Ask any question you want about Physics

originally posted by: dragonridr
a reply to: stormbringer1701

Thought you might be interested in this it's the strongest material known. And its made by nature amazing the stuff we find.

www.usatoday.com...

fascinating! that design principle could be applied to materials other than iron as well. add in borene, CNTs, titanium, tungsten all of similar dimensions and shape...

there is also a theory that was going around over a decade ago that if you could make the grain sizes small enough in a metal it might become transparent. i mean without zapping it with x rays; thats another way to do it. with the minor draw back that it will kill you horribly and stop being transparent when the x rays are turned off

a reply to: Arbitrageur

www.conspiracyoflight.com...

Is the vacuum of space a real object unto itself, or is it simply emptiness, a nothing that does not exist in the absence of matter? From the viewpoint of Descartes and Leibniz, without physical objects, "space" would be meaningless because space is the framework upon which we understand how physical objects are related to each other. Sir Isaac Newton, on the other hand, argued for an absolute space ("container space"), which can continue to exist in the absence of matter.

In the 19th century, James Clerk Maxwell introduced the idea of an electromagnetic ether - a medium of space capable of supporting the structures of the electric and magnetic fields or light. Maxwell's idea of space was that it had a density and a transverse elasticity - when stressed it would impose a restoring force, much like a solid. This made it suitable for the transmission of transverse waves that waved in the body of the medium. It was Maxwell's challenge for an experiment to detect this medium that led to the Michelson and Morley (M&M) experiment of 1881 and 1887. There is good reason to believe that the M&M experiment was the wrong one for the job, but at the time it confounded the understanding of researchers. This frustration opened the way for the introduction of new theories that might solve the dilemma, such as Einstein's relativity theory.

Does QEM offer any further answers? Feynman continues with Einstein's notion that light is a particle -Feynman refers to the particle existing in space time. Feynman implies that the wave-particle duality of the photon was resolved in favour of the particle. He says quite explicitly - "I want to emphasize that light comes in this form - particles. It is very important to know that light behaves as particles, especially for those of you who have gone to school, where you were probably told something about light behaving as waves. I am telling you the way it does behave, like particles." Feynman , QED, P. 15. He argues that even though wave theory correctly predicts the "why" of partial reflection, and particle photon theory does not, QED is only concerned with predicting the probability of the event and thereby the "why" is not something that the theory can or will explain. P.24 of Feynman's "QED".

and because you asked
1 Light Propagation in a Gravitational Field


now one thing is missing... what is gravity ??

I told you it has to do with field density and charge resonance.

here from Tesla...

It is the force which governs the motion of the atoms, which causes them to collide and develop the life-sustaining energy of heat and light, and which causes them to aggregate in an infinite variety of ways, according to Nature's fanciful designs, and to form all these wondrous structures we perceive around us, it is, in fact, if our present views be true, the most important force for us to consider in Nature.

what could this force be ??

originally posted by: pfishy
Has anyone with a strong background in particle physics, in this thread, ever taken a serious look at the model Swann has been trying to develop?

Arbitrageur already got this, but, yes I looked at it quite closely over a weekend, and came to the conclusion that it is an outstanding piece of numerology by all means... but it is not a predictive model nor does it work from first principles.

You might say what we have right now doesn't either... but... what we have now does allow you to predict the decay channels of say... the B quark to a fairly good accuracy, which is pretty cool given that bound b quark states and their decay paths number into the many hundreds.

What the model is, is something that allows you to play with a few numbers, put them into an 16th order quadratic equation with parameters that are... tuned lets say... which give you 16th solutions, which happen to be the particle masses.

Like i said, wonderful numerology, but it isn't really a model like the standard model is.

I was able in about 30 minutes to produce a polynomial equation that gave the masses of the down, strange and bottom. using input parameters of generation number... I just put wrote a very simple ROOT macro and fitted it using Minuit... Id hardly call what i did a model, as it doesn't predict or model anything.

This is my first post so here goes, if we were able to stay glued to this spot in space and remain so as the Earth travelled off in its orbit around the Sun when it returned in twelve months would we be in the same spot or moved to another location on the planet? I know this may sounds trippy, but I have heard that stellar objects continually drift regardless of size, so if we stayed in one point whilst we may be still on the Earth our position might not be the same. I’d really like to know if anyone can tell me, thanks.

a reply to: Entropy1971
Hi and welcome to ATS!

The sun is orbiting the center of the Milky Way and if you didn't also, you'd get left behind while the sun continued in its orbit. You'd see the planets making a corkscrew-like motion through space, as they followed the sun sort of like this, except the orbit of the planets is at 60 degrees, not 90 degrees, and this is not to scale, so this is slightly off, but it still gives you a good idea of the "corkscrew motion" (There's a video at the link that corrects the angle issue but not the scale issue).

astrorhysy.blogspot.com...


So in other words, 12 months later, the Earth would be over 7.2 billion kilometers away from you from this motion alone, since the sun is traveling at about 1/1300 the speed of light in its orbit.

There are even more motions which could be considered, such as the motion of the Milky Way (it's moving with respect to the CMB, or cosmic microwave background).

originally posted by: KrzYma
I told you it has to do with field density and charge resonance.

here from Tesla...

That seems to imply Tesla said something about charge resonance being related to gravity but your quote doesn't say that and besides, even if it did, we already know that Tesla was a great engineer but a terrible physicist, so he made lots of false remarks about physics that don't mean much. So what evidence have you that gravity has to do with "charge resonance"?

what could this force be ??

I think a deeper understanding of gravity than we have now is possible, but since we don't have that understanding yet, the question is open. I've seen nothing to suggest gravity has to do with "charge resonance".

a reply to: Entropy1971

Awesome reply by Arbitrageur as usual, and to add another little astronomy titbit, the definition of a day depends upon how you measure it.

So... how do we measure it? Well on Earth the way we set our time is such that the sun is in it's highest point when it is 12:00 on our clocks. So it is measured with respect to the sun.

BUT... how about measuring it with respect to the stars? After all, if we want to talk about a full rotation 360 around its axis, it will be with respect to the stars, and NOT the sun. What this is, is sidereal time, or the sidereal day. Which is 23.9344 hours long, rather than 24. This is because, within a single day, the Earth would have moved along its orbit and the direction of the sun, actually would be slightly more east if we are taking a fixed point of reference such as a distant star or other object.

It is actually a conversion that is required in astronomy when pointing telescopes

en.wikipedia.org...

originally posted by: KrzYma
and because you asked
1 Light Propagation in a Gravitational Field

Thanks for the link, now I see what you're talking about when you mention refraction.

I did spend some time trying to understand the thought process of the author of that paper, D. M. Marett. He posits this "distinction":

-With Gravitational refraction, the frequency shift is virtual and caused only by the mechanical effects of gravity on clocks.
-For Einstein, the speed of light across the beam is at different speeds in absolute time because local time is running slower on the side of the beam closest to the massive body.

I wondered what the observable distinction would be and he claims that in most cases there's no observable distinction, but finally I found what seems to be a prediction of some sort of difference between the two ideas related to gravitational redshifting or blueshifting as light leaves or enters the gravitational field of a star or planet.

The only way to tell the difference is to see if more energy is absorbed or not at S1. From my review of the literature, I can't find any experimental reference testing this idea that a beam of light gains energy in a gravitational field, or looses energy escaping it. This is hard to accept, since the emission and reception of light by electrons in atoms does not affect its mass.

So he seems to be proposing an experimental test, which can finally distinguish his proposed model from Einstein's model, but alas, I don't think he's really thought this through. He doesn't actually propose any specific experimental test and I think no matter what test he proposes I can find a flaw in it such that it won't really distinguish between "the mechanical effects of gravity on clocks" and "time running at a different rate", but if he thinks he can, I'd like to see such a test. This idea of a test has many flaws.

The energy gained by photons as they move closer to earth doesn't need to affect mass so I'm not sure why he raises that point. Photons entering and leaving the Earth are considered in climate models which predict global warming, which involve greenhouse gases that determine how much of the entering energy can escape, but in any event the net effect is on temperature, not mass.

The gain or loss of energy in a gravitational field isn't unique to light; in the following illustration an apple also loses energy if you throw it up from the Earth, so if he's not worried about the conservation of energy with an apple why is he worried about it with light? If the apple falls back to Earth or if you reflect the photon back to Earth, when they return to their starting point they have the same energy (less friction etc) so the energy is still conserved in both cases. It's not clear to me that Marett understands this.

casa.colorado.edu/~jdarling/astr-2030/lecture06.pdf


a reply to: ErosA433
Excellent point about sidereal time, which leads to an alternate answer to Entropy1971's question. The initial answer was qualified with this statement: "The sun is orbiting the center of the Milky Way and if you didn't also, you'd get left behind while the sun continued in its orbit."

So that scenario assumed when you left the Earth you cancelled both the orbital motion of the Earth around the sun and the orbital motion of the sun in the galaxy, but what if you only canceled the former but not the latter? In that case you'd be orbiting the Milky Way center along with the sun, and a year later the position of the Earth would come back to where you are, but using a calendar year, you wouldn't be in the same spot.

In order to get back closer to your original spot, you would have to wait approximately another 20 minutes on top of the calendar year, which would then be a sidereal year (the type of time you mention). Since the Earth rotates about 360 degrees in 24 hours which is 15 degrees an hour that means your longitude would be off by 5 degrees, and the actual distance of that depends on your latitude, but at the equator just take the circumference of the Earth, divide by 360 degrees and multiply by 5 degrees to get the distance you'd be off from your original distance after one calendar year.

Entropy1971, the sidereal year is different from the calendar year because of the Earth's orbit wobbling like a top wobbles when it spins, an effect called precession. If you waited the extra 20 minutes or so for the sidereal year, I think you'd be close to your original spot, if you weren't "stationary in space" but "followed the sun" in its orbit.

Actually it's hard to define what "if we were able to stay glued to this spot in space" really means since we usually think of motion in relative terms. The closest thing we have to a universal reference is the cosmic microwave background, so you could phrase the question "if you left the earth and took a position as an observer stationary with respect to the CMB..." in which case you'd see the Milky Way itself moving, in addition to the other motions of the Earth and sun orbits.

I have a question, why space often refers to vacuum and in it's turn vacuum refers to nothingness?

Really all three are synonymous?

a reply to: greenreflections
I suggest reading this post to see if that answers your question, but no those are not synonymous. We haven't got a good model yet for exactly what's in the vacuum but we're pretty sure it's not "nothing". Even if there's no baryonic matter present we think it probably contains at least some energy. Space is a more generic term that could be filled with air so it doesn't have to imply a vacuum, though it could be used that way also, but if you want to do that it would be better to give it a qualifier like "deep space" or "outer space" which would then imply a near vacuum.

originally posted by: Arbitrageur
a reply to: Entropy1971
Hi and welcome to ATS!

The sun is orbiting the center of the Milky Way and if you didn't also, you'd get left behind while the sun continued in its orbit. You'd see the planets making a corkscrew-like motion through space, as they followed the sun sort of like this, except the orbit of the planets is at 60 degrees, not 90 degrees, and this is not to scale, so this is slightly off, but it still gives you a good idea of the "corkscrew motion" (There's a video at the link that corrects the angle issue but not the scale issue).

astrorhysy.blogspot.com...

So in other words, 12 months later, the Earth would be over 7.2 billion kilometers away from you from this motion alone, since the sun is traveling at about 1/1300 the speed of light in its orbit.

There are even more motions which could be considered, such as the motion of the Milky Way (it's moving with respect to the CMB, or cosmic microwave background).

That is a really neat graphic! TY.

a reply to: stormbringer1701
You're welcome. Too bad it's not quite right. The physicist at the link made a corrected model but it's not a GIF so unfortunately the only GIF I could find was of that somewhat incorrect version. He also raised an interesting question about the orientation of our solar system for an entire orbit of our sun around the galaxy and he doesn't know the answer to that question and neither do I, but if his alternate model is correct, what is shown in that graphic could change significantly over time, but we are talking 240 million years per orbit so it's not something we will observe in our lifetimes.

By the way, I didn't notice it when I posted it, but I just noticed the graphic I posted with three slides from the university of Colorado on gravitational red shift and time dilation has an error, or at least I don't see any way to interpret it so that it doesn't have that error. Can anybody spot the error?

i have absolutely no interest in ways to make "better" atomic bombs. I do however take interest in anything that says it will be possible to make micro-grams of antimatter. Thats because micro-grams are enough to power spaceships on long distance/duration missions. so i give you this:

nextbigfuture.com...

and i put it here because we were arguing about antimatter here earlier. this is enough for an AIMSTAR or ICAN series spaceship engine.

originally posted by: Arbitrageur
a reply to: greenreflections
I suggest reading this post to see if that answers your question, but no those are not synonymous. We haven't got a good model yet for exactly what's in the vacuum but we're pretty sure it's not "nothing". Even if there's no baryonic matter present we think it probably contains at least some energy. Space is a more generic term that could be filled with air so it doesn't have to imply a vacuum, though it could be used that way also, but if you want to do that it would be better to give it a qualifier like "deep space" or "outer space" which would then imply a near vacuum.

other than the possibility of improper variables which i am to lazy to look up right now when you talk about extracting energy from an escaping mass i run into questions about gravitational self energy (ever since i read Dr Woodward's book.) it's one of those terms where there is a divergence or infinity involved. your point probably does not involve gravitational self energy though because most physicists have simply written it off as a math artifact and drive on with the rest of the equations. normally when i read about doppler shifts gravity is neglected. i.e a star is approaching our sun has a blue shift and one receding has a red shift. i honestly thought gravity doesn't extract energy so much as it curves the space an object is moving through; in extreme cases so that the path curves back on itself. an object held above a more massive object has potential energy. and as it approaches the potential energy is translated into KE. for an object in a gravity well but travelling away the potential energy would appear to increase.

originally posted by: Arbitrageur
a reply to: stormbringer1701
By the way, I didn't notice it when I posted it, but I just noticed the graphic I posted with three slides from the university of Colorado on gravitational red shift and time dilation has an error, or at least I don't see any way to interpret it so that it doesn't have that error. Can anybody spot the error?

Shouldn't time tick slower nearer the Earth?

a reply to: Arbitrageur

... you are welcome !

........

E=hv or ʎ=c/v has no meaning.

v is change in time, --> counting !!

I said once that "energy" in a wave is wavelength independent if you remember.
Only the work it is doing is different !
Work is the "change" done in time, energy is not.
What is energy anyway ?? just an expression for something that does the work

but you will disagree again

I see it this way, no change --> no time, because time is sensation and nothing real ---> counting !!

To explain my field density you need to imagine an predetermined range in infinity.
No beginning or ending however. ( quanta as perceived "scale" just for definition meaning)
Now, if the E field changes, a reconfiguration in the field happens, the B field is the manifestation of it.
Talking your language... imagine density as bits in one place. Like photons "stack" in one place.
Those "bits" have to take a new value after the change in E field.
Every change is "time" consuming --> actually it is the time itself as I see it
Like one "bit" transfers the "information" to the next "bit" and so on...
... denser field takes "longer" for the outside observer.

a wave of 1m has the same "energy" as a wave of 1cm...
explanation...
imagine just one free charge and nothing else.
EM wave, actually just the B field is displacing it.
1m/s wave will displace it the same amount as 1cm/s wave, it only "takes longer"
but you can not "count" any change if only one charge exist, can you ?

you need at least 3 charges and 2 distances between them, 1->2->3
"->" between any of them is the "change"
you compare one "->" (distance) to the other "->" (distance)to "see" the difference, or not ??
2 charges universe has no meaning at all because there is nothing you can compare to/with... (distances between them)

.....

because I am me I need to do some blasphemy


watch this... and the preview one and the next if you like...


haha...
so, if the math doesn't fit, the electron becomes a wave, the "solid" nucleus becomes a Huygen source, and the used material is always that to fit the experiment... oh gosh...

Sn is...

Tin is a malleable, ductile and highly crystalline silvery-white metal

I think what they have measured , is the lattice size...

originally posted by: Arbitrageur
a reply to: stormbringer1701
You're welcome. Too bad it's not quite right. The physicist at the link made a corrected model but it's not a GIF so unfortunately the only GIF I could find was of that somewhat incorrect version. He also raised an interesting question about the orientation of our solar system for an entire orbit of our sun around the galaxy and he doesn't know the answer to that question and neither do I, but if his alternate model is correct, what is shown in that graphic could change significantly over time, but we are talking 240 million years per orbit so it's not something we will observe in our lifetimes.

By the way, I didn't notice it when I posted it, but I just noticed the graphic I posted with three slides from the university of Colorado on gravitational red shift and time dilation has an error, or at least I don't see any way to interpret it so that it doesn't have that error. Can anybody spot the error?

I have a question about the first slide - I thought that gravitational redshift was photons climbing out of the energy well. Since they can't slow down, a photon lowers energy and frequency. The first slide shows an apple escaping the Earth - but the apple can slow down and can't equal its escape velocity. How does that slide fit with the other two - sorry for poor terminology.

originally posted by: KrzYma
a reply to: Arbitrageur

... you are welcome !

........

E=hv or ʎ=c/v has no meaning.

v is change in time, --> counting !!

I said once that "energy" in a wave is wavelength independent if you remember.
Only the work it is doing is different !
Work is the "change" done in time, energy is not.
What is energy anyway ?? just an expression for something that does the work

but you will disagree again

I see it this way, no change --> no time, because time is sensation and nothing real ---> counting !!

To explain my field density you need to imagine an predetermined range in infinity.
No beginning or ending however. ( quanta as perceived "scale" just for definition meaning)
Now, if the E field changes, a reconfiguration in the field happens, the B field is the manifestation of it.
Talking your language... imagine density as bits in one place. Like photons "stack" in one place.
Those "bits" have to take a new value after the change in E field.
Every change is "time" consuming --> actually it is the time itself as I see it
Like one "bit" transfers the "information" to the next "bit" and so on...
... denser field takes "longer" for the outside observer.

a wave of 1m has the same "energy" as a wave of 1cm...
explanation...
imagine just one free charge and nothing else.
EM wave, actually just the B field is displacing it.
1m/s wave will displace it the same amount as 1cm/s wave, it only "takes longer"
but you can not "count" any change if only one charge exist, can you ?

you need at least 3 charges and 2 distances between them, 1->2->3
"->" between any of them is the "change"
you compare one "->" (distance) to the other "->" (distance)to "see" the difference, or not ??

2 charges universe has no meaning at all because there is nothing you can compare to/with... (distances between them)

.....

because I am me I need to do some blasphemy

watch this... and the preview one and the next if you like...

haha...
so, if the math doesn't fit, the electron becomes a wave, the "solid" nucleus becomes a Huygen source, and the used material is always that to fit the experiment... oh gosh...

Sn is...

Tin is a malleable, ductile and highly crystalline silvery-white metal

I think what they have measured , is the lattice size...

This makes no sense at all. Time is in the equation because it's another way to measure energy. In light we can use frequency or wave lengths or energy levels. You can use whichever you like for mathematical purposes. To say they don't represent different energy levels is stupid.

In physics what your trying to do will decide what you would use. Like electron volts is useful for energy conversion if your discussing x ray or gamma you discuss wave lengths. If you want to talk about radio you use frequency. But you don't have to if you don't want to we can use energy levels. For example radio wave can have an energy of around 4 x 10-10 eV, a gamma-ray can have an energy of 4 x 109 eV. So you saying there is no difference in energy levels? this is just wrong and even people with understanding of electronics will tell you this.

And trying to say one method is an inaccurate way to measure it may indeed be true that's why we have other options whatever works best frequency, wave length or electron volts use it. Photons don't care they are all equally as valid.

originally posted by: EasyPleaseMe
Shouldn't time tick slower nearer the Earth?

Bingo! You get a star for that!

I'm not sure what the professor was thinking saying the opposite, maybe just a brain fart, we all have them. It's not like lecture slides are peer-reviewed.

originally posted by: stormbringer1701
i honestly thought gravity doesn't extract energy so much as it curves the space an object is moving through; in extreme cases so that the path curves back on itself.

Not-space, but space-time, and in this case, specifically time.

Thought experiment: Set up a laser on the SOHO satellite emitting photons of a known frequency. Now aim this beam of photons directly at the center of the Earth, so we can focus on time. As EasyPleaseMe correctly observed, clocks on Earth tick more slowly (than the clock on the SOHO satellite). So basically when an observer on Earth's surface measures the photon, it will have higher energy at the Earth's surface according to E=hf. This higher frequency and thus energy measurement is actually the result of the clock on Earth ticking more slowly.

originally posted by: KrzYma
but you will disagree again

I find it hard to disagree with something I can't even understand.

Now, if the E field changes, a reconfiguration in the field happens, the B field is the manifestation of it.
Talking your language... imagine density as bits in one place. Like photons "stack" in one place.
Those "bits" have to take a new value after the change in E field.

That's not "talking my language", I have no idea what that means. I tried to imagine a stack of photons reacting to a change in an E field but if you want me to understand what you're talking about you'd have to point to some kind of experiment where this has happened. Electrons will react to an e-field, did you mean to say electrons instead of photons?

originally posted by: dragonridr
This makes no sense at all.

I really tried but I couldn't make any sense out of it either.

originally posted by: Phantom423
I have a question about the first slide - I thought that gravitational redshift was photons climbing out of the energy well. Since they can't slow down, a photon lowers energy and frequency. The first slide shows an apple escaping the Earth - but the apple can slow down and can't equal its escape velocity. How does that slide fit with the other two - sorry for poor terminology.

I'm not sure if I understand your question because it seems to me like you answered your own question about the differences. However let's approach this another way and see if it clarifies the comparison.

Is E=mc² right or wrong? The answer is no, it's not exactly the right equation. This is the right equation, as explained in that thread:


The E on the left side is "Energy".
On the right side, the first term relates to "rest mass", "m". In the case of an apple or a photon leaving the earth, this term isn't relevant for measuring changes in energy, as the rest mass of the apple is unchanged, and the photon has no rest mass.
The second term on the right side is the one we are interested in. We will call it a "momentum" term. Both the apple and the photon have momentum, and this momentum is reduced as they travel away from Earth's surface, thus, so is their energy.

I'm not sure if this will make any sense to you but this shows two expressions of momentum:

p = mv
p = h/ʎ

Where:
p=momentum
m=mass
v=velocity
h=Planck's constant
ʎ=wavelength

So what does this mean?
It means we can calculate the momentum of the apple using p=mv and plug that p value into the energy formula which tells us how the change in momentum results in a change in energy. We can also calculate the momentum of a photon using p=h/ʎ, and plug that p value into the energy formula which tells us how the change in momentum results in a change in energy.

Since I wasn't sure I understood your question I'm not sure if this will answer it, but feel free to ask for further clarification if it didn't.

originally posted by: stormbringer1701
i have absolutely no interest in ways to make "better" atomic bombs. I do however take interest in anything that says it will be possible to make micro-grams of antimatter. Thats because micro-grams are enough to power spaceships on long distance/duration missions. so i give you this:

nextbigfuture.com...

and i put it here because we were arguing about antimatter here earlier. this is enough for an AIMSTAR or ICAN series spaceship engine.

and then there is this: Positron Ablative
Positron Ablative
Exhaust velocity 49,000 m/s

This engine produces thrust when thin layers of material in the nozzle are vaporized by positrons in tiny capsules surrounded by lead. The capsules are shot into the nozzle compartment many times per second. Once in the nozzle compartment, the positrons are allowed to interact with the capsule, releasing gamma rays. The lead absorbs the gamma rays and radiates lower-energy X-rays, which vaporize the nozzle material. This complication is necessary because X-rays are more efficiently absorbed by the nozzle material than gamma rays would be.

Drawbacks include the fact that you need 1836 positrons to equal the energy of a single anti-proton, and only half the positrons will hit the pusher plate limiting the efficiency to 50%.

This system is very similar to Antiproton-catalyzed microfission

Antiproton-catalyzed microfission, inertial confinement fission. See here.

Fuel pellets have 3.0 grams of nuclear fuel (molar ratio of 9:1 of Deuterium:Uranium 235) coated with a spherical shell of 200 grams of lead. The lead shell is to convert the high energy radiation into a form more suited to be absorbed by the propellant. Each pellet produces 302 gigajoules of energy (about 72 tons of TNT) and are fired off at a rate of 1 Hz (one per second). The pellet explodes when it is struck by a beam containing about 1×10^11 antiprotons.

A sector of a spherical shell of 4 meters radius is centered on the pellet detonation point. The shell is the solid propellant, silicon carbide (SiC), ablative propellant. The missing part of the shell constitutes the exhaust nozzle. Each fuel pellet detonation vaporizes 0.8 kilograms of propellant from the interior of the shell, which shoots out the exhaust port at 132,000 meters per second. This produces a thrust of 106,000 newtons.

The Penn State ICAN-II spacecraft was to have an ACMF engine, a delta-V capacity of 100,000 m/s, and a dry mass of 345 metric tons. The delta-V and exhaust velocity implied a mass ratio of 2.05. The dry mass and the mass ratio implied that the silicon carbide propellant shell has a mass of 362 metric tons. The wet mass and the thrust implied an acceleration of 0.15 m/s2 or about 0.015g. It can boost to a velocity of 25 km/sec in about three days. At 0.8 kilograms propellant ablated per fuel pellet, it would require about 453,000 pellets to ablate the entire propellant shell.

It carries 65 nanograms of antiprotons in the storage ring. At about 7×1014 antiprotons per nanogram, and 1×10^11 antiprotons needed to ignite one fuel pellet, that's enough to ignite about 453,000 fuel pellets.

Antimatter-Driven Sail

The sail is made of graphite and carbon-carbon fiber, infused with a tiny amount of uranium. It is subjected to a misting of antiprotons. These induce uranium atoms to fission, with the recoil pushing the sail. Since this is nuclear powered, the sail does not have to be kilometers in diameter, five meters will do. 30 miligrams of antiprotons could push the sail to the Kuiper Belt.