[AntonioLao]

Originally Posted by GUILLE

What does "isolated system" and "non-isolated system" mean?

matter and energy cannot cross the system boundary of an isolated system. That means no matter or energy cross from inside to outside or vice versa.

[Guille]

Originally Posted by AntonioLao

matter and energy cannot cross the system boundary of an isolated system. That means no matter or energy cross from inside to outside or vice versa.

And, have we (humanity) ever met/created such a kind of system?

According to what you say, then any system that is in or is part of a system, then the system must not be isolated. A system is isolated if and only iff there is no system "bigger" than it. It must be the system of all system. Or, as we were talking about in another thread a few days ago, the set of all sets.

[AntonioLao]

Originally Posted by GUILLE

then any system that is in or is part of a system, then the system must not be isolated

A closed system allows energy to cross the system boundary, while its mass remains constant.

An open system allows mass and energy exiting and entering its boundary.

The idealized isolated system cannot exist unless we take the whole universe into consideration. But this cannot be verified unless we go outside of the universe or at the least locate at the system boundary.

[Steve Hanson]

Greybeard:

Steve, i don't think you got any closer to the target than Antonio, just a bit more recursive. after all 'if you don't know all things, you can't know one thing'

Meaning, I suppose, that until I know all things I can't be sure of any one thing? But if that's the case, it would seem that I must certainly then know all things or I couldn't make that statement. How is that less recursive?

Steve

[Brian Jakub]

Originally Posted by AntonioLao

Physical existence is temporary. Mental existence is everlasting. Although it is probable that the same mental reality will again merged back into the same physical reality in a billion billion years. However, within infinity, a billion billion years is practically zero as if there never was an existence of the physical reality.

Antonio,

How do you know this? Do you have a source?

Brian

Ps I should have read your later comments before I submitted this.

[Graybeard]

It just seemed to me that 'any' and 'all' mean the same thing in this context. Threrefore if you don't know any thing you can't know one thing. A play on words. no offence

By inductive reasoning, I can only go as far back to about 10 or 15 billions years, which is the supposed beginning of the universe, the big bang. The fundamental concepts are energy, force, length and time. The first three are changeable and can be transformed into each other but the last one, time is not, it can only move at a constant speed, say light speed, and time is embedded in the mind. Without the mind, time would not exist. But infinite time can exist therefore it is embedded in an infinite mind.

Is this a philosopical or theoretical explanation? I have read many of your threads and, if i haven't always understood them, I am willing to be suitably awestruck. But not this time. I know of no scientific basis for your reasoning here.

A I said, i enjoy many of your articles, i just don't think this one will lead to a TOE.

[Guille]

Originally Posted by AntonioLao

A closed system allows energy to cross the system boundary, while its mass remains constant.

An open system allows mass and energy exiting and entering its boundary.

The idealized isolated system cannot exist unless we take the whole universe into consideration. But this cannot be verified unless we go outside of the universe or at the least locate at the system boundary.

ok, thanks.

Now, does this system calification (closed-open) have anything to do with the system calification of periodc-aperiodic or stable-unstable? If so, what is the conection?

[AntonioLao]

Originally Posted by Brian Jakub

How do you know this? Do you have a source?

Originally Posted by Graybeard

I know of no scientific basis for your reasoning here.

To reply to both of your comments, I like to use the physical concept of an isolated system.

An isolated system is defined as one such that mass and energy do not enter or leave the system boundary.

A human being is an open system, mass and energy continuously entering and leaving.

An electron is a closed system since its mass remains a constant at low speed, while its energy changes as seen by its radiation frequency.

There is no way we can find out whether the universe itself is an open system, a closed system, or an isolated system? Therefore, it seems that the universe truth cannot be determined by human intellects.

However, a true isolated system must be time independent in order to conserve energy.

Originally Posted by GUILLE

Now, does this system calification (closed-open) have anything to do with the system calification of periodc-aperiodic or stable-unstable? If so, what is the conection?

In any system, whether open, closed or isolated, their control volumes are subjected to change in the distributions of mass density and energy density. These variational distributions are capable of harmonic analyses (periodic and aperiodic) as well as instability analyses due to thermal fluctuations.

[Guille]

Originally Posted by AntonioLao

In any system, whether open, closed or isolated, their control volumes are subjected to change in the distributions of mass density and energy density. These variational distributions are capable of harmonic analyses (periodic and aperiodic) as well as instability analyses due to thermal fluctuations.

what states that san analysis is instable or harmonic?

[Steve Hanson]

Greybeard:

It just seemed to me that 'any' and 'all' mean the same thing in this context. Threrefore if you don't know any thing you can't know one thing. A play on words. no offence

None taken and I agree with you. It's one of those "there are no absolutes" kind of conundrums.
Steve