How much ground counts as ground?

[lekh2003]

I recently saw this joke where somebody attaches a ground wire to a small cup of soil and it got me thinking. How much ground really makes something able to be a ground.

Would it be just a cup like the joke, a bucket, or would it require the actual Earth to ever be a real ground? Can you make an artificial "Earth" ground in that case?

 

[davenn]

I recently saw this joke where somebody attaches a ground wire to a small cup of soil and it got me thinking. How much ground really makes something able to be a ground.

Would it be just a cup like the joke, a bucket, or would it require the actual Earth to ever be a real ground? Can you make an artificial "Earth" ground in that case?

it's a joke ... a cup of dirt is no more a ground than your body is or your computer mouse for that matter

This is yet another thread that can get into a prolonged discussion of the differences in meaning of the word ground

In general the ground refers to the 0V (DC negative) rail of a battery or other DC supply

An Earth (ground) on the other hand ALWAYS refers to a real connection to THE EARTH. Usually in the form of an "earth rod" hammered into the Earth (ground) outside a building etc

A cup, bucket or any other container full of dirt is not an Earth Dave

 

[lekh2003]

An Earth (ground) on the other hand ALWAYS refers to a real connection to THE EARTH. Usually in the form of an "earth rod" hammered into the Earth (ground) outside a building etc

A cup, bucket or any other container full of dirt is not an Earth

I understand. My question was kind of stupid. I think my little question arose from a mix-up between "ground" and "the Earth" and "literal soil".

 

[russ_watters]

I recently saw this joke where somebody attaches a ground wire to a small cup of soil and it got me thinking. How much ground really makes something able to be a ground.

Would it be just a cup like the joke, a bucket, or would it require the actual Earth to ever be a real ground? Can you make an artificial "Earth" ground in that case?

Part of your confusion may stem from not realizing that the Earth/ground is not isolated. A cup of soil is isolated (...though I suppose you could make a circuit where it isn't...).

 

[lekh2003]

Part of your confusion may stem from not realizing that the Earth/ground is not isolated.

I think I see that now. Thanks for your help guys.

 

[hyunxu]

I understand. My question was kind of stupid. I think my little question arose from a mix-up between "ground" and "the Earth" and "literal soil".

You know that sometimes we use anyone of these terms to represent the same.Moreover soil is just from earth(crust).

 

[Bystander]

a real connection to THE EARTH. Usually in the form of an "earth rod" hammered into the Earth (ground) outside a building etc

"Therein lies the rub."

 

[Rive]

Would it be just a cup like the joke, a bucket, or would it require the actual Earth to ever be a real ground? Can you make an artificial "Earth" ground in that case?

Ground counts as the ultimate reference and current sink for the relevant application.

Any engineer can make a ground from even a nail.
Well, it might be an adequate ground for a button cell... So all you have to do is to put the cell on top of it, then point and say:
THOU SHALL BE THE GROUND FOR THIS LOWLY CELL!
And it is done.

 

[sophiecentaur]

Any engineer can make a ground from even a nail.

An RF Engineer wouldn't reckon he / she could do that. Many antenna designs are 'unbalanced', needing the currents flowing in the ground to produce the required pattern and to allow the right power to be radiated. For a ground that can be considered to be almost as good as an infinite copper sheet. you can often get away with a pair of crossed half wave horizontal wires. For other designs, you need a good copper Earth 'Mat', covering acres of ground to make up for the inadequacies of the Earth / soil / land itself.