I'm trying an experiment on Patreon. I'm publishing two chapters per week of my sci-fi comedy novel, based on quantised inertia, and I'm also trying to write entries on the other days on whatever physics I happen to be thinking about at that time. A sort of online science diary. As my position in academia is becoming a little tenuous I thought this might be a good plan B, or a way to transition to more independence. The first chapter of the story is at: https://www.patreon.com/posts/38133557 I hope you enjoy it!
Wednesday 30 September 2020
I've just published what is possibly the most elegant paper I have ever written. I sent it to various journals who all turned their noses up at it (one sympathetic editor told me that reviewers were refusing to review it en masse) so thank you to Advances in Astrophysics for giving it a home. In it, I derive quantised inertia in eight lines from information theory, just by assuming that information is stored in Planck-length spaces.
Consider the diagram below. This represents, in one-dimension, an object (say, an owl) by the thicker vertical dashed line on the left. Initially the owl is just sitting there so it sees the cosmic horizon on its right, the right-most vertical dashed line. The owl has a lot of information about space. The Planck length is the smallest region of space in which information can be stored and in the diagram (not to scale!) Mr Owl can see 26 bits of space. Then imagine someone rudely moves him abruptly to the left. Suddenly information cannot catch up to him from far to the right and the horizon he sees moves closer - see the middle vertical line. Now the owl can only see nine bits of space.
Now, of course, this example is only one-dimensional but I think it offers a new, simpler and deeper way to understand quantised inertia, and derive it. I hope that information theorists will pay attention. It is a sign that their subject is just about to conquer the rest of physics. Welcome to a new branch of physics. And the owl? Understandably, he's chosen a new branch to sit on. Higher up in the tree.
McCulloch, M.E., 2020. Quantised inertia and galaxy rotation from information theory. Adv. Astrophy., 5, 4. http://www.isaacpub.org/4/2050/5/4/11/2020/AdAp.html
Tuesday 8 September 2020
Imagine a ball in space. Strictly speaking in physics and especially in quantised inertia you can't start talking about it being stationary or not because it has to be moving relative to some other object, so let's say it's static relative to a nearby teapot, but far enough away that the attraction from the teapot is small.
Now put a horizon on one side of it. According to quantised inertia this will damp the Unruh waves from the direction of the horizon and so the ball will be pushed by the imbalance in the Unruh radiation field towards the horizon. Another way to think about the same thing, the informational way (see reference) is that the horizon deletes the knowledge the ball has about the cosmos beyond it. Landauer's principle says that every time you delete information, say, you erase 101011 to 000000, then entropy decreases. That cannot be allowed, so the second law of thermodynamics says that high-entropy heat energy must appear to compensate. So computers get warm when you erase data. I've calculated this energy for the deletion of space, and it turns out to be just enough to power the movement of the ball predicted by quantised inertia (see ref).
So the ball accelerates towards the horizon. Now, as pointed out by several people online or in emails, what happens if suddenly the horizon disappears so the ball gets back all its knowledge about the cosmos behind it? The problem is, it still has the kinetic energy it picked up from the loss of information. Does it lose the energy when it gets the information back? The answer is not necessarily "Yes", because although the second law of thermodynamics says that 101011->000000 must release energy, there is no such imperative for 000000->101011, since there is no drop in entropy.
Can we use this asymmetry, and repeat the process to generate energy? I think that is what is happening with the cycling photons (near and horizon, then far..etc) in the emdrive. However, this brings up many fascinating new questions to ponder. Where is the information 'stored' while the horizon is close, so the system can get it back when the horizon is gone? Can information or heat be swapped between reference frames? How does this relate to the black hole information paradox?
Getting philosophical for a moment it makes sense that our new ability to model worlds ourselves (simulations, games) is inspiring new models of the one we are in, including my recent attempt to express quantised inertia using information theory. Is it just the latest useful analogy? (Probably). Is the cosmos a self-evolved bit-system? Or are we in a deliberate simulation? I'm sure the theologists will spend many a happy hour discussing that!
McCulloch, M.E., 2020. Quantised inertia, and galaxy rotation, from information theory. AdAp (accepted). Summarised in my ANPA talk here (the relevant bit starts at 16:24)
Thursday 3 September 2020
Sunday 9 August 2020
I am impressed with the six quantised inertia experiments that are going on around the world. The spirit of science and curiosity is being brilliantly represented by the people who agreed to be part of my DARPA project, and by some of those I met at conferences or on twitter. It is exciting to see the number of experiments growing every month. To recap, all you need to do is to get light to accelerate enough (bounce around, circulate) inside an asymmetric metallic setup.
However, there is a learning process due to my lack of experience in experimental design .. and telling people what to do! The aim is to prove or disprove quantised inertia in a lab test. To do that, we have to be able to make a specific enough prediction that the lab tests can detect or rule it out. With QI this is uniquely possible since, in its simplest form, the expected thrust is F=PQ/c. The power of the light used (P) is known, so is the speed of light c. What is difficult to know is the Q factor, which is crudely the number of times the light bounces around / circulates in the cavity before dissipating as heat. What thrusts the cavity in QI is not the force from the photons (F=P/c) but the metal cavity making a gradient in the Unruh radiation pushing on the cavity (F=PQ/c).
So far, in all the tests done by, for example, the lab in Dresden, we have not known the Q factor of the cavity. In Dresden this is because Tajmar could only determine that Q was "greater than 19" and also because, as a quick and dirty approach, he used a system (an open cavity) that our cavity model could not cope with. What has proved to be a better experiment is the fibre-optic loop being tested in Madrid. The great advantage of this setup is that the Q is simply the number of times the light goes around the loop - a sort of electromagnetic version of a Formula One race. Orderly & quantifiable!
From now one we need to make sure that in all experiments both Power P and Q are known. I should have listened to my mother who always used to tell me to "mind my Ps and Qs".
Saturday 25 July 2020
Tuesday 16 June 2020
McCulloch, M.E., 2020. Can nano-materials push off the vacuum? Progress in Physics, Vol 16, 2. http://www.ptep-online.com/2020/PP-60-02.PDF
McCulloch, M.E., 2017. Testing quantised inertia on emdrives with dielectrics. EPL, 118, 34003.