a question on mass/matter

[theseeker189]

I was just doing some digging thought id share this with you, obviously I don't know my physics well.
Here's a link to what I was reading with someone trying to find a simple answer, once again "science" has overwhelmed this question.

http://www.physicsforums.com/showthread.php?s=f3c26e192661f3a6e94404b87cfb4ef2&t=333642&page=2

So take I was in space what would my mass be? Ever thing that has matter has mass? It sounds to me these people are saying you need gravity to have a mass? Or do I need to change mass for matter to know how much of me there actually is?

I'm just curious,

[Buzi-Blu]

There is a trick question of what would the mass of an astronaut be on the Moon, if his mass on earth is 80kg? The answer is 80kg.

Mass is the amount of matter an object contains, whereas weight is the force produced from mass and gravity (or acceleration). It gets more complicated though because mass increases as velocity increases. Another way of thinking about mass is to consider inertia. This is independent of gravity so even in deep space a 1kg brick, for example, will give a certain resistance to being pushed.


It seems a simple enough concept, but is quite mysterious the closer you look at it. What really is mass? There's a famous puzzle (if it has a name I have forgotten it) about rotating a bucket of water. Now, this all has mass and as expected, if we spin it then the water takes up a curved surface. No surprise there. Now imagine spinning it at the North Pole - the spinning earth beneath makes no difference, it is not relative to the earth. Now remove the earth. Again, we would expect a curved surface, but what is it spinning relative to? To the distant stars? Are the not rotating? How does the water "know" what the fixed frame is and in particular, how can it communicate that so quickly?

A thought I had was how mass and time are related. Velocity is the change of position with respect to time. Just how that works I don't get because it seems a circular argument. A second is the time taken for object X to go from A to B, but the length AB is defined by the distance covered by X in 1 second - or have I got this wrong?

Momentum is velocity multiplied by mass, and it is momentum that is conserved during interactions. So, for example, a spinning gas cloud will spin faster (although that is angular momentum). But, what would we see if time changed, or everything was heavier, or space was smaller etc?

So, imagine a video where mass is doubled, say of a car hitting a wall. Momentum is therefore doubled, which is exactly like keeping mass equal but doubling velocity, therefore playing the video in slow motion can look exactly like normal speed with extra mass. Mass and the rate of time are directly related. I'm not going anywhere in particular with this, just rambling on.


This still doesn't help with answering what mass is. Does a single particle in an empty universe have mass? Does mass somehow come from the way everything is interconnected? More questions than answers I'm afraid but there is still so much unknown at the fundamental levels.

[theseeker189]

Mass I thought was simply the amount of matter in a object.

The notes on time are interesting though, now I know why Einstein's theory of relativity can allow time travel.

If a moving body is traveling at the speed of light in a infinite cylindrical universe,leaves point a, and travels to point a, they would be their as they where leaving(makes sense now to me)
Also at the speed of light everything travels as the speed it'd be going.ie a car passes you at 55 and your going 35, it seems it zips past, if you where traveling half the speed of light and you get past by something traveling at the speed of light it still seems its going the speed of light. I believe this is true because at those speeds are brain cannot process information fast enough.

[Buzi-Blu]

if you where traveling half the speed of light and you get past by something traveling at the speed of light it still seems its going the speed of light.

This is the heart of the original problem, just how is it possible for light to always be moving at the speed of light no matter how you (or the equipment measuring) are moving?

So, in 1887 the Michelson-Morley experiment set out to measure how light moves relative to the earth's motion. It did that by sending out two beams at right angles and looking for interference. Here's a nice little animation and explanation:

http://galileo.phys.virginia.edu/classes/109N/more_stuff/flashlets/mmexpt6.htm

This is the basis for relativity, and using imaginary experiments with fast trains and observers with touches, the principles of Special Relativity (ie the simple non-accelerating cases) can be determined. And all from this one simple observation.

[theseeker189]

That's a pretty neat little experiment, YouTube has some nice ones to give an idea too.
I've heard its impossible to travel at light speed, even if we could have something that would go that fast. I could totally understand this!

I found somewhere that they were teleporting objects around, de-materializing them the re-materializing them. Now if the human body can under go such chances it may be possible to travel at light speed?

I'll try to find where I read this about teleporting, I think it was in Europe somewhere, possibly France or Netherlands.

[Pons Asinorum]

So take I was in space what would my mass be? Ever thing that has matter has mass? It sounds to me these people are saying you need gravity to have a mass? Or do I need to change mass for matter to know how much of me there actually is?

These are great questions, Seeker. In science, I have found that the simpler the question -- like "what is mass" -- the more complex the answer.

I have not read Buzi-Blu replies yet, so he may have a better take on these questions that I do, but FWIW here is my shot:

"...in space what would my mass be?"

By definition, your mass would not change regardless of location -- (now for the complicated part, at least for me) provided your measurement was always in the same inertia frame.

WTH does that mean , in short, if you were not under acceleration (in other words, at a constant velocity relative to the speed of light (c)).

On Earth, the Moon or anywhere in the Solar System, the different velocities are so far small compared to c, that in effect your mass is the same. In fact, just about anywhere except say on the Starship Enterprise traveling near c, or inside the event horizon of a black hole accelerating toward c, your mass is going to be measurably the same.

So if asked this question on say, a high school exam, a teacher would likely accept "the same" as an answer. If on a university test, a professor would likely accept "depends on the relative velocities of the two locations."

--

"Ever thing that has matter has mass?"

Well this is a bit tricky for me, but here goes -- first yes, because matter is defined as having mass.

Now for the hard part: A massless particle can be said to have a "relativistic mass," which is not the same property as in matter. (Right or wrong, I think of it in terms of "ordinary mass" and "relativistic mass").

To fix that, science often defines (all) mass as the Total Energy divided by c or: E/c. Includes matter, for sure, but also includes energy. There are differences in how mass manifests itself, but this is the working definition.

Answer for the HS test: "yes"
Answer for the University test: "yes, to include relativistic mass for photons and where quanitativly m = E(total)/c"

--

"It sounds to me these people are saying you need gravity to have a mass?"

Every particle that has (ordinary) mass has gravity. That is, all matter has mass and all mass has a gravitational field.

But perhaps, more in the spirit of your question, if you were in deep space, would a ZERO-gravity environment affect your mass (lets say the gravitational fields from the various planets, stars and galaxies all cancel each other out, so your are truly weightless)?

No; as a quantity, mass is unaffected by a gravitational field. Remember m = E/c, which means mass is completely independent of gravity.

Weight would be affected becasue weight is a force-measure of mass and gravity. A little bit confusing in metrics:

• a kilogram is a measure of mass
• a newton is a measure of weight (aka, force)

So a 10 kilogram object on Earth would still have 10 kilograms of mass in deep space. Its weight would be 98 newtons and 0 newtons, respectively.

Answer for the HS test: "no"
Answer for the University test: "no, becasue for all mass: m = E/c and is independent of gravity."

--

Or do I need to change mass for matter to know how much of me there actually is?

If this is a question of how to measure in a ZERO gravity environment, then consider this:

Momentum (p) is a function of mass multiplied by velocity (p = mv).

If "Joe" is in space and knows his velocity (say by radar 10 meter/s), then he can ask his crewmates aboard his ship to cast off an 1 kg object toward him and they clock it as going 1 meter/s. After it strikes him, he can re-clock the velocities (say Joe as 9 and the object at 99, both traveling in the same direction).

Then this equation would allow him to calculate his mass, without a scale:

Joe's mv - object's mv = object's new mv + Joe's new mv

m (10 meter/s) - 1 kg (1 meter/s) = 1 kg (99 meters/s) + m(9 meters/s)

m (10 meter/s - 9 meters/s) = 1 kg (100 meters/s)
m (1 meters/s) = 100 kg meters/s
m = 100 kg

Piece of cake, provided Joe survives the strike.

And of course, on a planet, Joe can measure the acceleration constant and weigh himself on a scale:

On Earth, the acceleration constant is g = 9.8 (m/s^2), and say his scale indicated a weight of 1000 newtons --> 1000/9.8 = about 100 kg. This is from Force = ma or Weight = mg. (Actually, his scale would already be calibrated to account for g, so he would just read his mass directly as about 100 kg and call it his weight, even though technically, that is not proper usage of the terms. Pounds is a unit for force and therefore is a proper unit of weight. We may have horrid numbers for our units compared to the metric system, but at least we got that part right ).

Answer for the HS test: "no"
Answer for the University test: "no, besides (ordinary) mass is a property of matter; no mass = no matter."

--

Now imagine spinning it at the North Pole - the spinning earth beneath makes no difference, it is not relative to the earth. Now remove the earth. Again, we would expect a curved surface, but what is it spinning relative to? To the distant stars? Are the not rotating? How does the water "know" what the fixed frame is and in particular, how can it communicate that so quickly?

Geez Buzi-Blu, you got me spinning

How about this: The inertia frame does not change just becasue the Earth has been removed. The person is still spinning relative to where the surface of the Earth was at that time, as observed by someone in space (the inertia frame of an observer on the Earth changed, becasue the Earth was accelerated away).

A thought I had was how mass and time are related. Velocity is the change of position with respect to time. Just how that works I don't get because it seems a circular argument. A second is the time taken for object X to go from A to B, but the length AB is defined by the distance covered by X in 1 second - or have I got this wrong?

Not sure if this helps, but rather than calculate the average speed, take the instantaneous speed dx/dt (does time even exist when talking about instantaneous?). What is dt: -- I went a whole thread on that (http://www.legendarytimes.com/forum/viewtopic.php?f=9&t=3162 -- in short, centuries after calculus' introduction by Newton et al, what dt meant was hotly debated. It took centuries before that was answered by solely inductive means [and "it's something that approaches ZERO" is not the answer becasue that is not a definable quantity]). The answer had to do with set theory and the different degrees of infinity...just narly stuff.

Anyway...

This still doesn't help with answering what mass is.

The heart of all this...

Some choices:

• Mass is the amount of matter an object contains
• Mass is the resistance an object has to a change in velocity
• Mass is defined as total energy divided by c

My final answer is...

hmm....

[theseeker189]

Well that about sums it up! Answered my question. And yes, I was referring to a zero gravity of space.

After watching some videos on the subject it became more clear, gravity is a relativity weak force compared to other. This through leads me to something even better, Einstein's unification. It seems so right and I can feel where he was coming from, seems like string theory was just added to make things more complex!

[Buzi-Blu]

Was string theory not added just to wrap it up?

[Pons Asinorum]

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Heh! Good one Blu!

[theseeker189]

I believe its just gotten to the point where they are trying to make it work... I see it as though it should just fall into place, not saying that would be easy! Another theory is that we are just not to know everything of the universe. What where doing is just jumping the gun, we haven't traveled to another star yet, at least to the publics knowledge, so why try and travel to a new dimension when we can't even see it, let alone know if we could exist their.

Basically id like to understand our universe as a whole, all they've done is add equations to make it work and complicate it. Ive been working on my own theory, everything had to exist before it began, what if we, the universe, are just a creation of another being? This is possible even more so that string theory exist.

I'm not so convinced on the whole string theory. I believe in a higher being of intelligents, and then they to must have a higher intelligents, and so on. So than I guess, whence we've found our intelligents we might understand more, if they have found theirs and so on. It's a chain of command almost. But still at the end we are all puzzled as to where did it all come from, this answer will Never be known I believe! And even so, when it is known, we just create our own universe and the process starts again...

[Pons Asinorum]

I share your misgivings about string theory (now called M Theory). M-theory is a mathematically compelling theory that makes use of highly abstract concepts involving the symmetry of higher dimensions. As far as I know, there is no inductive proof supporting it, but a large number of physicists seem to have devoted their lives to understanding it -- so it probably will not be shelved anytime soon.

I believe its just gotten to the point where they are trying to make it work...

Agreed -- one might argue that this is the hallmark of any human endeavor of discovery.

Today, there are many physicists trained in M-theory, with many of them devoting their lives to it, so without question, there is a biased interest in proving M-theory correct.

One of M-theory's strengths is that it can be molded to explain all the phenomenon that we already "know" along with many that we do not. In short, M-theory keeps the Standard Model and explains many of its short comings.

Its weakness is the same thing: It can be molded to explain just about anything. M-theory is solely a mathematical construct (all the equations work or can be made to work), but there is no empirical proof to its validity.

Also, M-theory itself has different variants, which should be expected becasue in math there are often many different solutions to the same problem.

(To science's credit, it so far has not claimed M-theory as valid).

Another theory is that we are just not to know everything of the universe.

Yes, there are many that beleive this to be true. There truly might be forbidden knowledge, but it seems that almost every time such a claim is made, someone creates a light bulb, or airplane, or computer; or discovers the Laws of Relativity, or the atom, or cells; or someone breaks the sound barrier, travels to the Moon, or explores the bottom of the oceans...

Perhaps what is meant is that science cannot know everything about all creation, which is true by definition, IMO. Any claim in science, including physics, requires testability (at a minimum) -- either from repeated experiments or field observations. If some aspect of creation falls outside of our reality, then we may not be able to test it in a scientific manner. Such is called meta-physics.

Not sure if that is the same as "we can never know."

(Besides, did not our ancestral Mother partake from the Tree of Knowledge, in which case we should be good to go? ).

What where doing is just jumping the gun, we haven't traveled to another star yet, at least to the publics knowledge, so why try and travel to a new dimension when we can't even see it, let alone know if we could exist their.

Not 100% sure what you mean here Seeker, but the two terms may not be mutually exclusive: Perhaps star travel requires some sort of access to other dimensions.

Basically id like to understand our universe as a whole,...

Me too

...all they've done is add equations to make it work and complicate it.

Is this a dismissal of mathematics?

If I may object, two reasons:

First, math has not complicated our understanding the of the universe, but simplified it. Many of the mathematical proofs are incredibility complex; but often, usually, simplify to easy equations:

E = mc^2
F = ma

Even more complicated solutions like Schrödinger's Wave Solution is a model explaining probability (and models are by definition much more simple than a comprehensive description of reality).

Also, as the math gets more complicated for a given theory *cough, M-theory* that is usually a red flag that it is wrong (See Kepler for a clear example, oh, which reminds me: He came up with P^2 = a^3 to describe the orbits of worlds).

Second, math works .

I believe in a higher being of intelligents, and then they to must have a higher intelligents, and so on. So than I guess, whence we've found our intelligents we might understand more, if they have found theirs and so on. It's a chain of command almost. But still at the end we are all puzzled as to where did it all come from, this answer will Never be known I believe! And even so, when it is known, we just create our own universe and the process starts again...

Have you ever noticed how π is in just about all the physical relationships involving fundamental particles?

[theseeker189]

theseeker189 wrote: ...all they've done is add equations to make it work and complicate it.

Is this a dismissal of mathematics?

If I may object, two reasons:

First, math has not complicated our understanding the of the universe, but simplified it. Many of the mathematical proofs are incredibility complex; but often, usually, simplify to easy equations:

E = mc^2 F = ma

Even more complicated solutions like Schrödinger's Wave Solution is a model explaining probability (and models are by definition much more simple than a comprehensive description of reality).

Also, as the math gets more complicated for a given theory *cough, M-theory* that is usually a red flag that it is wrong (See Kepler for a clear example, oh, which reminds me: He came up with P^2 = a^3 to describe the orbits of worlds).



Second, math works .

I do take this back, it was my misunderstanding of advanced maths, after doing some research and such its much more easily understood.

I never really thought about pi, I'm sure as a student I will learn lots about that in my field of study(I'm only finished intro algebra, and need differential equations) plus haven't really touched the sciences yet!

Yes as much as I disagree with m-theory I do believe its important and something will come of it, but I don't believe it will be a a unification so to say, as it was intended for.

What where doing is just jumping the gun, we haven't traveled to another star yet, at least to the publics knowledge, so why try and travel to a new dimension when we can't even see it, let alone know if we could exist their.

Not 100% sure what you mean here Seeker, but the two terms may not be mutually exclusive: Perhaps star travel requires some sort of access to other dimensions.

I am looking at a hundred years into the future, or millennia. Space travel is possible, nothing is too far away. We need, if we want to keep our race preserved, send out at least one fleet of ships with a human population to find and colonize other worlds. With that, we will have open the doors to a new age of man. We will have contact with another presence, it may sound radical me saying this but to risk a "handfull" of human genes, of volunteers, to journey through space is just one more step in saying we actually except life in the universe.

I do think theirs other dimensions, but can we survive in them? Maybe this is why we cannot see them. Are dreams a dimension we can see but cannot survive in? I'm going to actually post a new thread about this as I had a "powerful" or profound dream id like to share as it relates to AA and dimensions.