studiot

Even though you have failed to answer my questions. You have chosen a relative velocity of u = 0.6c The relativistic doppler shift for two bodies moving with an inline relativistic velocity is given by [math]\frac{\nu }{{{\nu _0}}} = \frac{{\sqrt {1 - \frac{{{u^2}}}{{{c^2}}}} }}{{1 + \frac{u}{c}}}[/math] Where the observed frequency is [math]\nu [/math] and the shifted frequency is [math]{{\nu _0}}[/math] and u is the inline relative velocity. Which I make half and double the original frequencies (no doubt why you chose that value for u). So what effect does that have on the observed reading on the clocks as tabulated?

The whole matter is neither clearly nor unambiguously explained by yourself., though Janus has added further meat to his bone for your benefit. Start with a very simple example that has nothing to do with 'relativity'. Take a clock with hands and an observer that views the clock via a mirror. The observer will directly see the clock running backwards (anticlockwise). So he makes a (perhaps mental) adjustment to the reading to compensate so that he can consider (the posh Physics term is transform) what he actually sees to his own form of reckoning. In the same way the travelling observer directly sees a clock fact that is acting differently from his own clock, but in your case he is monitoring the changing of the numbers. So, like any good Scientist, he records his readings. He will have a table with readings on his clock in one column and tabulated against each entry he will have another reading of what he notes on the Earth clock, which will generally be different. So your first task is to make clear in which system are we reckoning time? Because he will need a third column transforming the readings in either the first or second column to the other system as they are not directly comparable. This would be true in both Galilean and Einstinian relativity as there will alway be a time lag between the Earth clock display and the traveller reading. Further this delay will be a function of time or separation and not constant.

Having received the book I can now definitely recommend it. However the proviso that you need a bit more than just just algebra definitely stands. Experts often overlook just how much subject lore they use unconsciously. It is also refreshing to see such an offerening from a small independent publisher, and at such a reasonable price.

The post you replied to doesn't belong here but here There was some kind of screw up in the system last night. I blame Trump.

Here is a plot (courtesy Lawden) of the Friedmann solutions to the Einstein Field equations showing the time evolution of universes with different input cosmological constant (k) With negative k the universe expands without bound With zero k the universe becoems asymptotic. With positive k the universe expans and contracts cyclically. So the real question is not Is the uninverse infinite, but Will the universe ever be infinite, and if so when?

Every time the gas heater fires up there is a flow of wasted gas until everything settles down to running conditions. This is the same as the fuel used when cold starting a standard car is equivalent to consumption in the 5 - 15 mpg range. In heating terms the phenomenon is known as boiler cycling (which you don't want) So there is a trade off between tight control and lots of small inputs which waste fire up fuel and longer bursts which overheat more. One solution is an intermediate buffer heat store.

I think it is the sheer two-facedness (Sorry Janus I like your posts really) of the heirarchy, in not practicising what they preace to the lower ranks about how people 'should' behave that turns many off religion. They suffer no 'dissonance' at all , they just don't like being lied to.

Yes I also wondered that.

I wonder if this was a reply to my question, since your assertion shows a misunderstanding of the basics of Physics. Energy and Force are different things. If you sit on a chair (and don't fall off ) There is no involvement of Energy whatsoever. Yet there is a balance of opposing forces countering each other. It take no energy to generate a force. Energy becomes involved when that force moves something. Before tackling your more detailed/advanced questions you need to understand the meaning of these fundamental words or you will not progress. Do you need more detailed explanation?

I don't know why you seem determined to change the OP, which was Is there a ratioanl reason for religion? Neither Faith nor Logic were mentioned. So in short, yes there is a rational reason for religion because Religion offers a harmonius code of conduct and a sufficient proportion of religous people live their lives in this way. That is not to say that there are not disharmonius religous people or disagreable aspect of religion. That is a rational reason but not a logical one. Given the premise that religion leads to harmonius people a logical 'conclusion' (as you put it) would be that there is a reason for religion. I don't know if you can see the differences in the two statements.

Good Feynman quote, Pavel. +1

Wow, you never know when you wake up and log on to SF what new things you might learn. Thank you for fonding that Eise +1 I have never heard of absement and I couldn't think of a use for the second (or even third fourth etc) integral. If we take the velocity as some function of t and integrate it we indeed get the distance travelled (but not necessarily the displacement) To get the second integral we obviously integrate again with respect to t. I will take the example that v = f(t) = v1 (a constant) to work from. More complicated functions will necessarily lead to more complicated integrals. So generally [math]I = \int {f\left( t \right)dt} = \int {vdt} [/math] performing the integration yields [math]{I_1} = \int {{v_1}dt} = {v_1}t + C[/math] performing the second integration yields [math]{I_2} = \int {\left( {{v_1}t + C} \right)dt} = \frac{{{{\left( {{v_1}} \right)}^2}}}{2} + Ct + D[/math]

All I can say is that phi has more patience with these folks than you or I do. Pretty well all the people I know who have turned away from their religion did so as a result of some traumatic event in their life, such as a stillborn baby or worse. I have never known one turn away by reason from other folks, though some have realised the hollowness of it all for themselves. But having said all that I am unsure of your point or question, was it how to persuade these people?

There is a big difference between the processes of 'rational' and 'logical' and thought. As I already said logical thought is concerned with establishing a truth value of something consistent with initial premises or axioms. Those premises are simply statements of fact ie they have assuumed truth values and no more. Such as' the grass is green' On the other hand rational thought processes have a much wide ambit. They can analyses aims, goals and desires and provide courses of action. Wanting or not wanting an ice cream have no different truth values. Few would say I fancy an icecream is alogical thought, but many would consider it a rational one in the right circumstances. Actually the North Americans have not moved forwards, like the English so have kept many of the words they their founding fathers took with them, whilst the English have enhanced the dictionary with new words. A prime example would be your faucet and our tap coming from our jolly tradition of tapping a beer barrel. Cheers.

Ravell, I asked you a polite direct question to which you have not responded, contrary to the rules of this forum.

Yes, but that is not the essence of my comment. Mathematically the variable that forms the parameter in Mathematics is a dummy variable and can be replaced with another so long as the mathematical form is maintained. However my comment was about comparison of something, say the value of g or perhaps the water level at inlet and outlet, at one location with the value of that same something at another location, irrespective of time. This process allows us to establish a change, irrespective of time.

Perhaps I should offer the use of my famous toilet seat that does not have nothing in the middle. Good explanation. +1 In this case time is mathematically called a parameter. This means that both processes are functions of the same variable. This has implications in the study of dimensions.

Thanks +1 But you could always join the discussion.

First of all neither time nor space are things so their fundamentality is moot. Yes indeed they are abstractions, but distance is not the same as space (or a generalisation of it) any more than an interval is the same or a generalisation of time. An no, time is most definitely not the most general abstraction of change, if it is an abstraction of change at all. Change is (a process of) comparison which may or may not involve time as Marcus pointed out, but they are separate abstractions. For instance I can measure/observe the value of pretty well any point variable at two or more points and compare the change from one point to another. Which brings me to my thoughts that both sides of this dicussion have made valid and questionable points but have not articulated either particularly well (don't claim any better I just hope that another worm's eye view might help) I can sympathise there since it is very difficult to get one's head around these ideas. Personally I think of the abstractions (both time and space) as chosing and naming variables as suitable for the purpose of working (mathematically) with what we observe about the world around us. I often find this approach to entropy switches on the light bulb for people who find that idea difficult. I do indeed (often) say that nothing exists - and offer demonstrations / rationalisations. But I also say that Nature is more perverse and diverse than Man's best endeavours and has more tricks up her sleeve. So space is a set of some or all points. The points are members of the set. But Nature offers us sets whose members are conspicuous by their absence. For example a shadow is a set of points there there is an absence of light.

Interesting exchange that leads me to ponder thus: We think we are the highest level on evolution on our planet, and further as far as we know we are the only religous creature. But what does that mean? Well for one thing perhaps there is a critical level of evolution that is needed to be religous. But taking this one step further, Animals know about fire, but are a fraid of it and run away from it. A bit like humans and religion. Humans have learned to control fire, to some extent, but have they learned anything but the most basic aspects of religion. That is, are they at the same evolutionary level with religion as animals are with fire? Could a future more evolved human then surpass religion?

Exactly so +1

Oh, sorry. I thought it was a type of ice cream. (one cornetti)

Well I can't remember learning about this one so I got out my 1960 copy of Vogel and hey he has a whole chapter on the subject. Here is the first page

No, but I do have a soft spot for Koti's infinetti.

Logic implies premises, rationality does not. So no, I think the original was best put. I also note that eveyone has so far assumed that religion is about 'good'. Why so? How about self worship? Or the worship of Mamon? Are they not both rational in that they are compatible with the principle of natural selection and the theory of evolution? Zapatos have I stirred your pot enuff?