I chose the title Physics from the Edge mainly because the theory of inertia I have suggested (MiHsC) depends on local physics being determined by the Hubble-horizon. My webpage is here, my twitters here, and I've written a book on MiHsC called Physics from the Edge.

Friday, 26 September 2014

Back to the Flyby Anomalies


Ah, the flyby anomaly. I had a lot of fun with that back in 2008 and maybe the game is not yet finished. Spacecraft Earth flybys are used by NASA to save on fuel. If they want to get a probe to Jupiter for example, but don't want to launch the heavy fuel needed, then what they do is launch the probe slow, loop it round another planet and bring it in behind Earth in its orbit, and the Earth then pulls the spacecraft forward and transfers some kinetic energy to it. An analogous method was used by Marty McFly in Back to the Future: he hitched a skateboard ride by holding onto a car. These flyby spacecraft are monitored as they zoom past the Earth and in 1990 the Galileo probe gained 4 mm/s of speed more than it should have. This was not a lot given the actually heliocentric (relative to the Sun) speed of 31 km/s, but well outside the uncertainty. This also happened for a few other flybys as well, the largest anomaly being for the NEAR (Near Earth Asteroid Rendezvous) probe which gained 14 mm/s speed from apparently nowhere. Anderson et al. (2008) collected all the data together and showed something that got me very excited at the time: there was a pattern. Spacecraft that came in at the equator, and left nearer the spin axis (the pole), sped up more!

After a lot of thinking and calculation I managed to show that MiHsC predicts something like this. When a spaceship comes in at the equator the mutual accelerations between it and typical masses inside the spinning Earth are big because the acceleration vectors are often along the same line (the Earth mass accelerates towards the spin axis, the craft also towards that axis). So MiHsC predicts the Unruh radiation seen has a short wavelength and fewer waves are disallowed by the Hubble-scale Casimir effect, so the inertial mass is close to the normal mass. Conversely, when the craft exits at the pole, the mutual acceleration between it and the masses in the Earth is smaller since the acceleration vectors are now perpendicular, so MiHsC predicts longer Unruh waves, more of which are disallowed by the Hubble edge, and the craft loses inertia slightly. To conserve momentum it has to speed up. Calculations show that this does a pretty good, but not perfect, job of predicting the flybys without any adjustable parameters (see my paper below). The way I derived this result is not perfect though, since I have not yet calculated the 'total' mutual acceleration including the spacecraft's own acceleration, and this I need to do. For this I could use the brilliant NASA Horizons web-interface, that I've used before, and where spacecraft trajectories are available for free. http://ssd.jpl.nasa.gov/horizons.cgi

What reminded me of the flybys was a recent article, in the Spanish SINC website (see SINC reference below) which piqued my interest by saying that "One of the last [flybys] was that of the spacecraft Juno in October 2013, from Earth en route to Jupiter. NASA has not yet published data on this journey, but everything indicates that its speed as it flew over our planet was once again different to estimates". This was news to me because I pestered ESA and NASA last year and they told me there was no Juno anomaly. It's probable that the comment in the recent article was based more on expectation than evidence, but ESA/NASA have not yet published anything formally on the Juno flyby. MiHsC predicts a small positive anomaly (but as I said before I don't yet consider the motion of the spacecraft itself, which needs trajectory modelling). Time to do some fortran programming..

References

Antreasian P.G. and J.R. Guinn, 1998. Paper no 98-4287 presented at the AIAA/AAAS Astrodynamics specialist conference and exhibition, Boston.

Anderson J.D., J.K. Campbell, J.E. Ekelund, J. Ellis, J. Jordan, 2008. Phys. Rev. Letts., 100, 091102.

McCulloch, M.E., 2008. Modelling the flyby anomalies using a modification of inertia. Mon. Not. Royal. Astro. Soc., Letters, 389 (1), L57-60. Link to pdf

SINC: http://www.agenciasinc.es/en/News/An-anomaly-in-satellites-flybys-confounds-scientists

Tuesday, 16 September 2014

EmDrives & MiHsC


It's a gamble, but I think it's important to focus on anomalous experimental results since the new stuff always comes from there so I thought it would be useful to recap what I have been thinking about regarding Shawyer's EmDrive results. You should bear in mind that this is an example of me wildly playing around with ideas and I may decide tomorrow it is wrong. So, just to remind you that the EmDrive is a cone-shaped microwave resonant cavity, like a microwave oven built into a megaphone. When microwaves are resonated in there, it has been shown by Roger Shawyer, also a Chinese group and recently a NASA group that a small anomalous force is produced and the cavity moves towards its narrow end. This apparent violation of the conservation of momentum has not been explained.

To explain it, I've assumed the following: the microwaves bouncing around within the cavity have inertial mass (em radiation does: that's why it can push a Solar sail) and their inertia is determined by MiHsC (quantised inertia). In MiHsC the Unruh waves are allowed only if they fit exactly within the Hubble horizon or within a local Rindler horizon, but what if the cavity wall in this case was acting like a horizon? Well, then the microwaves at the wide end would have more inertia than those at the narrow end since more Unruh waves would fit. This means that as a microwave beam goes from the narrow end to the wide end it gains inertial mass. Now I can try something I've used before (for the Tajmar effect) and say, in order to still conserve momentum (mass*velocity) for the whole system, if mass goes up then velocity must go down, and the only way to achieve that is to have the whole structure move towards the narrow end.

I've done the calculation using MiHsC for Shawyer's EmDrive assuming an input power of 850W, a frequency of 2.45GHz and a Q factor (number of times the waves bounce before dissipating) of 5900 and I predict a force of 12.75mN, close to the 16 mN they saw.

Again, do take this in the spirit of 'playfulness'. There are huge questions: How can I throw out the rule book on photons like a hippy on LSD, and then insist on conserving momentum like an accountant with OCD? It could be a just a coincidence that it works, but it is interesting. Comments welcome!

Tuesday, 26 August 2014

Breaking the speed of light limit?


Special relativity says that as you accelerate, say, a spaceship, towards the speed of light its inertial mass increases so it gets harder to push it any faster. At the speed of light its inertial mass is infinite so you can't increase its speed at all. Hence relativity predicts a speed of light speed limit. However, MiHsC makes a slight correction to this. The wavelength of the Unruh radiation that causes inertia in MiHsC lengthens as the acceleration reduces which means that, for the spaceship case above, as the speed levels off and acceleration tends to zero near the speed of light, the Unruh waves making up its inertia exceed the Hubble-scale and cannot be observed. This means, using the philosophy of Mach that special relativity itself was based on, these waves should dissapear, and the spaceship's inertial mass should reduce. Indeed, putting MiHsC and relativity together (in a very preliminary way) you can show that there remains a residual relativity-proof acceleration of 2*(speed of light)^2/(Hubble scale) even at the speed of light: this is the minimum acceleration allowed by MiHsC. Interestingly this is close to the cosmic acceleration that has recently been observed and is usually explained in an ad hoc manner by dark energy.

For such a claim of course, far more direct evidence needs to be found. There are ways in which observations of quantum systems demand non-locality and superluminal information transfer (Bell's inequalities), but my favourite possibility at the moment involves the more direct evidence of galactic jets. Looking at the movement of blobs of light within the jets streaming out along the spin axes of galactic cores and quasars, and knowing the distance of these objects, it is possible to show that these blobs appear to move faster than light (eg: Porcas, 1983, Biretta, 1999). Before we get too excited, Martin Rees (1966) showed that light-emitting objects moving at sublight speeds can appear to travel faster than light if they are moving at a small angle to our line of sight. However, that being so, one would expect the jets that show faster than light speeds to all be apparently 'shorter' since they should be pointing towards us, but it has been shown that they are not shorter on average than all the other ones, which implies that they are not on average close to our line of sight. A particular case is M87 (Biretta et al., 1999). The blobs of light in its jet are moving at six times the speed of light. To explain this away as the Rees effect one would need this jet to be within 20 degrees of our line of sight, but an analysis suggests that this angle is 44-64 degrees, and to get it within 20 degrees would 'present several problems' (Biretta et al., 1999).

I know this is a horrifically complex area to get into, and causality will have to be thought about too which means that thinking about it is rather like taking an axe to the floor one is standing on, but I do think this is important, doubly so since I'm one of the few arguing that FTL (Faster Than Light) is possible. I've had some problems publishing anything on this. I've submitted papers, and I gave a talk on MiHsC and FTL at the 100 Year Starship Symposium in Orlando in 2011, and my talk was filmed and was supposed to be made available. Nothing happened, and nothing happened to the paper I sent to them either, so I'm very glad to finally have a chance to publish something on FTL in my book.

References

Biretta, J.A., et al., 1999. Hubble space telescope observations of superluminal motion in the M87 jet. The Astrophysical Journal, 520, 2, 621-626. http://adsabs.harvard.edu/abs/1999ApJ...520..621B

Porcas, R., 1983. Superluminal motion - astronomers still puzzled. Nature, 302, 753-754. http://adsabs.harvard.edu/abs/1983Natur.302..753P

Rees, M.J., 1966. Appearance of relativistically expanding radio sources. Nature, 211, 468-470.

McCulloch, M.E., 2014. Physics from the Edge: a new cosmological model for inertia. World Scientific Publishing.

Sunday, 17 August 2014

Shawyer's EmDrive


I remember an article in New Scientist a few years ago that discussed something called the EmDrive. This article was criticised at the time by some theoretical physicists, but they couldn't explain the actual anomaly found by Roger Shawyer, an aerospace engineer. He used an asymmetric radio frequency resonant cavity (cone shaped) and pumped a few hundred Watts of microwaves in (just like an asymmetric microwave oven). The cavity then accelerated slightly in the direction of its narrow end, in blatant violation of the conservation of momentum. Shawyer claims this result is predicted by special relativity, while most theorists say a violation of momentum conservation just can't be, but the anomaly itself now seems more solid because it has been reproduced by the Chinese (Juan et al., 2012) and recently by NASA (Brady et al., 2014). The experiment hasn't been done in a vacuum yet, but the abrupt termination of the anomaly when the power is switched off, has been taken as a preliminary demonstration that it is not due to movements of air, but this needs further testing.

This is exactly the sort of naughty violation of momentum conservation that one would expect from MiHsC. It is possible in MiHsC because what is conserved is not mass-energy but Energy-Mass-Information (EMI) and so you can extract energy in a new way, from apparently nothing, by inserting an information horizon into the zero point field. In papers in 2008 and 2013 (see below) I proposed that one could use the recently discovered metamaterials (regular arrays of metal shapes) to make artificial information horizons and thereby interfere with the Unruh radiation that is assumed to cause inertia in MiHsC, and by this means cause anomalous motion. Therefore, the asymmetric metal structure used by Shawyer is of interest to me. Nevertheless the proof is in predicting the right numbers and I haven't worked out how to model Unruh waves in a cavity, in my usual simplified manner yet. Anyway, thanks to the engineer Roger Shawyer, the Chinese and NASA for providing an interesting anomaly to think about.

It is common for engineers to accept the reality of phenomena that are not yet understood, and it is common for physicists to disbelieve the reality of phenomena that seem to contradict contemporary physics - H. Bauer.

References

Brady, D., et al., 2014. Anomalous thrust production from an RF test device measured on a low-thrust torsion pendulum. Conference proceedings. Abstract

Juan W., 2012. Net thrust measurement of propellantless microwave thrusters. Pdf

Shawyer, R., 2014. SPR Ltd. Website

Shawyer, R., 2008. Microwave propulsion - progress in the emdrive programme. Pdf

McCulloch, 2008. J. Brit. Interplanet. Soc., 61, 373. Can the flyby anomalies be explained by a modification of inertia?

McCulloch, 2013. Inertia from an asymmetric Casimir effect. Europhys. Lett., 101, 59001. Preprint

Sunday, 20 July 2014

Backwards Supernova


Einstein's special relativity was a great and very bold insight, and was based on a sceptical philosophy of Ernst Mach's. This philosophy is that abstract concepts like time and space modify so that whatever it is you see of a process, in your reference frame, that is 'real', which means the normal laws of physics have to apply to it. That includes, presumably, the second law of thermodyamics that entropy/disorder must increase.

Now imagine, just for the sake of argument, that you're zooming away from a supernova at more than the speed of light. As you go, you're overtaking the light coming from the supernova, so you'll see the supernova going backwards in time (rather like the introduction to the film Contact, where a spaceship traveling away from the Earth at speeds greater than light relives radio history backwards). A layman might explain this as just being how you see it, but if we accept special relativity (and it has been well tested in this way, by Hafele and Keating, 1974) we have to go further and say that this backwards supernova is 'real' so the laws of physics must apply to it. This is alright for most of the laws of physics since most are easily reversible. For example, you can reverse the velocity of every particle in the supernova and they still obey Newton's laws, but if you see the supernova converging on itself then there is a reduction of entropy in time, since it is approaching a special state. This violates the second law of thermodynamics. So special relativity's insistence on what you see being 'real' forbids faster than light travel if we accept this second law. A related problem is that causality is violated too.

A more famous reason that relativity forbids faster than light travel is that when an object approaches light speed its inertial mass approaches infinity and you can't push it any faster so it has constant speed. However, MiHsC challenges this because at a constant velocity the Unruh waves that MiHsC assumes cause inertia would become larger than the Hubble scale and vanish, so the inertial mass would dissipate in a new way. This means, if you do the maths, that MiHsC predicts that a tiny minimum acceleration remains, even at the speed of light, meaning that this barrier can be broken.

The problem I have now is that, if this is true, how can I reconcile MiHsC and its tentative faster than light possibility, with the supernova problem and the violation of causality I mentioned above?

Quote by Werner Heisenberg: "How fortunate we have found a paradox. Now we have some hope of making progress!"

Saturday, 12 July 2014

Proxima Centauri: a test in our cosmic backyard?


I recently looked into the Alpha Centauri system in preparation for a talk I went to see on it. This system is also called Rigil Kent, a great name for a superhero, and is the closest stellar system to us (only 4.37 light years away) with two stars, A and B, similar to the Sun which form a tight binary system orbiting every 79 years, and a third called Proxima Centauri which is much further out and far smaller in size. The interesting thing for me is that little Proxima is so far out (13,000 AUs) that its acceleration with respect to the other two is in the regime where MiHsC should apply (of order 10^-10 m/s^2).

MiHsC says that a body with such a low acceleration relative to nearby matter (stars A and B) will lose some of its inertial mass in a new way, and this means it will be more easily bent gravitationally into a bound orbit even by a lower than expected central mass. This is exactly how MiHsC predicts bound galaxy rotation without dark matter (McCulloch, 2012) and it also predicts that Proxima should be bound gravitationally to A and B even though their masses should appear to be too small to bind it.

From my limited reading of papers so far, this seems to be the case. Proxima moves through space with stars A and B so it looks like it's bound to them, but Matthews and Gilmore (1993) found that according to Newton's laws Proxima should not be bound. To fix this problem they suggested increasing the mass of A and B to hold Promixa in to the system. Of course, this sounds just like the dark matter fix used to allow galaxies to remain bound without changing Newton's laws. The great thing for me about this Centauri mismatch is that dark matter cannot be used to explain it, since dark matter has to stay spread out on these small scales if it hopes to explain the galaxy rotation problem.

To prove MiHsC I've been looking for a problem for which it is the only possible solution: a crucial experiment. I might have found one in our cosmic backyard.

References:

Matthews and Gilmore, 1993. MNRAS, 261, L5

Wertheimer and Laughlin, 2006. Are Proxima and Alpha Centauri Gravitationally Bound? Astron. J., 132, 1995-1997. http://arxiv.org/abs/astro-ph/0607401

Tuesday, 1 July 2014

New book

I've written a book about inertia and MiHsC, titled: 'Physics from the Edge: a new cosmological model for inertia'. It's being published :) by World Scientific, and is advertised online here.