary" muscles, notice) and in the course of doing so. The very complex and feedback-ridden firing patterns we experience as conscious awareness take time to form, is all, involving as much of the brain as they do.

I agree with you; most if not all of the brain contributes to consciousness. "Center of consciousness" is an idiom, which I should not have used. Jeff Hawkins and others say higher order thinking including consciousness is associated with the neocortex, which tends to indicate the cortex is especially important in those thought processes, but that is different than the spiritual idea some have of a center of consciousness.

When a reflex action occurs, signals are sent throughout the brain simultaneously, but neurons are organized hierarchically; thus, it seems there must be some time differential between signals arriving at high vs. low level neurons in the hierarchy. My recollection of reflex reactions is as if the reaction occurs, and shortly afterward I am aware of it.

No problem. I said all I'd intended and know the issues.

National Geographic made a documentary that includes a nuclear bomb propelled interstellar ship.

See: "Nat Geo Evacuate Earth"

Quantum mechanics is weird. Subatomic particles aren't like baseballs. Thus, one just has to memorize the QM wave-particle characteristics and equations. Our bodies and minds have not evolved to sense QM things and interactions.

Engineering will give you a good background in math, which is essential.

Youtube has many videos about physics, some that require no math and some in which math helps. You may get quite a bit of physics as part of your undergraduate degree. I know electronic engineering students get a lot of physics.

Leonard Susskind of Stanford has recorded some of the ones that require a little math. I know other universities have videos on youtube, but I have listened to only a few and don't know much about them. After you watch the no math and little math videos you should find studying physics with full math a little easier. Here is short video.