1

COVID-19 / Re: What's the transmission risk at two-metre separation for large grids of people?

« on: 27/03/2020 21:53:40 »

It's also plausible (if simplistic) to assume an inverse square law for infection.

We are familiar with the inverse-square law in physics because phenomena like light and gravity radiate out as a sphere in 3 dimensions.
- If a light ray travels 2 x Distance, it spreads out over 4 x Area.
- At 2 x Distance, the intensity is Intensity/4
- This is an inverse-square law
- The inverse-square law still works if you emit light from a point on a flat surface, so it only fills a hemisphere, rather than a full sphere (eg an FM radio transmitter on "flat" ground).

However, if you constrain that third dimension with floor and ceiling, the spread is not like a 3D sphere (Area α Radius²), but like a 2D circle (Circumference α Radius).
- This suggests an Inverse Distance law, rather than an Inverse Distance² law.

Of course, the range of light and gravity is infinite (in a vacuum), but other physics is at play with virus-laden water droplets...

If you spray tiny droplets of water into the air, they just float about for ages without falling much at all.

I heard about some tests done with lifetime of virus-laden water droplets. Apparently, the lifetime depends on the size of the droplets.
- Large droplets(as big as raindrops) fall down immediately
- Small droplets (such as you might see in a backlit sneeze) fall down in seconds
- Very tiny droplets can linger for an hour in the air

The size of these small droplets depends critically on the humidity
- These droplets have large surface area for their volume
- So they exchange water molecules easily with the surrounding air
- If the humidity is around 40%, these droplets will stay small, and linger longer in the air. This is a problem for dry, air-conditioned air in the winter months.
- If the humidity is 60% or above, these droplets will grow, gravity will dominate over random Brownian motion, and they will fall out of the air more quickly.

Perhaps humidity is a useful factor to consider in air conditioning for hospitals, supermarkets and cruise ships?

2

Physics, Astronomy & Cosmology / Re: If you throw a mouse or elephant at someone in space, which will move them more?

« on: 07/01/2020 21:59:58 »

What is the cutoff mass for [projectile returning to first person]?  This is not the same mass as the answer to my post 12 question.

I don't know how to calculate that without using trial and error. You likely use calculus

It's actually just complicated algebra, but I did my reply-12 thing by guessing, and hit it in my 2nd guess, the first guess being 50kg. I had a hunch and it turned out to be correct. This is the case of the 2nd guy returning the projectile with the same energy as the first throw, not at the energy of the incoming projectile.

One more thing on a different but related issue. If I wanted to write a snooker simulation but with variable-mass balls and with the angles of impacts leading to the balls going off at different angles, can the same maths as above still be used just by breaking things down into vectors?

Snooker is complicated.  It isn't frictionless balls in a vacuum, which is actually pretty easy arithmetic.  Snooker has to deal with table friction, especially immediately after the impacts where the balls are moving at a different rate than their spin.  That spin deflects both balls from their initial trajectories, and I'm not up to the challenge of computing the angular inertias and funny spins with non-horizontal axes.

Yes, it's quite easy to do with frictionless balls in space.  Target ball moves directly away from its impact point and incoming ball is deflected in a way that preserves momentum and energy.

3

Physics, Astronomy & Cosmology / Re: If you throw a mouse or elephant at someone in space, which will move them more?

« on: 05/01/2020 01:55:25 »

I'm still trying to find out how you work out how fast the two objects will move apart for a fixed amount of input energy.

I started with the elephant which is posited to mass 10x myself.  So I chose a speed for myself that was 10x the elephant speed, or 1 and 0.1 m/sec respectively.  This is an arbitrary speed but not an arbitrary ratio.  Then I computed the energy (1/2mv²) for each.  50 + 5 totals 55 joules, so that's the energy of the spring that would impart those speeds on those two objects.
Then I had to do the same with the mouse, but starting with a known energy this time, and I got 0.104 and 10.4 m/sec for myself and the mouse respectively, a ratio of 100 this time.  It still adds up to 55 joules.

If spring efficiency wasn't an issue, you could simply divide the total energy equally between both objects.

You can't do that.  The elephant gets a 10th the energy that you do when you throw it.  The mouse gets 100x the energy when you throw it.  Energy can only be divided equally when an equal mass (the wife) gets thrown.
Momentum gets divided equally.  Both total momentum and energy is preserved on the throwing event.  The former is preserved upon catching event and the energy is lost to friction (or possibly captured if the friend has a smaller spring).

4

Physics, Astronomy & Cosmology / Re: If you throw a mouse or elephant at someone in space, which will move them more?

« on: 03/01/2020 22:21:57 »

It comes down to conservation of momentum -
m₁v₁ = m₂v₂
where
- m is the mass of the object in kg
- v is its velocity in m/s (the sign is important)
- 1 & 2 are the two objects involved in the interaction.

At takeoff, using a compressed (massless) spring
Elephant: 1000v_e = 100v_h
So the human travels 10x faster than the elephant (in the opposite direction)
Mouse:v_m = 100v_h
So the mouse travels 100x faster than the human (in the opposite direction)

Let's assume that the friend also has a massless spring of the same kind, so it is an elastic collision...
Elephant: 1000v_e = 100v_f
So your friend's velocity changes by 10x as much as the elephant
Mouse:1v_m = 100v_f
So the mouse's velocity changes by 100x as much as your friend

I have to go now, so I'll leave it for others to complete...

5

Physics, Astronomy & Cosmology / Re: Why do we have two high tides a day?

« on: 13/12/2018 07:33:24 »

D.C. and Colin2B:
Thanks for your words, and Merry Christmas and Happy New Year !
D.C.: beyond any "political correctness", I beg your pardom for my frequent rather "strong" words ...
Colin2B: I consider this thread should be kept open, just in case somebody else wanted to send some comments, or to ask any further question relative to the issue ... And thank you again !

6

Physics, Astronomy & Cosmology / Re: Why do we have two high tides a day?

« on: 11/12/2018 21:59:49 »

May I congratulate you both on being able to keep this going for so long with interesting arguments on both sides.
Much more engaging than Wimbledon.

Merry Christmas to both of you 

7

Just Chat! / Re: mensa members

« on: 17/11/2018 20:18:53 »

I believe the forum (SIG) is only open to members of Mensa.

8

Physics, Astronomy & Cosmology / Re: How does dark matter affect galaxy rotation?

« on: 26/09/2018 06:18:48 »

First off, the "halo" is not a ring. It is a spherical volume in which the galaxy is embedded. A ring shape is not what the word "halo" means in astronomy.
  Also, within such a spherical volume, at any given point The only gravitational effect would be caused by that material closer to the center than that point (Newton's shell theorem).
The visible matter of the galaxy is mainly confined to the bulge and disk.  Once you get away from the bulge and into the disk region, moving further out does not add much to the contribution that the visible matter contributes to to your orbital speed. The dark matter, however extends well above and below the visible matter disk and the thus the amount of DM closer to the center of the galaxy grows quite fast.
 For example, the density of DM in the vicinity of the Solar system is so low that it would only adds up to the equivalent of a small asteroid within the entire volume of the Solar system. At that same density, the spherical volume of the region closer to the center of the galaxy than the solar system would hold a significant fraction of the entire visible galaxy's mass. 
Thus extra mass, plus the mass of the visible matter closer to the center of the galaxy is what determines the orbital speed of the solar system ( and makes it higher than it would be is there just was the visible mass.)

9

General Science / Re: A couple of questions regarding eyes and vision

« on: 20/11/2017 10:34:48 »

I look to one side and gently press the corner of my eye on the opposite side

These are phosphenes - seeing light when there is no light. They can be produced mechanically or electrically.
See: https://en.wikipedia.org/wiki/Phosphene#Mechanical_stimulation

When I’m in dark room, i know the room is dark but i see tens of thousands of tiny dots of various shades of grey or white.

Your eyes have an enormous "dynamic range" - they can adapt from full sunlight to a moonless night.
There are a number of mechanisms that contribute to this range of sensitivity:
- The iris can open (dark night) or close down (bright sunlight)
- Switch from cones (bright colors in daylight), to rods (night, limited to black and white)
- Changing the concentration of enzymes in your rod cells
- The integration time can increase (like increasing the exposure time on a camera)

This is similar to the automatic gain control on an old analogue AM radio or analogue TV.
- When the signal is loud, the sound (radio) or image (TV) is clear
- When the signal is faint, the amplification is turned up to maximum, and the electrical interference is also amplified. Often the interference is as great as the signal.

It takes 10-30 minutes to adapt to the dark, if you are going to look at faint stars through a telescope.
See: https://en.wikipedia.org/wiki/Adaptation_(eye)#Dark_adaptation

10

New Theories / Re: LET: gravity and magnetism explained

« on: 24/06/2017 05:47:03 »

I've been thinking about the functionality of matter slowing as it descends into a gravity well, and the business of how the kinetic energy which it appears to acquire in falling downwards is equal to the amount of energy lost by its functionality slowing. But what happens to that energy when it gets deep enough for the functionality to slow towards a halt while its progress towards the event horizon of a black hole also slows to a crawl? I wonder if it starts to manifest itself more and more as some equivalent of relativistic mass.

Well looking at gravity exclusively with time dilation only works with weak gravity fields. It also definitely holds true for an observer falling into the gravity well that doesn't notice their time slowing down (one doesn't notice this effect on themselves). It correctly predicts acceleration towards an area where time dilation is more extreme. However, the full treatment must include the Lorentz Contraction effect. Matter and energy gets compacted according to the outside observer as it approaches the event horizon. Time slowing down doesn't cause the matter to disappear.

Also time may dilate slowing some interactions but some other interaction is drastically increasing. Gravity is most likely an effect where the wavepackets of particles overlap and start to interact (some physicists have thought the effect could be due to entanglement of particles and "spacetime" in one way or another is emergent). This interaction has one direct effect. It slows down the clocks including the proper time of particles. Light falling into this area of time dilation will naturally contract as it enters the field (similar to light entering a medium). Matter particles will also contract just like the light. We measure distance with light so space seems to warp. The matter and energy doesn't disappear as the inertia of the blackhole increases. The gravitational field is also increasing in size as matter falls towards the blackhole. The particles may be ticking their clocks slower but they're "entangling" much more (whatever you want to call it; actual quantum entanglement may play a role) .

I look at photons going into a medium for some inspiration as the medium slows down the photons due to the large number of interactions with the charge structure of the medium. The photons also compress together but classical medium don't slow down time.

I could easily see gravity working by matter/energy interacting slowing down time and (as a result) contracting objects. The speed of light would be maintained as c locally in all directions to preserve the ratio of the strength of the fundamental forces. To have the speed of light as something other then c (as locally measured) is really demanding that somehow the fundamental forces don't maintain their strength ratio. Which force and which field excitation wouldn't transform like the other forces / excitations? If everything follows the same transformation then c must locally remain the same.

Frame dragging would also be predicted. If I orbit around the equator counter to the Earth's rotation I fly over more ground per second than if I fly with the Earth's rotation. If time dilation increases by interacting with more particles then going against the rotation would increase time dilation and going with rotation would lessen it. If extreme enough one might be forced to rotate with a body (or lose the fight with gravity) and hence we have a frame dragging effect.

So to recap:

1) Matter/energy interacting with matter/energy leads to time dilation (the more there is and the closer together the greater the effect). How the matter/energy is moving affects this interaction.

2) Time dilation leads to an acceleration effect towards the massive body (as explained with the red and blue shift in previous comments).

3) Entering an ever increasing area of time dilation naturally leads to length contraction (as explained before and can be explained similar to light entering a medium like water; metamaterials can simulate this effect by continuously changing the refractive index; this also leads to a curving effect). Conservation of wavetrain/information also demands this effect. Gravity is of course different because of its effect on time/frequency.

4) Preserving the strength of the fundamental forces relative to one another forces the preservation of c locally. Wavenumber in x, y, and z will stretch/contract as time dilates such that c remains the same locally in all directions. This would look like space "warping."

5) The Plank length is derived from the strengths of the fundamental forces. The Plank length would transform just like everything else. The Plank length like the speed of light is a locally measured value.

6) Mass wouldn't disappear entering into a gravity well even if approaching an event horizon. Sure, time is dilated but the matter is also compressed and the inertia and gravitational field of the mass is very much present.

7) Gravity may dilate time (shift frequency lower) and thus increase/decrease wave number in x, y, and z to maintain a constant c locally. However, I don't think this fundamentally changes the background of the universe whatsoever. An entire blackhole gravity well Lorentz Transforms relative to a far off observer just like a small spaceship would (actual acceleration [changing speed] still causes some ripples AKA gravitational waves just like acceleration causes EM waves but Lorentz Translation, constant speed, does not).

I never invoked a change in any kind of background at all to explain gravity. I have gravity as an effect of matter/energy interacting with matter/energy. You could say the total speed of light is c everywhere (in an absolute sense). The gravitational interaction of matter saps some of this speed (ability to interact) just like moving at high-speed through space slows down one's progress through time. This changes the speed of light viewed non-locally (it's speed through space). Gravity isn't a "change in a 3D background medium" and it can't be (Relativity wouldn't make any sense). However, gravity caused by excitations (particles) interacting with other excitations within a medium (fields) slowing time isn't limited to the same rule. You can't have frame dragging effects / time dilation and describe gravity with a classical medium. However, gravity warping space and time has always bothered me. I find it much more likely waves are affecting other waves altering their structure (kx, ky, kz, and f shift).

Why keep a LET like viewpoint? Because it makes too much sense and fits together too well (as shown in my other post with all the math). Gravity as a change in an aether doesn't fit and doesn't work. However, gravity caused by interaction between mass/energy (as described above) riding on a preferred frame that Lorentz Transforms could work. Similar to how the tick of time slows as one approaches the speed of light the matter/matter interaction saps some of the fundamental propagation speed. Does this make sense? Everything is fundamentally moving at c (so it can Lorentz Transform). However, linear motion saps some of this speed (slowing time). Likewise, the tendency "to get stuck in the mud" interacting with a plethora of nearby particles also saps some of this speed (slowing time).

Everything in a blackhole must have a total speed of c because the entire blackhole (center of mass) can move at a maximum speed of c relative to a far off observer. It must Lorentz Transform in the same way as a whole as a small spaceship.

I'm not really sure what happens at event horizons but I wouldn't be surprised to find out that they don't really exist. Perhaps gravity wells "bottom out" with a time dilation extremely close to zero (blackholes effectively exist). We may learn more about the area around an event horizon with more study of grav waves. However, it won't be easy because of time dilation.

Again Einstein isn't wrong even if my ideas here are right as his theory matches experiments thus far done. You can change out x for kx, y for ky, z for kz, and t for f and think of GR in terms of waves as I do (although I go a little further than this). Invoking the equivalence principle and the speed of light being measured as c locally would tell you how these must shift (and would match GR if accounting for the flow of mass/energy). Nearly all physicists think GR needs modification somewhere between the event horizon and singularity but we don't have any experiments to decide where this modification is. This modification could lead to a slightly different description of gravity and I think GR is wrong closer to the horizon.

This is my best attempt to explain how gravity works.

11

New Theories / Re: LET: gravity and magnetism explained

« on: 15/06/2017 05:40:23 »

So there's no evidence even from gravitational waves of two singularities moving towards each other and merging into a single singularity, but only evidence of black holes moving together and their event horizons merging. That means they still no evidence for the existence of anything close to being a singularity.

Yes, exactly. Using Gauss' law mass uniformly spread inside the blackhole, existing in a singularity in the center, spread over the surface, or otherwise symmetrically placed would produce the exact same gravitational field. This is why the metric for a blackhole is used to model the Earth and Sun (except here r >> rs). Furthermore, according to General Relativity NO information leaves the event horizon including gravitational waves. Even the angular momentum of a blackhole manifests as frame dragging occurring outside the event horizon. From an outside observer's perspective using GR nothing crosses the event horizon and no structure exists to the outside observer. Why even discuss the inside? According to any physics we can do (if our theories are correct) the inside does not exist.

That's more convincing explanation - I can imagine that if a particle is really a wave of some kind that might lead to it moving continually within a zone of space, any horizontal oscillation of it (horizontal over a massive object like a planet) will turn into a curve which takes the particle lower and adds downward speed to it which it further builds on such that it accelerates.

Think about this: take f'/f = t'/t , kx'/kx = x'/x,  ky'ky = y'/y , kz'/kz = z'/z and input into GR and you get the same exact math as GR. For example replacing x for kx does nothing to how the math works (but then GR's equations make no sense inside the event horizon). Light is our ruler so a shift in kx corresponds to a shift in measured distance and a shift in f corresponds to a shift in time. I don't see gravity "curving space-time" but rather gravity distorting waves. The waves are distorted such that the fine structure constant remains... constant. This is required for the laws of physics to remain the same (locally) in all reference frames and this guides how GR forms it's solutions. I'm not sure what you mean by the horizontal and vertical.

If light is viewed as a constant locally then why can't we call "curvature of space-time" the "curvature" of wavenumber and frequency spectra? The principles would be the same. Noting c is a constant when measured by our rulers and clocks then stating space and time curves leads to the inescapable conclusion that wavenumber and frequency spectra must appear to curve (leading to an apparent change in c non-locally). Does the curvature of spacetime cause the apparent curvature of these wave properties or does the curvature of the wave properties cause the apparent curvature of spacetime? I think our current theory GR gets the cause and effect backwards.

I can't see a similar effect being possible for for any vertical oscillation of the particle, but I imagine that it will be oscillating in all directions and that most of those will involve curved paths which drag it down.

According to Quantum Field Theory "particles" are field excitations (waves). It's impossible by any method I've ever seen in Quantum Mechanics to explain particles without a wave nature. Wave particle duality is kind of a misnomer. 95% of what particles do can be fully explained as wave entities. The 5% is important and makes quantum mechanics hard to understand and a little bizarre. With interpretations like MWI or Bohmian Mechanics (or similar ideas) this last 5% may be explainable. However, "wave collapse" and the Plank Constant h doesn't change how the particles transform... as waves. Other particle like properties can be explained with the wavepacket concept.

Their clocks would stop completely if they reached the event horizon and no further ticks would be possible for them - the black hole will evaporate away as Hawking radiation in a cold, dark universe before another tick could occur for them and they would effectively evaporate away too as Hawking radiation before any further tick could happen.

Yes, this is definitely a possibility and to me makes the most sense. Perhaps the matter exists on the event horizon or it's distributed in the lowest state throughout the black hole. GR predicts that c goes to negative infinity from the outside observer's perspective at the singularity. Perhaps nature lower bounds this at 0 or very close to 0. What Einstein did makes sense as we have no experiments to input a lower bound into the math. Nearly all physicists agree something breaks but I think it's closer to the horizon than the singularity.

It's the idea of singularities or near-singularities and the near-certainty with which physicists appear to pin on them which has always led me to think the speed of light must be faster downwards than up - if the speed is actually the same up and down, then there's nothing remotely like a singularity in any black hole.

Well there could still be a thing like a singularity if c goes to negative infinity (where at any single point c is the same up, down (not left and right) but it is still decreasing towards negative infinity at the singularity from the outside observer's perspective; it changes slowly over a distance so up is c + dc and down is c - dc but it's not for example 0 upwards at the event horizon and 2c downwards). I'm not sure how people will say over and over that c is constant both directions when discussing Special Relativity when no experiment measures the one-way speed of light independent of two spatially separated clocks. We simply can't measure the one-way speed. These same people then go on to explain GR by stating c is larger downward into the black hole than it is outward (the event horizon traps light on the surface up but sucks it down in the other direction). Again... the one-way speed of light cannot be measured. The equivalence principle works equally well here. To measure it you're again relying on two spatially separated clocks. Two spatially separated clocks running at different rates is indistinguishable from acceleration. We can't tell if the clocks are in different environments and thus running at different rates or... the speed of light is truly anisotropic. This is why physicists have very weird things happening on the EH such as matter falling in but also plastering onto the event horizon (and entangling). This is a central reason they thought up the holographic principle.

I personally think changing to a different velocity is anisotropic but gravity is isotropic (gravity can be a mixture of both if the gravity well is changing velocities). I find that nature tends to use all options available to her.

Is your position on all this stuff part of a named camp with lots of people saying the same things as you or is it unique to you? You appear to be closer to the mark than anyone else I've ever encountered and I want to make sure I can continue to read up on this.

I don't like named camps. However, I've been looking into blackholes for more than 15 years and I'm no layperson. Many of the ideas in my explanation come from different physicists and some go all the way back to Lorentz. However, I don't know of anyone who pushes this wave interpretation of GR as much as I do.
 

12

New Theories / Re: LET: gravity and magnetism explained

« on: 11/06/2017 21:32:15 »

I don't know if anyone has a viable proposed account of what happens in black holes. I wonder if any information about how things behave inside them is coming from the gravitational wave data.

According to General Relativity NO information including gravity waves escapes the event horizon.

The radius of two merging blackholes of mass M is 2rs where rs is the event horizon of a single mass M blackhole. The volume we don't know anything about goes up by a factor of 8 when the two blackholes merge. Watch this video below (under number 4):

What you will notice in the video is the event horizon drastically grows when the BHs merge and even start doing so before the blackholes are 2rs away from each other.

A larger problem is that time dilates significantly close to the blackhole. Regardless of how you think this occurs the light escaping is severely redshifted and the wavelength will get severely stretched out. Notice how calm the gravity waves are around the event horizon in the videos in the link below? Gravity waves that we've detected on Earth have wavelengths of hundreds or thousands of kilometers. How much detail we can see depends on wavelength so we're severely limited with what we can see. We know we detected gravity waves, we know the waves move at c, and we know the approximate size of the blackholes that collided. We can't know what happens at the horizon or below and we're even limited close to the horizon because of time dilation.

https://www.theatlantic.com/science/archive/2017/06/gravitational-waves-black-holes/528807/

What I'm trying to say is that the light which hits the bottom of the box is transferring energy which must act on the whole box and not just on the base, and the same applies to light hitting the top - in propagating that energy through the whole box it looks to me as if it should equal out. The bottom of the box feels the light punch harder because its functionality is running slow, but it transfers a lot of that energy on up to the rest of the box where the functionality of the material there is not running so slow and will not feel it as such a strong downward force. Likewise, the top of the box feels a soft punch from the light because its functionality is running faster, but it transfers a lot of that energy on down to the rest of the box where the functionality of the material is running slower such that it will feel it as a stronger upward force. The net result of this should be no movement.

What you're not understanding is EVERYTHING is wavelike including the mirrors and when observed locally EVERYTHING has a propagation speed of c. Forget the entire light box (which you're seeing as a rigid object for some reason) and think of a single particle. Time is running slower on the bottom than the top. OK? Say the difference is 50%. This means time is 50% slower and the particle's frequency is oscillating 50% less on one side than the other. E = h f so if one side of the particle has energy lowered to half then like an airplane's wing the lower side of the particle will be lower "pressure." All processes will slow by 50% moving downwards doubling wavenumber. If the frequency drops by half and the wavenumber doubles this means the speed of light is 1/4 as viewed from infinity (but c viewed locally because objects are half as wide and frequency is half so light speed appears normal). A lowered speed of a wave in a medium ALWAYS curves the wave towards that medium classically. Again the only difference between gravity and a classical "medium" is that the slow down reflects in a change in wavelength AND frequency instead of just wavelength (the change in both as required by GR is ALWAYS such that c is measured to be the same locally; Leonard Susskind explains this in his series on blackholes).

Instead of the wavenumber going up by a factor of 4 and the frequency staying the same the wavenumber goes up by a factor of 2 and the frequency drops in half. This classically was viewed as impossible. Say cars evenly spaced at a mile go down the road at 100 MPH if the speed of the cars drops to 25 MPH when they cross a barrier you'd think the cars would space at 1/4 of a mile after the barrier. However, for light changing the value of c locally would change the fine structure constant, it would change the strengths of the forces relative to each other, and it would change physics as we know it. ALL Relativity requires is that frequency and wavenumber change such that c locally remains the same. Because we measure distance with wavenumber and time with frequency shifting the wavenumber and frequency corresponds to a shift in distance and time. Again k'/k = x'/x  and  f'/f = t'/t. We measure distance with light so changing wavenumber of light "curves" space and we measure time with oscillations so changing frequency of the fundamental forces changes "flow" through time.

Instead of the cars dropping to 1/4 of a mile separation they only drop to a half mile separation. This preserves c and the relative strengths of the fundamental forces. This automatically means frequency drops by 50% and f/k = .5/2 = 1/4. This doesn't require time as a fourth dimension or a true curvature of "spacetime" but rather requires nature to have a mechanism that keeps the strengths of the fundamental forces exactly the same locally. I want to figure out this mechanism. General Relativity does not give a mechanism but rather uses the equivalence principle to describe gravity.

What happens as something approaches the event horizon is that time slows down and wavenumber increases. At the event horizon wavenumber goes to infinity and time stops from the outside observer's perspective. This is exactly what Leonard Susskind says in the video below. He discusses it at about minute 10 of the video.

What I don't agree with is what happens from the perspective of the free falling observer. I think the Doppler Shift of the free falling observer does cancel the gravitational red/blue shift for the observer. However, the viewpoint for most physicists is that the time goes back to a normal rate (like you can tell what a normal rate is in your own frame). I think the time goes down to the lowered gravitationally dilated rate that locally exists. This means an in-falling observer runs slower through time and stops on the horizon. They don't know their time slows to a stop so they think they're accelerating and moving at an ever faster rate. I think blackholes are a highly compacted form of matter where time is running at the slowest rate possible and particles are crammed in to maximum density allowed for that amount of mass. I think the math we have for inside the horizon (or exactly on the horizon) is wrong. 

What do I think is the cause of gravity? Well classically light slows down in water because of the huge number of interactions with the charge structure of the medium. In a similar way particles (matter energy) may interact when their extended wavepackets start overlapping causing a slow down in c (observed from a distance) and thus shifting both frequency and wavenumber.
 

I'm still finding it hard to see how there would be such an effect unless you're using photons generated by something other than the object that's being acted upon by them. Is there any role for a difference in the speed of light downwards versus upwards?

You can't in principle measure the one-way speed of light. Why does there need to be a difference between the speed of light downwards and upwards? Again if the speed of light is 1/4 at r and this 1/4 is reflected in a 50% drop in frequency and a doubling in wavenumber the math works out perfectly (and matches GR from the outside perspective). One can certainly view gravity as space falling inwards towards the gravity well at an increasing rate. This is written into Einstein's Theory with the Equivalence Principle (gravitational acceleration appears the same as acceleration in open space). However, I don't see space in falling (or light speed increasing inward and decreasing outward) as correct. The exact center of a gravity well (say the center of the Earth) still experiences time dilation but it does not experience acceleration when viewed from the observer at infinity.

Again Relativity assumes the observer is unchanged and instead space and time change. The unchanged observer simply moves to a new time and space coordinate. I find it far more likely wavenumber and frequency changes for wavelike entities than space and time curves. The only problem is that I don't know how you'd prove a difference between the two unless one wants to take a one-way trip into a blackhole... and even more importantly they have one available. I don't think singularities exist. I think our math is showing blackholes do have a size AKA the radius of the event horizon.

13

Just Chat! / Re: Latest Forum Updates and Upgrades

« on: 10/06/2017 08:29:38 »

I looked for this when you first announced it, but still can't find any bookmark option on the green toolbar, so I thought you might want to know - all I see is Reply, Unnotify, Mark unread, Send this topic, and Print. Perhaps it's a browser issue of some kind - I currently use Chrome, but it's an old version that doesn't update any more as I'm still using Windows XP.

Thank you, David. I have investigated and discovered that this was caused by a permissions problem. Not all users were granted default access to the bookmarks function. This has now been fixed.

You should now see at the top (and bottom) of a thread:

bookmark_pic.PNG (19.16 kB . 667x249 - viewed 22616 times)

14

New Theories / Re: LET: gravity and magnetism explained

« on: 07/06/2017 03:50:30 »

I don't know if anyone has a viable proposed account of what happens in black holes. I wonder if any information about how things behave inside them is coming from the gravitational wave data.

Well many scientists think they do all the way down to a very close distance to the singularity. However, many other scientists admit they don't know. Inside of a blackhole is outside of science if GR is correct because we can't observe in there. No observation, no science. The physics community overwhelmingly agrees they don't have a full solution that makes sense yet. Many scientists and pop culture often raises some of the far out predictions of GR to fact when they're far from it. Questioning General Relativity is often seen as heresy which I find counter to the principles of science. Gravity is modeled as the curvature of spacetime that does not mean this model is fundamentally right just that it seems to work well because the model matches many experiments. Newtonian Gravity still works well but it's ideas aren't fundamentally right.

Gravity waves just like anything else don't convey information about what's inside a blackhole. If they do then GR is wrong.

But the forces must be transferred through the material of the box from top to bottom and bottom to top to affect the whole thing and they surely must in the course of that transfer be amplified or reduced as they are passed down or up, leading to an equalisation for both directions and no acceleration of the box.

You're differentiating stuff from stuff. The laser is just an example and gravity works on everything exactly the same as shown in many experiments. The "photon box" is much closer to reality than many people think and many scientists use it to explain what's happening. Particles according to Quantum Field Theory are wavelike.

If you take a single sine wave with wavenumber k it will be   y = sin(k x). k will define the cycles per unit distance. If you add two waves like this with slightly different wave numbers they will go through a complete cycle in a greater distance than either k1 or k2 alone. What happens if you add an infinite number of waves with slightly different k (and amplitudes)? You get what's called a wave packet. The repeating nature of the wave disappears because the repeat is out at infinity. The wave destructively interferes almost everywhere. Particles are best represented in our theories by wavepackets just like these (but you have to add in the finite speed of light). Now packets like these can be created in experiments and even with classical wave experiments. They can be made to move at many different velocities.

There is significant evidence to suggest ALL particles are excitations of fields. For example according to quantum field theory the electron is an excitation of the electron field. The photon is an excitation of the electromagnetic field etc. ALL of these fields have a fundamental propagation speed, the speed of light. There is NO exception. Now excitations can move slower than light but only if those excitations are interacting with another field such as the Higgs Field. Similar to how photons slow down when they go through a charge structure they interact with, some particles like electrons and quarks get some initial mass (a rest velocity) by interacting with another field. Particles like quarks can then get further mass by interacting with the gluon field.

All particles seem to be waves with the same underlying propagation speed. It's NOT just the photons that shift in a gravity field but rather ALL particles. The stuff in between is doing the same thing as the photons. Again

x'/x = k'/k    and  t'/t = f'/f    This is easy to prove in Special Relativity and in GR

Shift the propagation speed of everything and you symmetrically shift everything. The interesting part about this is a symmetrical shift is unnoticeable locally by any observer. The very tick of clocks is all governed by the propagation of change via particles and the very size of these particles is also governed by this propagation. It's VERY hard for me to think of a way to change the speed of light locally unless one changes the strength of the fundamental forces relative to one another. However, one can always choose to view their reference frame from the eyes of some other frame.
 
Again classically when waves are moving and there is a region where the propagation speed is slower those waves will curve towards the region. Lookup Snell's Law and Huygens Principle. The wave number will also increase and of course the velocity of the waves will decrease. The difference with gravity is that the waves are the force carriers AND all particles. The waves also carry momentum p = h k and energy E = h f. This means a non speed of light particle in a gravity well standing still relative to some observer at infinity gets hit harder by photons heading downward than photons heading upward. This causes an acceleration feeling that stops when the particle equalizes the shift (free falls). Just a TINY shift in the forces causes a fairly large acceleration for... everything.

I think one of the best ways to look at Relativity and a gravity well is to map out the "field" similar to how one uses iron filaments to show the magnetic field. The thing you use to map out a gravity field is wave crests of any single frequency of a light wave. I don't think gravity is the "warping of spacetime" because I think waves are much more likely to shift and warp than space. In fact I showed in my thread how length contraction arises simply by shifting a wave structure by v in the classical (and quantum relativistic) wave equations. Many medium naturally develop Relativistic symmetry when the wave emitters/receivers shift similar to the waves (an exact shift would exactly match Special Relativity but alas a perfect medium where fundamentally all of what makes the emitters/receivers shifts the same as the waves doesn't exist unless perhaps the universe is one).

15

New Theories / Re: LET: gravity and magnetism explained

« on: 06/06/2017 03:50:08 »

Light does not have momentum. It neither slows down nor speeds up. That violates relativity's postulate. Potential energy is just that. Tick rate and energy potential slows to the center of mass. Energy is dilated so energy particles are further apart. Light produced in lower energy potential has a longer frequency due to particles being further apart in the position of space more dilated. That approach is indistinguishable with momentum and does not violate relativity postulates. Light does not change frequency once produced.

Light does have momentum p = h k   This formula appears in Relativity, Classical Quantum Mechanics, Relativistic Quantum Mechanics, and Quantum Field Theory unaltered. When light hits an object it imparts momentum h k.

The equations below are straight out of a University text book by James B. Hartle on General Relativity unaltered (except replacing ω for f) for a stationary observer (an observer feeling acceleration and holding a position) at height r and rs is the event horizon radius:

c'(r)/c =  (1 - rs/r)

t'(r)/t =  √(1 - rs/r)    and    f'(r)/f = √(1 - rs/r)

k'(r)/k = 1 / √(1 - rs/r)   

f'(r) k'(r) = c'(r)

Light certainly does change speed over distances when under the feeling of acceleration either hovering in a gravity well or accelerating with something like a rocket. This does not violate Local Lorentz Covariance and this is why the word LOCAL has to be included in the law. Many don't understand this.

Something hovering close to the event horizon (maintaining station) is NOT stretched out but rather pancaked (contracted) because of the immense acceleration to stay still. Two lasers one on the top of the tower and one on the surface of the Earth are also not "stretched out" and the tower is actually under a large amount of compression to keep it's constant distance. Wavenumber spectrum actually shifts upward (what I call a ruler) when hovering at height r outside of a blackhole. This means you can fit say 1.5 meters in a spot someone far from the blackhole would call 1 meter. (I wrote this down backwards in my last comment).

The Schwarzchild Coordinates:

ds² = -(1 - rs/r) dt² + 1 / (1 - rs/r) dr²  + dΩ²

Relativity derives   t'(r)/t = √(1 - rs/r)  just like it derives  r'(r)/r = 1/√(1 - rs/r)
 
Now classically when waves enter a region where the propagation speed of the medium is less the wavenumber ALSO increases. Waves also curve towards the zone with a slower propagation speed. This is because the fast moving waves get into a "traffic" jam as they enter a region where the waves are moving slower. Think of going 80 MPH towards cars moving slower in front... this would close distance very quickly. This is exactly like General Relativity (at least outside of the event horizon; no one know what happens inside and suggesting we have any accurate model is probably wrong). If we use light as our meter stick (and we do) then when more cycles fit within one meter we count more meters. x'/x = k'/k just like t'/t = f'/f (when shifting the whole spectrum). This complies with 1 / (1 - rs/r) as this value is greater than 1 when r is greater than rs.  This is why a gravity well is modeled as an upside down funnel (ignoring the frequency shift). If we shot a light at a gravity well and looked at it top down the wave crests would be CLOSER together (remember time dilation is an effect not seen locally). However, observers are counting meters by using the fundamental forces. In fact ALL particles are wavelike structures (with the same underlying propagation speed) and they all undergo the same transformation. From the outside observer's perspective the waves would cram onto the event horizon (makes you wonder if the inside solution for a black hole in GR is just completely wrong). This plastering of particles onto the event horizon is where the "Holographic Principle" comes from. Some physicists think that if stuff can plaster onto an event horizon from one view but pass through it form another according to GR then the 3D universe may also be plastered onto a 2D surface.

The Michelson-Morley interometer taught me one thing: we measure distance with light and counting fringes is the best way to measure distance. Particles also measure distance with the fundamental forces. We don't have anything else we can use to fix our references to.

General Relativity is quite different than a classical medium because time slows down. Classically entering a medium does not change the frequency of the wave. A classical "medium" may slow some photons within a range of frequencies but many may not be affected much. Further than this it slows some frequencies more than others and doesn't do anything to force carriers and particles that do not interact with the charge structure of the medium.  However, what happens when you drop the frequency of the fundamental forces (shift the entire spectrum)? Well a lower frequency means that the wave crests of the fundamental forces propagate slower. Basically, t'/t = f'/f. So what happens if things are contracted by 50% (two meter long sticks fit in a space someone at infinity would consider 1 meter) AND frequency is lowered by 50%? Well to keep the speed of light seemingly the same locally it has to move at 25% of what it does at infinity. To someone locally the light would appear to move 300,000 meters in one unit of time. The person at infinity calls the 300,000 of their meters 150,000 meters and also says the one unit of their time is actually 2.

They see c = k f (very locally in practice nowhere near 300,000 meters because they are under heavy acceleration and light is curving towards the gravity well)  and the person at infinity sees c = k f in their frame but the person at infinity views their frame with c'(r).

Some interesting thoughts. When an object moves at velocity v it has c'/c = √(1-(v/c)²), the length contracts by c'/c (wavenumber goes up more cycles per meter), and time runs slower by c'/c (frequency goes down). The Big Bang says the universe "expanded." However, what if all bound objects are ever so slowly (at least now) contracting while time is slowing down. Instead of the early observable universe being the size of a pin why can't particles be the size of the observable universe with time running faster? How would we know the difference? These all preserve c and they all work similarly. I think the Big Bang being some huge shock to the entire universe that's been slowing for billions of years seems just as reasonable as space forming out of noting (I thought this up and researched it and in fact scientists have thought about this but couldn't differentiate it from the Big Bang and space expansion). We take the observer's view as golden and space and time change around them. However, we are made out of wavelike structures that should themselves warp so what if we've got it backwards? .

I don't see gravity as stretching spacetime. I see it as symmetrically shifting the fundamental forces and we just happen to use these forces to define length and time. We have nothing else to use. Now someone else may call a curved line straight but I do not.

  I've heard a description along those lines before, but I failed to consider all the implications, perhaps because there's a key part of it that doesn't add up. If the photon speeds up as it climbs out of the energy well, that extra speed energy should exactly balance out the loss in energy from the reduction in frequency, leading to the photons hitting the top and bottom of the box with exactly the same energy. Perhaps I'm missing something?

However, you've certainly shown me that the potential energy can be stored much more simply than I'd imagined - when you lift an object, it's functionality speeds up (and has to speed up) and you have to put the extra energy into it to enable that faster functioning. That's something I'd completely missed before.

The photon does speed up as it climbs out of the gravity well. However, the photons are a wave and they do not add wave crests as they rise (conservation of information). The wave crests spread out (like cars leaving a traffic jam on a highway) as they rise meaning they hit the upper mirror with lower momentum AND lower frequency ( p = h k and E = h f). The waves slow down as they drop into the gravity well so they bunch up. Now you'd think this slow down would hit the bottom mirror with less force but time and all the particles down there are also running slower. The crests of the photons bunch up as they drop into the gravity well. The bottom mirror receives more force and the top mirror less force. This unbalance requires an acceleration to counteract the red and blue shift. When the acceleration is equalized the particle acts like it's in an inertial state just like it would be in deep space. 

I discussed a lot of Relativity in my thread "Different View of Relativity." I did a thorough proof of how length contraction naturally arises when all particles are treated as waves (best done in the third post I did in that thread).

16

New Theories / Re: LET: gravity and magnetism explained

« on: 04/06/2017 02:33:33 »

When you lift an object, you are causing the fabric of space to accommodate it differently, and that involves putting energy into that fabric. This is like with bubbles in washing-up water which can accelerate towards each other as the surface tension rearranges the shape of the surface in order to minimise the amount of energy stored in it - that stored energy is turned into kinetic energy in the same way, and then it becomes heat. Once we understand where the potential energy is stored, it's all becomes obvious - all we have is a stressed fabric trying to get to a lower energy state.

I think this is answered partially by the Equivalence Principle. Accelerating in deep space at 1g is equivalent to standing on the surface of Earth.

I showed the following is true before:

t'/t = f'/f = (1 - v/c)/γ      where γ = √(1 - (v/c)²)

The above is the Relativistic Doppler Shift. Now

t' =  (t - t v/c)/γ     Now synchronize clocks/rulers with light. For light c t = x or t = x/c. This is an arbitrary synchronization convention Einstein used in his theories (you can definitely use it)

t' =  (t - x v/c²)/γ  =  Lorentz Time Transform

Why is this important? And why does it pertain to your post?

Because shifts in frequency correspond to shifts in energy. Light redshifts going out of a gravity well. Literally time runs faster for objects further out of a gravity well meaning frequency is higher. Using the equation E = h f straight out of Quantum Mechanics an increase in frequency IS an increase in energy.

Think of a photon box. This box is a bunch of photons with mirrors on all sides. If time slows down on one side of the box or equivalently the frequency lowers then the energy of the photons hitting that side of the box will be LOWER. If the photons leaving the mirror further in the gravity well are red shifted heading up to the top mirror they will hit it with lower energy. If the photons heading down from the top mirror are blue shifted they will hit the bottom mirror with HIGHER energy.

The photon box would be in equilibrium in open space. However, in a gravity well the difference causes the box to accelerate downwards. This is definitely the "cause" of gravity. We know for certain light blue shifts going into a gravity well and red shifts heading out. Particles and atoms are "excitations" of fields or wavelike entities and the frequency change that affects photons works the same on ALL particles. 

To keep the photon box in balance or really to keep any particle or collection of particles in balance they must accelerate to balance the gravitational shift. When they accelerate they produce a Doppler Shift that exactly cancels the gravitational shift.

Particles are actually storing the energy when they are further out of a gravity field because their time is running faster.

This isn't the whole story however. Wavenumber (1/wavelength) also gets altered when entering a gravity field.

x'/x = k'/k = (1 - v/c)/γ      where γ = √(1 - (v/c)²)

Wavenumber also lowers (c = f/k) meaning that "space" (or at least particles) must contract when entering the gravity field. The Doppler Shift again fixes this but here "re-stretches" the particles when they're free falling.

p = h k  where p is momentum. The momentum of the photons is affected the same as the energy. E/p = c. Because light is our best ruler (we define the meter using it) screwing with wavenumber screws with space or what I personally believe the particles existing in said space.

In QM the solutions (stable eigenstates) are generally  ψ = Φ * e^(-i f/(2π) t) = Φ *( cos(f/(2π) t) + i sin(f/(2π) t) )

Don't worry about the Φ that depends on the situation and doesn't affect the energy.

The above is just waves (sines and cosines) with frequency f. Energy seems to be stored as an oscillation which fits well with the wave nature of all particles. No one knows what's "oscillating." Some people think it's just a feature of our models, some think something like a super fluid is oscillating, and some think it's a "fifth" dimension etc.

17

Just Chat! / Re: Latest Forum Updates and Upgrades

« on: 30/05/2017 22:50:26 »

Hurrah, I made @David Cooper happy! And I've been using the "Unread Replies" function myself all day, so thanks for throwing down the gauntlet!

18

Just Chat! / Re: Latest Forum Updates and Upgrades

« on: 29/05/2017 13:21:56 »

SPECIAL EXTRA UPDATE 29/5/17

This is a special update for @David Cooper :

The old software could provide a list of threads that I had posted in which had subsequently had other people post to them and which I had yet to view

I believe that I have now got this working, David. You can access "Unread replies" under "POSTS" at the screen top:

Unread-replies.PNG (21.38 kB . 530x253 - viewed 22747 times)

This will provide a list of the posts in which you have previously been active and to which others have since added further posts.

[And David, for a valued member of our community, a bit of time spent sorting this out is a worthwhile investment as far as I am concerned. It's likely that other people would like this function too.]

19

General Science / Re: Why does the same note sound different played on different musical instruments?

« on: 28/04/2017 22:53:16 »

Missed this one.

The attack (start of the note) and decay (end of the note) time constants are important,

As usual Evan gets straight to the crux of the question.Early research into musical sounds was done by Helmholtz in the mid 1800s and he came to the conclusion that all sounds are a mixture of various sine waves and their harmonics. Although this is true it is far from the whole story and this became obvious when the first attempts were made to recreate or synthesis the sounds of various musical instruments. Adding together the various frequencies and their intensities, as found in the spectrum of an instrument, didn't produce anything which sounded like that instrument. Research soon uncovered the fact that one of the most important factors is the time envelope of the sound, this consists of 3 basic parts, attack, sustain (continuous or steady state), and the decay.
Of these the starting transient (attack) is essential for quick recognition of an instrument. The early evolution of hearing meant that recognising danger quickly was a big advantage and the brain is very sensitive to these starting transients as a means of recognition, far more so than the continuing steady state of the envelope (e.g. Saldanha & Corso 1964). What is curious is that these transients have a very different spectrum to the sustain part and can be very discordant and jangley before they settle down into a steady state - the violin can take about 200ms to do this although the brain can recognise a violin within 60ms. The attack also contains some very distinctive sounds - compare the breathy tone at the start of a flute note with the 'quack' of the oboe's double reed.
The rate at which this transient rises varies between instruments and depends mainly on the acoustic impedance between the sound producer e.g. a string, and the resonances in the instrument. If we remove this starting transient many instruments are difficult to identify correctly.

At the end of this attack phase the note settles into the sustain period or steady state. It is however not all that steady, and part of the unique character of an instrument during this phase is due to the variation of amplitude and frequency of the various parts of the spectrum. To give an example of these variations take the piano. In the central octaves there are 3 strings for each note, the tuner will bring these into unison, but given the nature of the strings they will drift slightly when struck by the hammer. Given this slight difference in tension and that the 3 strings will not start with the same phase relationship there is a very subtle variation in amplitude and frequency components of the combined strings. Contrast this to the single string of the hammered dulcimer.
During this phase the main frequencies and their harmonics give a feel of pitch to the instrument and also tone colour, for example a clarinet has mainly odd harmonics. They can also change with time e.g. the trumpet often starts with few harmonics and gains more. It is possible to change the harmonics without changing the recognition of the instrument e.g. changes to the soundpost and bridge of a violin change the harmonics and can be described by the player as boxy, strident, dull, etc, but all would agree it is still a violin.
The way the ear works can also affect the sound heard. Harmonics can be masked by a lower frequency e.g. 6th harmonic of a classical guitar can mask many of those above it, but in a steel string guitar the higher harmonics are loud enough to shine through. Also the ear can add sounds that are not there. The lowest note on a guitar is lower than the sound box can support and it shouldn't sound as loud as it does. However, there is an interesting psycho-acoustical  effect called the missing fundamental. If we mix together the frequencies representing the harmonics of a note (2nd, 3rd, 4th, etc) the ear/brain recognises that this is not a sequence based on the 2nd being the fundamental, so it 'inserts' the true fundamental even though it isn't present. Hence the lowest note on the guitar sounds louder than a sound level measurement would suggest.

The decay of a note also adds to the character of an instrument and can sometimes be useful in differentiating between similar types of instrument. Most woodwind and brass decay very rapidly, strings take longer. Organ pipes (church and concert hall) decay very quickly and the echoing final chord is entirely due to the hall reverberations, so in this case we might say the hall is part of the instrument.

20

Physics, Astronomy & Cosmology / Re: Why do meteors shoot across the sky? Why do I never see one coming towards me?

« on: 24/04/2017 23:05:53 »

We interviewed Phil Bland, who was instrumental in setting up fireballs in the sky, when we were in Perth in 2015, if you want to give him a listen...