Matter, Space, Energy & Time

[Speakpigeon]

How do scientists define matter? Energie? Space? Time?

Dictionaries give the ordinary definitions. Interesting enough but perhaps not quite the thing:

Matter
1. That which occupies space and has mass; physical substance.

Energy
4. Physics
a. The capacity of a physical system to do work.
b. A form, amount, or level of this capacity: "a searing beam of 30 trillion protons, with energies up to 50 million electron-volts" (Science News).

Space
1. the unlimited three- dimensional realm or expanse in which all material objects are located and all events occur.

Time
1. A non-spatial continuum in which events occur in apparently irreversible succession from the past through the present to the future.

I understand there's a close relation between matter and energy and between space and time. Is there any such relation between matter and energy on the one hand and space-time on the other?

Is there anything that's regarded by scientists as the one really fundamental thing in nature?

And if not, do scientists expect all these things to eventually come down to just one unique thing?


And, please, no metaphysics. Keep to a strictly empirical and scientific perspective on these questions. And if all there is to it is E = mc², so be it.
EB

 

[fast]

We are told there are three states of water: solid, liquid, gas

Maybe matter and energy are two states of stuff

Kinda like, matter is to energy like solid is to gas.

 

[skepticalbip]

We are told there are three states of water: solid, liquid, gas

Maybe matter and energy are two states of stuff

Kinda like, matter is to energy like solid is to gas.

Actually mass is convertible to energy and energy is convertible to mass M=E/c^2 and E=M c^2.

In a proton-proton collision, the kinetic energy of the protons are converted into a spray of particles.
In a nuclear explosion, the mass loss in fission is converted to the energy of the blast.

Any physics calculations of these events must balance the energy-mass before and after the event.

 

[repoman]

I think that protons and neutrons being so much more massive than their constituent quarks is pretty cool.

 

[steve_bank]

1. Matter is everything that exists.

2. Energy is defined as the capacity to do work, and work is defined as force times distance, Newtons x Meters.. Force is nass time acceleartion, Nentos = Kilograms x dv/dt wher v = velocity in merers/second and t seconds. Units for heat, work, and energy is the Joule.

Energy is derived from relative states of matter. Water at the top of a waterfall has gravitational energy. Falling water can turn a turbine doing work. Gravitational energy converted to electrical energy.

You can get a bucked of matter, you can not get a bucket of energy. Scifi usage of the term energy is generally fiction. Energy is not an indepentdent reality.

Scroll down to energy and work. Energy is a definition based on primary units of killograms, meters, and seconds. As is all of science.

https://physics.nist.gov/cuu/Units/units.html

 

[steve_bank]

We are told there are three states of water: solid, liquid, gas

Maybe matter and energy are two states of stuff

Kinda like, matter is to energy like solid is to gas.

Actually mass is convertible to energy and energy is convertible to mass M=E/c^2 and E=M c^2.

In a proton-proton collision, the kinetic energy of the protons are converted into a spray of particles.
In a nuclear explosion, the mass loss in fission is converted to the energy of the blast.

Any physics calculations of these events must balance the energy-mass before and after the event.

Matter and energy can not be created or destroyed. Energy can be used to change the form of matter. Mass and energy are units of measure.

 

[steve_bank]

Joule's paddle wheel experiment was one of the most important in science. It demonstrated a quantifiable relationship between gravitaional energy, work, and heat. A falling weight turned a paddle wheel in a tank iof water raising the water temp.

Energy was trhe initial gravitaional energy of the weight, work was force times distance - gravity and mass and gravitational acceleration. Work also turning the paddle against the water. And finaly the temperaure rise in the water as trasfer of energy.E in joules represents enegy, heat, work, and friction losses.

E gravity_potential = Efrictio_in_system_losses + Erope_tension_losses + Eheat_added_to_water...Conservation of energy, energy can not be created or destroyed.

http://www.eoht.info/page/Paddle+wheel+experiment

http://www.eoht.info/page/Paddle+wheel+experiment

 

[steve_bank]

I fwe avoid metaphysics, space is defined as distance in meters, time is defined as duration in seconds.

See base units on the linked NIST site for how they are defined. Outside of that you are off to the metaphysical races.

 

[skepticalbip]

We are told there are three states of water: solid, liquid, gas

Maybe matter and energy are two states of stuff

Kinda like, matter is to energy like solid is to gas.

Actually mass is convertible to energy and energy is convertible to mass M=E/c^2 and E=M c^2.

In a proton-proton collision, the kinetic energy of the protons are converted into a spray of particles.
In a nuclear explosion, the mass loss in fission is converted to the energy of the blast.

Any physics calculations of these events must balance the energy-mass before and after the event.

Matter and energy can not be created or destroyed. Energy can be used to change the form of matter. Mass and energy are units of measure.

Mass and energy are not destroyed but can be converted to each other. Are you trying to say that nuclear weapons and nuclear power plants are a hoax? Are you saying that the work at CERN is a sham? If you don't think they are shams and hoaxes then have you ever tried to understand how they work?

 

[bilby]

How do scientists define matter? Energie? Space? Time?

Dictionaries give the ordinary definitions. Interesting enough but perhaps not quite the thing:

Space
1. the unlimited three- dimensional realm or expanse in which all material objects are located and all events occur.

Time
1. A non-spatial continuum in which events occur in apparently irreversible succession from the past through the present to the future.

I understand there's a close relation between matter and energy and between space and time. Is there any such relation between matter and energy on the one hand and space-time on the other?

Is there anything that's regarded by scientists as the one really fundamental thing in nature?

And if not, do scientists expect all these things to eventually come down to just one unique thing?


And, please, no metaphysics. Keep to a strictly empirical and scientific perspective on these questions. And if all there is to it is E = mc², so be it.
EB

E = mc² is the starting point, but far from 'all there is to it'.

Relativity describes the relationship between mass-energy and space-time. Energy implies mass (and vice versa), but don't forget the c² - c is a velocity, and velocity is about distance (space) and time. Relativity ties these four concepts together and allow us to understand how they interact. Mass-energy curves space-time, and objects trace out world lines that are geodesics (paths of least action in curved space-time) unless acted upon by a net external force.

Forces are due to fields (which can also be thought of as the exchange of particles), and the only important one of these above the molecular scale is electro-magnetism, which is mediated by particles called 'photons'. (The other two forces are the imaginatively named 'Strong' and 'Weak' forces; The Strong force (mediated by Gluons) holds atomic nucleii together, and the Weak force (mediated by W and Z bosons) control electron interactions such as Beta decay and K-capture).

And some of those interactions are really counterintuitive to those of us used to living with slow moving objects in a shallow gravity well. Objects with zero rest mass (eg photons and neutrinos) must travel at c in a vacuum, and do not experience time at all. Objects with sufficient mass to have an escape velocity of c (Black Holes) behave in very strange ways - so strange that many physicists and cosmologists thought that they were purely theoretical, until they actually found them.

Relativity accurately predicts everything big, in particular gravity. Quantum Mechanics accurately predicts everything small, in particular almost everything that's not gravity. Sadly, they contradict each other in some critical ways in extreme conditions, such as large amounts of mass in a very small space (eg at and before the Planck Epoch).

A LOT of effort is being expended on trying to find a unified theory that generates the same accurate predictions of both, and which might then make new predictions that can be relied upon where the two existing theories contradict each other. Unfortunately, the universe is under no obligation to be easy to understand. Quantum theories imply that gravity is a force, like the other three forces in the Standard Model. But relativity says that gravity is NOT a force; that it is instead the curvature of space-time caused by the presence of mass-energy.

Over the course of the last century or so, we have been able to show that a number of apparently competing theories were, in fact, different aspects of Quantum Mechanics. So Quantum Physicists are pretty confident that, having swallowed up all the other theories bar one, (by producing the same predictions as those theories where they matched observation, but better predictions where the old theories did not match observation) it is only a matter of time before they can swallow up Relativity as well, to produce a Grand Unified Theory of everything. Many Relativistic Physicists are similarly confident that, having avoided being swallowed up by QM for so long, the Quantum Physicists might never unify Gravitation with the other fundamental forces of nature.

The Standard Model allows us to boil down everything that exists into four (or maybe three, plus curvature of space-time by mass!) forces and seventeen particles (or fields). This can further be condensed to four fermions in three 'families' of increasing mass; Plus four 'spin 1' bosons, and the 'spin 0' Higgs, whose positive amplitude at its minimum energy allows other particles to have rest mass - the Higgs field tends to be non-zero in empty space, and other fields interact with it, slowing their associated particles below c in a vacuum, which implies rest-mass. The recent demonstration of the existence of the Higgs Field/Boson by the LHC may help with the incorporation of gravity into QM, as it at least provides a known mechanism for the existence of mass in the first place.

Of course, it's a lot more complicated than that - the above is a hugely simplified summary of a vast amount of knowledge, and as such is deeply flawed in may ways. But I have neither the knowledge, skills, nor time to write the many volumes of text and mathematics that would be needed for a more accurate description of what is known. Still, I hope the above is a touch more 'fleshed-out' than the mere statement that "all there is to it is E = mc²"; And I strongly recommend following the links I have included if you want more details about Relativity, the Standard Model, or the anticipated Grand Unified Theory - these links all point to the rather neat Physics Hypertextbook, which is an excellent resource IMO.


So, to summarize the summary:

I understand there's a close relation between matter and energy and between space and time. Is there any such relation between matter and energy on the one hand and space-time on the other?

Yes, Relativity.

Is there anything that's regarded by scientists as the one really fundamental thing in nature?

Not quite; The Standard Model of Particle Physics is close. But it needs some tweaks because it doesn't (yet) describe gravitation.

And if not, do scientists expect all these things to eventually come down to just one unique thing?

Most seem to. Certainly in Quantum Physics, many people expect that there will eventually be a Grand Unified Theory that incorporates both Gravity and the Standard Model.

 

[steve_bank]

Matter and energy can not be created or destroyed. Energy can be used to change the form of matter. Mass and energy are units of measure.

Mass and energy are not destroyed but can be converted to each other. Are you trying to say that nuclear weapons and nuclear power plants are a hoax? Are you saying that the work at CERN is a sham? If you don't think they are shams and hoaxes then have you ever tried to understand how they work?

E=MC^2 is about the atomic energy stored in matter, E being the same units as E=0.5MV^2. Atomic and Newtonian kinetic energy are both forms of energy stated in Joules. It is interesting to note that energy is always proportional to a magnitude squared, energy is always positive.

I'd have to look up the balace equations for an atomic explosion, chemistry and nuclear physics is not my thing. In general in an atomic explosion atomic energy is converted to thermal heat energy, electromagnetic energy, and motion of the particles released in the event. In any process there is what is called a continuity equation that descrbes all of the matter and energy before and aftrer an event. Conservation of mass and energy applies.

In any real process be it a nuclear reactor, an accelerator collider, a dishwasher, or baking a cake the energy and matter in, losses and matter i and energy in the system, and matter energy out must balance. No exceptions. That is why the Laws Of Thermodynamis are foundational.

Ohm's and Kirchoff's law in electric circuits are continuity equations expressing conservation of energy.

Everything in science and technology is an expression of LOT.

 

[skepticalbip]

Matter and energy can not be created or destroyed. Energy can be used to change the form of matter. Mass and energy are units of measure.

Mass and energy are not destroyed but can be converted to each other. Are you trying to say that nuclear weapons and nuclear power plants are a hoax? Are you saying that the work at CERN is a sham? If you don't think they are shams and hoaxes then have you ever tried to understand how they work?

E=MC^2 is about the atomic energy stored in matter,

Yes. It is "stored" as mass (the M in that equation). Split a U235 atom and the total mass of the fission byproducts will be less than the original mass of the U-235. But there is also photons released (energy or E) which accounts for the lost mass by M=E/c^2 and balances the mass energy equation from before to after the event. These photons released are the energy released in nuclear weapons and the energy that powers nuclear power plants.

Collide two protons at relativistic velocities and the sum of the resultant particles will have a greater mass than that of the two original protons. The extra mass comes from the kinetic energy of the protons in the collision. And again the mass energy equation is balanced from before to after the event.

 

[bilby]

Matter and energy can not be created or destroyed. Energy can be used to change the form of matter. Mass and energy are units of measure.

Mass and energy are not destroyed but can be converted to each other. Are you trying to say that nuclear weapons and nuclear power plants are a hoax? Are you saying that the work at CERN is a sham? If you don't think they are shams and hoaxes then have you ever tried to understand how they work?

E=MC^2 is about the atomic energy stored in matter, ...

Not just atomic energy. Energy and mass are interchangeable. As you begin to accelerate an object, the force applied to the system manifests mostly as acceleration (increased velocity) and only a tiny amount as increased mass, but as the velocity tends towards c, the proportion of energy added as mass increases, and so the required energy to accelerate also increases (as kinetic energy is proportional to mass, and to the square of velocity). That's why an object with a non-zero rest mass cannot travel at c; As you approach c, the relativistic mass tends to infinity, and so the force needed to get more acceleration (f = ma) also tends to infinity, and the additional acceleration due to any amount of applied force tends to zero.

The harder you push, the faster it goes, and the heavier it gets, and the harder you need to push, in order to get it to go any faster.

 

[steve_bank]

Give an equation which shows matter and energy are somehow interchanfeable.

In equations you substitute energy for energy. Joules do not equal kilograms. An eqhation must be dimensionaly correct in SI units.

In an inertial frame an atom at rest has an energy E=MC^2. In motion total energy of an atom is E= MC^2 + 0.5MV^2.

A rope is attached to a weight through a pulley. You lift the weight by pulling on the rope adding gravitaional potential energy to the weight, Did energy flow through your ams and the rope to the weight? Where is the energy? If you can not answer simply you do not understand energy.

Mass does not physically change, relativistic mass is relative to a frame.

 

[steve_bank]

E=MC^2 is about the atomic energy stored in matter,

Yes. It is "stored" as mass (the M in that equation). Split a U235 atom and the total mass of the fission byproducts will be less than the original mass of the U-235. But there is also photons released (energy or E) which accounts for the lost mass by M=E/c^2 and balances the mass energy equation from before to after the event. These photons released are the energy released in nuclear weapons and the energy that powers nuclear power plants.

Collide two protons at relativistic velocities and the sum of the resultant particles will have a greater mass than that of the two original protons. The extra mass comes from the kinetic energy of the protons in the collision. And again the mass energy equation is balanced from before to after the event.

Thank you, simple and complete. When I learned to think in terms of matter, energy, and conservation learning new seemengly complicated science became easier.

 

[skepticalbip]

Give an equation which shows matter and energy are somehow interchanfeable.

.

E=M c^2
M=E/c^2

In these equations E is energy and M is mass and, of course, c is the speed of light.

Those equations certainly have proven to be damned accurate in all instances where they have been employed.

 

[steve_bank]

Give an equation which shows matter and energy are somehow interchanfeable.

.

E=M c^2
M=E/c^2

In these equations E is energy and M is mass.

Those equations certainly have proven to be damned accurate in all instances where they have been employed.

Mass and energy have different dimensions, you can not equate E to M in the equation. In atomic physics you can substitute E/c^2 for M, that does not mean M=E, there is the C^2 term.

 

[bilby]

Give an equation which shows matter and energy are somehow interchanfeable.

.

E=M c^2
M=E/c^2

In these equations E is energy and M is mass.

Those equations certainly have proven to be damned accurate in all instances where they have been employed.

Mass and energy have different dimensions, you can not equate E to M in the equation. In atomic physics you can substitute E/c^2 for M, that does not mean M=E, there is the C^2 term.

If only c² were a constant in every reference frame. Oh, wait, it is. So they are interchangeable.

And of course, they can be equated; That's why it's called an 'equation'. And of course they are equivalent, hence the use of the 'equals' sign.

Algebra applies to units and dimensions just as much as to numbers; The units and the numbers for mass and energy are related by the universally constant value of c² = 8.98755179 × 10¹⁶ m².s^-2, and this makes them interchangeable, just as much as kg = g x 1000 makes kilograms interchangeable with grams.

Lots of people don't think that dimensions or units should be included as a part of calculations; They calculate using dimensionless numbers, then fill the units and dimensions in at the end by rote. But despite (usually) giving the correct answer, that methodology is wrong. Algebraic equations express the equivalence of the entirety of the expression on either side of the equals sign.

 

[Random Person]

In the first instance you are multiplying the speed of light squared and in the second it is being divided by the speed of light squared.

Both equations are correct but E doesn't equal M.

 

[bilby]

Energy and mass are interchangeable (with a factor of c²), which is why particle physicists tend to talk about masses in electron volts. The eV is a unit of energy (equal to 1 joule per coulomb, multiplied by the charge on the electron in coulombs). A proton has a rest-mass of 938.27231MeV (the 'divided by c squared' never changes, so it is simply assumed).