exchemist

What "contact" was lost? I thought radio didn't work under water.

Sure but the image is effectively split into an infinite series of images, one for each wavelength, is it not? So it does involve splitting into colours. That's why its full name is "chromatic" aberration, surely?

I've told you how μ₀ is measured, the most modern being via measuring α, the fine structure constant and then applying the values of the charge on the electron e, Planck's constant h, and the speed of light c, by mean of the relation μ₀ = 2αh/e²c. This is all done in the lab and does not need to involve relativity. Acceleration does not come into it. The units of μ₀ are N/A², i.e. force/current squared, which falls out of the formula. α itself, i.e. the thing being measured, is dimensionless. You say "therefore light speed is relative to the frame" but this firstly does not follow and secondly it is contrary to observation, namely that the speed of light is not relative to the frame of reference. You seem to me to be looking at this from the wrong end of the telescope. This being science, it starts from the observations and then derives theories consistent with them. c is found by observation to be invariant and not frame dependent. So that is what we start from, not where we end up by some derivation or other. So it's pointless futzing around with formulae containing c and trying to show that it can't be constant, due to some claimed frame-dependence of one or more quantities in a formula, when experiment says otherwise.

This is nonsense. So long as observer and the observed phenomenon are all in the same frame of reference, you don't need to concern yourself at all with the issue of reference frames. There is no "relative motion between frames" when you measure μ₀, or Sommerfeld's constant (the fine structure constant), α. Everything is in the same lab, including the observer, and the phenomena observed in the making of the measurements do not involve relativistic effects. Nothing in physics says that μ₀ is frame-dependent. You appear to be making this up, in a forlorn attempt to pick holes in relativity, without understanding what μ₀ is.

You have misunderstood this. The magnetic constant is still regarded as, er, a constant. The distinction is that it is now treated as measured rather than defined. But it is still a constant. It makes little sense saying it is frame-dependent, as it is measured via a pair of parallel wires in the same frame as the observer, or alternatively derived from measuring the fine structure constant (via quantum phenomena, again measured in the same frame as the observer) and applying defined values of the electron charge and Planck’s constant.

Good, so we are agreed we can forget the “simulation” stuff. I would not use the term “intelligent design” for what is really just the well-known “fine tuning” argument for God. That argument is older than ID and, unlike ID, is intellectually honest, though I am not convinced by it. Though I wouldn’t be surprised if the ID people have adopted it, now that their own pseudoscience has been so thoroughly discredited. I suspect the reason the fine structure constant intrigues people more than other apparently arbitrary constants of nature, say the values of magnetic permeability or electric permittivity of the vacuum, or indeed Planck’s constant, is that it is dimensionless, i.e. just a number.

In this Wiki article: https://en.wikipedia.org/wiki/Vacuum_permittivity there is a formula that plugs in the relevant values of the quantities and shows the relation between them. It's important to use consistent units. There are some notes showing equivalent ways of expressing the units.

Well I think Sabine is spot-on, as far as science goes. The whole notion of simulation is firstly untestable, so it's metaphysics, not science, and secondly it immediately demands the question: " Simulated by who, or what, and to what end?" It's God by another name, basically - just more IT nerdy, and therefore more hip and trendy. I'm not impressed by Tyson. For a start he dismisses philosophy as a waste of time, which shows a lack of understanding of the foundations of his own subject, (details here: https://scientiasalon.wordpress.com/2014/05/12/neil-degrasse-tyson-and-the-value-of-philosophy/ ) and then, that stated point of view notwithstanding, he starts indulging in metaphysical speculation himself! (I have not watched the video, as I find videos a very inefficient way of communicating information. If you can link a write-up of the ideas, I might read that.)

What equation are you working from?

No. It’s just a number. Every physical constant has to have a value. This “simulation” stuff seems to be just an IT nerd’s version of the “fine tuning” argument for God, which I have never found persuasive.

I hadn't heard about the prostate. What does milk do to it? As a 69yr old man, I have an interest in this.

That was going to be De Sanity Clause I think. But he seems to be proving so uncharismatic and unpleasant that he's not gaining the traction he hoped, even though aping TFG at every turn. By the way, "TFG" always makes me laugh. I instinctively think it means either That F***ing Guy or The Fat Guy, though actually I gather it doesn't stand for either. Suppose if it were the latter then Chris "Zeppelin" Christie would have to be (TFG)².

Bullshit. Don't try to play the Dance of the Seven Veils. You were asked a straight question. You owe the questioner a straight answer.

Not sure I’m persuaded of that. A yuge part of Trump’s success, surely, has been his cult of personality, hasn’t it? They can’t just transfer that to De Sanity Clause or some other loathsome specimen.

On the contrary, once you have determined the real explanation for the fireball, there is nothing left in the incident we are discussing, apart from an uncorroborated report from some panicky people. Nothing. It’s just like someone seeing the Blessed Virgin on a piece of toast.

Oh dear. You really have no idea what you are doing in the kitchen, have you? Potatoes take 25-30 mins to cook. If you don't have time for that, cook rice or pasta instead. I usually steam large potatoes, to avoid the risk of them disintegrating. Small ones are safe to boil. But one point I agree with you: they are best cooked in their skins. The skins add flavour, and nutrition, supposedly. I always leave the skins in when I make mashed potatoes.

Which is not a signature for the presence of life.

Agreed. But then we are discussing how baptism evolved.

But then baptism is a sort of purification ritual too, symbolically washing away Original Sin, if I remember correctly.

Don't be ridiculous, it doesn't at all. A building block is not evidence of a building. A brick is a brick, not a house. Phosphates are just one ingredient, of many, that would be needed to support terrestrial style biochemistry.

So what? All that says is phosphorus is needed for terrestrial biochemistry. If you actually read the paper, and take in what it says, it is quite clear about the mineral processes that lead to orthophosphate, i.e. the anions of the inorganic acid phosphoric acid, being present in the water. The finding is interesting in that people had thought one of the difficulties in life getting going elsewhere might be the relative lack of phosphorus compounds. In the case of Enceladus there seems not to be this deficiency. That's all.

OK so the water is alkaline, due to dissolved bicarbonate and carbonate and this favours leaching into solution of orthophosphate - which they think they have detected. (The element is phosphorus by the way. Phosphorous is an adjective like phosphoric, e.g. phosphorous acid is H₃PO₃, whereas phosphoric acid is H₃PO₄.) The presence of phosphate is explained as due to wholly inorganic mineral processes, i.e. there is no suggestion its presence is any kind of signature for life on Enceladus.

I must admit I don't see the difference. Surely the reason why the images for different wavelengths are different sizes is because refractive index is a function of wavelength, i.e., because of dispersion and thus refraction through different angles, just as it is for a prism? The light is spread out into a spectrum by this process, i.e. the colours are separated, in both processes, surely?

There are no recordings of any "UAP" , only of the fireball which was widely reported and has a completely conventional explanation.

That's putting it mildly. It is plain that the object did NOT land anywhere that has been found - and most likely did not reach the surface at all. Given this fireball was reported by 21 different individuals, spread across 4 states of the USA, it clearly must have been a very high altitude phenomenon and travelling very fast. This is not AT ALL consistent with something "landing" in someone's back yard - and then mysteriously taking off again. Aha, I thought as much. So you are trying to drag in other - unrelated - reports, over a period of years, as evidence that this incident must have involved an alien landing, even though the evidence from the incident itself is pisspoor? I'm afraid it doesn't work like that. We are discussing this one incident, to see what merit the claims have. The evaluation stands or falls on the quality of evidence from the incident itself.