finite or infinite?

[Tallim]

I remember giving a talk at university about the example of having infinite space in a finite area. Got a good mark for it too.

The "very basic" example is imagine an island which you measure the length of the coastline, as you are more and more accurate in your measure of the length of the coastline i.e. you start measuring along every grain of sand etc. the length effectively becomes infinite.

If you have a circle around the island it has set dimensions which you know for sure so it has a finite area.

I see no reason the universe can't be the same.

Quantum Physics and Astrophysics were the only things I was really good at on my course.

 

[Kpt._Rob]

I shall paraphrase Christopher Hitchens in saying that if the universe were discovered either to be finite or to be infinite, I should find whichever discovery equally mindblowing. If you want to knock me for going with what is basically a non-opinion that is fine, but I simply don't think that we have either enough evidence or enough of an understanding of how or why anything works to be making statements one way or the other.

 

[ezeroast]

(just a note I got all my info from the history channel and such so for all I know the moon could actually be the ass of a giant space elephant)

Well that sure does put the whole "Moon is made of green cheese" theory in a whole new light. XD

...

My reply to that

"Just because something can be measured does not mean that it is finite. I don't understand your reasoning here."

Well there's you're problem. Once you measure something, you acknowledge it's finite nature. If the measured distance is 30 miles, it's 30 miles. That's not infinite. If it is, my car should get infinite miles per gallon.
Ok, so to keep with the expanding balloon analogy: Today, the distance from point A to point B is 1 inch. (That's not infinite. Is it?) Tomorrow, it'll be 2 inches. (Still not infinite.) The day after, 3 inches, etc. It has infinite growth, but the exact distance at any given time is still finite & measurable.

What I meant was, say your cars speed is increasing (i know there is a universal speed limit but bare with me) so the speed of the car is increasing and at a certain moment the car is travelling at 30 miles per hour, after that moment the car is travelling faster but the individual moments can be measured.

 

[edthehyena]

It's very easy to point to an infinite set (a set that contains an infinite number of members). My favorite is the set of real numbers between 1 and 2, mostly so I can point out mind-blowing things like how the set of real numbers between 1 and 3 is also infinite, but twice as large.

As for anything existing within the universe with an infinite dimension, it's not really possible. Saying time is infinite is like saying height is infinite (they're both dimensions, not things). The universe itself is infinite and expanding (and if that's confusing, see my point on infinite sets).

A very common pitfall when thinking of infinity is to treat it like a number.

 

[Denamic]

Infinity is just a concept that is inherently impossible to even begin to comprehend in the first place.
There's no way to possibly affirm the truth either way.

Imagining infinity is like imagining a square with 5 corners.

 

[jaffar.abduraheem]

Cantor's Theorum proves that within infinite sets, there exist smaller though equally infinite sets. It therefore stands to reason that in a particular set there must be infinite sets of finite sets.

This seems to suggest that something is infinite. Arguing over what it is, is pointless because we will never know what it is when we find it. Counting to infinity would take infinitely long. It can never be done.

 

[ezeroast]

He is right, you are wrong, and a big problem with threads made to revolve around one guys internet argument with another is that the thread maker will be biased and choose what will and won't be included in the final draft of the thread.

I never gave an opinion, I only said that "his reasoning was wrong". All I wanted was people to discuss the topic.

 

[2xDouble]

There are varying degrees of infinity. From a purely scientific (observable) standpoint, you are both correct. Space is infinite. Space does not loop in on itself like a Moebius strip, it just keeps going on forever. If anyone disputes this, I challenge them to "sail around the universe" and prove it wrong. SPACE is not expanding, the UNIVERSE is expanding. The observable MATTER inside (aka the UNIVERSE) is finite. It is currently expanding faster than it is contracting thanks to a mostly unknown (but MUST exist, based on observation of deep space) type of energy called "Dark Energy". (yes, it is related to, but not the same as, Dark Matter).

The question at the hands of astrophysicists is "will Gravity overcome Dark Energy?" If it does, all matter and energy contained in our observable universe will eventually (trillions of years in the future) collapse in on itself in an apocalypse scenario known as the "Big Crunch". If it does not, Entropy will take over (because Gravity decreases exponentially as Distance increases) and all Matter and Energy will dissipate into the infinity of space (which IS infinite, again trillions of years in the future) and reach a universal "medium" referred to as the "Big Freeze". ...at which point Chaos Theory kicks in (short summary: in an infinite amount of time, anything that CAN happen DOES happen)and the circumstances of the origin of our universe (the Big Bang) happens again, thereby creating an illusion of cyclical time... but I digress...

Time is also not "expanding". Time is linear and causal. EVENTS are "expanding" thereby making POSSIBILITY infinite. It is the same relationship between Space and Matter. (Time is also fluid, to some great debate among physicists that I won't get into here). Time IS Infinite, but not Eternal (a religious designation). Think of the difference between an unending Ray (infinite, but in one direction) and an unending Line (infinite in both directions), if you've studied Geometry. Time, in theory, had a beginning, but will have no end.

The argument that something infinite cannot be measured is flat out wrong. According to Calculus principles of Exponential Growth, we can demonstrate incontrovertibly that there is an infinity inside any measured unit, as well as a possible infinite number of said units. Simply because the ENTIRETY of something cannot be measured does not mean that measurement is irrelevant. SEGMENTS of that infinity CAN be observed and measured (more basic Geometry) in the same way you can recognize a Constellation, but you couldn't count all the Stars (for exposition. not a real example because there are, theoretically, a finite number of stars).

I could go on, but I've run out of pompous for the day...
Remember, kids: Math and Physics are fun, and not just for the explosions!

 

[LongAndShort]

I believe that this ultimately becomes a question of understanding. My old physics teacher says that the reason so many people have trouble with infinity is people can't stomach the idea of anything being infinite. Its psychological rather than mathematical. I'll be honest, I have trouble with the idea of infinity.

Once this became a religious thread (and I am religious, so I think its okay for me to say) you should have said that the Bible and religion says that God is himself infinite. He always is and always will be. Isn't it therefore possible for him to create an infinite universe?

 

[DarthFennec]

I think space itself is infinite, and the amount of space that is taken up by matter (the balloon) is finite, and that's what's expanding. That's how I understand it anyway.

 

[Shinigami214]

Ok I accidently got into an argument with a creationist on youtube-

Fuck this thread, I'm outta here.

My thoughts exactly.

Also my first reaction.

 

[tsb247]

Ok I accidently got into an argument with a creationist on youtube. This isn't a particularly religious topic so that's why its here.
He was stating that space and time is finite and I was basicly telling him that his reasoning was wrong.

Here is the part of my comment he is replying to

"Ok there is a distance between 2 object BUT that distance is forever expanding, how is that not infinite?"

Here's a quote from him

"Imagine a balloon that is always expanding. At any point, it still has a finite size, and that's why it can keep getting bigger. If it was already an infinite size, how could it get bigger? Size is a statement of measurement, and measurement only works if something is finite enough to measure. Therefore, if space is expanding (like science proves, and The Bible says),It is I who made the earth and created mankind upon it. My own hands stretched out the heavens then we know space is finite."

"We also know time is expanding (space-time), since each moment "expands" on the moment before it."

My reply to that

"Just because something can be measured does not mean that it is finite. I don't understand your reasoning here."

His reply to this

"Something that is infinite is non-finite. Measurements require finite digits to measure with. Imagine a ruler without finite points. How could you measure anything with it?"

and my reply to that

"A ruler with infinite digits still has numbers on it yes? so there are an infinite numbers placed along the ruler to measure things with.
This conversation is going nowhere and if we keep this up it could go "Forever". So if you were to keep replying to me and I kept replying to you forever there would be no end to it correct? Would that be infinite?"


Just wondering what you guys thought.

TLDR : Is anything infinite? If so why and if not why not?

To put it simply, something that is infinite cannot expand. The universe can be shown to be expanding and therefore it has finite dimension. It's as simple as that. There is simply no way for something that is limitless to expand its limits (expand). The arguments you presented (especially the one about the ruler) don't really hold up.

See the comment I responded to about inflating a balloon. The universe is thought to behave the same way.

 

[HassEsser]

He is right, you are wrong, and a big problem with threads made to revolve around one guys internet argument with another is that the thread maker will be biased and choose what will and won't be included in the final draft of the thread.

I never gave an opinion, I only said that "his reasoning was wrong". All I wanted was people to discuss the topic.

Oh, I am sorry, I didn't mean you in particular were doing this, I just meant threads like this almost always include bias of some sort.

 

[Hawgh]

Even if something approaches infinity, if it had a fixed time of origin, it will at a given measurement be a finite distance.

I'm a little rusty on my mathematical notation, but something like this: x = 42 LIM(x->Infinity). I would be mightily obliged if someone who remember their math more clearly could throw out the correct expression.

However, if the two objects have been moving away from each other for an infinite time, their distance would be infinite, I think.

 

[Horben]

Some things are finite, other things are infinite. Only the things that are finite are useful, so stressing over the infinite is pointless. It's better to bake a bagel than pontificate on space and time.

 

[skeliton112]

Space and time are both infintite in my view

because once you get beyond a point there must be something past it

 

[Eclectic Dreck]

The creationist is correct. It doesn't matter if the distance between the two points is expanding at a faster rate than anything can actually travel (and thus you'd never reach the other point no matter how hard you try). If the rate of expansion is less than infinite (that is, after an infintessimal length of time the distance between the two objects has increased to infinity), then at any given infantessimal point in time the distance between the two objects is finite (even if it is very, very large).

 

[xXAsherahXx]

That guy loses the battle... -600 HP. At any one time an expanding balloon is not finite, because it is, get this, growing, and the size is increasing. For it to be finite, it has to stay the same size and not grow at all. Our universe is going to keep expanding until it pops, so at the time right before it pops it will be finite. But until then it will be infinite. At least scientists say it will pop.

No...

The balloon is finite. Finite need not mean stagnant , but rather of definite dimension.

The dimensions of the balloon can be measured using some simple calculus.

We'll take the radius of the balloon as being, "r."

The radius of the balloon (r) is ever-changing with time (growing), so at any point in time the radius of the balloon can be described by the derivative of the equation describing the radius of the balloon: dr/dt

dr = change in radius with respect to time (dt).

If we have an equation for the diameter (or radius) of the balloon we can know the exact dimensions of the balloon at any given time. Even if we do not know the exact diameter of the balloon, as long as we know the diameter at one specific time and the rate at which it is expanding, we can put exact dimensions on it at a given time in the future.

Expanding =/= infinite. Period.

I can't really explain what I am thinking, the way I chose to explain my thought process is not really the best way I could have. I actually do believe the universe to be finite. If you went to the very edge of the universe you would see it is expanding so you would know that the universe is finite by seeing the very edge. What I mean by infinite is that there is no end in sight at all, ever. By the balloon being infinite, I mean we don't know how big the balloon will get before it pops. I am not in calculus or physics so the best I can do is offer amateurish comments.

I wonder what you would see at the edge of the universe though.

 

[lenin_117]

Well I hate to say it, but the creationist is correct. The distance between any two real objects at any point in time is infinite. IDK about the universe, because the space they could occupy is infinite. They could be in any direction, infinitely far away. COULD.

 

[ClaptonKnophlerHendrix]

You are right, and debates that don't start as religious but quote the Bible will always end up going on and on, no matter what the subject unless someone stops them like one of Newton's laws, don't care to look it up.
And yes some things are infinite, and if any one says otherwise ask them what the last number is.

Right

you are rite and debates that dont start as religious but quote the bible will always end up going on and on no madder what the subject on less someone stops them like one of newtons laws dont care to look it up.
and yes things are infinites and if any one says others whys ask them what the last number is.

Wrong