mistermack

Ok, but it's pretty obvious that I'm asking what the field describes. I made that clear. I don't buy the comment that science doesn't study what things are, only how they behave. The study of the Sun didn't just discover how it behaved. The most important discoveries were about what they Sun actually WAS. I'm not trying to introduce ontological mystery to the debate. Studiot, you say you answered the question. You didn't. You said a field was a catalogue of values of a variable. It's the nature of the variable that I was inquiring about, and that was pretty clear in the OP. ie , what is that variable, in seemingly empty space? I'm getting the feeling that the answer is " I don't know " and that's fair enough. As far as gravity goes, there seems to be confusion. A warping of space time? OK, but that seems to definitely assume a physical structure of space time, rather than nothing. Or is the variable a particle that is passing between bodies? I asked the same question about a magnetic field. Is it a different kind of warping of space time, or the result of photons being constantly passed through the field?

If I asked the question, "what is the wind?" , then mapping the wind, describing interactions between temp and pressure, density, velocity etc etc doesn't answer the question. The question is what it IS. Sometimes, it seems that "field" is the mathematical description of "something". What is that something? Another thing that makes me curious, is that I just read in wikipedia " In quantum physics, the electromagnetic field is quantized and electromagnetic interactions result from the exchange of photons." Surely you can see photons, or detect them fairly easily. I've never heard of light streaming from a magnet. ??

Well, that's an easy and obvious answer. Yes it contradicts the creation story. If you take the view that both can't be right. Contradict doesn't mean disprove. But contradict? Yes of course.

I've been fascinated by the hooded/carrion crows for ages. I've come to the conclusion that (guessing) neither the hoodie, nor the carrion, knows what it is. If a hoodie were brought up in a purely carrion crow area, it would think that it was a carrion crow, and try to find a carrion crow mate. But the carrion crows would reject it, because it LOOKS different to all the other crows that they see. And vice versa with the carrion crow brought up in a purely hoodie area. Only in the margin, where the ratio is about fifty fifty, do you get interbreeding, with confusion as to what they are. But if a hybrid strays from the marginal area, it won't find a mate. Going by that theory, if you dyed the feathers of a hoodie, and released it in a carrion crow area, it would have no trouble finding a mate. But it's chicks would struggle, if they inherited the hood.

I'm no wiser. The mystery for me, is the action of a force via nothing. With gravity, they postulate a particle that transmits the force of gravity. That's after me struggling to accept that gravity is not a force. Is there going to be a similar particle, that is responsible for magnetic force? And electrostatic force?

I'm blissfully ignorant when it comes to fields. At school level physics, (a long time ago), the word was used widely, without any detail being thrown in. I took it to mean "field of influence" but the physics world must have moved on since then. A gravitational field is said to be the curving of space time. Is a magnetic field and electric field also due to curving of a different component of space time?

I'm sure that's right, but maybe it's not wanting to accept, rather than not understanding. I got evolution the second I heard it, at the age of about 13 or so. My mother, a lifelong Catholic, was plenty intelligent, but didn't really want to know, and who can stand up to a lifelong stream of indoctrination? Of course, all that was long before the Pope and his minions decided that evolution could no longer be denied.

Could it also be that there was sexual selection going on, and that female modern humans were not inclined to mate with Neanderthals or hybrids, whereas males were not so fussy?

The word "species" regularly causes this problem. It's not an exact definition, it's a word that just gives an indication of the relationship between discreet populations. A similar situation exists for brown bears. We say that Russian brown bears are the same species as American ones, even though they never interbreed. They are close enough to interbreed readily, if they ever did meet. The same seems to apply to modern humans and Neanderthals. They could readily interbreed, but were separated by distance for many tens, or even hundreds of thousands of years. You could call them the same species, and you wouldn't be wrong or right. You would just be outside of the current way of looking at them. Incidentally, with bears, even the Polar Bear has been known to mate with Browns, on very rare occasions. But they don't normally, even where they meet. So maybe they are a different species. BUT, I seem to remember that Polar Bears are found to be closer to Grizzlies genetically, than some Asian Brown Bears. So it's a very fuzzy subject.

Humans have a poor sense of smell, but good eyesight. So we mainly use our eyes to discern the suitability of a mate. The things we look for are health, youth, and lack of damage. And also, we instinctively look for our own species, and are repelled by features that might be closer to a different, but related species. So we like people who look more human, whatever that means. Having symmetrical features probably indicates a good mix of genes, and an easy birth. Interbreeding often throws up some exaggerated features, and we instinctively shy away from that. So maybe a pretty face indicates a low level of interbreeding. Mixed race people are often considered attractive.

Creation can be on any table it likes. But science is evidence based. That's why creation is ignored in science. The evidence is not there. Science needs more than old scribblings from the bronze age. There is plenty of evidence for science to study. And it all points to evolution, not creation. So unless god has a funny sense of humour, and planted all the evidence for evolution, then science has the right answer, and creation is just ridiculous. But, maybe god WANTS it to look ridiculous?

Ken, I agree that solar and wind are getting closer to fossil in price, and they are indeed saving a chunk of carbon going into the atmosphere. However, I really doubt that they will ever replace enough fossil to reverse the trend of rising CO2 in the atmosphere. Like planting trees, they aren't enough, but make a contribution. But your point about trees eventually returning carbon to the atmosphere isn't really valid. Of course that will happen, but if you plant long lived trees, it will be in about 2 to 300 years. By that time, by your own reasoning, fossil fuels will be long extinct and renewables will be super efficient, and generating all the power we need. Also, quality wood gets used, and might keep the carbon out of circulation for yet another hundred years. And the rest can be used in wood burners, instead of dug-up fossil fuel. To say that trees can't replace this or that, and therefor are not worth bothering with, could be said today about wind and solar. Because the global demand keeps rising, wind and solar aren't going to replace fossil. They will replace SOME. But CO2 will keep rising in the atmosphere for probably the next fifty years at least. Because of rising demand in the poorer countries. I personally have more confidence in fusion than you. It's a shame that they aren't putting more money into it to speed it up. I won't live to see it, but it will eventually be providing all the power we need, I'm sure of that. In the next fifty years, at the current rate of investment, it won't. But long-term, talking 100 years plus, it will. Investment will take off, once the big doubts start to reduce.

That's not going to happen. That's becoming more and more obvious. Unless the economics change drastically. But the Sun will never shine at night, and the wind will always be intermittent, so fossil fuel will always be the cheapest option till it starts to run out. Unless nuclear gets more economic, which might possibly happen with fusion. Like I said, if governments are seriously looking at carbon capture and storage, planting trees is the most economic way they could do it. It's not going to remove all the carbon in the environment, it's just one way of contributing. A very cheap way. One acorn grows an oak in 200 years that removes 4 tons of carbon. And has a cash value at the end of it. You don't have to plant over farmland, you just plant on empty land and hedgerows. Of course, that's not going to happen either. Politicians would rather spend millions on ludicrous CO2 capture schemes, than doing it the easy and cheap way.

I really doubt the water reservoir idea. It's far easier to dig a water trap, than to make one with raised walls. And it will work much better, and need no sealing. And if you did want to build a dam, you wouldn't build it circular, you would pick a spot, and build it across a depression. Even beavers worked that one out. Maybe it's a playpen for very young children. Otherwise, I would guess it's for rituals.

Yes, but that doesn't exclude the possibility of granitic intrusion from below, after the basaltic flow occurred. I read some of what was linked, and granitic intrusions were also mentioned for the area. It looks likely that the "towers" are of a different composition to the rock that surrounds them. It's only speculation, could well be wrong. But there does look to be more than one type of rock there.

The cheapest form of carbon fixing is planting trees. Oaks, redwoods, yew, and hundreds of other species live for hundreds of years. That would take us well past the time when fossil fuels would be running out. Trees cost hardly anything to plant, or maintain, and there is spare land all around. But we are actually reducing trees. If you want to lock up carbon, why would you go for expensive CO2 capture, when you can plant trees for a fraction of the cost? An oak tree lives at least 200 years. In 200 years time, we will probably have nuclear fusion energy on tap, and CO2 will be falling. The danger then will be an ice age, not warming.

I'm thinking that they are small scale granitic intrusions, where the magma forced it's way into gaps and solidified, leaving these shapes of harder rock standing, as the softer rock breaks up around them. I think you're right, they must have been buried at the last ice age, and only exposed in the last ten thousand years or so, as the softer rock breaks up and rolls away. Since the area gets very cold in winter, the action of ice breaking up the rocks is probably pretty rapid. But granite would be more resistant.

I don't think the word proof or disproof is appropriate to such questions. Overwhelming evidence is what it is. It doesn't need to be bumped up to proof status. The evidence is overwhelming, both in quality and quantity. That's good enough for me. The evidence for the Adam and Eve story is some scribbling in an old book, from a very superstitious time long ago, by some very superstitious bronze-age people. There's no comparison.

To grow Kelp in the deep ocean, you would need some kind of anchorage for it. That would have to be some floating device that supported some kind of submerged plastic netting. That would have to be extremely robust to survive a storm. Then there's the problem of nutrients, I doubt if you could get much of a yield without some kind of upwelling. I think it's a non-starter, on cost grounds. The infrastructure costs would be enormous, and the returns tiny. My own suggestion for capturing carbon using the oceans would be to pump up nutrients from the sea floor to the surface. You would then get huge plankton blooms, where once there was ocean desert. This would provide a huge increase in fish stocks, which could finance the operation, and the plankton would be producing hard shells, which would sink to the ocean floor, locking carbon in the carbonates for many thousands of years. This happens naturally, wherever there is a natural upwelling. We would just be replicating that in areas of ocean desert.

The problem with footprints is that they don't tell you WHEN they were made, unless you have a brain the size of a modern human's. The sense of smell tells a lot more than a footprint ever could. To many predators, it tells of size and age and strength, and health of the prey, and how far away they are, maybe even how fast they are moving, and whether they are stressed. They could learn stuff like that instinctively, from what they smelled on previous hunts. An expert human tracker might be able to tell stuff like that from a track, but no animal can match our powers of intuition and deduction. For a hunting behaviour to evolve, it has to help a bit, all the way from the rudimentary stage, to the sophisticated stage. Following a scent can do that. But following tracks at the rudimentary stage would lead to a huge waste of energy, in the vast majority of cases.

Both the genetic evidence, and the fossil evidence, indicate that humans evolved. If the story of Adam were true, it's highly unlikely that there would be fossils of apes that waked upright, in various stages of the evolution of the upright stance, and enlarging brain. So the evidence is abundant that man evolved from a small brained, tree living ape. That doesn't disprove the story of Adam. Nothing can disprove such stories. But if the story of Adam is true, the overwhelming evidence says that he would have met up with many bronze-age humans who were already enjoying the Earth.

I'm picturing something similar, a granitic intrusion, pushing up the sedimentary rocks, and then getting exposed when they are weathered. The wikipedia page for Laccolith gives a good suspect :

Some great comments on this. Arc, I agree, it does look like the multiple shorelines that somethimes happen when a glacial lake gets dammed to different levels. There's one in Scotland that I thought of straight away. It's quite famouse, and looks like ancient roads cut into the hillside. In this case though, it would have to be a huge lake, with a very circular island in it, to produce this effect. It seems like too many coincidences are needed for that to be the answer. I'm beginning to think it is an ancient volcano, that maybe pushed up the sedimentary layers into a circular bulge, and the weathering then exposed the layers in that shape. It's a fascinating area, incredibly rocky, if you look at some of the photos of the area. This is one taken down by the river. There are loads of weird towers left standing, like thousands of Stonehenge stones. Anyone know what they are called, and how they are formed?

Re the original question, if the two objects were connected by a stretched spring, then the kinetic energy that they gain as they are pulled together was potential energy, stored in the deformation of the spring, from it's natural shape. If you think of spacetime as a form of spring, then a very similar process is happening.

Yes, I agree. But it's in an area that's been swept many times by glacial ice-sheets. So any hollow would have been filled long ago with debris dragged along at the base of the ice sheets. The centre does seem to be loose material, as the streams have eroded it quite easily.