Best,

-cvj

To go futher.

Dust has a bit of an image problem in the public eye. If one looks in the thesaurus under dust, then they encounter an abundance of meanings that together hint at how trivial or unimportant dust is. I decided to pick out those various meanings when I wrote an abstract for a dust colloqium that I gave a few weeks ago. The colloquium was titled: “Charged Dust Odysseys”:

Charged Dust:
1. Intrinsic property of matter that occurs in two forms: positive or negative, dependent on the deficiency or surplus
of electrons carried by fine particles of matter
2. Obligated Trash
3. Loaded Confusion
4. Excited Lint

Odyssey:
1. An extended adventurous voyage or trip.
2. An intellectual quest

Every dust scientist hears the “dust-under-the-bed” joke when he/she tells someone what they work on. The joke gets old, pretty fast, but we all must admit that it is what people generally think about, when they hear dust, so why not play on the joke a little bit? Last year I discovered by accident a short story and video by a talented science journalist named Sonya Buyting about cosmic dust that I think does a nice job to explain more dust facts, and I think in a light, humorous way.

Because of dusts’ image problem, I am particularly open to the facets of our daily life that might help to explain the importance of cosmic dust when I write general dust material. So when I wrote the above in your recyling thread, I also cannot claim that the ideas I wrote are totally mine, even if they are my words. I recycled the recycled ideas too.

The first person who I read years ago that described how dust is recycled in the universe was Mayo Greenberg, one of the pioneers in the field how died about 5 years ago.

Another scientist who is talented in presenting her scientific ideas to the public is Alyssa Goodman. She published an article in Sky and Telescope in November 2000, titled: “Recycling in the Universe”, which is about the interplay between the births and deaths of stars. She began her piece with a description of her husband taking out the trash every Monday night, and then where that trash goes, and she proceeds to describe the recycling steps which metaphorically describe the processes for stars. It looks like this:

E = on Earth
G = in Galaxies

Storage: (E) Neatly, in a recyling bin (G) not as neatly in the ISM
Collection: (E) Big trucks (G) Gravity and supernova snowplows
Processing: (E) Recycling plants (G) Molecular clouds
Production: (E) Factories (G) Star-forming cores
Consumption: (E) Humans (G) Stars
Discarding: (E) Human tosses (G) Stellar winds
Efficiency, one cycle (E) Pretty low (~10 percent) (G) Pretty high (~90 percent)
Time scale, one cycle (E) Weeks to years (G) Millions to billions of years

I think that these same 6 recycling ideas (storage, collection, etc.) can be considered for cosmic dust as well, with similar processes in interstellar space, but different in the solar system, where the dust is most processed.

Anyway now you know alot more about the recycling aspect of cosmic dust and why I was ready with abundant material when you posted your post.

-cvj

-cvj

Does the flying include fuel funds and food for the bird?

I think you should fly in and give a presentation at a Categorically Not!

-cvj

Here is the ‘recycling’ perspective from a dust scientist. (FWIW)

Cosmic dust particles evolve cyclically; chemically, physically and dynamically. The evolution of dust traces out paths in which the universe recycles material, in processes analogous to the daily recycling steps with which we are familiar: production, storage, processing, collection, consumption, and discarding. Observations and measurements of cosmic dust in different regions provide an important insight into the universe’s recycling processes; in the clouds of the diffuse interstellar medium, in molecular clouds, in the circumstellar dust of young stellar objects, and in planetary systems such as our own solar system. As scientists, we accumulate observational ’snapshots’ of dust at different stages of its life and, over time, form a more complete movie of the universe’s complicated recycling steps.

The dust evolution cycle follows meandering paths from stardust to stardust. From the stellar winds of evolved stars, new dust is formed and is injected into interstellar space. Young stardust is mixed with old heavily-processed diffuse interstellar dust, and is subject to passing supernova shocks and ultraviolet radiation. Dusty clouds form. The protostar environment is a fertile ground for solids on all size scales, from dust grains to planets, to form. Star formation in cool molecular clouds becomes both a sink of old dust and a source of new dust. A typical dust grain anywhere in space will have undergone several cycles.

Dust in a planetary system is the most processed (being formed, destroyed, and/or locked into a nearpristine state) of the different populations of cosmic dust. Interplanetary dust is permanently replenished by dust ejected from cometary nuclei, the most pristine bodies in the solar system, and released from collisions in the asteroid and Kuiper belts. In our solar system, interplanetary dust exists alongside interstellar dust, which is flowing through the solar system, offering a tangible, physical link between our planetary system and the stars.

As humans on Earth, we are both the observers of the dust recycling process, as well as the result.