studiot

I think swantsont's comment is particularly relevent here. You need to read the actual paper and quote the reference in order to be able to make claims such as the one above about Einstein. I look forward to a proper reference/citation.

Thanks but what about trust in doctors? Surely we would give all the money we have (however rich) to save our own lives ?

I glad you found the quote interesting. However I'm not sure you cottoned on to its significance, perhaps due that the forum your quote came from (I has a quick look around there and found it very shallow and unimpressive) The important message was not about who said it (It was definitely Faraday) it was that no one could (or did) predict the course of (human) history subsequent to the nascent science of electricity that was represented as a baby, any more than anyone could tell whether that baby could turn out to be a Ghandi or a Hitler or a Bill Gates or just Joe Soap. Similarly all those discoveries or inventions listed had a major impact on subsequent human society, and sorry swansont, I disagree with your interpretation of the word Science. Perhaps we should all agree both what is meant by Science and what the OP means by 'reach', as several have asked. I understand Science to mean "An organised body of knowledge" without any restriction on what that knowledge is about. I understand the OP to be interested in a body of knowledge would allow us (human society) to move on from our present state and situation to an improved and improving one. By reach I understand a request, similar to the woman (who was not a dullhead) who asked Faraday about the baby, as to how far this might progress. So perhaps King Kobra would like to clarify my understanding.

We live in a country about to do away with juries. Perhaps the next step is to replace judges with AI ? This whole issue is much wider than just artists

No Yes What's the problem ? Artist's haven't made their own paint for more than a century, no one in their right mind has suggested the Rownney or Reeves or Dulux et al are credited along with the artist. Perhaps the picture framer should also be credited, along with the person who hammered the nail into the wall to hang it on as well as the person who made their sandwiches. At least they were all human. The whole post appears to be an 'influencer's' attempt to influence in an artistic subject. What does this have to do with SF Science news section, or even Science in general ? @exchemist +1 for the point, though I thought the imagery a tad garish.

Have you come across the phrase Look back over history could the inventors of Fire The wheel The catapault The place number system Have any idea how 'far reaching' their invention might be ?

I think America is alomost certainly going to get worse before (hopefully not if) it gets better. I also think there is an unjustified snobbery in the 'hard' sciences against the 'soft' sciences, which are nowhere so well developed or cut and dried. Perhaps one day Asimov's Second Foundation will be more of a reality than now.

What do think is an appropriate response for a person, knowing they don't fully understand what, is said to them to make ? To repeat a previous response, thinking they are the only correct person on the planet, or to ask can you explain what you mean in more setail so that I can fully understand. ?

Thank you for restating this but you need to be careful about relative motion since the phrase 'Jupiter is moving away from Earth' implies Earth is stationary and we should be working on the diameter of Jupiter's orbit of the Sun, not that of Earth. Which is why I phrased it as the Earth moving towards or away from Jupiter, since we are working on the diameter of the Earth' orbit around the Sun.

Lots of useful stuff there. A much better Wiki article than the one about zero point energy. +1

Indeed I do not want to give the idea that I am doing Roemer et al down. It is amazing what they managed to achieve in their time. It is also worth noting that it was a cooperative effort, not due to one individual. And the cooperators were in separate countries, sometimes at war in those days. Even more so.

let us look at these claims first. Roemer 1644 - 1710. Date of first metre 1799 Date of first second 1832 Both standards have changed since. So how exactly did Roemer make any of those calculations or measurements ? Or was it his ghost that did it ? Roemer was dead and buried 89 years before the first definition of the metre. He did not work in m/s or miles per something else, though he was apparantly as precise as he could be in his own system of measurement. Note that he did not have an accurate pendulum for timing. Not that it is a physical impossibility to deduce the speed of light or any acceleration from any two snapshots as you are suggesting. It is necessary to use at least one whole years worth of measurement. Of course Roemer never actually suggested measuring across a diameter of the earth's orbit. How could he since that would involve looking directly at the Sun in the middle ? His observations were taken at 'grazing incidence' which was known to be less than the diameter, but more than the radius. Further the actual values of these diameters were not known in his day. All they had were Kepler's astronomical units, define in terms of 1 AU is the distance from the Earth to the Sun. Everything else was measured as a ratio to this. But they did not know how many Danish (or other) miles or feet were in 1AU. Now let us look at acceleration. I asked about acceleration to give you the opportunity to say that light changes direction, either by refraction or by gravitational effects and this is an acceleration. Or to suggest some sort of refraction where light actually changes speed following refraction. I have no idea what this is supposed to mean. Please provide a proper derivation of these figures in conventional style. What would have 'entered at a speed greater than the speed of light' ?

You are the one that made 4 very specific claims. So either put up or retract them and shut up. The rules here are very very clear that if you make claims the onus is entirely on you to support them. Are you refusing to do this ?

Your question doesn't seem to point out my mistake, I'll avoid repeating the answer I've already given. Nothing else. Really ??? I mentioned no mistake. I neither agreed with you nor disagreed. Your made no answer whatsoever. Do you normally go about ignoring people who don't disagree with you ?

I note once again you are avoiding questions that have been asked. I asked these (and others) several times before and you appear to have blanked me. Do I smell bad or something ?

Well, that's just total nonsense. A transformer changes the AC voltage to a higher or lower one, while a resistor and a diode only cause a current limitation, rectify the sine wave to pulses, and still leave the voltage unchanged. The pulse frequency before and after remained the same. No I didn't say that. You must have been getting out of bed the wrong side recently, your responses have been so grumpy which may have been what has led to several inaccuracies, quite unlike your more usual input. This is a pity because Patch, although also needlessly grumpy, at least want to discuss hard technical matters ; he is not one of the flood of fantasists we get too many of. So please don't frighten him off.

I found this articel wallowing in woollyness. Unfortunately I see this as all part of the trend towards mysticism and woo replacing hard science and facts. As far as ZPE is concerned there are even books, websites and societies promoting magic wans to control the ZPE.

Let's try again. I asked for a few numbers. I understand you have a 120v transformer capable of supplying the 30 amps and rectifiers to suit. So what is the output of the transformer ? You say you want a variable voltage DC supply. Between what voltages ? You do realise that your design is unable to go right down to zero volts ? I understand you have a reservoir capacitor, or bank of them. What are their characteristics ? Have you thought about protecting both the load and the psu from overload - 30 amps is a lot of current ? What are you actually driving (supplying) - the requirements of the load make a real different to suitable circuitry ? (Good) engineering is requires drawing a balance between competing requirements and resources.

No of course it doesn't. But the very fact that you have bothered to state this shows that you have not understood the method of deduction. Again of course, but so what ? You are not considering the appropriate information. Today we know that the Earth is moving at an average speed of 2.575 million km/earthday In Roemer's day they knew the average period of Io's orbit of Jupiter to be around about 1.8 earthdays from Cassini's observations, taken over a complete earthyear. In that time, the Earth will have travelled about 4.5 million km. They did not know this because they did not know Earth's speed accurately enough. But Roemer realised that there was a big difference depending upon which direction that 4.5 million km were measured. Along the line of the Earth's path or perpendicular to it. This in turn makes a difference, not to the Io's period of obit, but to when Io appears and disappears. Perpendicular earth travel makes no difference to when Io appears or disappears. But when Earth is travelling ( as near as possible ) directly towards Jupiter that period appears to be shortened by 15 seconds and When the Earth is travelling directly away from Jupites (six months later) the period appears lengthened by 15 seconds So there is a variation in the apparent period of 30 (+/-15) seconds over a full year. Now it is very important to understand what this information will tell you and what it won't. The time variation from one Io cycle to the next will be nothing like this number because the Earth is still travelling towards or away from Jupiter. It is the comparison with the average that matters and where it shows up. So Roemer did not have a good radius for the Earth's orbit and records that have survived do not show an actual lightspeed calculation. He estimated that when the Earth was travelling directly towards or away from Jupiter the light had a corresponding shorter or longer distance to travel roughly equal to the radius of the Earth's obit, because of the geometry of the situation. So the peak to peak variation corresponds to the diameter of the Earth's orbit and the deviation to the radius. Does this help ? Actually I realise that I didn't put that very well. I should have said along the direct line between Earth and Jupiter or perpendicular to it. In other words when earthspeed is perpendicular to that line it make no difference to the transit time for light as the distance between the two does not vary over a couple of days. But when earthspeed is along the direct EJ line the distance Earth travels will be additive or subtractive from the EJ distance, that light has to travel, therby changing its travel time (slightly).

Yes I fully agree that a vacuum seal is developed. But the seal is separate from the clamping force, as shown in this video from Kilner. Kilner jars are the Uk equivalent of your Mason type. They are for home preserving, not commercial practice. The difference being that the commercial jars and lids are not designed for reuse and their 'screw' down force is minimal, unlike the home variety. This video is very clear.

Some switched mode supplies have no transformer, the better ones do, the sort of swmpsu you and I are used to, are relatively low power and may be implemented simply as a capacitor store type. Many of the cheaper ones do not in fact meet the UK wiring regulations. But the OP type is a 12 volt 30 amp+ supply. these are available commercially ( I have one) that are used by radio amateurs, marine folks, anyone who wants a mains supply to replace a 6/12/24 volt Lechlanche battery. Higher amperage ones are used as vehicle starters and fast chargers. in garage workshops. One way to achieve this is to put controlled rectifiers in the bridge, but at these current levels any design is always fighting the short time when positive current can flow into the reservoir, compared to the period of the ripple voltage, necessitating large value capacitances with robust rating to take the inrush current that may need to be several times the average current (so 30 amp might become 90 - 150 amps pulses ) . The ripple on commercial units is often acceptable because they are only powering lighting or machinery, both of which have inertia of their own.

Would any of those who favour the low pressure theory care to offer a mechanics explanation as to how a pressure differential developes the necessary restraining torque on the cap ? Here also is another picture this time of a marmalade jar. The new jar shows the cap in its unopened state, looking like thousands of other such lids with one-piece lids. And the particular supplier used to use that type of cap with several clutch tabs forced onto the ridges in the glass. But the supplier has recently changed to a two piece lid for reasons I don't understand, A dismantled new lid (sorry I had to distort it to get it apart) is also shown in the photograph. I can't see the gain to the manufactured that more than offsets the extra manufacturing steps necessary to fit the lids in this way. I am also not sure if the lids are mechanically crimped onto the jars or are fitted hot and allowed to shrink on cooling. Either way I think the restraining friction is a result of this clamping force.

I'm sorry you have chosen not to answer my questions. For those with a genuine interest in what Roemer did, or did not do, there is a good readable account not only of his part but the events leading up to his work and the necessary conditions for him to be able to cary it out in this book. It should be noted that the fact light has a finite speed was known to his employers Cassini and Picard at the Paris observatory.

This thread seems to have got bogged down in a dispute over Roemer's actual reading. Thus only the first of thye fout claims have been discussed. I am interested in the other three, particularly the last two. Please expand on both of these.

Well +1 for the whole post I never knew any of that. Thanks.