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Physics, Astronomy & Cosmology / Is there an error in this relativistic thought experiment?

« on: 14/11/2018 19:12:06 »

Suppose you have a Schwarzschild black hole with an event horizon.

I presume that a light beam shone upward from an event horizon would be infinitely redshifted before it travels any distance above the event horizon. The redshift from an event horizon up to any point in space is infinite. This is because the gravitational potential energy difference between an event horizon and any point above the event horizon is infinite.

Conservation of energy requires that gravitational redshift is reversible. Infinite redshift up mean infinite blueshift down. The blueshift a light beam will undergo when traveling from any point in space to an event horizon is infinite.

Thought experiment: Place a laser at some point outside of the event horizon, stationary with respect to the black hole. Point the laser radially downward toward the center of gravity of the black hole. Turn on the laser.

By the time the front of the laser beam intersects the event horizon, the beam is infinitely blueshifted. The light beam will contain infinitely many wave cycles. This means that, before the front of the beam reaches the event horizon, the laser must generate a sequence of infinitely many wave cycles. Before the front of the light beam can reach the event horizon, infinite time must pass at the laser.

This is true no matter where in space the laser is located. Before light can travel from any point in space to an event horizon, infinite time must pass at that point in space. This is also true for every point in space that the light beam travels through on the way to the event horizon. Each of those points can be considered as a light source and infinite time must pass in those points before the light can travel to the event horizon.

If light cannot travel a path in finite time, nothing can. Not matter or energy or information.

It seems to me that this sort of reasoning could be why Einstein insisted black hole event horizons are impossible.

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Radio Show & Podcast Feedback / THEWIREDGAME

« on: 23/09/2018 21:04:22 »

You mentioned TheWiredGame on the show, today. I checked out the web site. It looks interesting but I can't figure out how to make it work. There are no instructions, the only key that generates a response is the "a"... not the mouse buttons or any other keys. The video doesn't include any information on how to use the game.

I can get the gal to walk to the left until she reaches the dark (wet?) part of the path. Then the game doesn't respond to any keys or buttons.

Is this a problem with my browser? I've only tried the browser version.

Can someone give me a clue as to how to get the game to do anything?

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Geology, Palaeontology & Archaeology / What causes Earth's magnetic field?

« on: 19/09/2018 16:11:07 »

None of the explanations I've heard explain Earth's magnetic field. The field originates in the core where the temperature is well over the Curie temperature so the iron and nickel are non-magnetic. There is a metallic flow but that won't produce a magnetic field, either.

There must be charge separation and electrical current. Are there any physical models that explain this current?

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Just Chat! / Hand Washing

« on: 10/09/2018 01:21:48 »

I've read of different hand washing techniques, soap application versus plain water, but I've never read of the one I use.

When I use liquid soap or foam hand cleanser I apply it directly to my dry hands, scrub my hands so that the cleanser is smeared over the entire surface, then I rinse it off. It takes less water, seems like it provides maximum cleanser concentration, and my hands feel very clean afterward.

Any ideas, data, or opinions on this? I think at least a few medical professionals subscribe to this site.

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Just Chat! / Join Naked Scientists in Second Life

« on: 12/08/2018 17:43:39 »

Come join us in Second Life for The Naked Scientists on Sunday, 10AM SLT
Location: http://maps.secondlife.com/secondlife/Nuba/14/107/24
Live audio stream: http://www.bbc.co.uk/iplayer/console/bbc_radio_cambridge
Archived program: http://streaming.nakeddiscovery.com:8000/naked_scientists
Homepage:  www.thenakedscientists.com

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Physics, Astronomy & Cosmology / Why has action at a distance not been disproved?

« on: 20/02/2017 11:15:23 »

  The action-at-a-distance interpretation of entanglement requires simultaneity.
And, 110 years of testing Relativity has proven non-simultaneity.
So, doesn't that rule out AAAD as a possible theory?

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Technology / Are we Thinking About Cybersecurity All Wrong?

« on: 09/12/2016 07:22:23 »

Listening to a podcast about cybersecurity, today, I yelled at my iPhone, "You're totally on the wrong track!"

The experts were talking about how some industries are good at it and others not. That's goofy. It's not the job of bankers or hospitals or schools to all master the intricacies of security. The features should be built in, by default.

There is a standard 7-layer model for computing, from the hardware layer (e.g. ethernet card) up to the presentation layer that handles the user interface. When some layer communicates with another computer, each layer establishes some form of link with the corresponding layer in the other computer. When exchanging data, each intervening layer takes the data and packages it for delivery to the corresponding layer in the other computer. There is no reason that every time the message goes into a new envelope, the contents shouldn't be encrypted.

Before the data I type in this window on my screen leaves my computer, the text should be encrypted half a dozen times by independent computing processes.

All of the technology exists within the public domain. I can see no excuse for not requiring it.

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Technology / Why do phones beep, occasionally?

« on: 09/12/2016 05:59:14 »

I've not been able to figure out why my iPhone periodically emits a vibration/sound. There is never any sort of information message or icon or anything associated with it. I'd love to know what function it serves.

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Physics, Astronomy & Cosmology / Question about General Relativity, Field Tension, & Gravity

« on: 09/12/2016 01:41:24 »

Here be my think’n

Spacetime dilation is a function of total field tension in any region, right?

Thought experiment: Two identical, ideal springs, (A) & (B), each of rest mass M kg. (A) held under tension, storing X Joules of potential energy, (B) under compression, storing X J of P.E.

In this static state, the stored P.E. will add to the rest mass following E = Mc^2, each spring has an inertial mass of N, where N = M + Z, where Z = X/c^2

Agree, so far?

But, they would have different gravitational masses:
Mass of (A): M - Z
Mass of (B): M + Z

Set to oscillating, the springs would radiate energy via spacetime oscillations due to the tension/compression cycle, independent of any motion of masses.

I know people say that a gravity well just dilates time and curves space, but I disagree. If that were the case, c wouldn’t retain the same local value, everywhere. The apparent slowing of a light beam in a gravity well is because the path through space has been lengthened:
(1) Clocks run slower in a gravity well in proportion to the difference in gravitational potential energy, hence time is dilated.
(2) The time required for a light beam to traverse a region in a gravity well is increased in proportion to the difference in gravitational potential energy, hence space is dilated.

I see no reason to think the Shapiro Delay is constrained to low field conditions… it’s a direct consequence of the requirements of Relativity.

A clock within (A) would run faster than a clock within (B). A radioisotope in a diamond anvil press might have its decay detectably slowed by great enough pressure.

Or, am I totally thinking about this wrong?

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Physiology & Medicine / How much protection do the eyelids provide?

« on: 09/10/2016 06:04:11 »

How much protection do the eyelids provide? In UV? In visible light? Tanning might help with protecting from an excess of visible light, but I gather from what I've read that it only blocks about 25% of UV (SPF 4).

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Physics, Astronomy & Cosmology / What is the most puzzling thing about action-at-a-distance?

« on: 30/09/2016 23:46:23 »

There is a common misunderstanding that the only alternative to local hidden variables, as an explanation for the appearance of entanglement, is action-at-a-distance. Fortunately, it is not. I know of at least one category of local, causal interpretations that explains it, but it requires that we exist within a multiverse.

And, I have never seen the obvious problem with action-at-a-distance discussed: simultaneity. All of Relativity REQUIRES "non-simultaneity". Non-simultaneity is the verified fact that, for any two different reference frames, there will be some events that are simultaneous with respect to one frame but not the other.

Action-at-a-distance REQUIRES simultaneity. In the action-at-a-distance interpretation of entanglement, the observation of one particle of an entangled pair will alter, in that instant (simultaneous for all observers), the state of the other.

I, personally, do not find it plausible that "non-simultaneity" is wrong. I also do not believe observation alters the observed (which requires every observation to be a time-reversed process). The only reasonable position I can see available is to presume that observation doesn't alter the universe, observation alters the observer.

Until we run out of local & causal explanations we shouldn't presume explanations that are provably wrong. The most puzzling thing about action-at-a-distance is that people who supposedly understand special relativity think it's a viable model.

I've attached a diagram to highlight the problem. In a standard Bell's experiment, issues of simultaneity are eliminated. I set up a thought experiment to highlight the problem.

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Physics, Astronomy & Cosmology / What is a Resonant Cavity Thruster (EmDrive)?

« on: 01/09/2016 21:32:45 »

My gut instinct is to file this with perpetual motion. But, it keeps coming back in news articles.

https://en.wikipedia.org/wiki/RF_resonant_cavity_thruster

http://www.ibtimes.co.uk/emdrive-nasa-eagleworks-paper-has-finally-passed-peer-review-says-scientist-know-1578716

It would violate conservation of momentum, as I understand it.

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Geology, Palaeontology & Archaeology / What causes Earth's magnetic field?

« on: 28/07/2016 09:05:21 »

I've heard that spinning or flowing iron in the Earth's core causes the magnetic field. What is the physical process? Spinning iron doesn't generally cause a magnetic field. Molten iron doesn't have a net field, usually.

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Physics, Astronomy & Cosmology / Where does an event horizon first form in a Black Hole?

« on: 01/04/2016 01:09:52 »

A spherical, homogeneous planetary mass would have a characteristic escape velocity. If there were a vertical shaft reaching down to the center of the planet, there would be an escape velocity associated with this center of gravity. It would be the escape velocity from the surface plus the velocity needed to get from the center to the surface (equal speed & opposite direction to the velocity an object would achieve falling from the surface, down the shaft, to the planet's center.

An event horizon is thought to form when the escape velocity for some point(s) reaches the speed of light, c. So, if a homogeneous mass were to be uniformly compressed until an event horizon formed, the EH would first form at the center point and not at the surface.

Correct?

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Physics, Astronomy & Cosmology / Superfluid Question

« on: 13/03/2016 22:32:28 »

What happens to a superfluid under unequal gas pressures?

Suppose unequal pressure were applied to the apertures of a “U” shaped pipe half full of superfluid. Would it do something weird or would it just act like a regular liquid?

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New Theories / Why event horizons cannot form

« on: 23/12/2015 22:25:36 »

Einstein accepted that black holes, gravitational collapsars, are inevitable, but he insisted to the end of his life that event horizons are impossible. The reason they are impossible is they would require infinite time to form. Here, I present a simple thought experiment showing why they cannot form in finite time. I begin with the assumption that a Schwarzschild black hole does exist and then show how nothing, not even light, can travel from any point in spacetime to the event horizon.

Consider a gedankenexperiment with a platform, stationary with respect to the black hole. On the platform are a laser, a winch, and two light detectors. The rope payed out by the winch supports a mirror. The laser beam reflects on the mirror and is returned to the platform. As the light beam travels downward, it is blueshifted. As it travels up to the platform, it is redshifted the same amount so that when it returns to the platform, it has the same wavelength it had when it left.

The winch will lower the mirror, paying out rope at a constant rate, x m/s.

When the mirror has been lowered to the event horizon, just before it passes beyond the event horizon and the reflected beam goes out, the light beam will have been infinitely blue shifted going down and the return beam will be equally redshifted coming back up. The laser beam will possess an infinite number of light wave cycles. Because the laser generates light waves at a constant and finite rate, an infinite time is required for it to generate this beam. Before the time a light wave from the laser can reach the event horizon, an infinite amount of time will pass on the platform.

Note that the location of the platform and the speed at which the mirror is lowered are irrelevant.
Consider a freely falling object, dropped from the platform. At any time in its descent, it will have some velocity, y(t_0). To show such an object cannot reach the event horizon, redo the experiment with the mirror being lowered at velocity x=y(t_0). Because the falling object is accelerating from zero to y(t_0) and the mirror has been lowered at the velocity y(t_0) for the whole time, the mirror will always be ahead (below) the freely falling object. Because the mirror cannot reach the event horizon in finite time, the falling object cannot.

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Physics, Astronomy & Cosmology / Action-at-a-Distance vs Relativity: Are the two incompatible?

« on: 15/12/2015 08:15:21 »

Relativity requires "non-simultaneity"
Action-at-a-Distance requires simultaneity

Either Special Relativity is wrong at its core (universality combined with constant c make for non-simultaneity) or Action-at-a-Distance is the wrong interpretation for entanglement.

Multiverse models can provide consistent and local interpretations. Why are they not considered worth consideration?

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General Science / What process generates Earth's magnetic field?

« on: 15/12/2015 08:00:03 »

To have a net magnetic field, there needs to be a net electrical current. Spinning liquid metal, or anything, has no net current unless there's charge separation. Is the central core at a different voltage than the mantle? Does some aspect of the turbulence pull charge from one material to be carried away by another, e.g. electrons from metals captured in silicates?

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Physics, Astronomy & Cosmology / Looking for causally consistent view of entanglement

« on: 27/10/2015 22:19:07 »

The paradoxes (misunderstandings) associated with observations in quantum mechanics, the quantum measurement problem (what happens when "a wavefunction collapses”) and action-at-a-distance (in the contemporary interpretation of entanglement) cannot be explained by a self-consistent theory in a classical “universe" model. But, it’s simple enough in a multiverse model. Note: a multiverse model needn't have any redundancies, unlike the Many Worlds interpretation. In a multiverse, purely causal and local explanations suffice and "quantum weirdness", e.g. action at a distance, is also eliminated and all physics becomes local.

   •   Considering the problems inherent to observation altering the observed… An obvious (to me) problem is that the events leading to any observation alway precede the observation. If events are not defined until they are observed, then the past can have no specific state until the state information reaches “the" observer. At a quantum level, this is most dramatically represented in delayed choice experiments. Those require the unobserved state information to remain isolated from observation… a very special state of events.

   •   The current model requires that there can only be one “real” observer for any event in the whole universe. Consider Schrödinger’s Cat. Suppose the experiment is done in a specially designed laboratory, enclosed by a Schrödinger-catbox-quality wall. The wall is information-proof. Within the lab, the experiment is performed. Outside the lab, everyone knows the experiment has been completed. Yet, for them, the cat and the scientists that have observed it, exist in an indeterminate state. So, are the observations of the scientists within the lab insufficient to collapse the wavefunction? When the lab is opened and the rest of the world can learn the results, is that when the experimenters assume a definite state, including their memories? That is when the cat’s state becomes real for the external observers.

   •   The absolute requirement that the wavefunction collapse extend across limitless distance, instantly, is obviously absurd to anyone familiar with special relativity. Simultaneity doesn’t exist except for individual reference frames. For any two events, (A) & (B), in spacetime there these three categories of observers exist: Observers for whom the events are simultaneous, observers for whom (A) precedes (B), and those for whom (B) precedes (A). Relativity requires that all three of these perspectives are equally valid. There are no alternatives: either action at a distance is a misinterpretation of quantum entanglement or special relativity is entirely wrong in its fundamental assumptions.

    •   Relativity requires that all events in spacetime, future and past, exist as an unchanging backdrop. This is a consequence of non-simultaneity. For events to be past for some observers, while still in the future for others, requires that the same events be available to all possible frames of reference*. [*Einstein hated this because he (correctly) saw it and human free will as mutually-exclusive. I don’t think he would have liked it any better had he considered it in a multiverse context.]

All of these problems are resolvable only in multiverse models in which every allowed outcome instantiates for some observers, though their world views must be mutually incompatible. Any model that accepts both relativity and quantum mechanics must include the fact that all possibilities exist, measurably (’Bell’s Experiment’ or ‘Inequality’) and that every observed state exists in spacetime, not only after observation, but prior to observation, for every observer.

To me, the obvious conclusion is that observation alters the observer, not the other way around. We have QM modeled outside-in when it must be viewed inside-out (science is based on observation, assumptions about the nature of reality beyond the observable are just assumptions). From the observer’s perspective. The indeterminacy of unobserved, though measurably real, events just shows that observation doesn’t define the event to anyone but the observer. Observation determines the event the observer gets. The states that the observer can entangle with. We don’t see the alternatives because that would require the observer to entangle with at least one causally-inconsistent quantum. Observable reality cannot violate any conservation symmetries, so it can only be observed to be causally-consistent, for each observer.

So far as I can tell, the only arguments against a multiverse interpretation are aesthetic and require discarding causality as a physical principle. Without the presumption of causality there is no logical basis for believing observations have anything to do with physical events. Basically, physicists have thrown away physics in order to preserve the classical universe model and just declaring that QM cannot be understandable.

The obvious advantages to an observer-centric interpretation of QM is that it's causal, consistent with Schrödinger's equation & all QM observations... making clear that action-at-a-distance is an inevitable artifact of perspective and removing any weirdness from even the delayed choice quantum eraser experiments. The model makes QM consistent with relativity, so long as spacetime is expanded to include all allowed events, though only those consistent with any observer's state will be observable by that observer (we each have access to "cross-sections" consistent with us).

This doesn't eliminate the problem of observed vacuum energy being different from calculations by about 15 orders of magnitude, but that's a different error... modeling a microscopic region of vacuum as a microscopic universe instead of as a tiny part of a 14 billion light year radius volume... but one problem at a time.

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Physics, Astronomy & Cosmology / Has Time Rate Underground Compared to at the Surface Been Measured?

« on: 17/07/2015 01:50:38 »

As one moves deep into the Earth, the force of gravity will drop. At the Earth's center of mass, the force of gravity will be zero, since gravity will pull equally in all directions. General Relativity requires that time will flow faster in regions of lower acceleration (gravity or motion). Time should run faster below-ground than above.

Has an experiment been done to verify that time runs faster below ground than at the surface, by the expected amount?