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a reply to: Hyperia

No, just not efficient enough to generate more energy than it takes to make the fusion reaction happen.

a reply to: Hyperia

It is steam in a nuclear power plant which turns the turbines. The nuclear fuel generates the heat to produce the steam.

a reply to: Hyperia

Yes, there are other uses for splitting atoms besides explosives. The nuclear cycle in a power plant relies on the heat generated by fission (splitting atoms) to generated steam. Proton Beam therapy for cancer treatment relies on an elementary particle from within an atom to work.
However, splitting atoms and converting atoms to pure energy are entirely different. And the mass to energy conversion is what basic nuclear weapons rely on. As do more advanced nuclear weapons, partially.

a reply to: pfishy

So fission in Nuclear plant, and fussion in a nuclear explosion? Im really sry for my retarded questions,

originally posted by: Hyperia
a reply to: pfishy

So fission in Nuclear plant, and fusion in a nuclear explosion? Im really sry for my retarded questions,

Both fission and fusion can be weaponized into a bomb. both can also be used in a peaceful reactor.

the first atomic bombs were fission based. later fusion or more accurately fission initiated fusion bombs were created.

in terms of peaceful uses though a fission reactor is more hazardous than a fusion reactor. a fission reactor is subject to melt down and other disasters if something goes wrong. fusion is so hard to maintain that if anything goes wrong the process ends and the reactor shuts down. the fusion reagents or fuels are not very dangerous in the worst case (tritium based reactors) and often not even dangerous at all for high beta designs. the reactor components and shielding *might* become slightly radioactive over time but nothing like the stuff in a fission reactor.

originally posted by: Hyperia
a reply to: pfishy

There are actual way of direct generation via fusion technology, but these are still in their infancy, at best.

Still theoretical ?

No. there is no dispute they would work. the problem is technological and also materials. if you fuse boron and hydrogen you get two alpha particles. a light electrically charged ion. if this ion is shot through a conductive coil it induces electrical current in the coil which can be used in the grid. this is referred to as direct conversion where as using steam turbines and so forth is called indirect conversion because there is an extra step before you get from the reaction to having power. also indirect conversion requires extra plumbing, reservoirs, radiators or cooling ponds, pumps, monitoring and control systems and then there is the turbines and generators which adds points of failure.

But to get boron and hydrogen to fuse requires tremendous pressure and temperature. we haven't licked "easier" fusion chains yet but PB fusion is better because of the direct conversion possibility and because there are no neutrons in the primary reaction chain which means less radiation and less induced radioactivity and degradation of the reactor parts.

Direct conversion reactors would make excellent space craft, space station or lunar or mars colony power sources because they would be less complex less massive and smaller than indirect conversion systems. and terrestrially you could truck or plane or helicopter one anywhere it was needed like for natural disasters remote camps or villages...

a reply to: stormbringer1701

So lets get back to fission, whats the difference between a Nuclear power plant fission, and a Nuclear bomb fission?

Is it a heat wave, with the fission bomb?

Which are the direct conversion?

a reply to: stormbringer1701

no, this went way way above my knowledge, ill come back thank you for all the answers, im gonna do some research and be back

originally posted by: Hyperia
a reply to: stormbringer1701

So lets get back to fission, whats the difference between a Nuclear power plant fission, and a Nuclear bomb fission?

Is it a heat wave, with the fission bomb?

Which are the direct conversion?

a fission power plant or a fission bomb both makes use of the fact that all elements above lead are prone to breaking into less massive elements. when they do this is referred to as decay or fission. when they do some of the mass ties up in bonding the nucleus together is freed in the form of particles and photons. these particles (mostly neutrons) and photons carry energy and when they hit something it liberates heat in various ways.

ordinarily the radioactive element either does not produce enough fission particles (neutrons) to cause enough other atoms of the element to maintain a vigorous decay cascade which means not enough energy is produced fast enough to either turn water to steam or to explode in the case of a bomb use. there are lots of radioactive elements or isotopes of elements but only a few even have the potential to reach the cascade point (referred to as going critical) or enough to explode (a point called going super critical.) in reactors and bombs generally a special isotope of uranium or else plutonium are used. a third element thorium can be used as well though it has not been used nearly at all to this point except in research studies. and a few other radioactive elements could be used but the facts concerning how are classified to prevent proliferation.

anyway once you have enough neutrons shooting around you get a sustained critical reaction or even a super critical reaction. this is dependent on a lot of sensitive parameters such as purity, density, geometry, the isotopes involved, mass, neutron reflectors and absorbers and other stuff. when you have a critical reaction you get enough heat to turn water to steam which turns the turbines which turns a generator. or if you have the right parameters you get a super critical reaction and a bomb.

a fusion bomb requires a super finely controlled implosion of the nuclear pit material. at first this was accomplished with fission bomb on the outside of a plutonium pit and now is accomplished with super high chemical explosives uniformly detonated around the plutonium pit. the Russians use RDX or maybe PETN if i recall correctly. these are detonated with a sphere of photo flash initiators surrounding the explosives surrounding the pit carefully timed by highly precise timing circuits.

a fusion power reactor is not and cannot be made into a fusion bomb.

originally posted by: Hyperia
a reply to: stormbringer1701

So lets get back to fission, whats the difference between a Nuclear power plant fission, and a Nuclear bomb fission?

Is it a heat wave, with the fission bomb?

The main difference is how much of the available fuel is undergoing fission in a certain period of time.

To create an explosion the design tries to get as much of the available material as possible to undergo fission in a very short time period.

A fission power plant only tries to get a very small amount of the available fuel to undergo fission at any given time, and at a controlled rate.

For example, a Fukushima-style 784MW nuclear fission power plant would have to run at full capacity continuously for 22 hours, to produce the same energy that was released in one second by the Hiroshima fission bomb.

a reply to: stormbringer1701

Nice, now i get it, thank you!

And all the answers with it!

a reply to: Arbitrageur

Thank you!

a reply to: Hyperia

This thread and it's contributors are certainly one of the reasons this site is so fantastic.

a reply to: pfishy

You can come in here as a random person and ask any question, without any stories, you get it in your face, if you dont understand they dumb it down until you understand.

And you goo like ooooh, you can ask them the theoretical vs the empirical data, its like working Cortana. Hello Cortana how does this work, and you will always get an answer.

Here's a thought that managed to bubble up to the surface of my mental muck recently. The Big Crunch, in it's classical sense, is an utter impossibility. Even if the expansion of the Universe were slowing down it couldn't occur. Yes, in theory all matter in a static or slowing expansion model could be gravitationally drawn back together and form an unimaginable singularity, but what of space itself? What would decrease the size of the actual void space between the stars and galaxies?
And that brings to mind another question. What is the theoretical limit to the mass of a singularity? If all matter in a massive galaxy were to be streamed into a singularity at just the right rate so that it could be most effectively absorbed, would the singularity actually be able to keep growing until it was all gone?
Or from several galaxies? Hundreds? Could all of the mass in the universe be contained in one as it exists now. Not the Big Bang singularity, but one which has formed afterwards.

a reply to: pfishy
Part of the problem with singularities is that when the density is already infinite, you can add mass to it and the density is still infinite, plus what you added to it, but mathematically that doesn't work too well.

Here are a couple of key points that I know of:
The temperature of the cosmic microwave background infers that if the Hawking radiation theory for black holes is true, black holes will evaporate when their temperature is above the CMB temperature. Right now that means they must have a mass smaller than the mass of Earth's moon (and there may not be any such black holes). As time passes, the CMB temperature will cool allowing larger and larger mass black holes to evaporate. However we expect black holes to accumulate a lot more mass before this happens.

Exactly how many black holes will be involved in this I don't know, probably the one at the center of each galaxy. Some of those will combine like our black hole might combine with that of Andromeda galaxy after some billions of years.

But, I'm pretty sure they can't all combine into one black hole unless we learn something drastically new about the universe, because some are already too far away to interact with each other, and everything in our current observations suggests they will only get further apart.

Here's a timeline on Wiki that seems plausible:

Future of an expanding universe

By 10^14 years from now, star formation will end
...
10^15 years: Planets fall or are flung from orbits by a close encounter with another star
...
10^19-10^20 years: Stellar remnants escape galaxies or fall into black holes
...
10^40 years: All nucleons decay
...
After 10^40 years, black holes will dominate the universe. They will slowly evaporate via Hawking radiation.

The most uncertainty in that timeline is the nucleon decay as I don't think we know if that will happen, but the other events seem less speculative.

a reply to: Arbitrageur

I understand that most are too far away to ever interact, but in a perfect scenario, with the structure of space-time as we understand now, is it possible for all matter in the universe to be condensed into a single singularity? Obviously, this is purely a hypothetical, but if it were possible to leave spacetime itself as it is, but move all mass to a single area where it could all interact gravitationally, could it form one lone singularity?

a reply to: pfishy
It's interesting question.

The idea of such singularities is under attack by some theoretical physicists, as explained in this video:

BBC Documentary 2015 (HD) - What Happened Before The Big Bang


Basically the video profiles some theoretical physicists who a decade ago thought maybe the big bang started as a singularity, and are now thinking maybe it wasn't a singularity.

When you ask about such singularities, in my opinion they are breakdowns in the model of general relativity and quantum mechanics. Infinite density doesn't seem like a meaningful result, and in quantum mechanics a particle generally can't occupy a space smaller than its wavelength.

The question then becomes, if the big bang wasn't really a singularity and the mass in a black hole isn't a singularity, what were/are they instead? The professionals in the video are trying to find an answer to that question. The answer is still as far as I know that both general relativity and quantum mechanics theories are probably incomplete at the high energy scales associated with the big bang. In order to complete those theories regarding the high energy levels of the big bang, the profiled physicists seem to be looking for an answer other than a singularity.

This isn't really earth shattering however as the earliest phases of the big bang have always been highly speculative and beyond our theoretical understanding, but on the other hand it does seem to be a change in theoretical perspective.

originally posted by: KrzYma
QUESTION 1
how comes, those experiments smash billions of protons against billions of protons and the scientist still tell us, what we see as outcome is in any case true collision ??

This was the start of my answer, and I just noticed I forgot the "million" after 100,000.

originally posted by: Arbitrageur
It's hard to get two protons to collide. If we aim 100,000 protons at each other in the LHC, most of them will miss, and of the 20 that have some kind of collision, not all of those have a perfect centered head-on collision

I probably should have quoted the source instead:

lhc-machine-outreach.web.cern.ch...

-We aim to squeeze the beam size down as much as possible at the collision point to increase the chances of a collision.
-Even so… protons are very small things.
-So even though we squeeze our 100,000 million protons per bunch down to 64 microns (about the width of a human hair) at the interaction point. We get only around 20 collisions per crossing with nominal beam currents.

So it's only 20 collisions out of 100,000 million protons.

KryZma if you fire only two protons at each other, you'll have to conduct a lot of runs before the first collision at that rate, and even that probably won't be of interest because it's probably not a perfectly centered collision, meaning it won't have the highest energy.

a reply to: Arbitrageur

Thanks. I'll watch it as soon as I can.

a reply to: Arbitrageur

If you're a little puzzled by the vacuum, join the club as it's not well-understood. Our model of the vacuum doesn't predict the observed amount of vacuum energy which is an unsolved problem in physics. That's the big contradiction I know of, but if there are others you'll have to elaborate about what you think they are.

Thanks for the links. "This discrepancy has been described as "the worst theoretical prediction in the history of physics." Spent a few hours reading up on this. I don't understand it enough to have an intelligent question. But I am curious as to how they derive these measurements so will continue to read about it.

One thing I wanted to clear up though - the cosmological constant, dark energy, vacuum energy - these are all the same thing? The reason I ask is because when I pull up research papers very often these terms seem to be interchangeable. So I just want to confirm that the three terms are the same thing.

Thanks again.