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#26 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-26 05:27:54
Sekky wrote:Ricky wrote:I'm sorry, but I don't follow this logic.
Gravity, there's your answer
Huh?
Suppose you have two planets travelling away from each other at some velocity, gravity accelerates each planet towards the other, decelerating the expansion of the universe over time (for an insane system of gazillions of planets)
#27 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-26 05:24:17
I'm sorry, but I don't follow this logic.
Gravity, there's your answer
#28 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-26 05:20:55
Even if you are right, that is not the current view of the universe, since the scientist claims that the laws of physics were not invented by the time of the big bang. They claim that overlightspeed were legal back then.
Lol
Who are "they"? Link or this is nonsense.
#29 Re: This is Cool » FLT DEMONSTRATION By Anthony.R.Brown » 2007-05-26 05:07:05
Every Number in the Sequence is true from 1,2,3,4,5,6,7,8,9 ....
Nobody even knows what to make of that sentence.
"Every number in this sequence is true"?
You have no idea how to apply induction, stop making things up.
#30 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-25 10:58:49
Interesting hypothesis. It sounds mostly like a thought experiment, was any evidence presented to back it up?
Much, albeit the majority was theoretical physics beyond my comprehension, but the guys gave some decent analogies for the most part. Actually that presentation was part of a larger seminar on astrophysics, most of which I didn't understand, but I damned well enjoyed pretending I did 
#31 Euler Avenue » Simple Groups » 2007-05-25 03:41:16
- Sekky
- Replies: 1
Is there any discernable property of simple groups that can be used to quickly verify whether a group is simple other than to blast through trying to find normal subgroups?
#32 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-25 03:38:48
Let me get this straight, In the beginning, time did not pass, cause everything was so incredibly dence. Then after some time had past
#33 Re: Dark Discussions at Cafe Infinity » So how was your school year/ semester ??? » 2007-05-25 03:37:27
I finished my first year of uni this week, had some damned interesting exams. (Apart from Group Theorey, which was beyond dull, which is a shame because I love the field).
#34 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-25 03:17:27
I dont think it was the 'Big Bang'. The big bang theory says the universe started from an extremely hot and dense state, and has been expanding for around 14 billion years. But where did the material that started the big bang come from? And if there was no universe, what was it in?
Do you know the evidence for the Big Bang? A scientist came up with the theory to explain some observations, did some calculations, and came up with a new prediction. He predicted the existence of background radiation. They went to look for it, and sure enough, found it, and in just about the right amount too.
There is much other evidence for Big Bang, such as the ratio of light elements to heavy. Look into the actual evidence behind something before you dismiss it just because you don't like it.
The Big Bang doesn't explain everything. It does not explain how the universe started a t=0. Rather, the Big Bang starts just a few microseconds after this. How the universe started? No one knows, and some scientists believe it is impossible to know.
I went to a very well presented seminar not so long back where it was claimed that there is no t=0, as if you were to reverse time, space-time would degress to such a dense state that the "speed" at which time flowed would tend to zero, thus no discernable beginning.
#35 Re: This is Cool » FLT DEMONSTRATION By Anthony.R.Brown » 2007-05-25 03:12:21
Any so called Proof by induction! is still only Guess work
No it isn't, it's an induced proof, HENCE proof by induction.
a good example is " I state that in the sequence 1,2,3,4,5,6,7,8,9...for as far as we can see the numbers will always end in an Odd Number!
That's not an example of induction, you don't understand what you're talking about.
Both examples above are by induction!
No they aren't
#36 Re: Dark Discussions at Cafe Infinity » Advice needed! » 2007-05-24 04:21:55
Remember that if they didn't think you could do it then they wouldn't have it as a subject. Everything is within your reach if you put in the effort.
Why didn't I just say that? Listen to this guy, he's right.
#37 Re: Dark Discussions at Cafe Infinity » Advice needed! » 2007-05-24 03:46:13
Oh i thought it was meant to be a lot harder.
We've been told that regular maths and physics have by far the biggest step-up from GCSE, so it made me think Further Maths would be unbearably hard. I dont mind a challenge, but only a challenge i can do
You'll start thinking in a more abstract manner, that's what they mean by step up, but once you've made the leap it's really not that difficult.
Actually, maybe we should make a calculus thread in the Help Me forum when term starts, kind of like an open course where people can contribute materials in the standard order they're taught, and just have questions and answers along the way.
#38 Re: Dark Discussions at Cafe Infinity » Advice needed! » 2007-05-24 03:30:08
Thanks for the advice.. im still not 100% about further maths though. The only thing im really concerned about is what grade i would be able to get. Realistically i dont want to do an A-level unless im going to get an A in it, but i dont know whether i would be able to cope with further maths to get an A.
Well, put it this way, taking further maths will guarantee you an A in regular maths.
and an A in further maths isn't hard if you have a thirst for the subject.
Just because it says "Further Maths" doesn't necessarily mean it's harder, it's slightly harder, but really that means "there's MORE of it"
#39 Re: Dark Discussions at Cafe Infinity » Advice needed! » 2007-05-24 03:26:56
Hmm yes what is n?
I guess it shouldn't be n, it should be infinity
#40 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-24 03:24:48
But isn't that pretty much the same for a sphere?
No, because a sphere does not have a non-vanishing continuous vector field, as demonstrated by the hairy ball theorem:
http://en.wikipedia.org/wiki/Hairy_ball_theorem
Basically, looking at the ball, if you attempt to travel in a straight line from anywhere (taking into consideration lines which you have already fixed in the universe) you end up with points where you aren't moving at all. In the case of a torus, no matter which lines you fix, you can always fix the other lines parallel to it, which is not true for a sphere.
#41 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-24 02:47:46
Err... hehe... could someone remind me why we are talking about hyper-toruses?
because there is a non-vanishing continuous vector field on a torus, implying that you can travel in any direction and get back to where you started without destabilising.
but the universe isn't three dimensional, hence hyper-torus is the most obvious place to look next.
#42 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-24 02:25:38
Would you care to elaborate on hyper-torus... i.e. explain to me what the hell it is?!
A torus is what you described, a big donut, which is three dimensional.
A hyper-torus is a generalisation of a torus to n-dimensional space.
http://en.wikipedia.org/wiki/Torus
There's the page, and I have no idea what dimension this is projected from, but here's a spinning hyper-torus
http://www.lboro.ac.uk/departments/ma/gallery/hyper/mov/hyperTorus.mpeg
#43 Re: This is Cool » FLT DEMONSTRATION By Anthony.R.Brown » 2007-05-24 02:19:31
No, I was referring to proving that the principle of mathematical induction is valid on the natural numbers.
I thought that was a peano axiom.
Although I suppose it makes sense to deduce it, but it doesn't mean it can't be axiom.
#44 Re: Dark Discussions at Cafe Infinity » Advice needed! » 2007-05-24 02:16:39
Hehe, you seem to think further maths is a big deal.
I wouldn't recommend anything less than the whole course, maths, further maths, further further maths, further further further maths, further further further further further maths...
In fact, just take the
#45 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-24 02:13:14
So we're talking hyper-torus, right?
#46 Re: Euler Avenue » Power of 0 » 2007-05-24 02:11:15
Typically, 0^0 is left undefined.
The exponential series equates it to one, which I believe is the limit, rather than zero.
Neither here nor there really
#47 Re: Help Me ! » Prove algebraically - odd numbers » 2007-05-24 02:05:27
Daniel123 wrote:especially with 2 and a half months off
the extended summer holiday is nice isnt it?
Sekky the jammy naughty has already finished his year at uni
Oh yeah, three and a half months till the start of the year.
Lots of maths to do for then.
#48 Re: This is Cool » FLT DEMONSTRATION By Anthony.R.Brown » 2007-05-24 02:02:20
I heard it was something like 150 pages long.
The general proof is 150 pages long, yes.
I believe Ricky was referring to just a proof for n=3
#49 Re: Help Me ! » Prove algebraically - odd numbers » 2007-05-24 02:00:43
lol i like your thinking! i clearly used the word 'learn' inappropriately... i meant 'be examined on it'! anyway i joined this forum today... and have never been on the computer for so long
Well welcome to the forum! If you're in your GCSEs at the minute then most likely the first thing you'll meet next year will be single variable calculus. Everyone I know went through a phase of first seeing calculus and screaming "Holy hell...this is real maths!", but a year later they look back at how trivial it seems by comparison to the absolute mammoth you've just awoken.
So if you want to start early for next year, calculus is probably the way to go.
#50 Re: Help Me ! » Prove algebraically - odd numbers » 2007-05-24 01:55:49
I heard from other here that in some places you learn it early, for instance in 10th grade, and in other places you have to wait till uni.
What are you talking about? You don't have to wait for anything, it's written right there!