MigL

No, apparently he has back pain issues; he even walks funny sometimes. I had heard that, in the last seasons, the pain was so bad he wanted to quit. I always thought the premise for a kid being at the helm of a starship a little far-fetched. They could have put him in Security instead, and given him a red shirt ...

From your link http://blogs.scienceforums.net/swansont/archives/1043 "Starship Mine isn’t the only episode on which I had some influence. I tried to kill Wesley Crusher once (unsuccessfully, obviously)" A lot of people probably wish you had succeeded. He certainly was annoying, and continues to be a source of irritation for Sheldon Cooper.

@Markus Hanke I understand the concept of background independence, I simply meant that, while space-time is the immutable background stage on which QFTs act, in GR, space-time is itself an actor, and nothing else is required 'beneath' that. However, I was surprised to learn that QFTs require a background ( as you state ). It seems that 'background independent' QFTs are an active area of research, A google search provides quite a few links to background independent Quantum Field Theory of Gravity papers ( quite a few involving LQG ), so maybe the jury is still out on whether Quantum Gravity, and a Graviton ) is possible or not.

I had trouble finding the appropriate word. Updated implies there was a reality prior to a measurement ( carried over from any previous measurement ), but I am of the opinion that we don't, and can't, know the particular state between measurements. It is the measurement, or interaction, that 'sets', or 'establishes' what is real ( maybe I should put quotations around real also ). Your fault. Didn't you do some consulting for them ?

We are a science site, and we discuss evidence based facts, not beliefs, and certainly not this crap.

In very simple terms, 'reality' is ( as close as we can tell ) what we measure. The act of measurement collapses the wave function and ( sort of ) establishes 'reality'. In between the two measurements, what we have is a mathematical expression called a wave function that describes all possible states of the particle we will measure. This is not a 'wave' of the particle's field ( QFT ), as you ask in your other post. The square of the absolute value of the magnitude of the wave function, describes the probability of locating the particle, so the wave function is simply a probability amplitude or density ( not sure of the appropriate term ), rather than the 'waving' of a field. ( although I'm sure someone has used a 'probability field' to help their calculations; any field is a value associated with each point ) The term 'no local realism' simply references the fact that one of the most accurate models we have to describe 'reality', tells us that , between measurements, 'reality' is simply a mathematical expression devoid of any reality.

Not at all; but saying probability densities can manifest faster than c just isn't 'sensational' enough.

Thanks for that Joigus. It does relate to scale, as my original assertion was that at Planck time, or at Planck scale, physical geometry might vanish. And I've been unsuccessfully trying to make my position clearer to Genady that, while 'textbook' geometry does allow for singular points, the physical geometry of space-time cannot support such structures. IOW infinities are useful, and fine, in mathematics, not so much in the Physics of the real world.

Textbook geometry might be fine with singularities, but I don't think space-time geometry is. My opinion; take it for what it's worth.

OK. I like all the older ones up to and including Voyager, and I like Strange New Worlds. I hate everything in between. I didn't know you wanted me to be specific, or that anyone was that interested in my likes and dislikes.

As I said It may, however, have been global, as local would require a specific field configuration, not a homogeneous isotropic energy distribution. Exactly. As happens when geometric curvature goes to infinite at a singularity.

Maybe we can just agree that science itself has no bias, but it is done by humans, who do have biases. I, myself, prefer LQG over Sstring Theory. And TheVat and I prefer the older Star Treks over the newer ones.

GR is a geometric theory. Any geometry can be used by ( a version of ) GR to define that space-time. For example, a specific 5dimensional version of GR can be used to describe space-time with EM fields ( see Kaluza-Klein ). Absence of ( or undefined ) geometry makes GR fail. But if you don't wish to provide an example of GR without geometry, you don't have to. Any field will have an associated energy density, and any energy, be it in the form of mass, stress, or momentum, will be a source of gravity. Even the gravitational field itself, is a source of gravity. The symmetry break that precipitated the decoupling of electromagnetism from the weak interaction, and the acquisition of mass for leptons, quarks and some bosons, was due to a false zero energy level. It was the slow roll down from this false zero level that provided the impetus for inflation, which I thought happened between 10-35 and 10-32sec.

GR defines space-time using its geometry; if there is any 'geometry', GR can use it to describe the space-time. For GR to not be applicable there has to be an absence of 'geometry', such as geometry becoming infinitely curved. Or can you show me an example of GR describing a space-time without 'geometry' ( does that even make sense ? ).

There are two types of time dilation; one due to motion relative to the observer, and the other due to depth in a gravitational potential well relative to the observer. In the first case we would notice time dilation of distant galaxies if they were moving away from us, but this effect would be non-linear ( as Mordred has explained ) since dilation increases asymptotically as c is approached. The Hubble expansion constant is, however, just that, constant, and mostly linear ( except for the slight up-tic due to accelerated expansion ). The second case would involve everything we observe, in all directions, being deeper in a gravity well than we are, in order to see a time dilated red shift; and that makes no sense due to the shell theorem. If you know of another type of time dilation, please educate us ...

Ah, so many 'wanna-be' Philosophers who think the universe resides in their mind, and its reasons and workings can be divined in their own heads. Good Philosophers temper their ideas with science and evidence based facts, before attempting to preach to us peons.

Or the weapons used by the android world at the end of Picard S01, that looked like flowers. Maybe they should call Swansont back to consult on the science, as all the new shows are destroying a dynasty, and I will not watch them. Except Strange New Worlds, which I like.

If you don't wish to build anything, there are, at least for infrared, 'off the shelf' cameras that can be purchased, which detect infrared sources and dispay them on a screen. I used to use one for detecting integrated circuits that had failed ( or were close to failing ) and heating up due to excessive power draw. Digital multimeters are available for $20 on eBay/Amazon for detecting low voltages and low currents on automotive or digital circuits. If you are going to test for voltage/current on your mains or higher, I suggest something with good protection, like a Fluke. The cost will be much higher, but there's nothing worse than testing a 300 or 600 volt circuit, and having your meter blow up in your hand and catch fire.

Well, to be fair, he did say and, true to his word, he didn't present any, and there is nothing to dispute or discuss on this discussion forum. Might as well close the thread, then.

Why all the comparisons of human designed airplane wings to bird wings ? The first flying machines were balloons, and had no wings. Oh, and I could design a much better system than these crappy eyeballs I have in my head. The Nikon autofocus and stabilized lenses for my camera aren't prone to hi pressure and image loss due to glaucoma.

GR has no stage to act on ...

I have posted that there may be some biases in science, gave a few examples, and even posted my definition of a 'bias' to support my stance. That being said, science, and the scientific method, is like democracy; certainly not perfect, but way better than any alternative.

I would say that, since GR is geometric, and GR fails on approach to Planck time, any notion of geometry ( spatial or temporal ) is similarly not applicable. Fields have an energy density; any field will contribute to the stress-energy-momentum tensor, and curvature.

MiG is currently a division of United Aircraft Corporation, also including Sukhoi, Tupolev, Yakovlev, Ilyushin and others. It was originally known as the Mikoyan and Gurevich Design Bureau after the engineers who founded it during the first stages of WW2, Artem Mikoyan and Mikhail Gurevich. Both have been deceased for over 50 years, and design duties passed on to be succeeded by R Belyakov ( I believe ). Over the years they have produced iconic interceptor/fighter jets which have sold in great numbers because of low cost and 'simplicity' of operation, including MiG-15 ( Korean war ), MiG-19-21 ( Vietnam war), and MiG-25 ( Iraq, and V Belenko's famous defection in 1976, with vacuum tubes in the radar ). As with your other thread, I can't take this one seriously either.

@Airbrush Why do your posts often sound like sermons ?