Posts by bohm

2

How do delete my account?

by awakenyr2004 in

i'd like to start a new account with a different email.

i just google my email address and my cell number and i found some posts here.. how can i block them or delete my account.

i have some family on the fence about shunning me and i hate to put the nail in the coffin if they find me here.. .

bohm

Pm simon about the posts you want to have blocked out.

280

the flood, mammoths, elphants, and food.

by Crazyguy in

my question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.

also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .

.

bohm

Caedes: the dialog is like this:

Bob: george bush is six feet tall
alice no!
bob: how tall is he the?
alice: you understand nothing. He is not six feet tall
bob: this book sayes: "george w bush is six feet tall"
alice: you are taking it out of context. You are a joke
bob: but how tall do you think he is?
(two pages later)
alice: his net effective height is six feet
bob: ...so you agree?
alice: no! You understand nothing!
Bob: wth.
alice: i win!

around here bob realise that alice sees george bushs height as being composed by the distance from his toes to waist and from the waist to head, and so she is insisting we should say his net total height is six feet and not just his height is six feet, as if these were different things. I think viviane started out with a genuine disagreement with me four pages back (see the insistence the shell theorem involved two radiuses), but she realised this was not a good point and so settled for the above tiresome discussion.

Returning to the effective grav field vs just the grav field. I think we agree this is entirely about semantics at this point, which is not to say i am changing my mind. However here is a point to consider wrt the hollow sphere: if we use the term effective field, what does that mean? My intuitive notion is we might call it the effective field because it is a superposition of smaller "true" fields, however what are those fields? The system only consists of a spherical mass density, and so any insistence on a true division into finitely many "true" fields that are non-zero is both arbitrary and false. for this reason i think the word "effective" should be considered to have roughly the same status as another qualifier like "large", and i suggest this may be a reason it is avoided in a context where exactness matters like in the book cosmology. This may be reading to much into the text though.

Comparing the situation to electrostatics the situation here is simpler: we could say the electric field is that due to a single electron, and the effective field is then the superposition of many simpler fields. This is simpler and more sensible, however i am sure your three friends often use the word "electric field" to describe the field of something more than a single electron!

the point i return to is this: if we insist the use of "the gravitational field" is physically wrong, and not just a semantic difference, we need to endow the words "the gravitational field" and "effective grav field " with a specific meaning. I just cant tell what that should be in this context. If your friends have a suggestion i would be happy to hear it. Cheers.

280

the flood, mammoths, elphants, and food.

by Crazyguy in

my question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.

also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .

.

bohm

Bohm: yap viviane, I didn't use your preferred words and so I must be wrong.

Viv: You are. Thanks for admitting it. As, as someone with a physics degree, it seems like you would know something about how important is to be both precise AND accurate.

...I feel this is somehow lowering the trolling standards . Perhaps it is good of you to retire.

280

the flood, mammoths, elphants, and food.

by Crazyguy in

my question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.

also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .

.

bohm

aw come on viviane! the person made a very minor mistakes in the units! Force has units of newton, a sum of forces has units of newton, but the grav. field have units of newton per unit mass! Trolllololololol away!

sorry to hear you are going, but bye! Be on your merry way! i must admit i was quite frustrated before noticing you was trolling, but the last few pages have been fun.

74

7 Reasons Why Babylon the Great was Jerusalem

by Tiresias in

authors david chilton (1987) and james stuart russell (1878) propose that the revelation is primarily a prophecy of the destruction of ancient jerusalem by the roman armies.

the revelation is jerusalem's armageddon (mountain of assembled roman troops).

i see the revelation as a war siren warning the first century christians of the imminent destruction of the city.

bohm

Great post TD, I now learned one thing today!

39

I lost my family today.

by awakenyr2004 in

jw
friends

so far my oldest niece and oldest sister cut me off.

i'm waiting for the goodbye texts from my other siblings.

my parents asured me they would never cut me off.

bohm

++oubliette. Way to proove there is nothing odd about the wt..

Dont write anything down. Say you are hurt by how your words have been twisted. I am so sorry you have to go through this..

49

Faith - Virtue or Vice?

by nicolaou in

faith gives you permission to believe that jesus actually did feed thousands with a few loaves & fishes, walk on water and rise from the grave.

all the evidence proves that none of this happened so why persist with faith?

why be dishonest with yourself?

bohm

Bump.

280

the flood, mammoths, elphants, and food.

by Crazyguy in

my question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.

also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .

.

bohm

Viviane: Quick! I found someone you can troll! There is a person on this very thread who wrote:

I'm truly puizzled why you and I can plainly realize that field, the sum total of it's forces,

Since the field do not have units of force, but units of force per unit of mass, it cannot be the sum of forces and so you can write THIS IS WRONG YOU MORON YOU DO NOT UNDERSTAND PHYSICS!!!!11!!!! for about 10 pages! Do not miss this excellent trolling oppertunity, for once you will actually be discussing with a person who will be technically wrong under a hostile interpretation rather than simply not using your preferred words and phrases!

280

the flood, mammoths, elphants, and food.

by Crazyguy in

my question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.

also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .

.

bohm

yap viviane, I didn't use your preferred words and so I must be wrong. And the authors of the textbook didnt use your preferred words and so I must be reading them out of context.

Like, if someone claims the two sides of the lightbulb shines with an effect of 10 watts each, the inescapable conclusion is to say: "the lightbulb shines with an net effective effect of 20 watts". Simply saying: "the lightbulb shines with an effect of 20 watts" is somehow not getting the physics.

280

the flood, mammoths, elphants, and food.

by Crazyguy in

my question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.

also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .

.

bohm

Cades (*):

I have had a look at the link and it does say the field is zero but doesn't explain why the field is zero rather than simply being a result of opposing forces.

Well, I am a bit torn if I should try to answer this question since I feel i am being trolled to hell on this thread and everything I write will be given a negative spin, so I would like to start this post by saying this post is not meant to be water-proof to a hostile interpretation and is not intended for Viviane.

The first (important) caveat is the reply is NOT taking into account relativity/quantum theory at all; if we should take this into account the proper answer is the gravitational field (as discussed in the section of "Cosmology" and by me) does not exist at all except as an approximation of limited validity.

Secondly there is the issue of how physical concepts really "exists" (does e.g. "force" really exist? does "energy" really exist?). I will assume we can both agree that these questions have the common-sense answer that allow us to say these things exists.

There are now two ways to discuss gravity in classical mechanics:

Using a description where forces (computing using newtons law of gravitation) pull in the object(s) and determine the dynamics (I will call this the ropes-and-pullies view on physics)*.
For each configuration of matter, determine the gravitational field and use this to compute the dynamics*.

Both of these description raise a number of questions that has been important historically (what is the gravitational field really? does it really exist? vs. how do objects know which other objects pull them?) and are obviously in conflict with relativity*. The second approach (fields) is sometimes preferred to the first for a few reasons (this is in my oppinion why it is in a textbook like Cosmology*):

it generalizes naturally to a description of electromagnetism in terms of the electric field of a static configuration of charges (compare to the gravitational field for a configuration of matter)*
it blends more easily into more advanced physics like quantum-field theory or general relativity (with important and complicated differences)*
especially in the case of electromagnetism the formulation in terms of fields is "nicer" to work with; for instance Maxwells equations describe the electric/magnetic field. It also allow one to describe gravity in terms of a (scalar) potential function and allow one to "solve" for the electric field.*

This is not to say that the gravitational field "exist, period": In terms of more advanced physics it certainly do not*, and even in terms of Newtonian physics it should also simply be considered a convenient formulation*. However the "ropes-and-pullies" description of newtons law of gravitation, where one compute the force on an object by imagining it is connected by ropes to other objects that "pull" do not "exist, period" either for the above mentioned reasons*. The "ropes-and-pullies" view of gravity is also often very convenient for some computations and, at any rate, one often end up doing nearly the same computation (as in my argument for the shell theorem)*.

Now to return to the question. Suppose we allow ourselves to describe the system in terms of a gravitational field (as the authors of "Cosmology" does)*. Then the gravitational field is something we associate with a particular configuration of matter (per definition*). There exist a principle* (the superposition principle) that allow us to compute the gravitational field by (1) dividing the configuration of matter into several parts (2) compute the gravitational field individually for each of these parts (3) then the complete gravitational field is the sum of the individual fields; in the derivation i posted a few pages this is actually what I did by the integration and a similar result holds for electromagnetism. This naturally agree with the fact forces can be superimposed as in your argument*.

However in this case there is still just a single gravitational field for the final configuration: the gravitational field.

Suppose we then say: no-no, this is the "net" gravitational field, the "total" gravitational field or somesuch, then we must define what the "net"/"total" gravitational field is formally if we really believe these are different from the gravitational field, i.e. as an actual numerical quantity. What should that numerical quantity be? How should it be different from the gravitational field? I can't think of any meaningful suggestions.

Ofcourse you are free to say that as the gravitational field is just one way of phrasing the physics, and do not exist in the same way atoms exist, then we should define "no gravity" in terms of relativity/quantum gravity/string theory and take the discussion from there. Or you can say we should prefer the ropes-and-pullies version of newtons law and in this case "no gravity" can only be defined as the situation where we are assymptotically far away from any matter (as opposed to not being subject to acceleration due to gravity). I don't want to say these views are wrong which is also why in my original response to Prologos I formulated myself in terms of acceleration and not gravity except as a clarifying remark.

* this statement like everything else is not troll-proof.