danielj

Thank you, thats all very helpful. Would you mind expanding the above statement please? Cosmological Principle? at sufficiently large scales, the universe appears as homogeneous and isotropic Copied from Mordreds thread ‘Cosmological Principle’ there I go with a guess again 🫣

My take away from this is that I am lacking logical thinking skills, when it comes to physics. In that, I can’t make assumptions and expect to get the right answer. Understanding the question is more important than the answer I think. thank you

I see, yes. Thank you. I get caught in the details, not always helpful to me.

Thank you, much appreciated I’m just trying visualise some of the mechanics of this, so would it also be true to say that if I (tried) to take a ‘snap-shot’ measurement, with any combination of inertial/accelerating reference frames that in reality there is no way to take a snap-shot, as what was the time frame of the snap shot (by that phrase I mean a static measurement) and no matter how small the time frame, change will have occurred in one or more dimensions? The questions should get less stupid as I progress, but I can’t promise So they were above you if you used the ground as your reference frame, but not if you used the rotor itself? Your brain used the ground? reading this back I see there being potentially many different frames of reference, equally valid?

Would you mind just expanding that a little for me please? I can see that human perception skews reality somewhat, but I can’t work out that bit for myself. thank you

The relativistic effects of being in an accelerated frame of reference can be derived from special relativity. That is, acceleration doesn't produce relativistic effects separate from that of velocity. However, the relativistic effects of an accelerated frame of reference are nevertheless different from that of relative velocity. Specifically, clocks that are below you are slower, and clocks that are above you are faster, with the amount by which the clocks are slower or faster depending on the distance of the clock from your location in your accelerated frame of reference. Thank you , that is a very useful explanation that I can (just) grasp.

It does. Sorry, I didn’t mean it the way it came across. Obviously there would be an effect of time slowing at an accelerated rate from the (let’s say) constant acceleration. It was more the ‘are they equivalent’. I guess they are from your other answers and from the answer that time would slow for both observers from the others point of view. thank you

Could you clarify for me please: the statement ‘(the faster you go, the more slowly you age)’, quoted from World Treasury, T.Ferris. If it were me travelling faster ( and faster) would time be passing more slowly for me? (Would I feel it) or only from the viewpoint of some one else not in the same location taking measurements? Or, if I were taking measurements of them, would I record time speeding up for them. Do you see what I’m getting at? also, what would the difference be between me in an accelerating rocket going away from a planet, and measuring from the rocket, and standing on the planet and measuring the rocket receding into the distance? Are they equivalent? Simple as you can please thank you Or in other words, does the fact that the rocket is accelerating have a bearing on the measurement (the dilation effect)? I’m rambling a bit , I know but just trying to think it through. One question leads to another! does the orbiting planet also use energy (as the rocket does to accelerate) to stay in orbit, rather than just fly off in a straight line into space?

Thank you

Could anyone tell me what the proper name and meaning of the mathematical symbol that is a simple arrow pointing to the right please? for instance a2=c2-b2 arrow here a=square root c2-b2

No, I think I still got that wrong. Got a bit confused there somewhere along the line, swapping the n still wouldn’t give that answer. I’ll start writing it down, tough for me to do it in my head.

Ah, yes, got it now. And when I used 1 for n, I think I accidentally swapped the n to the wrong side. That’s cleared that mess up!, thank you

Is the zero degrees with 1 and 2 correct? And if so, what does that mean? does it prove that there are no regular polygons with 1 or 2 sides?

(can you say why?) From the free pdf, a Polygon is defined in Greek as ‘many-angle’, and with one straight line there are no angles or vertices, and with two straight lines there is one internal and one external. Also, one or two straight lines cannot define an area. Also, to try it out, I gave n a value of 1 and then 2 and in both cases it gives an answer of an internal angle of 0, which is nonsense I think? I can understand your teaching, it just takes me awhile and several reads through to digest it, thank you. I understand reasonably well x,y and z axes, positive and negative as I have to occasionally use a laser cnc machine at work. I can visualise it.

Could you confirm (or not) my understanding of the following equation please? I know it’s very simple, but that’s where I am. Formula to calculate interior angle of a regular polygon. Formula for Interior angle of regular polygon=180 degrees(1-2/n) interior angle of regular polygon Square=180degrees(1-2/4) 4 because there are 4 sides. Can you use the vertices instead? 1-2/4=1/2 1/2 x 180=90 interior angle of regular polygon square=90 degrees obviously I know that is the correct answer, but the 1 made me think. I didn’t know why there was a 1 in the equation, I guess that the 1 represents the ‘whole’ or ‘sum of all angles’ ?not sure how to describe that. also, if there is no gap between symbols, eg: 180(1-2/n), does that always mean multiply? thanks

Thank you so much for your advice, have ordered the book and started looking at the free resources. Just need to find some quiet time.

Thanks all, very helpful. My level of education is poor, caused by an immature attitude as a teenager. I left school at 16 with next to nothing to show for it. So just basic maths. Zapatos, you are correct, I do view time as mystical. Having had a think about that, I guess that even if time itself is a fundamental property of nature(?), that our way of measuring it is arbitrary and a consequence of our local star and our motion around it. I think? Thank you, I’ll give it a go.

I can see that my understanding is not good enough to understand this. Where did you start when you were learning about these concepts? Can you recommend any books that might help me move forward a little? thanks again to you both

does that mean that time and length are not fundamental, but that they are properties of mass and energy?

So ML2T-2 would be a way to describe an amount of energy in a given area and time frame? Why the need for T-2?? What part does it play in the equation?

Thank you. I am thinking of time from this viewpoint, at the beginning of the universe, either time already existed, or it was created from the constituents of that process. If we say that it was a beginning, then did it take an amount of the energy from the early universe to propel time in the direction it takes, then that amount of energy should be accounted for somewhere? Does that make any sense? I know that I probably have a fundamental misunderstanding here somewhere, I’m just trying to understand. thanks again for your reply

Hi everyone, I wonder if you could try and give me an answer to this question please? If everything that formed this universe is derived from various forms of energy/mass, how is time accounted for? Is it a result of interactions and if so how is it accounted for in physics/maths. I mean accounted for in the literal term (for example, is it given a value that can be transformed to energy or mass units) Question is from the viewpoint of someone with only a very basic understanding of scientific methods and a reader of pop science books. Thank you Dan

Hello all, I'm Dan and am just somebody with an interest in general science. I've a 'Pop science' level of understanding you might say. I occasionally pop over to your Forum and read through some interesting threads, the level of knowledge usually quickly surpasses my own, but each time I gain a little more myself. So, my question. I often like to have a little ponder on one very specific topic and try and follow some train of thought to some sort of a conclusion. Sometimes I think I have a good conclusion, sometimes not. Gaps (chasms) in my knowledge prevent me from finding the answer to the question, "Light does not accelerate or decelerate, what fundamental effect does this have on the laws of physics", or alternatively; "What effect on the laws of physics would there be if light had to accelerate and decelerate?" I've no doubt the answers are very simple, but I can't get very far with it myself. Help please? And go easy! Thanks all Dan

thank you. I find it very difficult to get my head around randomness. Effect with no cause? I understand that for progress to be made, it can be neccessary to accept these things and move on regardless. Perhaps it is a feature of the human brain that I find randomness unsatisfactory. Are there any theories that attempt to explain the random nature of atomic behaviour? dan

thank you. i will read up on wave function. Dan