studiot

Thank you Mordred, I downloaded the pdf though I have seen some of this before it is more modern than my knowledge.

Are you going to comment on my reply to this ?

In fairness I don't see that allowing the train to turn makes any difference, except to add needless complications to the mix. I don't know if anyone can remember th slow motion video I posted a while back of a slinky being dropped from a tallish building by first letting go the lowest part of the slinky so it started uncoiling, and then releasing the top from its mounting so the slinky as a whole aquired a downward motion, additional to the stretching of the coils.

What do you think the OP's original intention was? He presented a scheme for accelerating all the cars of a lengthy train together, and in another post he explicitly said it would need to be done without signals being sent between cars. I addressed that implicitly in my second post. In order to keep the cars all spaced properly as they get length-contracted, the rear cars have to initially accelerate faster than the forward cars, and then the forward cars have to catch up later. Actually he didn't. What he actually said, in a rather strange style, was If we want to accelerate a very long train. which makes sense. The next part was nonsense. So we are left with wanting to accelerate a conceivable physical object to whit one very long train. Perhaps that is what led you to make the next post which also seemed nonsense to me The differential timing of the motions between adjacent parts or sections of the train in the limit tends zero as the initial distance between the sections of the train tends to zero. This is the condition that allow the train to move as a whole. This will happen quite naturally in an orderly fashion without all the paraphnalia later described. It is also the 'long rod' example as Mordred has pointed out.

I feel this train is running further and further down the track of fancy, rather than fact and further and further from the OP original intention. This is another way of putting what I said earlier, though I didn't know it was called Born rigidity I can well believe that this line of thought was started by Max Born, he certainly discusses it in his book. No one has yet replied to it.

Kinematic treatments are point particle by nature. Furthermore in both SR and GR, as far as forces can be considered at all, the Newtonian condition that internal forces cancel out when considering systems, does not apply.

That's a good way to confuse you readers, but thank you for the reply. Talking of reading, I listed four undefined terms, you have only answered about one of them. No they can't be. Dates have a reference zero. It is one of the basics of relativity that there is no such thing as a reference zero. By the way, welcome and please note new members are allowed a total of 5 posts in their first 24 hours as a very effictive anti spam measure. So use your last one wisely, (I can happily wait another day for my next answer).

Nice point +1

Thanks for the reply, but you seem to have missed the point of the article and my headline question. The sham they called the recent climate conference (COP27 I think) produced at least one good result. Namely that richer nations are putting some resources into helping poorer ones play their part. To me at any rate an, I would think it would not take much of this money to help extend seagrass and also mangrove margins. It is also true that the oceans were and still are the largest carbon sinks on the planet, so it make real sense to promote their function.

interesting. +1

You first asked about packets, so let's deal with that first. When you switch on a lightbulb, the lightbulb sends out the beginning of a pulse or stream or whatever you like to call it, of 'light'. When you switch it off again there is an end to the light. That large chunk of light is a large packet in very crude terms. Now it turns out that a stream of light is composed of very much smaller chunks of light, rather like a chunk of copper wire is composed of very much smaller chunks of copper, called atoms. These smaller chunks of light are not atoms so they are called 'packets' and they share, with the copper atoms, the property that they are the smallest chunks of that particular type of light. These small packets have a beginning and an end, just like the big one you generate with the lightswitch. Does this help and are you ready to move on to the rest of your questions ?

This problem is a classic example of forgetting that both SR and GR are point function theories. Difficulties can easily arise if you try to apply either to 'bodies' or systems that are too large to be considered as 'point partcles'.

This is a classic fallacy / 'paradox', due to trying to combine too many mutually statements into one. If you break down statement A into singleton statements you can see this.

Can you please explain what you are trying to do here?

Mechanical wear by friction and by impact against the end stops is by far the biggest culprit, because such processes are much faster than long term deterioration. Components are normally (or should be) made of materials that can resist the acceleration/deceleration stresses they encounter in normal operation.

I fail to see a definition or explanation of what you mean by any of these four terms you are playing with words with. You start of with the premise that spacetime and by implication time exists. Yet in your second post you claim You need to post proper derivation and discussion of this claim here not on any linked website - Those are the rules here. Are you claiming that time does not exist ? What is the difference between what you call 'time' and what you call 'physical time' ? Since you have distinguished 'physical time' are there any other sorts of time and, if so, are they relevant to your argument ?

https://www.bbc.co.uk/news/world-africa-63901644

Very interesting comparison. +1

Noted thanks. Yes, I am watching with interest and learning lots as I don't really know much about AI.

Thanks for the info. So am I right in assuming that Your red box denotes an input question and your green box denotes the AI response ? It seems to me that the AI is conditioned to always give an answer, unlike a human. Isn't this a drawback ?

Going back to the original. In this modern day and age of AI's, surely AI's (along with everybody else) should be asware that B may not be deceased, but simply no longer a woman ? Furthermore in many countries the terms husband and wife are now blurred by same sex marriages. So my comment about was still stands By the way can somebody enlighten me as to what is CHATGPT please?

Welcome gobin, you may consider yourself anovice, but you seem a well informed one. Normally resurrecting such an ancient thread, rather than starting your own new one, would be inappropriate but I can see how your post follows on from the discussion. Classifying chemical bonds as inter (between) or intra (within) molecules only makes sense when molecules as indivisuals are actually present. More advanced authors, such as Cotton and Wilkinson, use the word aggregate, not molecule, to describe ionic bonding in solids. Other authors use words like lattice, crystal etc. So perhaps you would clarify what exactly did you wish to discuss, bearing in mind that science has developed the 'term' molecule considerably since Descartes first introduced the word in the middle 1600s. Indeed some technical disciplines have extended it further from being a definite physical or concrete noun into purely abstract concepts.

Well, as I said, I disagree, though it is a fine linguistic point. The correct tense to use would be past not present. However we all seem agreed that there are plenty of different possibilities.

+1 Yup I must own up to asking for one or two particularly stupid bobos to be put right that way, in case a later reader only read the first post and not my later apology and correction.

As I see it there are several possibilities not considered, either in the question or in the answer. My (correct) answer is: Since A's mother has not been declared alive, no one is a possible answer if A's mother is now deceased.