JohnF

It must be to do with guy1 and guy2 saying they know what colours the others are wearing. The only way that guy1 and guy2 can see more than one colour, but not know the colour of their own hat, is if the blind man is wearing a black hat and the other two are wearing red hats. Though the OP only asked "What color of hat is the blind man wearing, and how does he know?" rather than "What colour are they all wearing".

Well I'm at a loss here! I feel like I'm trying to explain colour to a blind man. Or I'm a blind man and you're trying to explain colour to me. Whichever way around it is describing red as, well red just doesn't make any sense. That's the problem here. Time is such an intrinsic part of our awareness that trying to discuss it from an outside point of view is practically impossible. Anyway, I'm happy to keep an open mind on whether time really exists or not. I doubt very much that independent evidence will ever be discovered, one way or the other.

Just think for a while what it would be like if we didn't have a concept of time. Think about how you would interact with things and people without using time as a reference. You can still use past and present tense in your thoughts because they can relate to an expected occurance of an event or a memory of an event having occured. When you drop a ball it will hit the ground; not because of time but because of gravity. You might measure how long it takes to hit the ground but time is not the cause of it doing so. Time does not cause anything, it has no effect on anything, it is just used to measure events. Can you change the length of a mile? Can you change the length of an hour? A measurement of distance is a constant whereas a measure of time is relative. This particular forum, being one of the forums here, is Pseudoscience and Speculations.

Well it seems I can reply. Whether you wrote this at an earlier time or not is unimportant. From my point of view it only comes in to existence when I see it. For all I know we all came in to existence just as I first read your post Every element about time requires memory. Without memory time does not exist.

Is it not true then by inventing the measurement of time we have in effect invented time. The measurement of time is done by counting events. I can move around in space and so it seems reasonable to assume space exists. I can't move around in time though. I can't go forward in time or backward in time. Events change around me and I mark those changes by using time as a reference. It's a very convenient reference but without an external event to mark time for me it's not very reliable. Assume for a moment that time is an invention; does it change anything? Well it does for people that believe time travel will be possible but for the rest of us it makes no difference. I don't agree with that. I need have no awareness of time to repond to the event of the sun being directly overhead. As long as I can detect the event when it occurs time is not required. Just because we use time to provide measurement of the events doesn't make time real; it just shows that between two events occuring we can have a specified number of other events occur on a time piece. The Cicadas don't have alarm clocks. An internal event that takes a set period of time to occur is all that is required to awaken them.

How do you know? Time is just an abstract created by man. It's convenient but we don't have to use it. We could arrange to meet people based on the position of the sun if we are close enough together in the first place. Alternatively we can arrange to meet based on how far the sun traverses the sky if we are not so close together. In fact any event that is normally located using time can be located using the positions of other objects. The problem is that describing the positions of enough objects to accurately define an event is much more difficult than specifying a time.

I agree with you there. I would think there's a relatively short period during which general radio noise is being emitted by a civilisation. I see the Drake equation as just an attempt to determine how many technology based civilisations there may be out there. Regarding the Drake equation though, I wonder if an additional parameter may be required. The value L = 10000 being the longevity of a civilisation seems to imply a dead end for a civilisation. It occurred to me that since the preceding requirements had been met, star has planets, planets can support life, intelligent life evolves and civilisation develops technology, then just having the civilisation removed from the count after 10000 years is not good. I would assume that if a civilisation does fall after 10000 years then the planet can still support life and intelligent life is probably still present. I have then assumed, for this exercise, that it would take 1000 years for the intelligent life to have technology again and put it back in the count. Doing this I've found that where the Wiki values provide for 2 civilisations, if I add this new parameter I get the following results... For 500000 years = 4 to 7 Average 4.5 others (with new parameter 90 to 107) For 200000 years = 4 to 7 Average 4.5 others (with new parameter 40 to 53) For 100000 years = 4 to 7 Average 4.5 others (with new parameter 12 to 31) For 50000 years = 2 to 6 Average 3 others (with new parameter 5 to 13) As you can see from the above the older the galaxy, and so the more stars there are, you also find a continued increase in the number of communicating civilisations when using the new parameter. Without it though the numbers remain relatively constant. What do you think? Is the new parameter a valid addition? What would you suggest as a good value for it? Perhaps I need to re-use the Fi and Fc values to determine if intelligent life re-emerges again and then goes on to develop technology rather than assuming it would after a set time period has elapsed.

I thought L was too high as well. I wonder though if a civilisation were to collapse then perhaps the knowledge it had acquired would, in the most part, be retained and allow a communicating civilisation to develop quicker. There may be down times in the 10000 years but they may be quite short.

I've been playing with the Drake equation by applying it to each individual star and only progressing the equation to the next stage if the previous stage allowed for it. My reason for doing this is to see what difference it makes when each star is treated as an individual that doesn't know that the intelligent communicating life quota has allready been met. I ran the program a number of times for each set of values and each number of years to get a minimum, maximum and average. In fact the first values at 10000 years quite often produced a result of no civilisations but I restricted the minimum to one since we know there is at least that many. I used the following values from Wikipedia as supposedly being the current best estimates http://en.wikipedia.org/wiki/Drake_equation#Current_estimates_of_the_parameters R = 6 (New stars per year) Fp = 50% (Stars with planets) Ne = 2 (Planets that can sustain life) Fl = 33% (Planets where life evolves) Fi = 0.1% (Planets where evolved life is intelligent) Fc = 0.1% (Planets where intelligent life can communicate) L = 10000 (Longevity of communcating civilisations) Over 100000 years: 4 to 7 civilisations (Average 5.5 - 64%) Over 50000 years: 2 to 6 civilistaions (Average 4 - 50%) Over 10000 years: 1 to 5 civilisations (Average 3 - 33%) Drake Equation: 2 civilisations Also, using the default values I found at http://www.activemind.com/Mysterious/Topics/SETI/drake_equation.html who are clearly more optimistic R = 6 (New stars per year) Fp = 50% (Stars with planets) Ne = 1 (Planets that can sustain life) Fl = 50% (Planets where life evolves) Fi = 20% (Planets where evolved life is intelligent) Fc = 20% (Planets where intelligent life can communicate) L = 10000 (Longevity of communcating civilisations) Over 100000 years: 646 to 675 civilisations (Average 660.5 - 9%) Over 50000 years: 631 to 675 civilisations (Average 653 - 8%) Over 10000 years: 559 to 643 civilisations (Average 601 - 0%) Drake Equation: 600 civilisations What is interesting is that the more optimistic values are more consistent regardless of how they are used. And if the Wikipedia values are more accurate then according to Drake there is only one other civilisation since we must be the other. If you know of any other values that are considered to be more accurate please post a link to them.

I certainly agree with that; there's no point in closing our eyes to what may be out there. My original question about the value of communication occurred to me after watching a programme about the discovery of a more Earth like planet being discovered. All the scientists involved seemed very enthusiastic about the discovery; with good reason I think since it advances our understanding of how planetary systems evolve. What never seems to get addressed is the practicality of communication over a great distance. I sometimes wonder if the programme makers take a sci-fi approach to what may be possible. I hope there are scientists that are seriously thinking about this problem and not just waiting for a solution to be sent to us from out there. Perhaps, as an experiment, someone should set up a forum that a user can only post to once every 30 years. This would allow two or more teams to simulate communication over interstellar space. It would also highlight many of the inherent problems in such communication like equipment maintenance, continuous standards and the determination of the teams to undertake the exercise.

OK, you've convinced me there may, just may, be an entertainment value... "Hello Alien PenPal, My name is John. I'll be dead 200 years before you read this so please don't reply" Scientific information may have value depending how far away they are... Alien: "Here's how to make a bow and arrow" Earth: "Well here's how to make a nuclear missile" Alien: "We figured that one out. We can now tell you how to recover from a nuclear winter" Earth: "How do you make a bow and arrow again?" Philosphical ideas probably won't make much sense to us and don't really belong in the realm of knowledge. I was thinking of economic in terms of time aswell as cost. It's still going to take many years to traverse the distance. I would think that if we found an alien civilisation within 20 or 30 light years then the possibilities would be great but if they were a thousand light years away then it would seem like an awful waste of time and money.

Streaming large amounts of data is fine but it's the content that is important. I wonder if governments on this planet would allow their latest research to be streamed to another civilisation; and therefore wonder if the opposite would happen. Regarding 'good relations with the human race' I have to ask "what would be the point of that?". The sharing of knowledge occurs for the benefit of both parties. Since one party is going to be more advanced, initially, than the other then there appears to be no incentive for the more advanced party to share knowledge. I really don't see contact as a prelude to invasion being a factor due to the distance and economics involved. Migration would seem the only reasonable purpose of interstellar travel. Given that of course then sharing knowledge as a prelude to migration would perhaps be of value since the co-operation of the destination civilisation would be paramount for such an undertaking. Thanks for your input Reaper and please continue to argue the point with me. I would like to think communication does have some value that I just can't see at the moment. I am very reluctant though to seriously consider intersteller travel being used for trade or invasion.

Thanks for those links ajb. What I'm more interested in though is the delay in any communication effectively rendering such communication to be of no value. Of course if we are sent instructions to build something that is new to us then such communication would be of value, but I wonder why another civilisation would send such instructions. And if they did the possibility exists that whatever they are attempting to teach us, we would have already learned before the lesson arrived.

Since meeting extraterrestrials is unlikely to happen I wonder if just communicating with them would be worthwhile. What I'm trying to determine is if any useful information could be passed between the two civilisations and since all they know about each other is what they are told how much information would they share? Is the search for extraterrestrial life of any value?

Perhaps this explains why the earth 'floats' in space; a bit like a hydrogen balloon. Maybe if it was filled with helium instead then miners would talk funny :D:D