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I accept that vlaiv . But could not my infinite universe with infinite "stuff" not refer to the infinite number line I have used as my measuring stick. The infinite stuff therein being the numbers. Is it possible for any infinite system to have an infinite value of one property while not another? And what if the mathematical model links those two variables, if one is infinite what doe that imply of the other? I honestly have no idea. Jim

Ok I sense you are toying with me now so I will accept the challenge; may I take an infinity of time to consider? Didn't Einstein invoke a comparison of sitting on a hot stove compared to a park bench with a pretty girl to describe time. That may have had to to with relativity of time I suppose. Ok so, I exist as do you or say water or a rock or light , heat, radio waves, or the electron. I don't think any of those would require a physical infinity for their existence to hold. We may be able to describe each of their nature's using an expression of mathematics which in turn may or may not rely upon the operator we call infinity. I think that is what I am getting at regarding my difficulty in accepting a physical infinity ! Jim ps I can well understand why Cantor was driven mad by this although that may be fake news pps. If infinity does have a physical nature would we be able to physically measure it to confirm its existence; would information be able to span the infinity of whatever property it exits in? Would that require an infinity of time? I have no idea - arghhh

Yes but those are more than the predictions of mathematics Andrew. While mathematics can use the concept of infinity as a useful operator it does not define what in reality exits. Consider that our laws of mathematics and physics no longer hold in the realm of infinity - the singularity whether it exists or not cannot be described by our mathematical laws of physics. In a sense I accept infinity exists in one respect - as I 've said if our universe has a size then that is by definition infinity but in practice I do not believe it has the meaning that mathematics ascribes to it that which it holds in popular culture. When it appears in our equations we generally take a sharp intake of breadth and say we have an incomplete understanding here as with the singularity. Jim

And that is the problem I have with the concept of infinity. The universe at it's beginning no matter how small or large was by definition infinite as it held everything. As that universe expanded it retained its infinite crown as by definition it contained everything. So infinity is not absolute , there are many versions of infinity. I go back to what I said before, I believe it's a mathematical construct resulting from our language mathematics. A curious artefact. Jim

The language we use to define the circle (mathematics) produces what we define as infinity. Infinity is a consequence of that language it does not follow it exits in nature. Jim

I've always treated infinity as an abstraction. To my understanding it does not exist in the physical world rather it's an annoyance that turns up in our equations when we have a less than complete understanding. I can't help but think like Cantor we just create models of infinity that would ultimately drive us crazy. Take for example a universe that has a fixed size, a measurable distance from one end to the other. By definition, being the largest dimension available we could argue that that represents infinity ( nothing can be larger than the universe). However that is unsatisfactory as infinity by definition cannot be bound. I'm happy for infinity to exist in mathematics where it serves a purpose in making our equations work. For it to exist in reality, I would find that difficult if not impossible to accept. The cartoon below I guess sums up my approach to infinity Jim

Thanks for that Vondragonnoggin. I think if we are going to see NV be a commercial success in the astro market then we need to watch what happens in the USA first , that's where it will happen. I think it's just waiting for that breakthrough moment where there is enough uptake to drive the retail price down. We needs lots of enthusiastic early adopters. I love that tag line on the Collins website "Messier would have owned one" brilliant and true . Jim

Really enjoyed the Sky At Night, entertained and learned a lot ; the Sky at Night team at their best well done. Lots of information on how to interpret that wonderful image of the super-massive black hole. Jim

That makes sense Dave thanks for explaining. Jim

Lovely shot David, nice definition and framing. Can I ask what effect does the red filter have? I mean I know it will allow red wavelength to pass but what is the intent/effect you are looking for in using it. I have never thought of using filters on the moon, Im generally using a one shot colour camera and my shots lack the nice tonal balance you have in yours. Jim

Thanks for that Gina I would have missed that otherwise. Watching Skyfall at the moment Jim

I have a working theory that all criminals are stupid, that's why they get caught. Jim

It is it really is and it's a pain if you are trying to loose weight. I guess in a way it could be thought of as 100% efficient. From a quick Google search some 40% of the available energy in glucose is converted in to ATP (fuel source for cells) the remaining 60% being converted to heat. The heat maintains the relatively high body temperature and is vital so it's not a waste product - hence we could argue the process is almost 100% efficient. I know it won't be exactly but it is still very efficient at extracting the energy.

You would be surprised just what level of activity you would need to do to burn off the calories in just one biscuit; and how long it takes. Its not fair. So unless you are doing extreme backyard astronomy don't look for any weight loss soon. Jim

James you are right they could teleport by touching their belt buckle they called it Jaunting - I've just watched the first episode on you tube. The theme tune is amazing brought back so many memories. I'm not embarrassed to say that as a kid I wanted to be a Tomorrow Person. Now look at me, I am one (minus the special powers) Jim