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Showing posts with label Stardust. Show all posts
Showing posts with label Stardust. Show all posts

Saturday, January 13, 2007

Aerogels and Stardust



IN a previous post on "Stardust," I was enamoured with "the product," that could do all the things that it said it could do.

-It is 99.8% Air

-Provides 39 times more insulating than the best fiberglass insulation

-Is 1,000 times less dense than glass

-Was used on the Mars Pathfinder rover


So having understood what "less gravity can do" in organizing of chemicals in space, it is of course of interest when such a chemical can be made into a product in it's "pure form," to have it "almost clear" in it's constitution and strong to hold weight.

It sort of opens the idea for me of manufacturing processes in space, and the construction of and use of those same products to build in space, and on, "planets of the future"

Almost as light as air, capable of withstanding a direct flame or catching speeding comet dust like a baseball mitt stops a hardball, aerogels are some of the strangest solids in the world. This "Space Age Styrofoam" was developed in a chemistry lab decades ago but is now appearing in snowsuits, explosives and even energy storage technology.

Aerogels are the lightest and lowest-density class of materials in the world. Up to 99 percent of the dry, rigid gels are air, while the rest consists of silica, carbon, metals and other substances; it feels like a Styrofoam peanut. Yet, some formulations can support close to two thousand times their weight (if it is lowered onto them slowly). "Enough force to crush a Rice Krispie will crush an aerogel," states Stephen Steiner, a nanomaterials graduate student at the Massachusetts Institute of Technology and aerogel researcher.


<Image: COURTESY OF LAWRENCE BERKELEY NATIONAL NATIONAL LABORATORIES-Aerogels are poor thermal conductors and therefore exceptional insulators for windows, snowsuits and spacecraft


Image: COURTESY OF NASA/JPL-CALTECH-Translucent silica aerogel is mostly air but two grams of the material is strong enough to hold a 2.5 kilogram brick

I was less then kind in my statements about stardust, as the images of dust in the air were given for introspection, about how we might see that dust in the universe.

"Last Sunday, after seven years in space traveling nearly three billion miles, Stardust landed in the Great Salt Lake Desert with a treasure from when the solar system formed 4.6 billion years ago," says astronomer Donald Brownlee of the University of Washington, who led the Stardust team. "We should have more than one million particles larger than one micron in diameter."


Image: D. BROWNLEE / NASA-Collecting of Stardust

Thursday, August 31, 2006

Now, here is a SuperNova for Real

The Crab Nebula from VLT Credit: FORS Team, 8.2-meter VLT, ESO



Now the "ultimate proof" is to hold in our hands the matters defined by objects. This is the culmination of all dimensional perspectives, being "condensed to the moment" we hold the stardust samples in our hands. In that case, it may be of a meteorite/comet in passing?

Now we are going back to our computers for a moment here.

Now we know what can be done in terms of computer programming, and what simulations of events can do for us, but what happens, when we look out into space and watch events unfold as they do in our models?

Interaction with matter
In passing through matter, gamma radiation ionizes via three main processes: the photoelectric effect, Compton scattering, and pair production.


Photoelectric Effect: This describes the case in which a gamma photon interacts with and transfers its energy to an atomic electron, ejecting that electron from the atom. The kinetic energy of the resulting photoelectron is equal to the energy of the incident gamma photon minus the binding energy of the electron. The photoelectric effect is the dominant energy transfer mechanism for x-ray and gamma ray photons with energies below 50 keV (thousand electron volts), but it is much less important at higher energies.
Compton Scattering: This is an interaction in which an incident gamma photon loses enough energy to an atomic electron to cause its ejection, with the remainder of the original photon's energy being emitted as a new, lower energy gamma photon with an emission direction different from that of the incident gamma photon. The probability of Compton scatter decreases with increasing photon energy. Compton scattering is thought to be the principal absorption mechanism for gamma rays in the intermediate energy range 100 keV to 10 MeV (megaelectronvolts), an energy spectrum which includes most gamma radiation present in a nuclear explosion. Compton scattering is relatively independent of the atomic number of the absorbing material.
Pair Production: By interaction via the Coulomb force, in the vicinity of the nucleus, the energy of the incident photon is spontaneously converted into the mass of an electron-positron pair. A positron is the anti-matter equivalent of an electron; it has the same mass as an electron, but it has a positive charge equal in strength to the negative charge of an electron. Energy in excess of the equivalent rest mass of the two particles (1.02 MeV) appears as the kinetic energy of the pair and the recoil nucleus. The positron has a very short lifetime (about 10-8 seconds). At the end of its range, it combines with a free electron. The entire mass of these two particles is then converted into two gamma photons of 0.51 MeV energy each.


I wanted to include this information about Gamma Rays first so you understand what happens in space, as we get this information. I want to show you that there is faster ways that we recognize these events, and this includes, recognition of what the spacetime fabric tells us from one place in the universe, to another.

Does it look the same? Check out, "Going SuperNova 3Dgif by Quasar9"

Now, take a look at this below.

Four hundred years ago, sky watchers, including the famous astronomer Johannes Kepler, were startled by the sudden appearance of a "new star" in the western sky, rivaling the brilliance of the nearby planets. Now, astronomers using NASA's three Great Observatories are unraveling the mysteries of the expanding remains of Kepler's supernova, the last such object seen to explode in our Milky Way galaxy


What can we learn about our modelling capabilties, and what can we learn about the events in space that need to be further "mapped?" How shall we do this?

Gamma ray indicators prepared us for something that was happening. Now with this "advance notice" we look back, and watch it unfold?

A new image taken with NASA's Hubble Space Telescope provides a detailed look at the tattered remains of a supernova explosion known as Cassiopeia A (Cas A). It is the youngest known remnant from a supernova explosion in the Milky Way. The new Hubble image shows the complex and intricate structure of the star's shattered fragments. The image is a composite made from 18 separate images taken in December 2004 using Hubble's Advanced Camera for Surveys (ACS).


If advance indication are possible besides gamma ray detection, then what form would this take? Could we map the events as we learn of what happen in LIGO or LIsa operations, and how the "speed of light" is effected in a vacuum?

Now this comes to the second part, and question of indications of information released to the "bulk perspective" as the event unfolds as this SuperNova is.

Bulk:
Note that in the type IIA and type IIB string theories closed strings are allowed to move everywhere throughout the ten-dimensional space-time (called the bulk), while open strings have their ends attached to D-branes, which are membranes of lower dimensionality (their dimension is odd - 1,3,5,7 or 9 - in type IIA and even - 0,2,4,6 or 8 - in type IIB, including the time direction).


Now advancement in model assumption pushes perspective where it did not exist before.

You had to understand the nature of "GR" in pushing perspective, in the way this post is unfolding. Gamma ray indicators, are events that are "tied to the brane" and in this sense, information is held to the brane. The "fermion principle" and identifcation of Type IIA and IIB is necessary, as part of the move to M theory?

Thus when we look at Gamma rays they are not "separate from the event" while the bulk perspective, allows geoemtrics to invade the "new world" beyond the confines of non-euclidean geometries.

As I pointed out, the succession of Maxwell and all the eqautions (let there be light) are still dveloped from the center outwards, and in this perspective gravitational waves wrap the event. Thus the "outer most covering" is a much higher vision and dynamical nature, then what we assume as "ripples in space."

Bulk perspectve is a necessary revision/addition to how we think and include gravitational waves, by incorporating the "gravitonic perception" as a force carrier and extension of the Standard model.

While it has been thought by me to include the "Tachyon question", as a faster then light entity, the thought is still of some puzzlement that this information precedes the gamma ray detection, and hence, serves to elucidate the understanding of our perceptions of the early events as they unfold, as a more "sounding" reason to how we look at these early events?

If those whose views have been entertaining spacetravel, as I have exemplified in previous post, then it was of some importance that model enhancement would serve to help the future of spacetravel in all it's outcomes, as we now engaged, as ISCAP is engaging.

See:

  • Einstein@Home


  • LIGO:
  • Monday, January 30, 2006

    Are We Made of Stardust?



    IN context of the cyclical nature of this universe, it is behooving to us to ask the question about what exactly that "stardust" is made up of. So we had some inkling for us lay people as to what had currently landed for us to answer this question.

    The primary objective of the Stardust mission is to capture both cometary samples and interstellar dust. Main challenges to accomplishing this successfully involve slowing down the particles from their high velocity with minimal heating or other effects that would cause their physical alteration. When the Stardust Spacecraft encounters the Comet Wild 2, the impact velocity of the particles will be up to 6 times the speed of a rifle bullet. Although the captured particles will each be smaller than a grain of sand, high-speed capture could alter their shape and chemical composition - or even vaporize them entirely.


    So while they had designed the experimental process to catch "stardust," did we in all our understanding see the reasons why this process was to become the experimental challenge it was? They had to be convinced, that using these dollars to make the undertaking part of the conclusions, on a supernova scale, these "elements" could have been comparatively analyized, as to what is left for us to inspect and measure in relation?

    Many of the more common elements were made through nuclear fusion in the cores of stars, but many were not as well. Because nuclear fusion reactions that make elements heavier than iron require more energy than they give off, such reactions do not occur under stable conditions that occur in stars. Supernovae, on the other hand, are not stable, so they can make these heavy elements beyond iron.

    In addition to making elements, supernovae scatter the elements (made by both the star and supernova) out in to the interstellar medium. These are the elements that make up stars, planets and everything on Earth -- including ourselves.


    Part of the expulsion from supernovic explosions is the evidence that we can gather. While the demonstrative fawcetts of analysis give us inklings in this model below, the real story is how such explusions had taken their place in the overall view in formation of this universe.

    It is as if we must put on a special kind of glasses, and see all that we are doing in a geomtrical expressive stage, that runs through the topological and homophoric relations that we could say, indeed D-brane analysis will have served it theoretcial purpose, and shed new light on this process.

    While I engage it simplistically and speak simplestically on it's developement, there are technical aspect that are very far from my having the native tongue of math, that I could show this. But other people are, which is quite satisfying.

    Sunday, January 15, 2006

    Radius of the Universe

    HUBBLE DIAGRAM AND ITS CONSTRAINTS ON COSMOLOGYBradley Schaefer


    A Hubble Diagram is presented based on 172 distance measures involving 52 Gamma-Ray Bursts out to redshifts of 6.3. The observed shape of the Hubble Diagram is a measure of the expansion history of the Universe, which will include the effects of the 'Dark Energy' that dominates over matter. Gamma-Ray Bursts can be seen to high redshift, and this uniquely allows for tests as to whether the Dark Energy changes with time. If Einstein's Cosmological Constant is a good representation of cosmology, then the equation of state of the Dark Energy won't change in time over the age of the Universe. The observed Hubble Diagram can be compared with the shape predicted by various models, including the model where the Cosmological Constant is a constant. The result is that the Cosmological Constant is rejected at a moderate confidence level. That is, apparently, Dark Energy changes with time. As with all such results, a consensus final conclusion can only be reached after the result is duplicated by independent experiments. To this end, over the next two years, the satellites Swift and HETE will discover another ~50 bursts that can be placed on the Hubble Diagram and this will serve as an independent test of the claim. The result also highlights the Gamma-Ray Burst Hubble Diagram as a new front-line technique to measure Dark Energy and the high-redshift Universe.



    As I relay in the earlier part of the thread containing responses to the Evolving Dark Enery of Sean Carroll's, certain insights that had been gained along the way raise the issue of how such a dark energy would have influenced, how we gain information from the luminousity of standard candles, and how we would gain from that information.

    Lubos Motl:
    The corresponding equation of state would give "w" (the pressure/energy_density ratio) smaller than "-1" (much like in models of phantom energy) which would violate the dominant energy condition - and potentially allow superluminal signals. This sounds highly suspicious. Gamma ray bursts had to be used for the analysis - and they are sufficiently poorly understood - and independent experimental astrophysical sources at Harvard also recommend you to ignore the news.


    Of course we are going to want to know why Lubos.

    This set the stage for me in wonder about gravitonic concentrations, and how these woudl have been indicators of the strengths and weakeness, which would influence this information gained. I guess, it is in understanding better how such information could be "skewed" that I am looking at the answers given as a further response by Brad is illucidated upon.

    So what is "dark energy" in relation to what gravitonic considerations might have on how we see such expasnion process say to us, the unievrse is indeed expanding.



    It is always interesting to me to see how the cosmological values contained in the universe could have ever held to "GR curvature indicators" and that such values if held in regard to Einsteins and Riemann's spherical relations, then how indeed could we have siad that the nature of the universe is

    As mentioned earlier, the value of is a measurement for the density of the universe. The definition of is such that,




    where is the critical density of the universe. A critical density is associated with an "Einstein de Sitter Universe" for which equals 1. It has the property that the curvature is zero, the universe is spatially flat. Light will travel in a straight line and the angles of a triangle add to 180 degrees (space is Euclidean). The other possibilities are an open universe ( ) in which space will expand forever, and a closed universe ( ) in which gravity will halt the expansion and force the universe to contract, eventually leading to a "big crunch". The consequence could possibly be an oscillating universe, which gives a kind of continuity to the model. Figure 2 illustrates the three cosmological models.



    Figure 2: The three cosmological models of the universe: open (), closed ( ) and flat ( )




    Part of my exercise is to see the underlying geoemtries that are evolving thriugh time as we keep our universe in perspective. Do we know where this center is? And if so can we see whwere such expansiotry calculations would have given some indication? Are we always looking to the furthest edge so that we can help understand this red shifting that is going on tohelp us determine this value of the open uinverse?



    Well within context of all this, the move to a higher lensing implications is most puzzling becuase it will shape the nature and kinds of infomration that is needed in order to make these determinations about unibverse values. Thus being inclined to pass by such galaxies in the forming state, as influencing the viability of the information given to us. So to me "Luminousity" is very important here as to the ejection of infomration that may reach us, and information that will held in context of those galaxy formations. So it is as if we are giving, an image in mind of these holes geoemtrically induced, along side of matter formation from causes that would influence the very nature of the repsonses we get.

    Critical density

    Sean Carroll:
    Last time we talked about dark energy and its equation-of-state parameter, w. This number tells you how quickly the dark energy density changes as the universe expands; if w=-1, the density is strictly constant, if w>-1, the density decreases, and if w<-1, the density actually increases with time. (In equations, if a is the scale factor describing the relative size of the universe as a function of time, then the density goes as a-3(1+w).) For comparison purposes, cosmological "matter" (slowly-moving massive particles) has w=0, and "radiation" (relativistic particles, including photons) has w=1/3



    So if we are to look for this center how would we find the valuation of what began?



    You would have needed to see a time when critical density would have said to you that the infomration that is being propelled from the center, and here, critical density would have partaken of this value, because gravity would have been very strong? Strong enough that for any infomration to be propelled from that center, to have continued on to this day as a expansitory consideration. So that we may still hold it in considertaion as to exactly what this universe is doing now.

    Once you have then held the unierse in a certain way you have to ask these question based on what you understood by implicating Lagrange points in your assesment of how the univere became the way it is. YOur lensing has created these holes for light to travel, and in those spaces, satelittes have found easier ways to have manueverd without expending a lot of energy.

    We can still tap the greater reserviors of energy and radiation, to help these vehicles continue their journeys. But it is more then that, that we might have sent this vehicle to collect the stardust to help shape our perspective on what constituted that beginning of the universe, as we sent our probes out for further material in which to judge?