On Jan 10, 2015, at 3:26 AM, Bill Bartlett wrote:
> On 10/01/2015, at 4:42 PM, Shane Mage <shmage at pipeline.com> wrote:
>>> I am far from being a physicist, but I conceive gravity as being a
>>> side-effect of the bending (compression?) of space/time by objects
>>> of large mass. But correct me if I have misunderstood?
>> But what is the meaning of the expression "space/time," its
>> *definition*? And what about "bending" (or "compression")? Let
>> someone try to make a sentence about gravity using, not those
>> words, but their *definitions*. I suggest that any resulting
>> sentence will be totally meaningless in terms of any conceivable
>> human experience. That is because in scientific usage the only
>> referents for those terms are not words descriptive of possible
>> experience but abstract mathematical equations quite divorced from
>> physical reality and our perceptions of it.
>
> Space/time is fairly obvious. The bending/compression thing is my
> conception and quite unscientific I presume. As for the scientific
> description, I think I saw somewhere some physicist put gravity as
> being about space/time being shifted by items with mass, rather than
> items with mass being moved in space. Something to do with mass
> influencing the time dimension, which warps space, thus space moving
> in relation to items with mass.
>
> As you can see, I can't really get my head around it properly. Thus
> my conception of space/time being compressed/bent is just a feeble
> way to expressing something beyond my understanding...
No amount of nicotine will ever let you understand an incomprehensible verbal construction. To demonstrate this I will take up my own challenge and reconstruct your sentence ("I conceive gravity as being a side-effect of the bending (compression?) of space/time by objects of large mass.") using the definitions of spacetime (or space/time) from my computer's dictionary ("the concepts of time and three- dimensional space regarded as fused in a four-dimensional continuum"), from Wikipedia ("any mathematical model that combines space and time into a single interwoven continuum"), and from The Random House Dictionary of the English Language ("1. the four-dimensional continuum , having three spatial coordinates. and one temporal coordinate, in which all physical quantities may be located. 2. the physical reality that exists within this four-dimensional continuum," plus the RH definitions of bend(v.) ("to force an object from a straight form into a curved or angular form or from a curved or angular form into some different form"), and compress(v.) ("to press together; to force into less space"). Thus we get six possible sentences:
1. I conceive gravity as being a side-effect of forcing [the concepts of time and three-dimensional space regarded as fused in a four- dimensional continuum] from a strait, curved, or angular form into some different form by objects of large mass.
2. I conceive gravity as being a side-effect of forcing [any mathematical model that combines space and time into a single interwoven continuum] from a strait, curved, or angular form into some different form by objects of large mass.
3. I conceive gravity as being a side-effect of forcing [the physical reality that exists within the four-dimensional continuum , having three spatial coordinates. and one temporal coordinate, in which all physical quantities may be located] from a strait, curved, or angular form into some different form by objects of large mass.
4. I conceive gravity as being a side-effect of pressing [the concepts of time and three-dimensional space regarded as fused in a four- dimensional continuum] together to force them into less space.
5. I conceive gravity as being a side-effect of pressing [any mathematical model that combines space and time into a single interwoven continuum] together to force it into less space.
6. I conceive gravity as being a side-effect of pressing [the physical reality that exists within the four-dimensional continuum , having three spatial coordinates. and one temporal coordinate, in which all physical quantities may be located] together to force it into less space.
As you see, none of these sentence-forms conveys any physical (or other) meaning at all. Can some physicist reading this do any better, verbally? I doubt it.
Shane Mage
This cosmos did none of gods or men make, but it always was and is and shall be: an everlasting fire, kindling in measures and going out in measures.
Herakleitos of Ephesos