studiot

Sadly, that dream is fraught with many perils. Would you recommend everyone in a household or block of flats uses the same toothbrush so there is only one toothbrush?

I am quite taken aback by this adverse reaction to my genuine attempt to draw out the meaning of your question, whatever it actually might be. I don't know what your question is or what you mean by your original post so I asked, politely, for clarification. As I don't know what your question is, no 'categorisation' was attempted. I do however know that the quoted post makes a bold assertion, quite at variance with Physics, ancient and modern. I hope this is not a back door attempt to introduce religous preaching about 'one force' . So I ask you again, do you wish to discuss wavelength or do you wish to discuss colour ? They are quite different things. Perhaps you might like to think about the fact that the colour of an object is not always the same. What colour do you think a red post office box appears under the light from a sodium lamp ?

Looks good, +1. Perhaps I could suggest cutting a toothed rack into the raking supports for the MKII ? Then you could adjust the rake of the wall, although it already looks prety fearsome.

Perhaps and then again perhaps it is something else entirely. It really depends upon what you mean by 'negative'. So over to you to completely define it.

In other words we don't know. But none of this is inconsistent with what I said. You get some covid virus on your hands. As String Junky said, some may be more resistant to soap than others or I suggest perhaps better protected by the destroyed (since you object to the word dead) outer virii. Whatever the mechanism the protection is not perfect so the soap acts as a selective environment. Exactly as I said, and you said and SJ said. Yes we know that covid has jumped species. Fear of that, as opposed to the welfare of the mink, was the reason for the mink cull. Yes there was a report of a man who caught covid from his dog. Again my 'assumption' of a perfectly tailored virus was taken from your first answer. Not word for word but this certainly implied to me that A virus that is right for a pig or bat cannot be an 'intact particle' in your words or 'exactly tailored' in my words for humans. Which is why I asked for justification.

For soaps there are no known mechanisms Here is a good example of misreading my English. All I did was quote your exact words "already resistant strains" and ask where they came from. Your response did not contain the answer to that question. So what is the response of other mammals to covid19 ? In particular since they are posited to have started in bats or pigs or somesuch how do they affect these mammals?

I am going to say +1 for your listening attitude here. This is so much better than many who come to lay out their pet cogitations. I see you are not fuly convinced about the number theory. Nor have you mentioned infinity again. That is possibly because there are some interesting twists that appear when you study number theory a bit more. Some of these would probably help you understand more about numbers and infinity. Do you wish to discuss this aspect some more ?

I should alsao like to point out that what Mathematicians mean by the word 'Field', particularly in relation to number theory, and what Physicists mean are quite different. You should disentangle the Physics and the Mathematics please.

Hello, Frank and welcome. I wonder if you are asking your question in this way because you have placed it in the Physics section and been looking at Physics sources, which all refer to wavelength ? But are you really interested in the colour theory itself, and the reason we have so many colours and how they all arise? Please confirm whether you are really interested in wavelengths - which is just a simple piece of Mathematics. or You are really interested on colours - which is an interesting blend of Biology, Chemistry and Physics ?

A few points ? So how did this virus, alllegedly exactly and perfectly tailored to the human race, suddenly arise from nowhere ? Again where did these already resistant strains come from ? I think also that you may not have fully understood my English.

My problem with what you have written is simple. As Joigus patiently noted,the quantity commonly denoted by the symbol 'i' is defined as the square root of minus 1. If you really want a quantity that is not the square root of -1 then you should start by saying so, defining what you want your quantity to be, and choosing a suitable symbol for it. Otherwise you will simply confuse your readers, and lead them to ask what other quantities and terms is the person playing fast and loose with ? Joigus also noted Note he did not say that you cannot differentiate a constant (which of course you can if you know what you are doing) Reading your response I agree with him that you are attempting to misuse the process of differentiation. For your information, you are starting at 'the wrong end'. Number theory starts at the beginning and uses 'successor theory'. It does not (can not) start at infinity for the very good reason that infinity is not an end or a number, it is a shorthand way of saying there is no end. But there is a beginning. You start by asserting there is a beginning (ie asserting that there is a number called zero, or a number called 1 depending upon your preference) And then asserting that every number has a successor. So there must be a successor to your given first number, say 1. You call this number 2. This in turn must have a successor, you call 3. And so on. Since this process never ends you have defined every number. But you have not defined or used 'infinity'.

Thank you for the reply. Your first paragraph makes a sensible and coherent point, but I could not understand your last line. In the minimal amount of microbiology I did, they stressed the idea that 'killing' and entire population is not instantaneous in normal environments, you need a 'nuclear option' for that. Some of a population will survive for a suprising amount of time in a hostile environment, even if degraded. The degraded survivors may go on to deliver their payload, whereby a mutation may occur. Some such mutations may 'evolve' into viable virii, more resistant than their parents, to the degrading agent.

Then perhaps you might like to address my original comments as you OP was too vague. As to 200 pages, I seem to remember that the manuals for the Tellurometers I worked with were longer than that. But never fear, you can rest your poor weary eyes, you only need to read the chapter on the voice communications part and the Thesis contains full circuitry for a simplified Tellurometer. You were asking about infrared, but seem now to be talking about visible light. Wikipedia has Themal Radiation as extending from the top of the radio spectrum, though microwave infrared and visible radiation. https://en.wikipedia.org/wiki/Thermal_radiation

Thank you for the reply, but you did not say why not.

Thank you for that link. +1 It is worth mentioning that the full programme is about 3 1/2 hours long but interesting nevertheless. The first 20 minutes offer a great companion summary to the emergence of early kingdoms in England in the timeslot (250 years) indicated but for more detail. I looked for the mid 6th century cold snap but couldn't find anything as dramatic as suggested in the video. http://www.longrangeweather.com/600bc.htm The programme also discusses events much further afield, covering Europe and into Asia. Here is a good compact verified souce written by a reliable historian and published just before Brexit in 2019. Unlike the dry list of dates and events (they are included but not prominent) so often found in formal history books, there is much sound analysis of causes and results, including many maps of disposition at different times. Approximately the last 2000 years is covered. Ireland is also included as are the rest of the British Isles.

After the Romans left, Britannia broke into fragments. What is now northern Scotland became part of the kingdom of Norway. Wales and south westen Scotland (Glasgow area) became one celtic kingdom. South east Scotland and most of northen England became the Kingdom of Northumbria. Central England became the Kingdom of Mercia Central Southern and Southwest England became the Kingdom of Wessex. South Eastern England didn't have a particular name. Following the Norman conquest the Normans united all the english kingdoms and Wales, leaving Scotland separate (except it was not then called Scotland) At this time a group of those living in central eastern Scotland gained effewctive control of their area and slowly annexed the rest of Scotland by force. The original name was the Kingdom of Alba. Roll on 5 centuries and Elizabeth first had nor heirs so after some failed relatives as monarch, James VI of Scotland was invited to ascend the throne of England as well. The two countries were not formally united for more than another century by the Act of Union.

I didn't think you as someone who jumped to conclusions. Britain is one (the largest) of the British Isles. The island of Britain used to host several separate Kingdoms Great Britain refers to the country formed from the last separate kingdoms on the island of britain. The full official title of the UK is the United Kingdom of Great Britain and Northern Ireland. There remain several semi autonomous states in the British isles apart from Eire.

Yes you are right. Thank you for the correction. Bicarbonate of soda is amphoteric and depends upon temperature and other compounds in solution. So with just cold water it has a ph of around 8 point something.

Bicarbonate of soda is actually a mild acid (in solution). Acids do not deal with fat/grease. That is what surfactants (posh name for soaps) are for. If you do not wish to use chemical prdoducts you might try soaps nuts from the soap nut tree. My family have found them to be quite effective even in cold water (which is how they are traditionally used). https://en.wikipedia.org/wiki/Sapindus We have also found them cheaper than commercial chemicals, and easily available in the UK.

Yes, welcome back. Tahnk you so much for this anecdote, +1 Do you have a reference to the mechanical action of cranberry juice ? I have expressed the opinion that medical science to often ignores the mechancial in favour of the chemical. Discussion of that would be a topic in its own right (if you wish). Like the things that you're liable To read in the bible It ain't necessarily so. A good counter example would be the production of high quality concrete. I have explained several times in this thread that 'greater' does not mean better. It means 'of larger size' that by some measure or other. What do you think Great Britain means ? In the case of Science outgrowing Philosophy, I suggest the scope and extent of scientific knowledge now well exceeds that of philosophic. However I note you argument about beginnings and endings and find that interesting enough to be worth further amplification. One point about you neolithic 'scientist'. It is not enough to "do an experiment" to be counted as Science. That experiment must be systematic and preferably part of a series of expeiments. Over to you.

Thank you whoever liked my comment from back last March. It should be noted that an old fashioned 'analog' meter is in fact a small motor and such meters can be used to detect current flow in buried cables.

Since you evidently don't wish to talk to me I will bow out.

By radio I assume you mean speech communications ? You have not distinguished between digital systems and analog systems but I am guessing that you mean analog ones. Here are 200 pages of an Engineering Masters thesis on how to do this with microwaves, which sit between what we call 'radio' in the spectrum and infrared. https://open.uct.ac.za/bitstream/handle/11427/8363/thesis_ebe_1987_marsden_m.pdf?sequence=4 Note microwaves are also heat radiation of a sort.

Well I think there is a great deal fundamental mathematics stuff missing from the OP block diagram. Perhaps you guys should get together with the author of this thread

At our age it is getting difficult to find good birthday presents for my wife. This year I remembered here great grandfather's garden bench, which was in a sorry state. I promised to restore it for her birthday. Work in progress showing the grit blasted and repainted metalwork, some partly finished extended new oak slats. The finished article reassembled.