J.C.MacSwell

Let's call an E-31 black hole "Olber's Mass". If you look far enough into space, eventually you'll see one!

Was the evidence of the acceleration that the redhift was not "as expected" for the galaxies/clusters viewed at that distance/age?

so you could have one radioactive or unstable nucleus (the element has a half life of 2 day or 24 hours) but yet you have no clue when it will really decay or emit radiation?

You have a "clue". If it has a one day half life it has a 50% chance of decaying in the "next" 24 hours.

If the moon is a perfect sphere it's probably not spinning. If it's spinning anyway there should be an effective weight difference.

If it's orbiting the earth there should be tidal effects making you lighter on the point closest to Earth and also lighter (by almost as much) on the point farthest from Earth.

so far there are only 2 theories of how the universe will 'end'

 

1- The big crunch: the gravity in the universe is so powerful that over-powers the expanding universe and it all comes back to one place and eventually we have a reverse-big-bang

 

2- The Big Freeze: the universe will continue to expand and all stars will eventually burn out and the universe will become dark' date=' frozen, and time will have practically stopped.

 

 

 

do i have this info right? wrong? close? Please add-on or correct this.[/quote']

 

Why will time practically stop?

the assumption is that dark energy density is constant throughout all space and time at a value of about 0.6 joules per cubic kilometer.

 

it stays that density even while space expands! this is why people sometimes refer to it as the cosmological constant.

 

but matter thins out as space expands!

 

therefore 5 billion years ago' date=' when the universe had not expanded so much, matter was much more concentrated and dark energy was relatively insignificant.

the attractive force of matter which slows expansion dominated!

 

up to 5 billion years ago (and people vary about when exactly, maybe changeover was only 1 or 2 billion years ago, but at least 5 billion years ago) was the MATTER DOMINATED period when matter was the dominate percentage of stuff and expansion was slowing.

 

but expansion continued enough so that matter got so thinned out that now dark energy is 73 percent and it dominates!

 

therefore because of the expansive effect of dark energy the expansion is accelerating.

 

Is that enough of an xplanation of the changeover or do you have more questions about it?[/quote']

 

Isn't Dark Matter required as an attractive force within galaxies?

JC what exactly[/b'] is string theory?

I don't know exactly but it's a multi-dimensional (10, 11 or 26?) theory based on 1 dimensional strings many times smaller than the particles we know/don't know so well. Hoped to explain all the known forces.

Newton, Einstein. Maxwell, Galileo in that order

Bohr is top 20 or so which is not too shabby either.

If String Theory sucks does this increase interest in other kaluza-klein theories or put a damper on the whole thing?

All right I have a question.

 

Take a body at rest' date=' and not spinning. Its center of inertia is at rest. So we say that the object isn't accelerating in the frame.

 

[/quote']

 

This is only true if there is no net force on it.

 

What happens when the black hole is smaller than the Schwarzchild radius?

?

Aren't they identical?

first let's both notice that this is purely theoretical' date=' [b']humans have not yet observed a black hole up close[/b] enough to detect its Hawking temperature and its Hawking radiation.

Except Geoffrey, and we all know what happened to him!

Greater uncertainty about whose velocity? Photons travel at c' date=' so there is really no uncertainty about their velocity.

 

If you mean the uncertainty of the target, that'll be tru regardless of the photon properties. If you know the position better, you have more uncertainty in the velocity. The reason you get better position information is that the light is more localized and there is less "smearing" from diffraction.[/quote']

 

Uncertainty of the target particle.

 

Edit: So you get less "smearing" and higher precision for position with a higher frequency/energy photon. Would you therefore get less precision for velocity? (for the targetparticle of course)

Does it matter?

 

I think the lesson of self-interference in the double-slit experiment is that while you can think of it as a photon when you create it and when it interacts with the detection screen' date=' you still have to think of it as a wave if you stick a wave-like measurement in its path.[/quote']

 

I think it would matter if there was a verifiable difference.

 

Apparently there is not (no known difference)?

I have a small (cross section 30" X 20") wind tunnel that is low speed (30 ft/s). For drag I use elastic from inside a bungy cord. I calibrated it and it was not linear (didn't follow Hooke's law) but it was reasonably consistent for crude measurements. For visualization I reach in with a wool tuft "tickler" on a coat hanger.I would like to use smoke at some point.

I'm guessing the extra drag induced by the wing would negate any gas savings.

Good guess, a lot of the drag reduction in recent years has been accomplished by reducing lift.

Longitudinal wave is destructive to a ship in an ocean while transerve is not really much' date=' right?[/quote']

 

In hydrodynamics the "transverse" wave is transverse to and produced by the ship.

 

I think in terms of physics water waves are generally transverse waves as they are mass/gravity waves with the transverse direction being vertical.

 

Sound waves, compression waves, (I think) are longitudinal waves. (correct?)

 

All that being said I think you are correct if you are saying the forward "momentum" is the most destructive. I have some sea containers that are used for storage that were damaged at sea. The sea "punched" the forward ends in as much as 4 feet. (You should see the ones that are unusable even for storage.)

 

However:

Remember the "Edmund Fitzgerald" in the Gordon Lightfoot song? I think it was sunk by the transverse "portion" of the wave/waves. The ship broke up from lack of support (buoyant forces) where a (large) trough coincided with a weakness in the ship.

well' date=' that gives your answer. one at a time produces interference, they interfere with themselves.

 

?[/quote']

 

Now send them billions at a time. Is the primary interference "self interference" or otherwise?

.

 

site note: for light' date=' is the probablility wave for a photon the same wave as the em wave?[/quote']

 

OK, this is a "blurt" so someone correct me who knows better (or confirm it on the off chance that I am right):

 

Photons of different frequencies have different probability waves. Higher frequencies can be used to more accurately probe the positions of particles, with greater uncertainty about their velocity than lower frequencies.

site note: for light, is the probablility wave for a photon the same wave as the em wave?

Are they not the same thing?

Oh, that's just terrible!

Sorry, couldn't avoid it!

General covariance indicates that the form of the theory is invariant under the most general Lorentz transformations' date=' just as General Relativity is. In other words, it should be frame-independent and background-independent. This gets back to what I was saying to J. C. MacSwell in the thread about the Cosmology Question (re: the relational view of space and time).

 

 

 

.[/quote']

 

Aether you believe in it or you don't.

 

If I were situated someplace' date=' a rotation through 2 pi radians brings me looking where I was looking before. I think this basically proves space is three dimensional, since it would be true in any plane which I start the rotation in[/b'].

A 2 dimensional guy made this argument the other day

If I were situated someplace, a rotation through 2 pi radians brings me looking where I was looking before. I think this basically proves space is two dimensional, since it would be true in the only plane which I know of.

It was a little more forgivable for him, afterall, he's only 2 dimensional.

What do you mean "interfere as originally thought"?

 

Wave superposition

I think they originally figured that the photons interfered with each other and not with themselves in the two slit experiment etc. I think it was the Aspect experiments that proved that photons sent one at a time would (eventually) create an interference pattern.

Does light of equal frequency interfere as originally thought or is it the individual photons primarily "interfering with themselves"?

Or do we know?