Posts by Caedes

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.. .

.

Caedes

Caedes: I do not insist you are wrong under all definitions of the word "gravity", but I think you are wrong under the simplest. It is at any rate completely accurate to say there is no gravitational field inside the sphere (it is zero).

Bohm,

That is funny, because I generally work on the principle that any understanding I have of physics is the simplest one!

As I said earlier this is right at the edge of my understanding and you are correct I am looking at this from a purely newtonian point of view (as any engineer would)

I have had a look through a number of my old text books and read through some of the stuff I found online but I can't find anything that specifically states anything other than what my current understanding of shell theorem is. If you could recommend something that explains the difference I would be most interested.

Thanks

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.. .

.

Caedes

Perhap as an example think of a ping pong ball hovering in a jet of air. The ping pong ball has two forces acting on it one from the gravity and one from the jet of air.

Is it correct to say there are no forces acting on that ball?

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.. .

.

Caedes

Oy vey; this is still going on?

Yes, we are having fun!

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.. .

.

Caedes

Do we agree I have just demonstrated the gravitational field of a hollow shell vanish at all interior points of the shell? Do we agree this mean the acceleration of an object inside the shell will be zero?

I have now done the math in the newtonian case.

This is a newtonian problem yes, The gravitational field doesn't vanish at all interior points, no. Yes the acceleration of an object inside the shell would be zero.

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.. .

.

Caedes

Caedes: As I wrote in my previous posts, it depends on the definition of when there is gravity. In my mind defining no gravity as meaning "the gravitational field is zero" is a reasonable definition, however you are free to disagree and say the phrase "no gravity" by definition refer to one being infinitely far away from any mass.

That isn't what shell theorem states, it is saying the forces on one side of the mass are balanced by the forces on the other. If you look at the equations on the link it shows the gravity force (G as per usual) all the way down the page, the fact that the equations sum to zero doesn't mean there is no gravity. I would agree that it is a small distinction but the equations are only telling you what the net effect of gravity is on a mass. Those equations are not telling you that gravity is zero just that there is no net effect of the gravity on your mass.

You are a clever person Bohm and I normally agree with your posts, I just think you have your definitions on this a little mixed up.

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.. .

.

Caedes

Winner winner, chicken dinner.

Excellent, you cooking?!

30

Article: If God saved an American doctor with Ebola, why did he let 1,200 Africans die?

by AndersonsInfo in

jw
friends

http://www.theguardian.com/lifeandstyle/2014/aug/25/ebola-africans-die-god-american-doctorif god saved an american doctor with ebola, why did he let 1,200 africans die?it must be lovely for people such as dr kent brantly to be so sure of god's existence.

for the rest of us, it's not so easy.

ebola survivor dr kent brantly.

Caedes

I think there is much, much more to this Ebola virus than they are telling us, like where it came from and why. Remains to be seen.

http://www.who.int/mediacentre/factsheets/fs103/en/

Jeanette,

There you go more than you could ever wish to know about the ebola virus. Wikipedia has a good article as well telling you where it came from and why.

http://en.wikipedia.org/wiki/Ebola_virus_disease

If there is anything else you wish to know please do ask.

Thanks

THEY

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.. .

.

Caedes

http://hyperphysics.phy-astr.gsu.edu/hbase/mechanics/sphshell2.html

The maths on that link is fairly straightforward and usefully it diagrammatically shows why your net force is zero. It isn't because there is no gravity it's because the forces are balanced.

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.. .

.

Caedes

Bohm,

I would say that the question of whether there is no gravity or it being cancelled out is at the outer edges of my knowledge. The reason I would tend to go with it being cancelled is because I am looking at it from an engineering problem point of view. Since gravity acts as if from the point centre of the mass then at a delta distance away from that centre there would be some very small gravitational force. This is because as per the shell theorem that mass beyond the radius of your test dummy does not act upon it. In other words if your test dummy was halfway to the centre of the earth all of the earth's mass that sits above that radius has no net effect on it.

On that point I would agree with Viviane that it is merely that your acceleration is zero. It would seem to me to be a fairly meaningless distinction from a practical point of view however since it is a single point in space.

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.. .

.

Caedes

Because of any friction, the almost weightless floater would start falling from lower and lower heights from the center, would be moving slower and slower, come to a standstill or hangstill at the center, ceased to be accelerated, for there is no gravitational pull in either direction at the center of such an ideal sphere.

Prologos,

Not at all, as I have said previously your acceleration would be zero, however your velocity would be at it's maximum at the centre.