J.C.MacSwell

'']Huh, I didn't know Venus was so far off, I thought it was pretty stable. But then it does have a retrograde rotation, so thats pretty wierd, I guess that kinda shows that its orbit isn't all that it should be.

It looks like Earth is used as the baseline. If Jupiter was used Venus would be closer than what is shown.

Question: How does the Sun's rotation line up?

Didn't I answer that tomorrow?

.

That's not what you said next week!

Perhaps if we knew what time fundamentally was' date=' we would know whether you can have a time warp.

 

As a small point, [b']if we live in "Space-Time", then wouldn't the deformation of space also deform time?[/b] I don't see how one could be effected, but not the other. If this is the case then "time" near a large mass would be different from "time" in intergalactic space.

 

If that were true, then it would show that "time" could indeed be changed. That being shown, perhaps there would be conditions where a "time warp" would be possible?

 

I'm not advocating the idea, just following the thought.

Don't you do this (immeasurably) every time you move (accelerate, decelerate, change direction)?

Sound doesn't have mass >_> It is a wave, so it can in theory go past light speed without screwing up anything

Does a "pendulum oscillation" have mass? (no?).

Could a pendulum swing at lightspeed in a strong enough gravitational field?

(no again?)

Yes' date=' but Bosons (as oppose to ferimons >_>) alone have the ability to violate certain classical newtonian physical laws such as occuping the same space at the same time with another boson. Correct me if I'm wrong, but doesn't Helium-4 only behave like a boson when chilled to almost absolute zero?

As regarding the medium for the sound wave to travel, I suggested the hydrogen under extreme heat and pressure. If the hyrdogen is hot enough, it should technically be able to transport sound waves faster than the light speed barrier >_>[/quote']

 

At high enough pressures sound can break the speed of light "according to Newtonian formulas" (which would not be valid in the same way F= ma does not hold at relativistic speeds).

 

Is this what you are getting at?

All I'm trying to ask is' date=' "What is Mass?".

 

As mass increases relative to velocity, due to kinetic energy increases, could it be that "rest mass" is [b']just a product of molecular kinetic energy[/b].

Not "just" but in part, the way I perceive it (which is probably wrong).

To be more precise (read wrong again) I see it as the rest mass of the object but not of the molecule.

Name the fixed point. Then explain why that's not arbitrarily defined' date=' and why it matters.

 

Timekeeping is generally done in the ECI, or earth-centered inertial frame, since that is most convenient for us. The rotation of the earth does not cause deviations, since the time dilation contribution from the motion is cancelled by the change in gravitational redshift that depends on the oblateness.[/quote']

 

Doesn't this mean that you "age" the same at the Poles as the equator?

 

Wouldn't you "age" faster at the center of the earth?

 

EDIT: Or assuming constant density of the Earth everything inside or on the surface would "age equally and someone at the top of (say) Everest, above this surface, would "age" faster?

What you heard was wrong. The Coriolis force is so small on the scale of a sink or basin that it cannot be responsible for forming any vortex. The reason water goes clockwise or anti-clockwise is due to the shape of the basin and any residual motion of the water; for containers with forced water, the rotation will be in the direction that the water is forced.

Won't it rotate counter-clockwise in the northern hemisphere all other things being equal? I live at 45 degrees latitude. I think the force is stronger here than, say, 5 degrees latitude. But is it also stronger here than at the North Pole?

My "completely still" 2 foot diameter basin of water would have more "potential" (insert correct terminology here for the differences in the velocity squareds) across my north/south 2 feet (relative to a polar axis rest frame) than in the other 2 cases.

In simpler terms, you would fall all the way to the center, then your momentum would carry you further until the the gravity wears away your momentum,[/b'] then you start going back to the center. This would be repeated until all you lost all your momentum, then you would stay at the center. Assuming the heat doesn't kill you.

Neglecting friction does gravity "wear away Your momentum"? (I think it does in some theories but not in others).

Isn't it just intensity?

If you dig a hole in the earth and jump there, the gravity pulls you down right? This is a hypothetic situation and I know it cant be duplicated but lets assume for a moment that you can dig a hole deep enough to go through the whole earth. You jump in that huge hole and the gravity will continue pulling you until you get to the center of the earth or what? Will you be suspended in the center or just continue falling until you get to the other side and then start falling again or what?

If the hole is between the poles and you neglect friction you will accelerate to the center starting at 0 velocity and maximum acceleration until you reach the center at maximum velocity and 0 acceleration. You would then reverse the process (acceleration wise) as you continue to the other pole and come to a stop (for an instant) before heading back.

Other "direct routes" would include a corriolis (sp?) like "force" (pseudo force)which will deflect you against the sides of the hole.

How would it affect Special Relativity if the speed of light was not a constant.

What if everything in the universe had a maximum relative velocity of C. This is because as an objects velocity increases' date=' so does its kinetic energy(which has mass), so does its total mass. This extra mass is relative to the observers velocity, so this explains the limit of relative velocity.

 

Light also is limited to C by the same rules.

 

But it would always appear the same to all observers because it is very close to C and when you do the reletivistic velocity additions it would appear the same.

 

Depending how close to C lightspeed is depends how many decimal places we have to measure light to. It could be that light travels at exactly this limiting velocity so we could never measure it any differently.[/quote']

 

Would your photon have have a very small rest mass and would it be possible in theory (the proposed theory) to catch up to it? Would there be a preferred rest frame?

Rat-tat! May I come in?

I sit in the room next-door “Quantum numbers – from sky to brain“ alone' date=' and I think of the same problems.

J.C.MacSwell wrote (02.02.2005 page ):

“If a photon is absorbed by an atom bumping up an electron isn't that an increase of matter (and therefore creation/transformation of energy into matter).”

In my opinion, he is right. But I would like to introduce some clarity.

For example, if to throw a ball onto a wall, from the wall the same ball will jump aside.

But if the photon will fall to a reflecting surface, it never will jump aside this surface.

At first this photon will be swallowed up by substance, then in substance there will be some transformations of the absorbed energy and only then from substance will fly out, so-called, «the reflected photon». Actually it is absolutely other photon. First, because the rotation of polarization in it will be opposite.

I want to pay your attention to the fact of 180-degree turn of rotation of polarization. As photons have no rest mass, they cannot act on substance the same as flying particles-balls. But in fact, the tails of comets deviate under action of solar light. So, it is necessary to search for replacement for rest mass in any other observable physical phenomenon, for example, in turning of an axis of rotation of energy.

One more incontestable fact of that rotating energy shows the properties similar to inert mass, shows behaviour of an axis of a gyroscope at attempt to change its direction.[/quote']

 

 

Picture a model of a spinning spring sent toward the wall. As it hits it digs in in a balanced way (say at two points about the central axis of spin) so that the spin cannot create a translational force vector other than to reverse its spin direction while imparting an equal and opposite spin to the wall at that point (locally). There will then remain the translational momentum/energy which will reflect in the usual way.

 

Just an analogy of course.

'']Also, if it was shot out below the water's surface the water would provide thrust directly forward. If it was shooting out of the water some of the thrust would be directed downwards.

Good point. As a minimum you would lose the "head" height of the jet trajectory (or exit) above the waterline. This would also add to the displacement (effective weight) of the craft unless the jet was redirected downward which would of course lose even more forward thrust.

its a particle, a physical thing, but it isnt matter? O.o

I think that's right.

In another thread I claimed a photon absorbed by an atom added/created matter to the atom but was convinced that strictly speaking (particle physics definition) that was incorrect. That portion of the energy did not represent matter even though you have a mass increase.

Whay do you think it matters?

Assuming all other things being more or less equal (diameter of jet etc.):

Below the waterline the surrounding water would provide more back pressure than the air above and therefore more thrust for the same power.

Because you would be effectively propelling more mass aftward (relative to the body of water or freestream) you would be imparting more momentum for the same power. (the exit velocity would actually be slower). So more of the energy would go to the craft and less to the jet.

Hope this makes sense.

Here's a possible method for faster than light communication:

 

Imagine two star systems (A and B) separated by a distance of 10 light years' date=' with a laser beam splitter exactly half-way between them. The laser beam splitter creates two entangled beams of laser light (A and B), each headed toward one of the two star systems.

 

After 5 years, the entangled laser beams reach the two star systems. At each star system is a receiver for the entangled laser beams consisting of a double-slit detector. If the two entangled beams arrive at each star system undisturbed, they will both create an interference pattern on their respective double-slit detector. This is because the probabilistic wave function for the entangled beams has not collapsed.

 

If laser beam A is disturbed (i.e. observed) just before reaching its double-slit detector, then the wave function for that beam collapses, as does the wave function for laser beam B just before it reaches its detector. This happens instantaneously across the 10 light year distance. The consequence of this is that laser beam B will NOT create an interference pattern at its double-slit detector.

 

It’s not hard to imagine that one can create a pattern of disturbance on laser beam A that can be translated instantaneously to the detector of laser beam B simply by observing whether there is an interference pattern or not. If the beam is continuous you can send a message just by encoding binary over short time period "frames". Interference pattern during the frame = 0. No interference = 1. From there all the complexity of digital communication protocols can be layered on top of this simple transport mechanism. In this sense, faster-than-light communication can be achieved.

 

Follow this link for a more in-depth discussion and implications for space exploration:

 

http://www.seti.org.au/spacecom/quantumcom.html[/quote']

 

The way I understand it:

 

If you observe a photon before it reaches the two slits, so that it could then enter either slit an interference pattern should still result.

In 3 slit experiments with a detector at one slit you should see a combination of no interference detections at that slit and interference otherwise between the remaining 2 slits.

 

So I don't see the collapse of the wave function with respect to interference as you have just described.

 

Please correct me if I am wrong.

 

I am not convinced that a message could not be sent FTL on a statistical basis. ( By altering the pattern from a random distribution over a number of tests on polarization for example) but it would sure change our perception of SR (or we could send messages into the past by prior arrangements of Code)

 

Sorry if that was vague.

I have always heard light discribed as being both energy and matter. if its matter' date=' it has to have mass. but according to E=MC^2, nothing with mass can reach the speed of light. so how can light reach light speed?

 

my understanding of this stuff is limited, so sorry if im missing something important.[/quote']

 

It can be considered a massless particle, but I don't think it technically can be considered matter.

I have a question about jet boats or personal water craft or jetskis or what ever you like to call them. It concerns the water jet propulsion unit in the back of the boat from which water exits as a jet stream and moves the boat forward. One of Newton’s laws at work here I believe. My question is: With an equal amount of power supplied to the system, forget about drag etc, is it better to have the water jet propulsion unit above the surface of the water or below it? Another way to put this is, do you get more measurable thrust, with the same amount of power applied, with the jet above the water surface or below the water surface?

Below.

an electrical current is a flow of charge or flow of electrons (same thing)

A stream of Beta radiation would fit that description. Would that be considered electricity?

How about a stream of alpha particles? That would also be a flow of charge although obviously not electrons.

If the streams above were deflected what differences would there be in the resulting Electromagnetic radiations?

Any "theoretical" upper limit on EM radiation. (seriously)

Could a "Rogue Wave" single photon come and wipe us out while we are carefully scanning the heavens for threatening asteroids?

I think this belongs in one of the mechanics threads' date=' and I'm pretty sure it fits here, but feel free to move it.

 

Anyways, I know that things like radio waves, light, and microwaves all fit under the Electromagnetism category. I'm curious to know what fits under the same category, so anyone interested in making/contributing to a list would be welcomed. Also, if someone could give me a basic reason why these fit under the same category, that'd be nice. I'll try my best to understand it.

 

Plus, are there ways to convert between these forms? Can you, for example, convert radio waves to visible light? Or could you possibly piggyback these things, like by (ignore practical uses, just can this be done) putting light waves on with the radio waves in order to make the waves visible?

 

I don't know where I'm headed with this, and I don't know that anyone wants to find out, but it always is nice to know [/quote']

 

If you get in a rocket and accelerate away from x-rays at some point they become visible light. Similarly for radio waves if you accelerate toward them.

Try this thought experiment.[/b']?

No question in my mind that in this thought experiment the clock that went further will be "younger", primarily due to the due to the SR effect. The GR effects could be symmetrical.

I do wonder: What is the "BEST" experimental evidence to support this. All evidence I have seen has a major GR component chomping into any margin of error.

It is impossible to get any results on SR without being exposed to some GR effects. The best we can hope for is to make them symmetrical (with respect to what though, time or distance etc.) or to factor them out based on theory.

It is also impossible to make them perfectly symmetrical or you would be duplicating the same test. No comparison could be made.

Apologies if any of that does not make sense.

You are adding mass in these scenarios' date=' but not rest mass. AFAIK rest mass of an atom assumes ground state. Excitaton at some level includes KE of particles, and as the bouncing rubber balls show, that's becoming absurd by the time you reach macroscopic systems.

 

Mass is a property of matter, but is not a synonym for matter. Matter is something that has mass and takes up space. Severian gave a more technical definition here.

 

Whether mass represents how much matter you have, I think is more to do with semantics. Is it energy or is it number of particles? One needs to define the problem more clearly, and declare which metric one is to use to measure it.

Thank-you. I was surprised that Sevarians particle physics description of matter excluded the gluon.

The point about not adding to the constituents' rest mass is why I would argue that you haven't created any matter. To make an energy argument, you would also have to say that a particle in motion constitutes more matter than a particle at rest.

But doesn't exciting an atom add rest mass to the atom, though (I think, not sure- I see it as kinetic?) not the electron?

By this definition (which I now suspect is wrong but was my original thought) I would have created additional matter.

Using the broadest possible definition if you had a big hollow sphere in outer space, filled with rubber balls bouncing around would their kinetic energy add to the "rest mass" of the big hollow sphere/system? I think it would be equivalent (add to it's inertia etc.) would it not? Obviously a stretch to call "that" additional matter.