spacesailor Posted November 30, 2019 Posted November 30, 2019 "My eldest Grand-son won't allow us to baby-sit as he thinks we've done our bit baby-sitting him," That (GreatGrandSon), young man turn nine yesterday. "Try going to a doctor when there is something unknown " Then your an Hypochondriac, Happened to the wife, as she had "Trigeminal Neuralgia" for five years before they new what it was. spacesailor
Bruce Tuncks Posted September 28, 2020 Posted September 28, 2020 I always thought that the universe being a figment of somebody's imagining was invented for the Matrix movie. But no, it was a middle-ages heresy idea that the universe was " the dreaming of a demon". So we are figments of a demon's dream. How would you disprove this? Occam's razor helps here by saying that the simplest idea is usually the correct one. And the demon business adds complication. This idea also makes a creating god unlikely on account of how it adds levels of complexity unnecessarily. Occam is not proof of course. But here is an answer to the question of "what was there before the big bang?" The answer is that time did not exist either. This I know is so counter-intuitive that I can't really take it in myself, but then I find it hard to take in the way that the speed of GPS satellites alters their time and without corrections, our GPS setups would not work. ( I really like how navigation is simplified down to keeping the blue plane near the thick pink line ) 1
Marty_d Posted September 28, 2020 Posted September 28, 2020 I've listened with fascination to Brian Cox theorising that perhaps new universes pop in and out of existence all the time. In fact there may be others where the fundamental laws of physics, such as the speed of light, or the radius of a circle, is different from ours. My brain can't quite handle it either, to be honest! 2
spacesailor Posted September 30, 2020 Posted September 30, 2020 You,ll have to watch " Sliders " on TV. All about parrallel universes. spacesailor
Bruce Tuncks Posted October 2, 2020 Posted October 2, 2020 (edited) It's a bit sad that physics has become so hard to follow these days. There was a time about 1900 when people were far more educated and interested than they are now. They used to have matinee science lectures and housewives used to go. Before this, American Presidents could openly say things like how the book of revelation was clearly written by a madman. No longer is this so. Edited October 2, 2020 by Bruce Tuncks
octave Posted October 2, 2020 Posted October 2, 2020 I think to fully understand physics in detail is probably a difficult task for most of us but there are many books that present it in reasonably simple terms, Examples are any by Brian Cox or Neal DeGrasse Tyson or Lisa Harvey- Smith. There are also many podcasts covering this subject in an easy to understand way.
onetrack Posted October 3, 2020 Posted October 3, 2020 (edited) Quote Before this, American Presidents could openly say things like how the book of revelation was clearly written by a madman. Perhaps the reason why it is no longer reasonable to deny the prophecies in the Book of Revelations, is because they are now starting to make some sense? Revelation 13:16 - "He (the 'Beast') causes all, both small and great, both rich and poor, both free and slave, to receive a mark on their right hand or on their forehead, (17) so that no one may buy or sell, except he who has the mark or the name of the beast or the number of his name." If you looked down upon the Earth today, as an observer from a previous century, what would you see? Nearly every person in the world carrying a smartphone in their (mostly right) hand, and carrying a PIN number inside their head! We are rapidly reaching the point where if you are not computer literate, do not own a smartphone, do not have an Internet connection, and do not worship the Great Gods, Google, Apple, Samsung and Money - you will be unable to buy or sell, or partake in any social activities in our modern "civilised" society! My old Italian neighbour Barney is 88, and "old school". He deals only in cash, doesn't use cards, doesn't use computers, doesn't understand them, and wonders why he get virtually no mail today. He is very angry and frustrated at his (official) treatment, of rapidly being "left out of society and communication with authorities". The "False Gods" of the Bible are the Global Corporations that rule our lives more distantly, and more powerfully than any Pharoah or other ancient Deity, and of course the biggest False God is the total worship of Money, before anything else. We cannot speak to anyone in a Global Corporation (tried getting hold of someone important in a Bank, in eBay, in Google, recently?), and they only speak to us on their terms, with messages sent from addresses to which we cannot reply. I don't know what else describes a modern-day "Beast" better than that description of Google, Apple, Samsung, etc., in Revelation, Chapter 13. Edited October 3, 2020 by onetrack
Bruce Tuncks Posted October 3, 2020 Posted October 3, 2020 I do like your stuff onetrack. And I agree about corporations being impossible to communicate with. But the bible has no clear mention of mobile phones or atom bombs or germs or plastics or quantum physics or electricity or anything beyond what those bronze-age tribesmen knew of. You need to put these things in yourself, interpreting vague bronze-age stuff just so. Alas this indicates to me that there was no divine inspiration behind the bible. Just one reference to something more would have sure impressed me. Just like how a fossilized rabbit in jurassic sediments would destroy the theory of evolution, a reference beyond common knowledge of those ancient days would impress us now. Alas, it is not there. Germs is the biggest omission for me. They had them in those days but had no understanding or knowledge of their existence. If the Jesus character really knew everything, why did he not tell his friends how to avoid germs? 2
onetrack Posted October 3, 2020 Posted October 3, 2020 Bruce, who knows? Maybe he did, and the knowledge and technology was lost in the turmoil of invasion by other, more vicious, baser, destructive tribes? I reckon a lot of knowledge has been lost from ancient times. Apparently the Library of Alexandria was just amazing with its records and information, but it was all totally destroyed.
Bruce Tuncks Posted October 4, 2020 Posted October 4, 2020 About the library of Alexandria... there is a theory that the world was unburdened with a bunch of rubbish and this freed science from some shackles. Certainly the ancients wrote a lot of turgid alchemy nonsense. But I really like the story about how Erastothenes, then a librarian at Alexandria, calculated the size of the earth. He would have been right, except for the "reference distance " from Alexandria down to the village where the sun shone down a deep well on just one day of the year (syrena i think ). Erastothenes took the distance to be 300 stadia when it was more like 400. This had ramifications for the discovery of America, and explains why the indigenous there were called indians. 1 1
onetrack Posted October 4, 2020 Posted October 4, 2020 (edited) The Greeks did make some serious scientific errors as regards their attempts at Alchemy - but they're not alone in their bungled scientific attempts. We've had more than our share in the last 100 years. The Greeks often went astray because they still hadn't figured out how to record time precisely - the basis of much of science advances. But they knew all about the planets - and they produced the Antikythera Mechanism! - their version of the computer! https://www.theverge.com/2017/5/17/15650210/antikythera-mechanism-discovery-anniversary-analog-astronomical-computer Edited October 4, 2020 by onetrack
old man emu Posted October 4, 2020 Posted October 4, 2020 The problem with ancient measurement systems was the lack of set standards. Obviously, measurements first related to parts of the body, hence "foot", "hand" and "finger" still feature in non-metric systems of units. The problem with using these measurements without set standards is if workers come from different areas to work together on a project, things get out of whack. When the Greeks were building the Parthenon in Athens, someone carved a reference stone showing the lengths of an arm (cubit), hand and foot that were to be used by all in the construction. The ancient Greeks used an architectural measure that was based on the spherical dimensions of the earth, a geodetic measure. It certainly was not based on the length of the human forearm or any other mythical human body parts. Furthermore, some unknown person or persons in antiquity had defined the earth circumference into the divisions of degrees, minutes and seconds we use yet today. The ancient Greeks used this definition. But this was not the end of the difficulty. In ancient Greek architecture, the platform on which a Greek temple is constructed is called a stylobate, giving rise to a length called the stylobate short length. The division of the stylobate short length was in 100 parts of a Greek foot. The Greeks used a "foot" measure similar to ours. If the stylobate short length was not an accident, then the number 100 also could not be an accident. This meant that:the Greek "foot" derived from geodetic measure and was equal to 1/100 part of a second of earth surface arc! The Greek, and Roman architects could measure things with an accuracy we now need laser beams to achieve. 1 1
pmccarthy Posted October 4, 2020 Posted October 4, 2020 The Parthenon ended up a bit too small because they were short-handed. 🙂 3
old man emu Posted October 4, 2020 Posted October 4, 2020 It was supposed to be built at the foot of the Acropolis.
pmccarthy Posted October 4, 2020 Posted October 4, 2020 To check the cubits they held a short-arm parade.
onetrack Posted October 5, 2020 Posted October 5, 2020 It's interesting how the richest and most powerful superpower on Earth built its wealth and power, using a measurement system that is archaic at best - and which system, they still utilise today. However, their archaic system did create one major financial and technical loss for them, in their Space Programme, when they lost the Mars Climate orbiter.
octave Posted October 5, 2020 Posted October 5, 2020 The US does actually use the metric system just not among the ordinary folk. NASA was mostly metric even during the Apollo program Calculations were done in metric (the language of science) and then converted. In the US all imperial weights and measures are defined by metric. Quite well explained in these 2 videos. . https://www.sciencealert.com/watch-the-us-has-been-using-the-metric-system-all-along https://www.youtube.com/watch?v=hid7EJkwDNk 2
willedoo Posted October 5, 2020 Posted October 5, 2020 Apologies for thread drift, but it got me thinking how much work must have been involved with metric conversions. The Soviet license built DC-3, the Li-2, was re drawn to metric measurements. Also the pirated B-29 bomber would have been the same. Possibly these days, there would be computer programmes to speed the process up.
Marty_d Posted October 5, 2020 Posted October 5, 2020 5 hours ago, willedoo said: Apologies for thread drift, but it got me thinking how much work must have been involved with metric conversions. The Soviet license built DC-3, the Li-2, was re drawn to metric measurements. Also the pirated B-29 bomber would have been the same. Possibly these days, there would be computer programmes to speed the process up. Multiply by 25.4 - it's not rocket science... 😁
Bruce Tuncks Posted October 8, 2020 Posted October 8, 2020 Its much harder than that Marty. For example, what if the thing you need ( drill, sheetmetal, bolt etc ) does not come in the exact metric size you want? Daffyd llewellyn once explained just why AN bolts were used instead of metric ones. They are more documented and more available was the gist of his comments. What bad luck that our main source of supply is stuck back with old english stuff huh. The Jabiru uses AN fittings so your spanners need to be imperial. But the dimensions of the plane are in metric. So you can look up the wingspan in metres but you need a 7/16 inch spanner to remove the wing. 1
onetrack Posted October 8, 2020 Posted October 8, 2020 (edited) I find it amusing that the Americans demand decimal inch figures, when carrying out engineering work and manufacturing - yet their spanners are stamped in British fractions? Packard engineers redid all the RR Merlin blueprints to convert them from British fraction measurements to decimal inch measurements. To be consistent, the Americans should be stamping a 7/16" AF spanner, as a "0.4375 inch" spanner. Edited October 9, 2020 by onetrack 1
old man emu Posted October 9, 2020 Posted October 9, 2020 2 hours ago, onetrack said: I find it amusing that the Americans demand decimal inch figures, when carrying out engineering work and manufacturing - yet their spanners are stamped in British fractions? To be consistent, the Americans should be stamping a 7/16" AF spanner, as a "0.4375 inch" spanner. The use of units of 1/1000th inch is for precision work in engineering. The conversion between the two systems is not "neat" ( 1/1000 = 0.0254 mm) so you have to choose one or the other for precision work. When you are talking about maintenance work, using fractions based on increments of 1/64" is accurate enough for hand tools. I suppose that these day-to-day measurements are derived from the inch, which was once defined as the length of a thumbnail. I wonder how many know what the AF label means. 1
Yenn Posted October 9, 2020 Posted October 9, 2020 I find it amazing that anyone considers fractions are a good tool to work with. The yanks even have a fractions calculator, which is a ready reckoner that you look up to compare one with another. One of the great things I have is a calculator that I can enter fractions in and it converts instantly to decimal. Ie I enter 1 . 2 . 3 and it returns 1.6667. 1
old man emu Posted October 9, 2020 Posted October 9, 2020 50 minutes ago, Yenn said: I find it amazing that anyone considers fractions are a good tool to work with It all depends on the size of the thing being built. A bridge could be built to the nearest inch or centimetre without being too far out, but a skyscraper has things like windows and doors are built to the millimetre or half inch. And how useless would an engine be if the cylinders and pistons were made to the nearest inch or centimetre? 1 1
Bruce Tuncks Posted October 9, 2020 Posted October 9, 2020 There is a letter from James Watt about how this wonderful new cylinder was only 3/8 inch wider in one diameter than another. I guess that this is why they invented piston rings. 1
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