2 questions, one in math the other in physics

scifes

In withdrawal.
Valued Senior Member
math:

is it true that there is no mathematical proof for the number zero??

physics:

if the more the difference in density between two fluids is, the stronger the float force will be, then why don't containers with vacuum inside them fly up?
 
math:

is it true that there is no mathematical proof for the number zero??
True. Zero is axiomatic.

physics:

if the more the difference in density between two fluids is, the stronger the float force will be, then why don't containers with vacuum inside them fly up?

Because the mass of the container divided by its volume is greater than the density of air. Hydrogen at 1 atmosphere is almost as buoyant as vacuum.
 
Because the mass of the container divided by its volume is greater than the density of air. Hydrogen at 1 atmosphere is almost as buoyant as vacuum.

hey man, hold on a sec..how did you assume that..

take this: a strong incollapsable ballon falls slowly in the air when filled with helium..i floats when filled when hydrogen will it go up if vacuumed?

and the problem of net wight can be easily solved with lowering the ratio between the volume and size..(lower the weight of the ballon incollapsable material to reduce overall density of the ballon)
 
That maybe so, but how is that proof that zero does not exist mathematically ?
What about the number 1, is there mathematical proof for that ?
You don't need zero or one to have valid mathematical systems, it's just you need them if you want particular structures in your mathematics. For instance, suppose you want a set of objects which can be combined together in pairs to make other objects in the set. If you want one of the objects to be such that it doesn't do anything to any of the other objects then it's like wanting a zero under addition, ie x+0 = x for all x, or a 1 under multiplication, x*1 = x for all x. You don't need these to do some mathematics, there's systems which are interesting but do not possess these concepts. If you're doing 'usual algebra' (ie the kind you do in school) then you do need 0's and 1's but that's because you're making the unspoken assumption to be working over the reals, which are a field and therefore by definition have a 0 and a 1.
 
You don't need zero or one to have valid mathematical systems, it's just you need them if you want particular structures in your mathematics. For instance, suppose you want a set of objects which can be combined together in pairs to make other objects in the set. If you want one of the objects to be such that it doesn't do anything to any of the other objects then it's like wanting a zero under addition, ie x+0 = x for all x, or a 1 under multiplication, x*1 = x for all x. You don't need these to do some mathematics, there's systems which are interesting but do not possess these concepts. If you're doing 'usual algebra' (ie the kind you do in school) then you do need 0's and 1's but that's because you're making the unspoken assumption to be working over the reals, which are a field and therefore by definition have a 0 and a 1.

Ok, so what what about any number ? It seems rather foolish to me to ask for proof of a number :shrug:
 
i agree with enmos.

found this interesting, maybe it is relevant here:

The Mesoamerican Long Count calendar developed in south-central Mexico required the use of zero as a place-holder within its vigesimal (base-20) positional numeral system. Many different glyphs, including this partial quatrefoil—Image:MAYA-g-num-0-inc-v1.svg—were used as a zero symbol for these Long Count dates, the earliest of which (on Stela 2 at Chiapa de Corzo, Chiapas) has a date of 36 BCE.[11] Since the eight earliest Long Count dates appear outside the Maya homeland,[12] it is assumed that the use of zero in the Americas predated the Maya and was possibly the invention of the Olmecs. Many of the earliest Long Count dates were found within the Olmec heartland, although the Olmec civilization ended by the 4th century BCE, several centuries before the earliest known Long Count dates.

http://en.wikipedia.org/wiki/0_(number)

as far as the second question, can you describe the vacuum?
 
That maybe so, but how is that proof that zero does not exist mathematically ?
1-1=0 is not a proof of zero. You are implicitly depending on the definitions of the operation '-' and on the numbers 1 and 0. You haven't proved anything.

What about the number 1, is there mathematical proof for that ?
Nope. 1 is the successor of 0, by definition. In other words, 1 is axiomatic.


I suggest you read http://en.wikipedia.org/wiki/Peano_arithmetic as a starting point.
 
I think a container of vacuum with zero mass would float in air. The problem is that the container would need to be strong enough to resist 1.2 kg/m3 of air pressure, and anything that could would be heavier than the amount of air the container would displace.
 
1-1=0 is not a proof of zero. You are implicitly depending on the definitions of the operation '-' and on the numbers 1 and 0. You haven't proved anything.
I know that.. :p
My point was that it is that it is meaningless to ask about proving a number in itself.

Nope. 1 is the successor of 0, by definition. In other words, 1 is axiomatic.

I suggest you read http://en.wikipedia.org/wiki/Peano_arithmetic as a starting point.
Yes, just like any number. You can't prove a number.
 
if the more the difference in density between two fluids is, the stronger the float force will be, then why don't containers with vacuum inside them fly up?
What spidergoat said.

A container with a vaccuum inside will float if the mass of the container is less than the mass of surrounding medium displaced by the container.

If the surrounding medium is air (density 1.2 mg/cc) and the container density is 3 g/cc (a very light alloy or ceramic), then a container will float if its total volume is 99.96% vaccuum.
 
I think a container of vacuum with zero mass would float in air. The problem is that the container would need to be strong enough to resist 1.2 kg/m3 of air pressure, and anything that could would be heavier than the amount of air the container would displace.

What spidergoat said.

A container with a vaccuum inside will float if the mass of the container is less than the mass of surrounding medium displaced by the container.

If the surrounding medium is air (density 1.2 mg/cc) and the container density is 3 g/cc (a very light alloy or ceramic), then a container will float if its total volume is 99.96% vaccuum.

well can't you find some way around that..for example make the containor veeeeary big..that way i guess you can have a strong heavy material to prevent collapse..but all you have to do is make the vacuum bigger..

i mean the relation between them isn't linear..but parabolic..right??
 
I admit that you are doing a very good job at being an annoying idiot.
well i'm learning from the best:D.. and enjoying it
Ok, so what what about any number ? It seems rather foolish to me to ask for proof of a number :shrug:
trust me it isn't as foolish as to ask a proof of god..
I know that..
My point was that it is that it is meaningless to ask about proving a number in itself.


Yes, just like any number. You can't prove a number.

lol that's why i used this example in our discussion..can you see now??

:shh:(think before you reply)
 
well i'm learning from the best:D.. and enjoying it
You don't have to learn anything about that, you're a natural.

trust me it isn't as foolish as to ask a proof of god..
Agreed. The only thing more foolish is to assume God exists in the absence of any evidence.

lol that's why i used this example in our discussion..can you see now??
Perhaps you should learn to read then. See post 2.

Are you actually admitting that you started a thread in Physics & Math for religious purposes ?
 
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