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originally posted by: pfishy
a reply to: stormbringer1701

He never created fissile material. But that's not to say it's impossible. Also, to continue in that experiment to the point of actually obtaining enough material to create a bomb with would have both been extremely costly, and probably killed him before completion.
I wouldn't exactly call that easy.

i think that since he was never trying for a bomb that that is not germaine. he wanted to build a reactor.

but that does not mean that someone with more money and a modicum of safety precautions and even less scruples could not use the slow neutron thing to do just that without using the resources of a modern nation state like thousands of centrifuges scientists and engineers etc.

personally i would like to try that slow neutron trick on element 115. you know just to make sure.

a reply to: stormbringer1701

If you can get a sample of element 115 stable enough to use a slow neutron enrichment on, pm me. I have some Lazar drawings I'll sell you...

a reply to: ErosA433

The world never ceases to amaze me.

Here's an idea/concept on how Iron Man's chest reactor could work. I'm not scientifically literate enough to be able to understand every aspect of this. Any ideas or thoughts, could it work?

www.quora.com...

Make sure you hit the little "more" button, sometimes it doesn't open the whole post.

Oh, and he mentions the fact that he mixed comic book physics in with real physics. An example being: "I propose that Howard Stark found a way (using comic-book physics) to utilize the beta decay of Pd-107 ions as an electron source for the electron capture of Pd-103, thereby producing an electric circuit between two different radioactive isotopes. Pd-103 is very radioactive (17 day half-life) compared to Pd-107 (6.5 million year half-life) so there would need to be dramatically more of the heavier isotope to compensate for the disparity in decay rates."

Just how "comic book physics" is this, could there be a way around it?

originally posted by: ImaFungi

Time is only movement.

If you disagree. Express your reasons for disagreeing.

Then why do massless particles experience no time when moving at light speed?

originally posted by: pfishy

I never said GR is wrong in general. Just that the use of infinites shows certain areas where it's ability to make accurate predictions breaks down.

All of the theories break down at certain extremes.
There are infinities in quantum mechanics also, they are cancelled out because there is an even amount but it's still considered sketchy by some people.

The problem with GR isn't so much that it can't describe a singularity, the problem is it can't be quantized. Mass/energy is quantized into it's constitute parts and understood through mathematical rules that generally work out. If you try to do the same with gravity then an infinite infinities arise in the math. The problem is that quanta of gravity or "gravitons" can interact with themselves which makes things far too complicated. So gravity makes sense on the large scale but on the very small scale, where it may be divided into individual quanta, cannot be figured out.

originally posted by: IAmTheRumble
Here's an idea/concept on how Iron Man's chest reactor could work. I'm not scientifically literate enough to be able to understand every aspect of this. Any ideas or thoughts, could it work?

www.quora.com...

Make sure you hit the little "more" button, sometimes it doesn't open the whole post.

Oh, and he mentions the fact that he mixed comic book physics in with real physics. An example being: "I propose that Howard Stark found a way (using comic-book physics) to utilize the beta decay of Pd-107 ions as an electron source for the electron capture of Pd-103, thereby producing an electric circuit between two different radioactive isotopes. Pd-103 is very radioactive (17 day half-life) compared to Pd-107 (6.5 million year half-life) so there would need to be dramatically more of the heavier isotope to compensate for the disparity in decay rates."

Just how "comic book physics" is this, could there be a way around it?

The guy is smart enough to tell us the reasons it won't work. First his electron source is not really an electron source and he says so. Second, even if it was an electron source, how how many electrons will you get from a fist-sized or smaller chunk of matter which takes 6.5 million years to release half the electrons? One of the fist-sized batteries powering my UPS (uninterruptible power supply) would yield far more power because it doesn't have to wait 6.5 million years for the electrons to be produced, but still not enough to do what Tony Stark could do.

There's obviously not enough space for a conventional boiling water/turbine/generator setup so the electricity needs to be extracted more directly, which the author says and I agree.

Everybody already knows antimatter is the way to store a source of energy in a very compact form. So you just combine some protons and antiprotons and channel the resulting charged particles into MHD (magnetohydrodynamic) generators to extract the power. You could get plenty of power that way, in theory.

In practice the idea has a lot of problems, including but not limited to these:
1. You wouldn't want that kind of reactor strapped to your chest. It's so small there's not much room for shielding from heat or high energy particles. There would be excess heat but Tony Stark could build some sort of radiator into his suit to deal with that, maybe.
2. MHD generators are a neat idea but it's not easy to find materials that can stand up to the punishment they take from high temperature plasma blasting through them. For example, we make cutting torches that use high temperature plasma to cut through things.
3. Antimatter may be one of the most expensive substances ever. Tony Stark might be able to afford some antiprotons, but otherwise it's out of the budget, and not that easy to store. Someone suggested we might be able to scoop up some antimatter from the Van Allen belts around the Earth more inexpensively than we can make it, but I don't think it's been tried yet.

This paper mentions the sort of idea I'm referring to, so it's actually somewhat scientific and not entirely comic book, but the problems mentioned above make it still somewhat comic book as far as I know, but probably closer to being realistic than the source you cited.

arxiv.org/pdf/physics/0507132

annihilation has two important characteristics: the release of energy in a matter-antimatter explosion is extremely fast (ten to a thousand times shorter than a nuclear explosion), and most of the energy is emitted in the form of very energetic light charged particles (the energy to mass ratio of the pions emitted in annihilation is two thousand times higher than the corresponding ratio for the fission or fusion reaction products). With the help of magnetic fields, very intense pion beams can be created, of the order of 100 mega-amperes per microgram of antiprotons. Such beams,if directed along the axis of an adequate device, can drive a magneto-hydrodynamic generator, generate a beam of electromagnetic waves, trigger a cylindrical thermonuclear explosion, or pump a powerful X-ray laser.

That's more or less what Tony Stark needs, except 100 million amps is probably too much for a chest sized device so that would need to be scaled down. It even mentions the "powerful laser" capability that Tony Stark apparently had, in addition to MHD power generation.

a reply to: joelr

The problem with GR isn't so much that it can't describe a singularity, the problem is it can't be quantized.

...it is using only one "force"... G, without counter counting other real existing forces/fields.
But G is an observable and not a force/field, not a real thing that can be created or changed, like electric or magnetic fields...

originally posted by: pfishy
a reply to: stormbringer1701

If you can get a sample of element 115 stable enough to use a slow neutron enrichment on, pm me. I have some Lazar drawings I'll sell you...

You don't get stable 115 first and then shoot neutrons at it. you get unstable 115 and shoot neutrons at it before it decays in the hope the right number of neutrons stick in the nucleus without breaking up the nucleus. If you had stable atoms there would be no point in shooting neutrons at it to make it stable; chances are you'd break the atom you were trying to preserve (redundantly.)

there were two unstable isotopes verified in the independent replication at LL. the second isotope was more stable than the first and so lasted a reasonable amount of time. probably long enough to be able to try neutron enrichment. however-----

Since the number of specimens is very low in the first place and their position is unknown until they decay it would be problematic to aim and time the neutron beam within the pre-decay window.

in theory if you tuck a neutron into a nucleus at just the right speed you can transform an element without breaking it up. in practice there are issues particularly with so few targets an so little time.

maybe using a cone shaped barrel for the neutron gun (rather than a small bore tube) in thousands of thousands of collider shots...

and if you made any you'd need a different way to detect them since they will not exhibit decay traces.

QUESTION !!
Nova explosions are said to be thermonuclear, so there should be a relatively homogeneous mix. Nuclear explosions are not known to sort materials. So what could be the cause of these anomalies?
And why is it not spherical?

Combined image of Nova Vulpeculae 1670 from the Gemini telescope (blue), a Submillimeter Array map showing the dust (yellow) and a map from the Atacama Pathfinder Experiment telescope (red). Credit: ESO/T. Kamiński

en.wikipedia.org...

so one species half life is 100 milliseconds and the more stable one is 220 milliseconds.

you kind of sneered at the idea of being able to pop a few neutrons in that time in a wee sized collider target chamber.

100 miliseconds is forever. we have way better timing than that.

you use computer timing circuits to time the unshuttering of the gun (do you even need to?) to a few milliseconds or nanoseconds after the collider shot arrives in the chamber.

a reply to: KrzYma
A novae is not an homogenous event, it occurs in binary star systems where one of the stars is a white dwarf and the other is a larger companion, either main sequence or an advance age star that is in close proximity.

This configuration allows material to transfer between the star at a large rate, an accretion disk forms and material spins around the white dwarf onto its surface.

Now, this is where it is important, because it is spinning material accreted will hydrogen enrich the equatorial regions of the star. Eventually this hydrogen will heat enough in a compressed space enough to ignite fusion. This fusion will not occur over the whole surface, but likely only in the equatorial region, it will be a chain event, due to pressure shock waves passing through the star.

THUS, it does not have to be homogenous at all, its shape will be determined by

1) the size/mass of the white dwarf - (Mass range of 1.4 to about 2.0 i think)
2) the size/mass of the companion
3) the physical separation between the two stars
4) the rotational velocity of the stellar surfaces
5) the magnetic environment
6) the age of the companion star


i suspect those 6 parameters would give you a host of different outcomes... remember, not all nova are the same, some of them do appear more spherical than others.

a reply to: stormbringer1701

Major challenge is a high intensity collimated neutron beam at the right energy... they are quite tricky little beasts to make, plus a shutter... for neutrons a shutter doesn't do very much, neutrons can pass through a significant amount of material

originally posted by: ErosA433
a reply to: stormbringer1701

Major challenge is a high intensity collimated neutron beam at the right energy... they are quite tricky little beasts to make, plus a shutter... for neutrons a shutter doesn't do very much, neutrons can pass through a significant amount of material

agreed. but neutron sources are kept in (arguably portable) lead containers so there was that. OTOH i don't thing using the shutter for timing would help. the big thing is the velocity and maybe the geometry of the intersection with the target nucleus. (and probably a little luck)

cesium? cadmium? berylium? the stuff used as neutron reflectors in some nuclear reactors?

a reply to: Arbitrageur

Thanks for helping me understand! Anti-matter is certainly up there for ideas, maybe we'll get lucky and discover an easy method to producing it.

I like this: “The only place where your dream becomes impossible is in your own thinking.” – Robert Schuller

originally posted by: IAmTheRumble
a reply to: Arbitrageur

Thanks for helping me understand! Anti-matter is certainly up there for ideas, maybe we'll get lucky and discover an easy method to producing it.

I like this: “The only place where your dream becomes impossible is in your own thinking.” – Robert Schuller

we can make positrons by the trillions and trillions in desktop machines. because a proton or anti-proton is over 1800 times more massive it takes at least that much energy to make one anti-proton. but you can't just make one particle without making it's anti-particle. I'd guess to make anti-protons the same way we can make positrons you'd need about 4000 times the energy to do positrons all told. but that is doable. the energy cost is not prohibitive. and the materials and engineering issues are not insurmountable.

originally posted by: KrzYma


...it is using only one "force"... G, without counter counting other real existing forces/fields.
But G is an observable and not a force/field, not a real thing that can be created or changed, like electric or magnetic fields...

That is the whole mystery, it hasn't been solved yet. GR describes gravity as geometry. Physicists who specialize in GR do not yet know if it can be quantized similar to electromagnetism as well.

There may or may not be a quantum version, we don't even know that. It might be like electromagnetism, except the fundamental quanta would be much smaller than EM, likely near the Planck scale. It's simply unknown right now.

originally posted by: stormbringer1701
we can make positrons by the trillions and trillions in desktop machines. because a proton or anti-proton is over 1800 times more massive it takes at least that much energy to make one anti-proton. but you can't just make one particle without making it's anti-particle. I'd guess to make anti-protons the same way we can make positrons you'd need about 4000 times the energy to do positrons all told. but that is doable. the energy cost is not prohibitive. and the materials and engineering issues are not insurmountable.

In the context of IAmTheRumble's question about Iron Man's hypothetical power source, I suggested proton-anti-proton annihilation because the charged particles that result can power an MHD generator.

Electron-positron annihilation won't give such useful annihilation byproducts, just gamma rays which it's hard to do much with for Tony Stark's purposes, though they are useful for PET scans I suppose.


You're right that positrons are cheaper than anti-protons, but I wouldn't say cheap:

Antimatter_cost

In 2006, Gerald Smith estimated $250 million could produce 10 milligrams of positrons[56] (equivalent to $25 billion per gram); in 1999, NASA gave a figure of $62.5 trillion per gram of antihydrogen.

So yes $25 billion a gram is cheaper than 62 trillion dollars a gram, but what else costs even 25 billion dollars a gram? I'm not sure how much the costs have come down since 2006 but in this paper the authors suggest that antimatter may never be very economical to produce:

Antimatter_paper

A study by the RAND Corporation gives a cost estimate of $500 to 1000 million for a prototype factory providing 10 to 100 micrograms (of anti-protons or anti-hydrogen), and $5 to 15 billion for a full production factory with an output of about 10 mg per year[4]. As a consequence, civilian applications of antimatter for power production are very unlikely.

For Tony Stark, cost might be no object and he apparently has more money than he knows what to do with, but he is a comic book character. In the real world, cost matters.

a reply to: joelr

That is the whole mystery, it hasn't been solved yet. GR describes gravity as geometry. Physicists who specialize in GR do not yet know if it can be quantized similar to electromagnetism as well.

you can't quantize geometry, also electric and magnetic fields are not quantized as well!
The frequencies in EM radiations are, as a consequence of emitters, but not the fields themselves !

There may or may not be a quantum version, we don't even know that. It might be like electromagnetism, except the fundamental quanta would be much smaller than EM, likely near the Planck scale. It's simply unknown right now.

Plank's units are not the smallest possible, it just makes no sense for us to calculate smaller values, this has nothing to do with any "pieces" in the infinity of distances.

math is the reason for "pieces" or quanta, like 1, 2, 3...
but a distance from mathematical 1 to 2 is "infinite big"
We can however only stay in a range and that's the only reason someone invented what we are told today.

originally posted by: ErosA433

... for neutrons a shutter doesn't do very much, neutrons can pass through a significant amount of material

Are you sure you don't mean neutrinos here? Neutrons, although electrically neutral and thus more penetrating than charged alphas or betas, are massive and do interact with matter. Something dense.