capo

I've heard it's impossible to accelerate an object to the speed of light. I've heard this is because the amount of fuel (in this example, hydrogen fuel) required would outweigh all the hydrogen fuel available in the universe. Okay, but what say, if you weren't actually trying to reach the speed of light..just getting as close as possible to it. And what say if you had a fuel (and propulsion system) with a bit more of a kick, say something like an anti-matter nuclear fusion hybrid..or whatever. Now, I'm not an expert of course. I'm barely an amateur. So I'm gonna hope that someone who really knows their stuff will step in here and fill in the gaps. First of all, I assume that only effectively massless particles (such as photons) are capable of travelling at light speed anyway, so reaching maximum velocity is outta the question for this reason alone. And as you accelerate an object (like a space ship), you give it more energy..you effectively increase its mass? Am I right? Anyway..anti-matter is created in particle accelerators, right? And now they have methods to store and transport it in special vacuum containers right? And "they" reckon you can kick start a nuclear fusion reaction with a bit of anti-matter to produce a much more efficient propulsion system, right? Well...my questions are this: 1. For arguments sake, let's say we take a ship which is the mass of..I dunno, the international space station, and then try to accelerate it to as close to the speed of light as possible using this anti-matter nuclear fusion propulsion drive..at the greatest extremes, just how close to the speed of light could you possible get it to? 0.0001%? 1%? 101%? (queue Dr.Who music) And just how much fuel would you need to do this? 2. At this speed, what kind of time-distortion(s) might the people aboard the ship experience? If you travel at the speed of light, would you experience that time normally? Or would you be frozen in time in some way? What about a substantial fraction of light speed, say 50% of it? The journey to Proxima Centauri would take 8.4 years from the perspective of someone watching the ship travelling...but what about those aboard the ship? How long would the journey seem to take to them? Lots of questions if anyone can answer them. I may have made some inaccurate remarks..or may be talking garbage all together, so feel free to point out my faults. But..not too brutally! I find it all very interesting and would like to learn more.

Congrats to you too matey (Everyone who wrote something) B)

Sorry, that's my bad. I did actually mean a cube with internal cubes as everyone else figured, but nice bit of maths there imatfaal. Okay, it's time to round it up. The answer I was looking for was 6/155. Sisyphus basically got it right with his/her working, but (s)he (as you pointed out imatfaal) got one of the values wrong. The other mistake (s)he made was again a minor one (125 instead of 124 in one place): [(8/125)*(3/125)]+[(24/125)*(4/124)]+[(54/125)*(5/124)]+[(27/125)*(6/124)] should have been [(8/125)*(3/124)]+[(36/125)*(4/124)]+[(54/125)*(5/124)]+[(27/125)*(6/124)] which evaluates to 6/155 = 0.0387096774193548... = Approx. 3.871%. Congrats to everyone who contributed.

You're again, very very close but unfortunately it's not quite the right answer. It's so close however that I feel it'd almost be wrong not to hand out congratulations...

That's not right either I'm afraid...but you know, when I said my friends struggled with it, what I really meant was that none of them could solve it. So you're already doing better than they did!

Unfortunately neither answers are correct, but they're very close and you're along the right lines.

Hey there. This is one I made for my friends (which they struggled with somewhat), so when I saw the puzzles section in these forums I thought I might as well share it... Q: Imagine a cube made of smaller cubes (like a Rubik's cube). Instead of measuring 3 by 3 by 3 however, this one measures 5 by 5 by 5. If you pick any two of these smaller cubes at random, what is the probability that their faces will be touching one another?

Simple when you know how! Thanks for pointing that out.

Hey there. First of all, hello to everyone! I'm new to the forums. I recently got my hands on a Mac machine and idly sitting there looking at the wallpaper, I got thinking as to the causes of the heptagons in this image (one on the blade of grass, one in the lower-left-center, etc): The explanation may be remarkably simple, I don't know. But I ask myself, why heptagons? Why not pentagons, or hexagons, or circles? And what causes this optical effect in the first place? Thanks in advance.