What’s with the Law of Conservation stating that matter can neither be destroyed nor created? Was Lavoisier really sure about this? To be honest, doesn’t it seem like he missed out something? If matter can’t be created, then…how did earth come about? Is he stating that the Earth is eternal?
Give me some explanation here. 
The Law of Conservation of matter states that there is no detectable change in the quantity of matter during an ordinary chemical reaction.
The Law of Conservation of energy states that energy may neither be created nor destroyed. Therefore the sum of all the energies in the system is a constant.
You can convert between the two, that is what drives an atomic bomb, but sum total in the universe, according to Einstein, is constant.
These laws were combined, along with several other properties of the universe, such as entropy, heat and absolute zero, into the three Laws of Thermodynamics:
The field of thermodynamics studies the behavior of energy flow in natural systems. From this study, a number of physical laws have been established. The laws of thermodynamics describe some of the fundamental truths of thermodynamics observed in our Universe. Understanding these laws is important to students of Physical Geography because many of the processes studied involve the flow of energy.
First Law of Thermodynamics
The first law of thermodynamics is often called the Law of Conservation of Energy. This law suggests that energy can be transferred from one system to another in many forms. However, it can not be created nor destroyed. Thus, the total amount of energy available in the Universe is constant. Einstein’s famous equation (written below) describes the relationship between energy and matter:
E = MC2
In the equation above, energy (E) is equal to matter (M) times the square of a constant ©. Einstein suggested that energy and matter are interchangeable. His equation also suggests that the quantity of energy and matter in the Universe is fixed.
Second Law of Thermodynamics
Heat can never pass spontaneously from a colder to a hotter body. As a result of this fact, natural processes that involve energy transfer must have one direction, and all natural processes are irreversible. This law also predicts that the entropy of an isolated system always increases with time. Entropy is the measure of the disorder or randomness of energy and matter in a system. Because of the second law of thermodynamics both energy and matter in the Universe are becoming less useful as time goes on. Perfect order in the Universe occurred the instance after the Big Bang when energy and matter and all of the forces of the Universe were unified.
Third Law of Thermodynamics
The third law of thermodynamics states that if all the thermal motion of molecules (kinetic energy) could be removed, a state called absolute zero would occur. Absolute zero results in a temperature of 0 Kelvin or -273.15 degrees Celsius.
Absolute Zero = 0 Kelvin = -273.15 degrees Celsius
The Universe will attain absolute zero when all energy and matter is randomly distributed across space. The current temperature of empty space in the Universe is about 2.7 Kelvins.
This was taken from:
Effectively true, but pure randomness can cause small temporary exceptions. To nitpick you’d have to say something like overall, heat tends to pass from hotter bodies to colder bodies.
The universe will attain maximum entropy when all energy and matter is randomly distributed. The actual temperature will be above absolute zero. And to take quantum physics into account, you have to redefine absolute zero as the lowest possible energy state, not zero energy.
There isn’t a law of conservation of matter is there? Mass yes, Energy yes, mometum, angular mometum, charge, hadrons, leptons, etc, etc. yes.
Or is the conservation of matter just an arcane phrasing for the conservation of mass, I don’t honestly know.
Matter can rearrange itself into different configurations of course, so no problem with the creation of the Earth.
Something that is often overlooked when discussing the laws of “classical” thermodynamics is that they were promulgated from observations of macroscopic systems at a time before atomic theory was complete:
Themodynamics does not require and does not address molecular or atomic structure.
As atomic theory was worked out, the basis for the classical laws was refined and described in molecular and atomic terms, much as Newtonian mechanics was supplanted by quantum mechanics.
Minor nitpick, but I remember reading that the prohibition of heat flowing from a colder body to a hotter one was the “Zeroth” law. The second law states that the entropy of the universe will always increase.
How does something like Hawking Radiation effect the net balance of the Universe? Normally virtual particles pop into and out of existence so the net balance should remain but if the virtual pair get split apart at the event horizon of a black hole then aren’t you adding to the net energy balance of the universe?
The Principle of Conservation of Matter was combined with The Principle of Conservation of Energy after Einstein published his famous E=MC[sup]2[/sup] formula.
No, because new particles are created at the cost of the black hole. Hence Hawking hypothesised the quantum evapouration of blackholes.
You have to include the black hole in your calculations as part of the universe.
If a lump of matter gets squeezed into a black hole, the black hole will radiate energy until it finally disappears.
That means all you have done is changed part of the total mass of the universe into energy.
Sci-fi worldbuilding at
http://www.orionsarm.com/main.html
mass = measurement of the quantity of matter
Can the mass inside of a black hole still really be considered a part of the Universe? Certainly it maintains a gravitational effect but beyond that the energy/mass inside of the black hole is lost to the Universe. You can never get it out.
As an aside does the ‘negative’ virtual particle that gets sucked into a black hole thoroughly cancel out whatever it meets? Matter/antimatter collisions produce energy so even in such an instance the universe’s balance sheet should remain the same. People speculate about ‘negative’ matter although no such thing has been seen. Is our ‘negative’ virtual particle essentially negative matter? Certainly it cannot produce energy when it collides with whatever inside the black hole since if it did the black hole would not evaporate via Hawking Radiation…you’d just be exchanging mass for energy.
Maybe I should clarify that I am talking about the virtual particle pairs in Hawking Radiation where the ‘negative’ particle falls into the black hole and the ‘positive’ particle escapes.
As one other aside shouldn’t the positive partical fall into the black hole as often as the negative particle thus stopping the evaporation of the black hole? That is, the black hole will lose some mass to the negative particle but be just as likely to gain the mass back with the positive particle.
If anyone thinks this or my last post deserve a thread of its own as it constitutes a hijack here just say so and I’ll repost.
The mass-energy of a black hole can indeed be recovered through Hawking radiation.
The question is whether the information of the things falling in is somehow preserved in the radiation – or indeed, whether quantum events actually destroy information.
That’s somewhat beyond the scope of these boards, though.