unifying gravity and electromagnetism

[dafydd]

The only things I can see wrong with that are:
1. I don't know what "pick up" means when you're weightless. (unless we are talking about something like a pen)
2. Ditto for "balance on his finger"
3. The astronaut doesn't have anything to push against, except the space shuttle itself, so if he tries to move it around, he'll be moved too.

So... on second thought I guess i see your point. But I don't quite see how it relates to weightless not meaning weightless. Of course, weightless doesn't mean "inertia-less". (see highlighted bit, I'm just saying I don't quite understand your choice of words there)

Not my words. I was repeating what others have said to me. One of the others was a lady who thought that there were rooms on Earth where you could switch off gravity. It turned out that she had seen footage taken inside a vomit comet. I was using the story as an example of how some people know nothing of physics.

 

[dafydd]

<SNIP>

The mass remains the same- that's what I also believe.

Edited, breach of rule 0, rule 12.

Replying to this modbox in thread will be off topic  Posted By: Locknar

Then I have no idea what your point is.

 

[MattusMaximus]

Altough mass is expressed in kg, we should not forget that this is an inertial figure relative to earth at sea level... In other words, IMO, mass should only be considered as sort of inercial reference.

I think you are confusing mass with fictitious forces observed in accelerated frames of reference. Mass isn't the same thing as force, so your comparison makes no sense.

 

[Bodhi Dharma Zen]

I think you are confusing mass with fictitious forces observed in accelerated frames of reference. Mass isn't the same thing as force, so your comparison makes no sense.

Care to explain more? 9.8m/s is an accelerated frame of reference, for convenience, we use it as a unit (like astronomical units for instance), but that doesn't change the fact that mass can be viewed as an inertial reference. Oh well, maybe is just semantics.

 

[MattusMaximus]

Care to explain more? 9.8m/s is an accelerated frame of reference, for convenience, we use it as a unit (like astronomical units for instance), but that doesn't change the fact that mass can be viewed as an inertial reference. Oh well, maybe is just semantics.

First of all, your units are wrong. Acceleration is measured in m/sec², not m/sec (that's velocity); so the acceleration due to gravity at the Earth's surface is 9.8 m/sec². But what you're saying still doesn't make sense regarding frames of reference, because if you look at the Earth's gravitational field as just another reference frame (as Einstein did when formulating GR) then it is an accelerated frame. Accelerated frames are, by definition, not inertial frames of reference.

So it is much more than semantics. If you don't use the correct language and terminology you will get a lot of things wrong.

 

[MRC_Hans]

He's saying this:

Mass is constant, but when you use a scale to measure the mass of an object on the earth, and it tells you: "the mass of that object is 60 kg", if you then took both the object and the scale to the moon, and made the same measurement, the scale would read "10 kg". Of course, that's because what the scale really measures is the weight.

Yeh, I realize what he is saying. However, it is wrong. The scale is not affected by gravity. Either it measures force, in which case it will correctly show that the force (=weight) on the moon is lower, or it is a different construction, which measures mass, in which case it will correctly show that the mass is the same.

Similarly, if you take a clock on the earth, and an identical clock on the moon, and sync them, you'll find that they don't run at the same rate. But in the former case we still say, "mass is constant", whereas we are saying that in the latter case this shows that time is not constant.

And again he says that the clock is affected by gravity, but this is wrong (assuming this is not some archaic construction, which might indeed be affected by gravity). The clock correctly measures local time, but the progress of time has changed.

As I said, the difference is that we can make a measurement of mass that will be unaffected by gravity. But there is no conceivable clock for which that is the case.

Agreed.

Also, drgsrinivas claims that we only observe the speed of light as constant because time changes, but this is also provably false, because we can observe that light coming from a moving object has constant speed, in spite of the fact that we are not experiencing dime dilation. Also, from a speeding object (Earth speeding through space), light beamed forwards and backwards is observed to move at the same speed (c), but obviously time dilation can not account for both.

Hans

 

[Cuddles]

It's not just a matter of clocks running slow...everything runs slow, because clocks are simply an arbitrarily defined subset of physical processes. There's nothing special about turning a physical process into a clock that makes the physical process act differently.

Yeah, I think this lies at the heart of the misunderstanding - drgsrinivas seems to think that time is a local property of an object. Just as an object has a certain mass, it also has a certain time. The weight of an object can change, but we explain that by local variations acting on an unchanging mass. So he thinks that similarly, measuring different times must also be local variations acting on a similar unchanging property.

Of course, the point he's missing is that time is no such thing. Time is a dimension, it's not a property of an object at all. You don't measure the time of an object, you measure the rate at which that object experiences time passing. You could remove the object entirely and time would still behave in exactly the same way (although measuring it without using any objects may be a little tricky).

Basically what he's saying is that the sea is wet and a swimming pool is wet, therefore a piano is really G# and not middle C. The former makes sense because being wet is a property of the objects, but the latter is just nonsense because notes are not a local property of a piano. I piano can be wet, and it can have mass. But a piano cannot have time or G#, because that just doesn't make sense as a concept.

 

[Bodhi Dharma Zen]

But what you're saying still doesn't make sense regarding frames of reference, because if you look at the Earth's gravitational field as just another reference frame (as Einstein did when formulating GR) then it is an accelerated frame. Accelerated frames are, by definition, not inertial frames of reference.

Ok lets see, Yes, it is accelerated at 9.8m/s 2 (dont know how to put it right), and so, for convenience, is taken as the measuring unit. And I do believe it is matter of semantics, because I don't see why an accelerated frame ceases to be an inertial frame? It is a reference, as I said, for convenience, like Astronomical Units.

Care to explain it a bit more?

 

[bjornart]

Ok lets see, Yes, it is accelerated at 9.8m/s 2 (dont know how to put it right), and so, for convenience, is taken as the measuring unit. And I do believe it is matter of semantics, because I don't see why an accelerated frame ceases to be an inertial frame? It is a reference, as I said, for convenience, like Astronomical Units.

Care to explain it a bit more?

"A non-inertial reference frame is a frame of reference that is under acceleration." http://en.wikipedia.org/wiki/Non-inertial_frame

Inertial reference frames and accelerated reference frames are different by definition.

The unit g is a unit of acceleration, but so is m/s^2, km/(h*s) and furlongs/(fortnight*day), this is irrelevant to the fact that the laws that govern inertial frames and accelerated frames are different. (Although the differences can be ignored in most everyday calculations.)

 

[Bodhi Dharma Zen]

"A non-inertial reference frame is a frame of reference that is under acceleration." http://en.wikipedia.org/wiki/Non-inertial_frame

Inertial reference frames and accelerated reference frames are different by definition.

The unit g is a unit of acceleration, but so is m/s^2, km/(h*s) and furlongs/(fortnight*day), this is irrelevant to the fact that the laws that govern inertial frames and accelerated frames are different. (Although the differences can be ignored in most everyday calculations.)

Got it, thanks

 

[Tubbythin]

Like many here, you are blessed with ignorance and I don’t think I can drive that of you but I will try.

Ok... This could be fun.

If some mass weighs 6kg on earth and only 1kg on moon, we wouldn’t say that the mass is ‘shrunken’ and hence mass is a relative thing. We know that weighing machines get affected by gravity. It is nothing to do with accuracy of the machine.

No. if something weighs 6 kg on Earth and 1 kg on the moon then we would say it has definitely lost some mass in transportation. If we measure that an obect weighs 6 kg on Earth and 1 kg on the moon then we'd probably conclude that the mass measuring device does not function as desired in one of the environments.

Likewise, if a clock measures 60 seconds on earth, it may measure more seconds on moon for the same duration. It doesn’t mean that the time has actually dilated but it is due the fact the clock gets affected by gravity. One may introduce something like ‘timeness’ (analogous to ‘weight’) to account for the measured difference in time (analogous to mass).


When electromagnetic radiation can get affected by gravity, why not the atomic clocks?

So describe this method by which clocks get affected by gravity. Give a precise mathematical formalism to this effect and explicitly show how this leads to the same effects as observed in experiments that test special and general relativity.
If you can't do that then you have nothing.

Of course, it is not easy to convince people to get rid of the ‘deep rooted’ scientific beliefs (like the case with religious beliefs!)

Sure. You haven't taken the first and most important step, however. That is to provide some evidence that there is something wrong with the current paradigm and that you have a solution that can correct this whilst being consistent with all the observations that the original paradigm is consistent with. Until you do this you have nothing.

To quote again Stephen Hawking, whom I consider as my virtual teacher in cosmology,
“Any physical theory is provisional, in the sense that it is only a hypothesis: you can never prove it. No matter how many times the results of experiments agree with some theory, you can never be sure that the next time the result will not contradict the theory. On the other hand, you can disprove a theory by finding even a single observation that disagrees with the predictions of the theory.” (A Brief History of Time)

Uh-huh. Now show where the mainstream is in the wrong.

My thought experiment, whose predictions go against the notion of constant speed of light, is open to interpretation by anybody and needs only minimum sense of logic.

Your thought experiment was complete and utter garbage and highlighted that you don't have the slightest clue about relativity.

It shouldn’t make Einstein any less. I don’t dare to discredit this great personality.

How nice of you.

Though Einstein’s theory of general relativity proved Newton wrong, Newton’s theory still holds true in the vast majority of situations. Einstein’s theory helped us understand the universe better and helped us move forward in Science. But this wouldn’t have been possible without the Newton’s theory.

For once I agree.

If we insist that Einstein’s theory is the ultimate and nothing beyond to think, out of our love and attachment to this great personality, then science becomes a religion.

Nobody is insisting that. So that is a completely moot statement.

(After all this, don’t come and ask like a child “Did you mention all this on your original post?--- Yes or No?”)

I'm the one acting like a child?

 

[Tubbythin]

I can see the crowd overwhelmed by their ignorance

I did differentiate between the Mass and Weight. And also I proposed a similar distinction to be made between Time and ‘Timeness’.

You proposed it. Just because you proposed it doesn't mean your proposal is anything more than complete rubbish. And until you provide evidence that it isn't complete nonsense, don't be surprised if people assume it to be complete nonsense.

 

[MattusMaximus]

Still not seeing any math here...

 

[drgsrinivas]

wrong track

Well, yes, but the point I was getting to is that even clocks using physical processes that aren't affected directly by gravity are affected by time dilation. And even gravity-affected clocks can be affected by accelerated motion and/or speed.

My thought was that he seemed to think that clocks would slow down but that didn't mean anythig else did. My point was that you can base a clock on almost any physical pehnomena, including the same types of physical reactions that (for example) occur in our bodies, and they still show the time dialtion effect. If there's no physical process that isn't affected, then that means all physical processes are affected. And since the only meaningful way to determine time is to measure something physical, this means time slows.

We're on the same track, just targetting different mis-conceptions I think

Good argument but--

Any physical process including the mechanism of atomic clocks can ultimately be broken down to the level of fundamental particles that include the weird photons. Gravity affects even photons (but weirdly only their frequency and apparently not the velocity). So is my question- when these particles get affected by gravity why not the atomic clocks?

 

[drgsrinivas]

For once I agree.

That’s nice of you.
But, how come, without the evidence and the weird maths?
Any way, you have understood everything except the point!

 

[drgsrinivas]

Ahh, that is what you were trying to say. However, it is wrong. Time dilation due to speed is exponential, just like the formula e=mc². However the addition and subtraction of velocities of different moving entities is, of course, linear. For a pertinent example, the velocity of Earth around the galactical centre can amount to up to 10% of the speed of light, but the corresponding time dilation is far lower (about 1%)

Time dilation- exponential
Addition and substraction of velocities- linear

Fantastic explanation!!! Even if I agree with this silly arguement, what changes is only the magnitutde of time dilation.

Let me argue for you-

Relativistic addition of velocities always result in the same Speed of light ’C’


but the same weird theory also proposes (‘concludes’ in your words) time dilation to explain the constant speed of light.

You know, if you were to not shroud your statements in condescending remarks.

Hans

Pardon me but that is because Newton’s 3rd Law is in force. You know, it's not that easy to appreciate both sides of the coin.

 

[Tubbythin]

That’s nice of you.
But, how come, without the evidence and the weird maths?
Any way, you have understood everything except the point!

You didn't have a point for me to understand.

 

[Sideroxylon]

This all one big temper tantrum at the universe for being incomprehensible on a common sense level and at our best attempts at understanding requiring too much hard work to grasp while contradicting his wishful thinking.

 

[MRC_Hans]

Good argument but--

Any physical process including the mechanism of atomic clocks can ultimately be broken down to the level of fundamental particles that include the weird photons. Gravity affects even photons (but weirdly only their frequency and apparently not the velocity). So is my question- when these particles get affected by gravity why not the atomic clocks?

Because atomic clocks work from different principles. Your argument above is like saying: "Birds can fly, so why not pigs?"

Gravitational time dilation is not just the timepiece being affected by gravity, it is time itself that gets changed. We know this because we can observe it from the outside (among other things by the frequency of photons being changed, as you note).

Hans

 

[MRC_Hans]

Time dilation- exponential
Addition and substraction of velocities- linear

Fantastic explanation!!! Even if I agree with this silly arguement, what changes is only the magnitutde of time dilation.

No, it shows that the reason we observe relativistic effects on speed is NOT explained by time dilation.

Let me argue for you-

Relativistic addition of velocities always result in the same Speed of light ’C’

No, from a local reference frame velocities add linearly. The Large Hadron Collider at CERN accelerates particles to 99.9999991% of the speed of light. At times the accelerator moves through space with Earth at a speed of nearly 10% of the speed of light. So, we should think that some of the time those particles mover at 110% of the speed of light. They don't. However since the particles move in a circle, completing 11,245 rounds per second, they are alternatively adding and subtracting their speed form that of Earth. Obviously, time dilation can't account for this observation, since no matter what the particles 'perceive' our time doesn't change.

Pardon me but that is because Newton’s 3rd Law is in force. You know, it's not that easy to appreciate both sides of the coin.

Elucidate, please.

Hans