Empty Definition and 268 Threads

need help, VERY CHALLENGING a hemispherical tank of radius 6 meters, is posiitoned so that its base is circular. how much work is required to empty the tank? liquid density is 100 kg/ m^3

From what I understand, empty space has a temperature of 2.7 degrees K? And that empty space still gives off micro-wave radiation from the big bang? Can someone help me visualize this? For me, the idea of empty space giving off radiation and having a temperature that isn't absolute zero is...

Recently i read: "atoms turn out to be 99.99999999% empty space" (source: http://www.futurehi.net/docs/Reality_Consciousness.html ) Is this correct? Does a more accurate measurement of the percentage of empty space in an atom exist?

A tank in the shape of an inverted right circular cone has height 8 meters and radius 6 meters. It is filled with 7 meters of hot chocolate. Find the work required to empty the tank by pumping the hot chocolate over the top of the tank. Note: the density of hot chocolate is 1510kg/m^3 m =...

In reviewing explanations on evaporating Black Holes using Hawking Radiation, based on how the black hole might treat Quantum “Vacuum particle pairs”. Although direct observation of Black Hole radiation has not been confirmed it implied that “Antiparticle – Particle creation, and self...

Do I understand correctly that the universe, x, is empty just in case [\exists x (Px)] is false and [\forall x (Px)] is true? Is there anything interesting about empty universes? I don't have any problems with them yet, but I'm not sure how to think about them. That is, they seem to be lacking...

I was given this problem to think about from my professor. It's not for any class. It went something like this: Imagine there is some magnetic field in empty space (tightly-packed lines curling around in a circle) at t=0. What happens to the field as t -> infinity. I figured Maxwell's...

The question is: Suppose W and X are subspaces of R^8. Show that if dimW=3, dimX=5, and W+X = R^8, then W \cap X = \{0\}. I can see this is obvious iff W and X are disjoint sets. If we add members of W to X in the usual way, and we get the new set W+X whose dimension is now 8 (given), then...

Following Hubble's discovery of the expanding universe, George Gamow postulated that the universe began as a big bang & calculated the temperature of empty space to be around 3 degrees Kelvin. In the early 60's this temperature was confirmed. We now know that rate of expansion is...

When I took a math foundations class we only did naive set theory and took as an axiom that the empty set is a member of every set. The book had formal set theory and thus listed the ZFC axioms. One of them was that the empty set exists and that it was a member of every set. I've looked at a...

http://www.nature.com/nsu/040126/040126-19.html I thought this was interesting:

I apologize that I don't know how to make the math equations. Alright it's going to be kind of complicated trying to describe this in words, but I'll do my best. There is a tank shaped like a right cylinder on it's side. The length of the tank (or height of the cylinder) is 6m, and the radius...

It is very important to define a fundamental concept like set before we use it. The set concept can be useful iff there is clear separation between two basic concepts, which are: container and content. Before we are going to check the ratio between these concepts, we first have to...

I suppose this has been asked before, but I am somewhat new to this forum. Beyond our known physical universe, there is a region of "empty space" Fine. And if I were on the "edge" of our observable physical universe, and I traveled faster than C away from it, I suppose I would eventually...

Is gravity being the place that is empty?

I have just recently read a book entitled THE HOLOGRAPHIC UNIVERSE in which it is suggested that what we now call empty space is only called empty because we are like fish that cannot see the water they swim through. Is there a reason to consider that any area of the universe is empty?

For the past few thousand years or so, the philosophy of space has occupied a lot of time among philosophers. There is really no argument as to the traditional definition of "space" as it usually relates to volume, being length width and breadth. But the big debate has typically been over the...

If a spaceship throws a boomerang in the vacuum of the space but with some gravity from earth. Will it have the same trayectory than if you throw a stone of equal mass than the boomerang with equal force? thanks