Random Math Discussion

Time travel is theoretically possible through worm holes

.999 is not one.
Because it's an entirely different number.

Oh lord. I look up, see Doughty's math ray on full-blast, then decide it's time to leave.

We really need a Biology hub...

NastProd

DoughtyI am confused, if your saying -1 cannot equal sqrt(-1*-1) then think of it this way: sqrt(-1^2) the square and square root cancel out, leaving you with -1.

The definition of sqrt(x^2) is abs(x). you must follow the order of operations, meaning square x first, then take the square root. so sqrt(-1^2) would be sqrt(1) which is 1, or abs(-1).

Fine, let's just leave it at what I originally had, sqrt(-1*-1) = sqrt(-1)*sqrt(-1) = i*i = -1

DoughtyI am confused, if your saying -1 cannot equal sqrt(-1*-1) then think of it this way: sqrt(-1^2) the square and square root cancel out, leaving you with -1.

The definition of sqrt(x^2) is abs(x). you must follow the order of operations, meaning square x first, then take the square root. so sqrt(-1^2) would be sqrt(1) which is 1, or abs(-1).

Animatrix
Also,time and the speed of light aren't really related, due to time being the word we use to describe the passing of hours (yet another word we made up).

Actually, Time has everything to do with the speed of light. If you have ever studied time dilation or length contraction, you'd know that the closer to the speed of light you travel, the slower your internal clocks tick, thus making time relative to you slow down. The whole phenomenon is wrapped up in Einsteins theory of relativity, and he goes into much greater depth about how it all works, much more than i can explain in this thread. I have written a small (10 page) research paper on this topic for relatively inexperienced people, if you want me to send you a copy of it.

mist13Also, time travel is impossible. Not because the reasons you gave (the hell?) but because nothing can go faster than the speed of light. Not because of time travel crazziness. Anyways, since everything is relative, I'm sure that someone going back in time would go through a different reality, leaving the true past unaffected(but time travel is impossible so... yeah...)

Scientists are studying ways to not necessarily travel faster than the speed of light, but instead create a sort of corkscrew to go back in time by bending the fabric of space and time itself. This would require a massive gravity well that could be expansive enough to bend adjacent space and time with it, but it would need to be something much greater than a black hole, so it is very unlikely. The main point is that traveling faster than the speed of light may not be the only way to travel back in time

Feel free to let me know if I have given any false information, all of this is correct as far as i know, due to many TV shows (Science channel FTW) and personal studying as part of my physics classes and that sort of thing.

Fuck this, x(x+y) is x squared + xy. Its the formula for time. X is you. X in brackets is your dad, your mom is y. If you donat have those two integers, you cant make yourself. You cannot travel back in time. Period.

1) This is true, a friend has proved it to me. Here is the proof:
a.1/9=0.11111...
b.1/9 x 9=0.11111... x 9
c.9/9=0.99999...
d.1=0.99999...
2) Time machines can exist, because if you go back in time and destroy the blueprints, then when you travel back, you are in a different timeline, or you have caused a time paradox/hole in the space-time continuum, so that we never exsisted.

Nevermind. Its in step 4 and 5. You square one -1, but not the other. Each would become their own i^2, making a total of 1.

mist13

Doughty
Math is irrelevant, now correct me if any thing looks wrong, but here it goes:

2 = 1+1 = √(1) +1 = √(-1*-1) +1 = (√(-1)*√(-1)) +1 = (i*i) +1 = i^2 +1 = -1+1 = 0

So through that 2=0, and it could also = -2 if you did the same thing with the other 1.

This also means that 1+1 is actually 2,0, or -2

Your problem is in step 2. You use the root of only one 1, rather than the whole thing(also, you would have to square the other side).

No, I am just substituting 1 with the square root of 1, because it is the same thing.

Math is irrelevant, now correct me if any thing looks wrong, but here it goes:

2 = 1+1 = √(1) +1 = √(-1*-1) +1 = (√(-1)*√(-1)) +1 = (i*i) +1 = i^2 +1 = -1+1 = 0

So through that 2=0, and it could also = -2 if you did the same thing with the other 1.

This also means that 1+1 is actually 2,0, or -2

.99 does not equal 1. Especially if you have been asked to go to 8 dp for an assignment on integration and finding the area under a function to the x axis. 19 pages of irrelevant math later, I have myself, a thesis :3

Zaphod, I have already said that.

Woah

Zaphod; both of those proofs have come up and been disproved already... I forget the specifics.
~Karenthian~

Some proofs:
x = 0.99999
10x = 9.99999
10x - x = 9x = 9.000000
x = 1.00000

or something like:

x= 0.999999
x/3 = 0.33333
x/3 = 1/3
x = 1

0.99... = 1 because:
1 - 0.99... = 0.00...1
There are, however, an infinite number of zeros before that '1', so that '1' will only occur after a never-ending number of zeros. So, while the '1' exists, it never occurs, and as such doesn't exist. In short, 0.99... = 1.

Being more of a philosopher then a mathematician, there is the theory that every person hosts there own parallel universe and that each thing that person does only affects there universe otherwise basic imprints of what other people have done stay in uoryay universe, so by those means if you built a time machine you could use it but as you host what is technically your own world you can't affect other people with it.

0.99 recurring does equal 1 and can be proved with basic algebra.

Regarding time travel, your argument that the time travel would have already occurred is totally flawed based on time loop and parallel universe theories.

Oh cmon waterskier, you could post that all in one post ;/

time travel is theoretically possible by wormholes. if the wormhole was traversable than time travel would be achievable by accelerating one end of the wormhole to some significant fraction of the speed of light and then brought back to the where it started. Alternatively, another way is to take one entrance of the wormhole and move it to inside the gravitational field of an object that has higher gravity than the other entrance, and then return it to a position near the other entrance. For both of these methods, time dilation causes the end of the wormhole that has been moved to have aged less than the stationary end. translation: you can use a wormhole for time travel.

"Practical" and "accurate" must be different to maintain good science and good maths. If you disregard accuracy for practicality you end up with .999 = 1.
~Karenthian~

Truth, but Imma disregard that until it becomes practical. Its more practical for it to be a constant anyways,

The speed of light may be the fastest thing we know of, but it is no longer a constant. Light has successfully been "slowed down" as well as bought to a complete halt. Don't ask me how they did it, but there is a special material which doesn't "block" light, but simply slows it to the point of no movement.
~Karenthian~

This video states .999...=1
So....
Her statement that there are 9,999... reasons that .99..=1 is actually:
100 reasons 1=1
Also, the statement 99.999...% of mathematicians agree that .999...=1 is actually:
100% of mathematicians agree that 1=1


Well, .99 does = 1 when rounded up, which is probably the easiest way shown as it could have endless nines... Like .9999999999999999999999999 recurring.

Let's solve this once and for all! Bury this thread...


If you're from the future post on this thread!

Y1ram
2) Time machines cannot exist.
Why? It's simple. By human nature, someone is going to go power crazy, and alter time with the created time machine. But if something goes wrong, it would have already happened. Also, someone would also destroy the time machine or the blueprints before it was created to prevent that, thus preventing it form ever being created.

1) Time machines already exist, getting in a plane and traveling to a different country can allow you to relive those last hours, not in the same place, but you can still go back in time or forward. They're a thing called time zones.

2) Who said they went this far back in time to alter this time, here, right now. they could have gone to our future, (which I may add does not exist because it has not been made yet. By THEORY we're the first run of time and even if there are 2 runs they'll both be the first. because its a duplicate.) and messed that up there.

3) People would not go back in time because just the time machine being there would alter the whole future, not by much but it would, thus the future would be re-written, which would remove the original time line and continue from the moment it change thus the alternate future would not exist, that person would have to live from the moment they arrived in the "past" to get back to where they were originally at.

4) Following three, if someone did alter the timezone our old timeline would be destroyed yes? Therefore our alternate timeline wouldn't know because we're a different person to our originals.


Think it through...

I Agree As 0.99999* as ur will natualy round it. it would be to one. lets say it was money 99p or 99cent in usa. when u c it u class it as look at that it costs 1 pound/ 1 dollar. so natualy in maths 0.9* is 1. Thats My Statement And Im Only The Age Of 11.
or we could go onto shapes... lets say a square for example is the square the line.. the Area inside the line or is it the area outside the line???

Well, 0.9* would be equal to one, because for each decimal, you get closer to creating the number 1.

Imagine a circle. Now image 9/10 of that circle coloured. Now image 9/10 of the non-coloured area coloured. This would continuously go on until there would be such a ridiculously small gap left over, that if you were to look at that circle, you could quite honestly say that it was all completely coloured in.

*= recurring symbol

However, as for the matter of time-travel, it would be very difficult to do, as there would be so many paradoxes going on at the same time at any moment. If someone were to go to a different time period that they don't belong in, then the very slightest of changes could cause greater destruction in the future (our present day). Also, nobody would dare go in, unless they were power-crazy (as said in the first post) or mad.

Just thinking, if you were to do something so small, as to step on a plant it could cause so many problems in that area that could cause certain certain events to happen. It may very well cause geographical things to happen such as a hurricane

If you wanted to do something majorly massive such as the Axis to have won WWII, then so many events would have changed. There would be the constant fighting between the far left and the far right of the political spectrum, battling it out as Russia and Germany show their national strength to become the greatest ruler of the world. The world would never be anything as it is now. The world would be a much racial but also more technological place to live.

However, somehow, if this all were to happen ,then it would mean that a huge paradox would have been created and a rip in the universe would be formed alongside it. Because of that, different universes could jump through one another to see so many variations of our own universe created by events. The rip would get so big that all of time and space wouldn't exist any more and nothing would exist.

That just shows how serious it would be.

Yes! That's exactly what I'd heard! I can't find the damned thing now, but there was a very impressive article that listed what this person had hypothesised the first 8 dimensions to be, but obviously after 3 (us being only 3 dimensional beings) there's just no way we can comprehend more than 4, or less than 2.
Think about it, can you actually comprehend a point with no width, height or depth?
~Karenthian~

I've heard one interesting theory once:
1D - Is a point
2D - Is length and width
3D - Is length and width and depth( our world )
4D - Is the length, with, depth and THE TIME, which we can present as a parabolic line

To us as a 3D entities it's hard to understand one more dimension, however it's still possible.

Nothing is for certain, I'm just saying whats true for what we know right now.

It's not necessarily impossible to go backwards in time, though the speed of light has proven difficult to break
If it were possible, then time travel would be. The difficult part would be the enormous energy requirements to do it. That also explains why you don't see time travellers; the further back you want to go the more energy it takes... small jumps backwards take 1-buttload of energy, longer trips take 1-buttload^2 of energy... The longer we wait, the mroe chance of time travel
But it does all hinge on the lightspeed barrier being breakable, which is looking less than likely... though with technology advancing so quickly; who is to say it will be impossible in a hundred years?
~Karenthian~

Time is relative. No one knows quite yet what time even is.

But traveling into the past is impossible, you'd have to break the light barrier. Imagine superman, flying faster than the world to catch up with the past. You'd have to be faster than the speed of light to do that, and since nothing can go faster than the speed of light, its impossible.