Primordial Heat: how fast do supernovae cool?

If Earth's heavy matter arrived

livinglava wrote:

If Earth's heavy matter arrived

It didn't. The planets formed from the raw material of the solar system in the same general time period that the sun formed from the same raw material.

The raw material of the solar system came from the ashes of supernovae long ago.

unless the material that coalesced to form the sun also 'blew in' with the supernova 'ashes' that formed the Earth.

The material didn't arrive. It was here already.

It likely cooled pretty fast. Space is cold.

The origins of the supernovae (probably plural) are lost to ancient history. This was a long time ago.

Some of the stellar remnants of the supernovae that created our raw material might now be part of the Milky Way's central supermassive black hole. But there is no way to know for sure.

you said it "arrived long ago,"

I'm no expert, but I think it would make sense to look at some other supernovae and estimate at what distance material emanating from them cools and falls into orbit around other stars, such as the sun.

I assume that if we were 'fresher supernova ash,' there would be more material closer to us in our region of the galaxy. The further the supernova spreads out, the less dense it gets.

If what you're saying is right, that multiple supernovae contributed material from different directions, then the question becomes what form the 'ashes' took as they traveled and arrived. E.g. did they come as cold interstellar meteors? Or did at least some arrive as hot magma or even more sparse, hot uncondensed cloud-like material?

livinglava wrote:

you said it "arrived long ago,"

There was no arrival. It was already here.

livinglava wrote:

I'm no expert, but I think it would make sense to look at some other supernovae and estimate at what distance material emanating from them cools and falls into orbit around other stars, such as the sun.

It is very unlikely that such a thing happens often, if it happens at all.

livinglava wrote:

I assume that if we were 'fresher supernova ash,' there would be more material closer to us in our region of the galaxy. The further the supernova spreads out, the less dense it gets.

There are nebulae and clouds of interstellar dust all over the place.

livinglava wrote:

If what you're saying is right, that multiple supernovae contributed material from different directions, then the question becomes what form the 'ashes' took as they traveled and arrived. E.g. did they come as cold interstellar meteors? Or did at least some arrive as hot magma or even more sparse, hot uncondensed cloud-like material?

The ashes didn't arrive.

And they were not likely to be hot. Space is cold

But "sparse, uncondensed cloud-like material" sounds pretty accurate.

Why did you say it "arrived long ago" then?

Furthermore, it has to arrive

because it couldn't have been generated by the sun, which only turns hydrogen into helium. There had to be some other furnace making it and spewing it out somehow.

Supernovae are a big topic in astronomy/astrophysics, so I assume a lot have been discovered.
Also, there are models that can estimate answers to this kind of question, even if direct observation of actual supernova remnants aren't available.

Yes, but those are mostly hydrogen, as I understand it.

Heavier elements require stars to fuse the hydrogen into helium and so forth, and then supernovae fuse them into elements heavier than iron, which doesn't happen otherwise.

They had to arrive.

Our sun hasn't made elements heavier than helium yet, according to current astrophysics modeling.

oralloy wrote:

"sparse, uncondensed cloud-like material" sounds pretty accurate.

Yes, but it's interesting to consider that it could consist of heavy elements from a supernova and not just clouds of light elements from dying stars or however else such material would emerge.

livinglava wrote:

Why did you say it "arrived long ago" then?

I didn't. I said it was already here.

livinglava wrote:

Furthermore, it has to arrive

No it doesn't. It was already here.

livinglava wrote:

because it couldn't have been generated by the sun, which only turns hydrogen into helium. There had to be some other furnace making it and spewing it out somehow.

Yes. Supernovae from long long ago.

Supernovae are a big topic in astronomy/astrophysics, so I assume a lot have been discovered.
Also, there are models that can estimate answers to this kind of question, even if direct observation of actual supernova remnants aren't available.

livinglava wrote:

Yes, but those are mostly hydrogen, as I understand it.

Mostly, yes. But some nebulae have heavier elements too.

livinglava wrote:

They had to arrive.

No they didn't. They were already here.

livinglava wrote:

oralloy wrote:

"sparse, uncondensed cloud-like material" sounds pretty accurate.

Yes, but it's interesting to consider that it could consist of heavy elements from a supernova and not just clouds of light elements from dying stars or however else such material would emerge.

No "could" or "might" about it. That's definitely what happens.

You are contradicting yourself. You are saying 1) it was already here; and 2) it arrived from supernovae long long ago.

What I am talking about is/are the supernovae 'long long ago.'

What 'non-existant phenomena' do you think I am talking about?

I am talking about how fast the material expanding outward from a supernova cools as it spreads.

Nothing can be 'already here' without arriving from somewhere.

Debris from a supernova doesn't slow down as it spreads out, does it?

If it arrived 'long long ago' from a distant supernova, it had to get captured by the sun's gravity as it expanded away from the supernova blast center. I supposed some interactions could cause it to spin off in a way that slowed its speed relative to the sun, but at whatever speed it drifted into our solar system, it traveled until it arrived. It couldn't have arrived long ago and just sat around waiting to become a planet; or is that what you are saying it did, and if so, how?

whenever you make a statement/claim about what "definitely happened," you should provide your reason/grounds for believing it with so much conviction. Simply stating adamantly that something is 'definitely' so implies you have good reason to believe it, so readers will want to know what that reason is.

Our Sun is a second generation star (at least). We can tell this from its composition.

Stars in general can be categorized by the "metallicity" which give us an indication of what generation they are.

As far as planetary formation goes, the material which forms the planets doesn't need to be hot before it accumulates into a planet. The compression from gravity and the accumulated impact energy are contributing factors for planetary heat. Other factors are nuclear decay and frictional heat from convection.

So does that mean the star that preceded the sun formed from hydrogen and fused all the way up to iron?

What about metals/elements heavier than iron? Those have to come from a supernova, right?

So all the uranium, gold, silver, and everything else heavier than iron had to arrive from elsewhere, no?

So do you think primordial heat was mostly endogenous within the local (light) material that coalesced to form Earth, and that the heavier elements that 'blew in' from distant supernovae were cold by the time they arrived?

livinglava wrote:

So does that mean the star that preceded the sun formed from hydrogen and fused all the way up to iron?

Most likely stars (plural). But otherwise yes.

livinglava wrote:

What about metals/elements heavier than iron? Those have to come from a supernova, right?

More or less. Colliding neutron stars are another source of heavy elements.

livinglava wrote:

So all the uranium, gold, silver, and everything else heavier than iron had to arrive from elsewhere, no?

No. There was no need for them to arrive, as they were already here when the solar system formed.

livinglava wrote:

So do you think primordial heat was mostly endogenous within the local (light) material that coalesced to form Earth, and that the heavier elements that 'blew in' from distant supernovae were cold by the time they arrived?

The heavy elements were already here when the solar system formed. They did not blow in from anywhere.