studiot

Yes a good idea and link, except that your link is short on detail of the hydraulic ones. +1 Here is a link to one such near me https://en.wikipedia.org/wiki/Lynton_and_Lynmouth_Cliff_Railway Each car has an underslung tank which is filled with stream water at the top of the cliff and emptied at the bottom. The view is fantastic as you go up or down. There are actually quite a few of these. There is a smaller one on the cliffs of the Severn gorge at Bridgnorth and I went on one on the side of the Rhine gorge a few years back, somewhere near Koblenz.

Thanks for pointing out the spelling mistake. at old smiley (did i mention Ama _o_ ?)

Surely this belongs in the enginnering section, you even asked for an electrical engineer. It is not rocket science after all. However asking for an engineer is a good idea since there is much engineering commonsense and experience involved. 'Line of sight' is funny thing because it begs the question "who can see what ?" Height is important, but not all important. It depends what is in the way. You can (sometimes) achieve the same result moving two feet to the right or left to avoid a nearby chimney stack as 20 feet or more vertical elevation to look over the top of it. I agree with the underlined words of this extract from StringJunky's link But Amazon as a first class engineering supplier ?? The linked site seems only to shop at old smiley. Some advice if you are doing this yourself. Only a vey small part of the antenna is actually the receiving or pickup device. Most of the antenna is either focusing/directing/filtering metalwork. So dimensional and alignment accuracy and stability are vital in assembly. (Most DTV antenna come as self assembly flat packs). Small errors of twisted or displaced parts can ruin the performance of the best antenna. To answer your two questions directly, The range depends mostly upon the height of the transmitter, not the receiver. Which is why these are placed on mountains where possible. And yes if the transmitter can place a signal 200 miles away, that signal can be received. As an example, my antenna is about 75 miles form the Bristol Transmitter, which is placed on top of the Mendip range of hills. It is installed in my attic (roofspace) simply hanging by two cords. I get a better signal inside the roof than on top of it because of nearby chimneys. I get almost zero signal at ground and first floor level, even in the trees in the garden away from the house. The antenna picks up a better signal from the Mendip transmitter than the nearer Blackdown Hills transmitter, which is only 20 miles away.

As I already noted IQ tests are a century out of date Intelligence testing the 2020 way was examined on BBC Horizon on 4th May. Sorry this broadcast has been and gone but some may be able to access it on catchup and there is a web based activity to go with it. https://www.bbc.co.uk/programmes/articles/2xhbqsm0NyPLfRzYqNl966M/how-intelligent-are-you

I'm glad my discsussion thread has taken a milder turn. Since 'The Hydrographic Office of the Navy' has long been located near me, the local library is exceptionally well supplied with its own cartography section. Amongst their books is a history of the US hydrographic service. This is a fascinating story of up and downs, establishment, growth, financial cutbacks, regrowth, more cutbacks.........

Not long ago we had a long ill tempered thread about the meaning of the word electricity. Since this thread was closed I don't want to rake over old coals but I was reading some history and came across this snippet and thought it might be of interest to some.

Agreed +1 again. But please remember that not everyone is a fan of Griffiths. I only know his Electrodynamics and find it not sufficiently to my taste to want to look at other books by him. So be aware there are already several approaches and unfortunately notations to QM. I don't understand why you seem so doggedly determined not to discuss differential equations?

Not enough information. Did you for instance have the flushing speed wrong (too fast) ?

+1 Well considered.

When I first saw your thread on list of current Activities tab, my first thought from the title was Oh no, not another one of these. However I looked quickly through the first few lines that is displayed in the Activities tab and saw the stuff about 12 this and 12 that. So my second thought was no, this is even worse. So I didn't even bother to open to your thread. In order to fairly respond to this thread I have now looked it up and the first thing that springs to mind is the Moderator's stated reason for closing the thread. You had apparantly already been told not to bring the subject up again. Evidently you chose to defy moderator instructions. Unlike the moderators as an ordinary member I can choose which threads to look at and which not to bother with. So I salute them for performing this unpleasant but necessary task on my behalf.

Well I'm speaking for Mankind so I suppose one could say benefit arises when the knowledge gained becomes useful. But I realise benefit is a subjective word.

Are we spending too much (relatively) on glory projects that may/will not bring benefits for centuries, if ever ? Some examples 1) Gravitational lensing was mooted in the 1920s and confirmed in 1979 and has yet to find a use. 2) Quantum tunnelling was mooted in the 1930s and first realised in the 1960s and is important to most people today. 3) The existence of other forms of life than our own developing on Earth was has been mooted several times and confirmed in the 1990 at the subsea hydrovents. 4) Fullerenes were first mooted in the 1980s and realised in that decade and are of developing importance and use. How much did each discovery cost and what is the cost /benefit ratio?

What does that have to do with the point of this thread? You have yet to establish that IQ is in fact declining, and received several comments to the contrary.

Like too the distinction between chemical thermo and physics thermo. That causes so much difficulty with students. +1

+1 for the out of date part. It's also social 'norms' that are buried in the tests. The IQ test was introduced well over a century ago now, and today's social norms are quite different from those of 1904.

This is the really worrying situation. More than half of the 30 - 50++ million deaths in the 'Spanish Flu' epidemic a century ago came as a result of a second wave mutated virus (though they didn't know it at the time). Coronavirus has mutated in a more virulent way. https://www.bbc.co.uk/news/health-52557955

No, I am trying to discuss and dissect rationally the proposition that the Himalaya is a good example of carbon 'fixing' by geological processes. 1) The Himalaya is a very recent geological structure, thrown up by the impact of the indian plate into the asian plate. This was accompanied by substantial vulcanicity, which will have released much geologicallly held carbon dioxide. The vulcanicity also metamorphosed many of the rocks involved which will have reduced their susceptibility to chemical solution weathering, which is the process that sequesters carbon dioxide. 2) The impact was sufficiently violent to throw up the currently largest mountains in the world. So high that they have a near permanent snow cover. At such low temperatures any chemical activity will be considerably slowed. 3) There are still some limestone and dolomite layers left intact. These will obviously be the most susceptible to this type of weathering. But they are a small % of the total rocks exposed or within the depths reached by percolating acid groundwater. 4) I posted a link recently of a Chinese study in the limestone foothills where they discovered underground lakes actually sequestering above average carbonate stores. (I will try to find that again) 5) Carbon dioxide concentration reduces with altitude So at 25000 ft the CO2 % will reduce by 25 * 3 = 75%

Not quite I was actually asking what is proportion of calcium and magnesium in the upper rocks of the Himalaya ? I would imagine this is quite different from the upper rocks in say the Sahara.

Whilst you are awaiting your next chance to post, think about this. (some) Atoms have been around since near the beginning of the universe (if it had a beginning). That seems a pretty stable system to me. Can you show how the internal energy of an atom is evenly distributed throughout the volume occupied by that atom?

Are you are only here to be provocative and tweak noses and post false statements. The most massive things in the universe (and the most energetic) can be net recipients of energy flow. At best they are in simple dynamic equilibrium.

Thanks for the extra info. You are way ahead of me in the biosciences. +1 Joigus and Area54 As to authorities, it is well known that I favour books over internet articles, here is one by the Professor of Paleoclimatology at Sheffield University. David Beerling The Emerald Planet. It is the only history of the atmosphere I know of.

And buried in the link you posted is the following So what % of the silicates are calcium or magnesium silicates?

How would you define T in a non revesible process ?

Thank you for this potted essay, it is really good and introduces several things that were new to me. +1 However I would appreciate more information on why you think the Himalaya removes much carbon dioxide, given this description of the principal rock types There are some carbonate rocks in the Himalaya, but much has already been metamorphosed. https://mynepaltrek.com/rock-types-in-nepal/

Perhaps you shouldn't mix well defined scientific concepts with guesswork. If you genuinely want answers please indicate some of your background as you have made several basic mis-statements such as mixing up force and energy. We need to know where to start to discuss this.