The Big Bang Theory

[juvenissun]

The equation relating energy density to expansion rate is the the first of the Friedmann equations.

The information of Friedmann Equation given by the Wikipedia is good enough for me. The scaler factor a is more complicate than I thought, and is related to the shape of the universe. This by itself if a very interesting topic.

I got what I want to know, and I am satisfied with the education. Thanks.

 

[Chalnoth]

The information of Friedmann Equation given by the Wikipedia is good enough for me. The scaler factor a is more complicate than I thought, and is related to the shape of the universe. This by itself if a very interesting topic.

I got what I want to know, and I am satisfied with the education. Thanks.

Any time.

 

[ChordatesLegacy]

The collective experiences of those who have believed in God over the centuries speak to us about him from the pages of a compiled volume called the Bible. Since these people are dead, what we have left is the words that they left behind, the accounts of their lives in their own words and those of others. As these are the words of the people of God and that deity speaks through the words and actions of their lives, in a sense, that collection, the Bible, is the word of God.

Then the word of god is wrong, because we all know that Genesis is wrong. Also the Gospels were not written till long after the life of Jesus, whom I suspect did live, but was most defiantly not the son of some magical mystical deity.

 

[ChordatesLegacy]

Well, if memory serves there are a few plants proper that don't (including Rafflesia, IIRC). Of course these creatures are parasites and dependent on plants that do photosynthesise.

Yeah, except for the bacteria and archaea the whole community is based on

Of course the argument was about "plants before the sun" and not "autotrophs before the sun", but still my heart weeps for all the neglected prokaryotes

Totally agreed, even if it's pretty much impossible to avoid.

I was a bit simplistic, but I was pre-empting the comeback from Juv,y if I said plants live in the deep ocean.

i.e. if plants can live without sun light, then there’s no problem with the sun being created after plants!!!.

One of my prize objects, now sitting on a shelf in my house is a 30 cm piece of a hydrothermal vent, not that I collected it, it was a present from a biologist I was working with on sulphur reducing bacteria on the Atlantic Ridge and the precipitation of metals by these bacteria.

So it would be true to say, the basis of life around hydrothermal vents is sulphur reduction; as in the following equation.

SO4^2- + CH3COOH + 2 H^+ → HS^- + 2 HCO3^- + 3 H^+

So I thing it fair to say “plant life is not the bases of life around deep sea vents” although I think that some available organic material is needed.

The bit I was interested in was as follows which is basically the removal of ions from solution to form highly insoluble sulphides

HS^- + Me2^+ → MeS + H^+

Me2^+ can for example be copper, zinc etc.

 

[juvenissun]

I was a bit simplistic, but I was pre-empting the comeback from Juv,y if I said plants live in the deep ocean.

If you will, I like to start from the very beginning.

What is your definition of a "plant"? If you think the photosynthesis is a must for a plant, then put it in the definition.

 

[edrogati]

Then the word of god is wrong, because we all know that Genesis is wrong. Also the Gospels were not written till long after the life of Jesus, whom I suspect did live, but was most defiantly not the son of some magical mystical deity.

We "all" do know this, eh? Jesus, was "defiantly" not the son of God? And yes, I know that you meant "definitely". It's good to be confident, but not to be arrogant making assertions that are either false (I do not know that Genesis is wrong and many others do not know this either) or are not as certain as you would make them out to be.

It's one thing to disbelieve someone's religion; it's quite another to assume that you can with complete certainty say that it is untrue (and yes, Christians are guilty of this too). Complete conviction of one's take on the reality of something (or lack thereof) doesn't equal its reality (or lack thereof). There's got to be more than simple conviction or belief when it comes to that reality or that lack of one. There's got to be evidence or absolute lack of it.

 

[Chalnoth]

If you will, I like to start from the very beginning.

What is your definition of a "plant"? If you think the photosynthesis is a must for a plant, then put it in the definition.

A plant is a multicellular eukaryote with chloroplasts.

 

[Chalnoth]

We "all" do know this, eh? Jesus, was "defiantly" not the son of God? And yes, I know that you meant "definitely". It's good to be confident, but not to be arrogant making assertions that are either false (I do not know that Genesis is wrong and many others do not know this either) or are not as certain as you would make them out to be.

It's one thing to disbelieve someone's religion; it's quite another to assume that you can with complete certainty say that it is untrue (and yes, Christians are guilty of this too). Complete conviction of one's take on the reality of something (or lack thereof) doesn't equal its reality (or lack thereof). There's got to be more than simple conviction or belief when it comes to that reality or that lack of one. There's got to be evidence or absolute lack of it.

I don't see why, not when your religion is self-contradictory on the one hand (e.g. problem of evil), and so vague as to be saying nothing on the other (e.g. the trinity), there is no reasonable conclusion but that it is wrong.

 

[juvenissun]

A plant is a multicellular eukaryote with chloroplasts.

Does this definition apply to a single plant cell?

 

[Naraoia]

A plant is a multicellular eukaryote with chloroplasts.

That definition makes plants badly poly- (and para-?)phyletic. AFAIK eukaryotic family trees nowadays tend to have (red algae + (some green algae + (other green algae + land plants))), and brown algae somewhere way outside this grouping. Green and red algae contain both uni- and multicellular members. "Multicellular eukaryotes with chloroplasts" is not a natural grouping.

Of course the only classification that makes sense to me is an evolutionary one, so bear with me

 

[Tomk80]

Does this definition apply to a single plant cell?

A single plant cell is not a plant, if that is what you are asking. Just like a single animal cell is not an animal.

 

[Tomk80]

That definition makes plants badly poly- (and para-?)phyletic. AFAIK eukaryotic family trees nowadays tend to have (red algae + (some green algae + (other green algae + land plants))), and brown algae somewhere way outside this grouping. Green and red algae contain both uni- and multicellular members. "Multicellular eukaryotes with chloroplasts" is not a natural grouping.

Of course the only classification that makes sense to me is an evolutionary one, so bear with me

In that case you'd have to define plant as the "Archaeplastida". A plant would then be a eukaryote with plastids surrounded by at least two membranes. Plastids are organelles containing pigments that can be used for photosynthesis.

This definition still includes non-photosynthetic plants (parasites and heterotrophs), since these plants retain their plastids even though the plastids are not used for photosynthesis. As far as I know.

 

[edrogati]

I don't see why, not when your religion is self-contradictory on the one hand (e.g. problem of evil), and so vague as to be saying nothing on the other (e.g. the trinity), there is no reasonable conclusion but that it is wrong.

I suggest that you go to the Apologetics forum to try to get that answer. Neither of the things you've cited have one thing to do with Creation or Evolution. Your goal posts keep moving and your straw men are turning into an army.

Again, it is arrogance to conclude that because you consider something self-contradictory and that because you can't figure out an admittedly perplexing theological principle, that it is wrong. I have a hard time wrapping my brain about both of your examples, but I would never essentially say, "I can't figure it out, therefore it's false". My conclusion is that you just don't want to bother with it. Being intellectually lazy is no criteria for determining truth.

 

[Naraoia]

In that case you'd have to define plant as the "Archaeplastida". A plant would then be a eukaryote with plastids surrounded by at least two membranes. Plastids are organelles containing pigments that can be used for photosynthesis.

At least? I think I've just read that some eukaryotes have plastids with more than two membranes, indicating that they got them by a second (third, fourth...) endosymbiotic event. *searches* Aham, it's on Wikipedia:

In some algae (such as the heterokonts and other protists such as Euglenozoa and Cercozoa), chloroplasts seem to have evolved through a secondary event of endosymbiosis, in which a eukaryotic cell engulfed a second eukaryotic cell containing chloroplasts, forming chloroplasts with three or four membrane layers. In some cases, such secondary endosymbionts may have themselves been engulfed by still other eukaryotes, thus forming tertiary endosymbionts.

And from another encyclopaedia-thingy:

The exact nature of the chloroplasts is different among the different lines of algae, possibly reflecting different endosymbiotic events. There are three groups that have primary chloroplasts:

• Green algae, together with higher plants
• Red algae
• Glaucophytes

In these groups the chloroplast is surrounded by two membranes, both now thought to come from the chloroplast. The chloroplasts of red algae have a more or less typical cyanobacterial pigmentation, while the green algae and higher plants have chloroplasts with chlorophyll a and b, the latter found in some cyanobacteria but not most. There is reasonably solid evidence that these three groups originated from a common pigmented ancestor; i.e., chloroplasts developed in a single endosymbiotic event.

If that information is correct then if anything, a plant should be something that has chloroplasts with exactly two membranes.

 

[juvenissun]

That definition makes plants badly poly- (and para-?)phyletic. AFAIK eukaryotic family trees nowadays tend to have (red algae + (some green algae + (other green algae + land plants))), and brown algae somewhere way outside this grouping. Green and red algae contain both uni- and multicellular members. "Multicellular eukaryotes with chloroplasts" is not a natural grouping.

Of course the only classification that makes sense to me is an evolutionary one, so bear with me

what is it?

 

[juvenissun]

A single plant cell is not a plant, if that is what you are asking. Just like a single animal cell is not an animal.

Why not? What is the difference?

 

[Chalnoth]

Does this definition apply to a single plant cell?

A single plant cell is not a plant, any more than a single human skin cell is a human.

That definition makes plants badly poly- (and para-?)phyletic. AFAIK eukaryotic family trees nowadays tend to have (red algae + (some green algae + (other green algae + land plants))), and brown algae somewhere way outside this grouping. Green and red algae contain both uni- and multicellular members. "Multicellular eukaryotes with chloroplasts" is not a natural grouping.

Of course the only classification that makes sense to me is an evolutionary one, so bear with me

Eh, I suppose you're right. Just showing my ignorance of the phylogeny of plants here. But I'm sure that you don't have to add that much more to define plants.

 

[Chalnoth]

I suggest that you go to the Apologetics forum to try to get that answer. Neither of the things you've cited have one thing to do with Creation or Evolution. Your goal posts keep moving and your straw men are turning into an army.

Again, it is arrogance to conclude that because you consider something self-contradictory and that because you can't figure out an admittedly perplexing theological principle, that it is wrong. I have a hard time wrapping my brain about both of your examples, but I would never essentially say, "I can't figure it out, therefore it's false". My conclusion is that you just don't want to bother with it. Being intellectually lazy is no criteria for determining truth.

Been there. Done that. And, by the way, I am only being lazy in the sense that I don't want to write out all of my reasons here for believing it's false. That would take a number of pages worth of text.

 

[Tomk80]

Why not? What is the difference?

Because part of the whole is not the whole. The arm of a human is not a human. The jaw of a tiger is not a tiger. A single skin cell of a human is not a human. Or do you think that all the dead skin cells floating around in the air are dead humans?

 

[Tomk80]

If that information is correct then if anything, a plant should be something that has chloroplasts with exactly two membranes.

You're probably correct.

So, definition of plant: a eukaryote with plastids surrounded by two membranes.