A Fusor is a device that uses an electric field to heat ions to conditions suitable for nuclear fusion. The machine has a voltage between two metal cages inside a vacuum. Positive ions fall down this voltage drop, building up speed. If they collide in the center, they can fuse. This is a type of Inertial electrostatic confinement device.
A Farnsworth–Hirsch fusor is the most common type of fusor (as seen above in the gifs). Farnsworth’s original fusor designs were based on cylindrical arrangements of electrodes. Fuel was ionized and then fired from small accelerators through holes in the outer (physical) electrodes.
Once through the hole they were accelerated towards the inner reaction area at high velocity. Electrostatic pressure from the positively charged electrodes would keep the fuel as a whole off the walls of the chamber, and impacts from new ions would keep the hottest plasma in the center. He referred to this as inertial electrostatic confinement, a term that continues to be used to this day.
Hip science: Rock-star physicists make tough concepts easier to understand
By Rachel Weaver
It doesn’t take a rocket scientist to see why a certain subject is so popular these days.With a ubiquitous presence in pop culture and a slew of its scholars reaching celebrity status, science is shedding its daunting reputation, academics say.“There is a movement on both sides with academics and nonacademics to try to make science less intimidating,” says Jonathan Pruitt, assistant professor of behavioral ecology at the University of Pittsburgh. “It’s really not. It’s really a social thing. There’s a push from scientists and the general public to demystify it.”Pittsburgh will host two celebrity scientists in coming weeks when theoretical physicist Michio Kaku comes to Heinz Hall on April 29 as part of the Pittsburgh Speakers Series, and astrophysicist Neil deGrasse Tyson speaks at the Benedum Center on May 7.Kaku, 68, co-founder of string field theory, is a frequent host of TV specials for the BBC, Discovery Channel, the History Channel and the Science Channel. He is host of the widely popular national weekly radio program “Science Fantastic.”Tyson, 56, who recently revived Carl Sagan’s “Cosmos” for Fox, has nearly 3.5 million Twitter followers. His new science talk show debuted April 20 on the National Geographic Channel.These types of “rock star” science popularizers are making the field more accessible to audiences who might otherwise shy away from seemingly complicated subjects, insiders say.“Scientists don’t always do a good job of explaining what we do and why and what we learn from it and how that fits into larger society,” says Graham Hatfull, University of Pittsburgh professor of biotechnology. “Having some folks who are really good at doing that and can distill what are often complex ideas in ways that they can be understood is a gift. Science needs people who are able to do that.”Society’s reliance on technology makes science more accessible to the masses, says Steven Little, chairman of Pitt’s Department of Chemical and Petroleum Engineering.“These days, especially with devices that we carry around with us, it’s easier for people to see how technology changes their lives, maybe even to the point where they’re not sure how they’d live without it,” Little says. “Because of computers, you can really ask a question anytime you want. It used to be you could only ask a professor in a classroom. Now, you can push a button on a phone and talk to Siri. There is so much information at our fingertips, it’s almost overwhelming.”People look to figures like Kaku, a professor of theoretical physics at the City College of New York, and Tyson, who is head of the Hayden Planetarium at the American Museum of Natural History in New York, to help them navigate that information, Little says.“People are inherently programmed to really enjoy the wonderment of the world, but a lot of people think science takes that wonderment out by explaining it,” Little says. “People like Neil have this wonderful ability and charisma to really help people with that wonderment.”
Analogies can be made between the Hilbert space we use in quantum mechanics and the standard 3-dimensionally real Euclidean (or Cartesian) space that we use in
classical physics – such as in kinematics wherein we have vectors with components in the x-, y- and
z- directions. By defining in which directions the corresponding unit vectors ex, ey and ez act, we
can know an awful lot about the state of the vector in that space by projecting it onto those unit
Consider a general vector V in ℝ3 (i.e. 3-dimensional, real) Euclidean space using Cartesian co-ordinates.
The projection of our vector onto each axis is given by the 3 Cartesian components of the vector; Vx, Vyand Vz. We’ll discuss later how these axes are defined and, in turn, how a vector can be projected onto
Now, if we define our Cartesian unit vectors by the basis state
(note that each unit vector is orthogonal to one another since their inner product is zero) and define our vector by
its three components
we can find each of our vector’s components by projecting its state onto the x, y, z basis (i.e. the basis vector given by ⟨ e |). So,
This gives us the probability amplitude of finding the vector V in the Cartesian plane.
This is the vector explicitly in Cartesian space, formed by projecting our vector onto another set of vectors. This
projection was achieved using the inner product of V with e. As such, we can infer that any vectorial resolving we’ve met before is a
simplified inner product. Let’s quickly examine this.
Let’s set up the inner product of V with one of the unitary axial components of e, say ex for instance. In regular vector notation, i.e. to better examine the scalar product, we have
Now, we know that the unitary vector ex has a length of one by definition. Therefore,
which is often the equation we use to find a certain vectorial component when resolving vectors, depending between which axis we have defined θ. Therefore, we can infer
We can examine the projection of this vector onto every component of ⟨ e | individually to understand how
the vector acts in that particular direction. We can either do this by re-defining ⟨ e | V ⟩ = V(e) and
projecting this new function onto the individual components of e or by doing this implicitly within
Dirac notation. Since we know that we’re dealing with discrete quantities here, let’s use the latter for
Let’s first start by continuing the analogy with Dirac notation and represent the state |e⟩ as a superposition of all
the possible states within it:
which makes its basis vector
since, in general, | ψ ⟩* = ⟨ ψ | and where by the definition of the e-components,
(recall the conjugate transpose discussed above).
Take equation 1 and multiply through by the particular axis (or representation) we’re interested in. Take the
x-component first, ⟨ ex | and project ⟨ e | V ⟩ onto it:
Using the above definitions of components of e,
and since ⟨ ex | = (1 0 0),
and so, by multiplying the matrices we find that
which is exactly the same result we found above while performing the scalar product between V and ex.
as a consequence.
The same can be done for all components of the bases represented by ⟨ e |.
We could also ‘cut out the middle-man’ and instead find the direct projection of the vector V onto one of the
and so on, to find
Thus, the above diagram in Dirac’s notation becomes:
The two are completely analagous but come from a different approach. Notice how the vector “state” in Dirac notation (shown in the pink square) has no initial representation until projected onto the representation given by e.
Using this analogy of Cartesian vectors in Dirac notation can help us to understand some of the similarities and differences between Euclidean space and Hilbert space, which we will look at in a future post.
I love physics because for pretty much 500 years it followed certain rules that everybody thought were perfect and correct and then Einstein comes and he’s like “you know what? fuck it you’re all wrong”
Space Dandy is probably one of the most kickass anime’s I’ve seen in a long time. My inner astrophysics nerd came on full speed. A print I did for Chibi Con, and I’ll also sell at this year’s Anime Next.
Five things scientists could learn with their new, improved particle accelerator
The world’s most powerful particle accelerator, the Large Hadron Collider (LHC) has been undergoing two years of upgrades. Now, particles are zipping around its ring once again, and scientists will start colliding particles this summer. Here are five things scientists hope to learn from the new, improved LHC:
1. Does the Higgs boson hold any surprises? Now that we’ve found the Higgs boson, there’s still a lot we can learn from it. Thanks to the LHC’s energy boost, it will produce Higgs bosons at a rate five times higher, and scientists will be using the resulting abundance of Higgs to understand the particle in detail. How does it decay? Does it match the theoretical predictions? Anything out of the ordinary would be a boon to physicists, who are looking for evidence of new phenomena that can explain some of the unsolved mysteries of physics.
2. What is “dark matter”? Only 15% of the matter in the universe is the kind we are familiar with. The rest is dark matter, which is invisible to us except for subtle hints, like its gravitational effects on the cosmos. Physicists are clamoring to know what it is. One likely dark matter culprit is a WIMP, or weakly interacting massive particle, which could show up in the LHC. Dark matter’s fingerprints could even be found on the Higgs boson, which may sometimes decay to dark matter. You can bet that scientists will be sifting through their data for any trace.
3. Will we ever find supersymmetry? Supersymmetry, or SUSY, is a hugely popular theory of particle physics that would solve many unanswered questions about physics, including why the mass of the Higgs boson is lighter than naively expected—if only it were true. This theory proposes a slew of exotic elementary particles that are heavier twins of known ones, but with different spin—a type of intrinsic rotational momentum. Higher energies at the new LHC could boost the production of hypothetical supersymmetric particles called gluinos by a factor of 60, increasing the odds of finding it.
4. Where did all the antimatter go? Physicists don’t know why we exist. According to theory, after the big bang the universe was equal parts matter and antimatter, which annihilate one another when they meet. This should have eventually resulted in a lifeless universe devoid of matter. But instead, our universe is full of matter, and antimatter is rare—somehow, the balance between matter and antimatter tipped. With the upgraded LHC, experiments will be able to precisely test how matter might differ from antimatter, and how our universe came to be.
5. What was our infant universe like? Just after the big bang, our universe was so hot and dense that protons and neutrons couldn’t form, and the particles that make them up—quarks and gluons—floated in a soup known as the quark-gluon plasma. To study this type of matter, the LHC produces extra-violent collisions using lead nuclei instead of protons, recreating the fireball of the primordial universe. Aided by the new LHC’s higher rate of collisions, scientists will be able to take more baby photos of our universe than ever before.
Contrary to other transparent surfaces, the wings of the glasswing butterfly (Greta oto) hardly reflect any light. Irregular Nanostructures of the wings could be applied to lenses or displays of mobiles which might profit from the investigation of this phenomenon.