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Physics, Astronomy & Cosmology / Re: How does the length of a tunnel, at constant depth, vary with length?

« on: 25/12/2009 16:33:46 »

Offhand, I don't see why the regular barometric equations wouldn't work.  You're talking about a tunnel into the earth and the pressure at various depths, right?

I don't know if it would apply. I'm assuming the tunnel is at a constant level.

Let's assume that this tunnel is in construction and only has one entrance and no traffic is yet going through it. if you needed to ventilate the area for workers while trying to remain efficient you would need to calculate how the pressure inside the tunnels are affected by its growing length. As mentioned breathable air at some point will not be able to reach the end of the tunnel at some point. So what factors must be taken into account and what are the existing formulas that would fit into this?

thanks guys, the dialog is inspirational so far.

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Physics, Astronomy & Cosmology / How does the length of a tunnel, at constant depth, vary with length?

« on: 24/12/2009 17:10:54 »

How does the length of a tunnel at a constant sea level directly relates to increasing atmospheric pressure in quantitative terms?

I understand that the atmospheric pressure increases with the length of the tunnel, but my google searches have failed to produce any data concerning any formula or model that could express in quantitative terms the effect of the length of a tunnel from a single entrance (such as a mine shaft or a tunnel digging operation in progress). Anyone know where I can find such data or can anyone have knowledge of a formula that I could use to gather data with?

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The Environment / Is Total Ocean Heat Content Going Up or Down

« on: 22/12/2009 19:30:30 »

The quick answer to your question is no.

However, just as your first paper you cited talks about is a variation in the temperature of the upper layer of the ocean. The temperatures are directly related to barometric pressures around the world and will vary the temperture of the ocean's upper layer accordingly. The deeper you go in the ocean however, given that you are not near volcanic activity, will become more constant and no vary as widely as the surface. The upper layers of the ocean act as a sort of insulation for the lower depths. Think of a cave. The deeper the cave the more constant the temperature, regardless of the temperature outside. Because of this natural phenomenon. Many Green enthusiasts have built homes out of caves (natural or constructed) which allows them to save energy because the temperature maintained in caves on average is a pleasant temperature for most of mankind. Also, when barometric temperatures change outside the cave a draft will occur. Hot weather has a low barometric pressure, so air from the cave drafts outward, and vise versa with pressures associated with poor weather or low temperatures.

Because this same phenomenon goes on in the oceans we get currents of the upper layers that are different from the currents of the lower depths. Meaning that all the ocean temperatures will never be the same, except for some global catastrophe.

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Technology / What happened to efficient solar panels?

« on: 22/12/2009 19:11:51 »

Often scientist will make claims of potential break throughs they are working on without having all the details sorted out or completely developed.

Why would they do this? For some face time in the popular science circuit in a hope to gain much needed funding to continue their research. Often times people are faced with a financial crunch and need to show some work in order to gain investor interest in the project. I personally see it as a desperate bid. Any other company that develops products does the same thing, but only to raise attention to their products for higher sales upon release. Anyone who has followed the trends of the video game industry can tell you of the many pushed back deadlines and project cancellations that come about (even upon a game with much promise) because of finances, controversy, and/or lack of general interest.

There is hope though! A number of different companies are still working on improving solar technology. Some even sell their new and improve solar tech, but at a cost that is too pricey for shrewd business types.

check out some of these companies as an example

http://www.kyosemi.co.jp/product/pro_ene_sun_e1.html


https://inlportal.inl.gov/portal/server.pt?open=514&objID=1269&mode=2&featurestory=DA_101047

And for a humorous take on this concept, check out the latest xkcd.com comic strip.

Author gives permission of use for any nonprofit reproduction, websites, and/or forums.

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Famous Scientists, Doctors and Inventors / Historic Science: Nikola Tesla, How did he generate his alternating currents?

« on: 22/12/2009 05:51:10 »

I'm curious to hear what you all have to say. From another Tesla post it is easy to see that opinions on Nikola Tesla range in a great degree from being a quack to the most talented scientists ever. Whichever is true is none of my concern in this current pursuits of curiosity. I have studied some of the posthumously published papers of Tesla and apart from being difficult to grasp (mostly for late 19th century English and his own unique terms, ie "condensers" = capacitors,) it also is not written for the layman. His writing resemble more of a journal, which the papers are probably from and so assumes a high knowledge of his research subjects.

My question:

How did Nikola Tesla generate high frequency alternating currents?