They are really basic programs, and i'm sure pretty much everyone in this thread would find them kind of boring since we know basically all the information they're telling us already. As I was watching last night I would finish their sentences for them because it was obvious what they were going to state.
Anyway, one thing did pique my interest, and that was when they were talking about how the universe recycles everything.
We all know everything in the universe was "born" out of the big bang. Everything that exists now is from then.
What i'm having trouble understanding and wasn't really aware of was the recycling that the universe does. In the program, they made it seem like there is a constant amount of matter. That atoms are neither lost or gained since the beginning of the universe, but rather rearranged and recycled. Atoms are blown up and fused all the time, and these combinations make up the elements. But these atoms have been around forever, and will always be around. Just in different combinations.
Carl Sagan said we are all star stuff, and I just took that to mean that basically we were created here on earth because of a supernova that took place somewhere near by 5 billion years ago which caused our solar system to form.
Yet, if it is indeed true that no atoms are lost or gained, and that they are always around, then that means that the oxygen i breathe and the water i drink are made up of atoms that made up someone or something else on this planet or in this universe at some point.
They said on the program that basically, when you drink a glass of water, you are drinking atoms that were once a part of a star, which I understand, but I didn't fully comprehend maybe. And that when you breathe oxygen, you're taking in a couple atoms that passed through the most famous people to ever live.
It doesn't totally make sense to me because don't atoms decay? We know they do, and they do at a predictable rate. So if they decay, I suppose they decay into a smaller atom? Atoms are not lost or gained, rather re arranged again. Is that correct?
We all know everything came from the big bang. But that doesn't seem significant to me. It just seems so far removed. Like so much has changed since then. But when I heard that the atoms that were born then (few hundred million years after the big bang I think) are the exact same atoms that are floating around now and make up me and you, that kind of puts a different spin on things. Not so much an evolution into us, rather just a rearranging into life.
They are among the true monsters of space - colossal stars whose size and brightness go well beyond what many scientists thought was even possible.
One of the objects, known simply as R136a1, is the most massive ever found.
The star is seen to have a mass about 265 times that of our own Sun; but the latest modelling work suggests at birth it could have been bigger, still.
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Size comparison of huge objects in the universe, for those who haven't seen it.
I find that video utterly humbling every time I see it. What is so cool is the diameter of VY Canis Majoris would actually reach past the orbit of Saturn if it were placed in the centre of the solar system. About 2 weeks ago, I caught my first glimpse of Andromeda through my telescope. It was just awe inspiring to think I was looking at another galaxy that probably contained thousands of other civilizations.
And at the same time you were looking out, one of those civilizations was looking back at our galaxy with its thousands of possible civilizations and wondering if they are best served with white or red wine.
Be afraid of the universe children, be very afraid.
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What i'm having trouble understanding and wasn't really aware of was the recycling that the universe does. In the program, they made it seem like there is a constant amount of matter. That atoms are neither lost or gained since the beginning of the universe, but rather rearranged and recycled. Atoms are blown up and fused all the time, and these combinations make up the elements. But these atoms have been around forever, and will always be around. Just in different combinations.
Not completely accurate, as some matter is lost in the act of fusion; turned completely into energy.. and atoms = elements, combinations of elements make molecules. There are some processes which can completely change one atom into another kind of atom, but the general gist of the idea is right.
Quote:
Originally Posted by worth
Yet, if it is indeed true that no atoms are lost or gained, and that they are always around, then that means that the oxygen i breathe and the water i drink are made up of atoms that made up someone or something else on this planet or in this universe at some point.
They said on the program that basically, when you drink a glass of water, you are drinking atoms that were once a part of a star, which I understand, but I didn't fully comprehend maybe. And that when you breathe oxygen, you're taking in a couple atoms that passed through the most famous people to ever live.
Yup, that oxygen or hydrogen atom in the water molecule had to come from somewhere, and the most common process to make oxygen is in the hearts of stars. Since that point it just goes on its merry journey, becoming part of a planet, being blown out to space again in a nova, becoming part of another planet, being eaten by Issac Newton in an apple, being peed out later, becoming part of the ocean, evaporating, raining down on your head...
Quote:
Originally Posted by worth
It doesn't totally make sense to me because don't atoms decay? We know they do, and they do at a predictable rate. So if they decay, I suppose they decay into a smaller atom? Atoms are not lost or gained, rather re arranged again. Is that correct?
Radioactive atoms decay, but not all atoms are radioactive. Oxygen 16 (the most common form of oxygen, 8 protons and 8 neutrons) is stable, and does not decay. So unless something extreme happens to an atom of oxygen 16 (gets fused in the heart of a start to become a heavier element, gets hit by a cosmic ray, falls into a black hole) it'll stay an atom of oxygen for a looooong time.
Quote:
Originally Posted by worth
We all know everything came from the big bang. But that doesn't seem significant to me. It just seems so far removed. Like so much has changed since then. But when I heard that the atoms that were born then (few hundred million years after the big bang I think) are the exact same atoms that are floating around now and make up me and you, that kind of puts a different spin on things. Not so much an evolution into us, rather just a rearranging into life.
There's my rambling for the day.
After the big bang there was pretty much only hydrogen, helium, and a little bit of lithium and a few other heavier elements, so all the heavier elements have been formed by other processes. Fusion in the cores of stars, and in the case of elements heavier than iron, formed in red giants and in the shockwaves of supernova.
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And at the same time you were looking out, one of those civilizations was looking back at our galaxy with its thousands of possible civilizations and wondering if they are best served with white or red wine.
Be afraid of the universe children, be very afraid.
So is there anyway to destroy atoms.. besides radioactive atoms?
Is that theory for black holes?
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So is there anyway to destroy atoms.. besides radioactive atoms?
Is that theory for black holes?
Sure, though I guess it depends on what you mean by destroy.
If you compress and heat them enough they'll fuse into different atoms, so it'll stop being hydrogen/helium/whatever and become carbon or some other heavier element.
You could shoot protons at it and if one sticks in the nucleus it could be a different element (since the element is defined by the # of protons in the nucleus). Or shoot neutrons at it and the nucleus might split into 2 or more different atoms.
Fission/fusion will actually completely destroy some of the atoms involved, converting them to pure energy.
You could bring an atom (or a subatomic particle) and its anti-particle together and the two will annihilate completely into energy (and new particles will precipitate out of the energy).
You could feed it to a black hole and that'll hide it for a long long time, but eventually the black hole will evaporate and whatever you added will be given off (not in the same form though).
If you smash two atoms together with enough energy they'll blast apart into a spray of new particles and energy.
I can't think of any more at the moment.
For the most part though all of these things obey the laws of conservation of energy, so if atoms are unmade or disappear, the energy and mass and momentem etc of the result will balance out. Matter and anti-matter annihilate, the resulting energy is equal to the energy bound up in the matter in the first place. Smash two gold atoms together and the resulting spray of particles retains all the energy and mass of the originals, etc. So in a sense nothing ever truly becomes unmade or undone, it just changes form.. and because of entropy because less usable.
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This also may provide an answer to the fate of our universe.
Since Black Holes "evaporate" by emitting Hawking Radiation, if we are located in a Black Hole it would seem that our universe is destined to fly apart like a water drop on a hot surface.
Interesting article, although with Keppler don't they have to observe multiple transits before confirming it's a planet? Does that mean that all these discoverd so far have super quick orbits?
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Interesting article, although with Keppler don't they have to observe multiple transits before confirming it's a planet? Does that mean that all these discoverd so far have super quick orbits?
Cool. I met the head of the Kepler project last year at JPL.
140 of the 700 identified bodies are much like Earth.
“The figures suggest our galaxy, the Milky Way will contain 100 million habitable planets, and soon we will be identifying the first of them,” Dimitar Sasselov, a scientist on the Kepler Mission said. “There is a lot more work we need to do with this, but the statistical result is loud and clear, and it is that planets like our own Earth are out there.”
In order to separate true transiting planets from other phenomena that mimic the transit effect, scientists try to follow up on each of Kepler’s discoveries with radial velocity observations of each star. This method measures the slight shifts in a star’s spectrum as it rocks back and forth to the tug of an orbiting planet, and has been responsible for the majority of exoplanets discoveries to date. Significantly, whereas transit detections like Kepler’s provide a good estimate of a planet’s diameter, radial velocity measurements provide an accurate estimate of a planet’s mass. If the RV study shows that a planetary mass object is orbiting a star where Kepler detected a candidate planet, then the candidate is almost certainly a true exoplanet. If, however, the orbiting object turns out to have the mass of a star, then Kepler’s “transiting exoplanet” is, in fact, no planet at all but a binary star whose two components periodically eclipse each other.