Recent content by Ike47

Sounds just like me, lol. I should put a disclaimer into a sig saying all my posts may be incorrect.

I don't see why curvature requires a finite space. Hyperboloids and paraboloids are infinite curved shapes, so why couldn't a curved universe be infinite as well? That doesn't mean that the universe can't be curved and finite of course, but just that the one doesn't force the other. Of course, I...

True, DaveC. But if your object was to explore the galaxy, or at least the relatively nearby stars in it (for example, all the stars and possible associated planets within, say, 50 parsecs of the Sun), I'd think you could find target stars from Earth with much less intervening matter than other...

My thanks to Danda22 and others who revived this thread. I asked a question in the stickied Cosmological thread and have been waiting (hoping) for an answer from Marcus. Now I find he's already given the answer here! And I never would have found this thread if it had not been revived. Of...

Thanks, Qraal, and sorry for misreading your name. First, just to respond about interstellar drag, your numbers are right, but probably overpessimistic. (My number, 1 atom m-3, applies to intergalactic space, e.g., Smoot and Davidson, Wrinkles in Time, p. 158.) I say overpessimistic, in that...

Hi, Graal. I'm still waiting and hoping to get answers from Janus about calculating exhaust velocity and about how to determine when coasting should start in an accelerating-coasting-decelerating scenario. I want to be able to vary the inputs to see the effect on flight time (both ship...

That is great! Ευχαριστω ! Haven't figured out yet if there's any way to add accents and breathings, though they aren't needed for scientific notation, of course.

I'm leery of trying to answer questions rather than ask them, but I think I can add a bit to this description. I welcome both corrections and clarifications to what I have to say. In any case, I think we can give a^6 a bit more info. Once the universe cooled enough (after the 'big bang') to...

Thank you again! I've tried to find out the price of purchasing an online copy, and whether I can print it for my personal use, from the link location, Wiley... no luck so far, but I've submitted queries. Once I get answers, I'll be happy to purchase the 8 page article if the price is nominal...

Thanks for the reference. While it sounds like an article I'd really like to read, I've looked at the link and it seems there is a fee to see it, or presumably to download it. I don't believe in trying to circumvent copyright laws (e.g., taping something on TV is fine, but downloading the item...

Cool. However, I think I'll wait on a new computer till I can get one that is a significant upgrade on my current pc (which has all of a 700 MHZ chip).

I have no argument or problem with most of your answer, but it does touch on a question I raised in your sticky thread in this forum, which I still hope you'll respond to. I understand, specifically, that there is no edge. But as for there being no point of origin, is it not true that if the...

Thank you2! As for getting a Mac, when I finally someday have the funds for a new computer, I'm certainly considering that option already. :)

Thank you again, Janus. Obviously I was a bit optimistic when I thought I'd be ready to work on this by last week. But I have finally made some progress, coming up with 'statistics' for my vehicle (mass, mass ratio, total energy available from fuel, etc.), and as I try to apply these parameters...

Thank you for that link, Turbo. More broadly, for mathematical notations (powers and roots, integrals, etc.) is there any way to 'type' those into the forum, or are all such symbols in posts pasted in from other sources each poster may have? If the latter, as I suspect, is there any simple...