Air Horns (Era Horns?)

National Museum of American History

The other day I was chatting with a friend about my long-ago job as an assistant curator at the Smithsonian history museum and we began to muse about what the quintessential artifacts of today will someday be. When historians of the future try to represent our time will they display a bunch of obsolete computer kit (which can not be made to works after a couple of years—much less decades or centuries), or Britney Spears memorabilia, or Segue scooters, or “as seen on TV” junk like salad shooters and such? What is the quintessential object which shows who we are and how we live? We came up with all sorts of answers—most of which did not paint contemporary culture in a wholly positive light—but the one which struck me as the truest was the simple disposable air horn.

An Air Horn

An air horn is a plastic noisemaking reed attached to a jar of compressed air. When the player (possessor?) presses a button, the infernal device issues a hellish shriek of ear-piercing volume. I do not mean that last descriptor as a metaphor: air horns, like firearms and jet engines, are very capable of causing serious irreparable hearing damage. These horrid novelty items are available everywhere for next to nothing. People use them at sporting contests to distract the opposing team or sometimes in cruel pranks to make an unwitting victim panic. Mostly they are just used to call attention to the loutish person with the horn. Air horns have only one note, but that note is so loud it drowns everything else out—a perfect description of today’s celebrity personalities, advertising tactics, and political discourse.

Air horns evolved from the whistles of trains and the mighty horns of ships. These horns used compressed gasses from engine function in order to warn of eminent departure or collision. They had a real purpose. Yet, while it is possible that Alfred Hitchcock or Tom Clancy (or some other master of contrived suspense) could invent a scenario where a disposable air horn saved the day, I doubt it has ever happened. These objects exist only to make insufferably loud noise. If someone on the street was blowing one to warn of North Koreans, Godzilla, or zombie attack I would ignore it in the belief that it was just some drunken oaf showing off.

or we could just rename it the “fun horn”

Worst of all, I think an air horn speaks directly to the reptile/Kardashian part of the brain which lurks in us all. I do not like air horns, but if someone gave me one I would be fascinated by it and would want to push it. It would sit there menacingly, like Chekov’s gun, just waiting till I could resist no longer and gave it a tiny test. I wish it were not so, but I would have to push it, despite the deleterious effect it would have on my personal relationships and happiness. Because they bear this unwholesome power, I would be shocked if air horns do not end up in a “late 20^th/early 21^st century” display case highlighting the nature of our times. They will sit there with other loud self-aggrandizing artifacts like Nascar jerseys, Jeff Koons art, MySpace, and Kanye West.

“I will go down as the voice of this generation, of this decade, I will be the loudest voice.”  [Actual Quote]

Air horns do indeed draw attention to us and tell everyone exactly who we are. It is a very well-made item—at least until someone invents something even louder and more annoying.   Or you could ignore my cranky jeremiad and write to tell me what you would choose as the quintessential object of this age!

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Messier 82 (Home of Cosmic Mysteries and Exploding Stars)

A mosaic image taken by the Hubble Telescope of Messier 82 (NASA, ca. 2000)

Twelve million light years from Earth lies Messier 82, a starburst galaxy 5 times more luminous than the entire Milky Way galaxy.  Messier 82 (AKA M82) is a very happening and dynamic galaxy: stars are being created there at an exceptionally high rate—most likely because the galaxy is “interacting” (or possibly colliding) with its neighboring galaxy M81. In 2005, the Hubble Space Telescope detected nearly 200 massive starburst clusters near M82’s center. Within these huge masses of dust and gas, stars are being birthed (and dying) at an astonishing rate.  The high energy released by this cosmic upheaval is nearly constant and the outflow of charged particles from M82 is evocatively known as “superwind”.

Lovell Telescope, Jodrell Bank Observatory (Mike Peel; Jodrell Bank Centre for Astrophysics, University of Manchester)

In 2010, astronomers working at Jodrell Bank Observatory in England discovered a mystery at the heart of M82: an unknown object was emitting high energy electromagnetic radiation in a pattern unlike anything else so far observed in the universe.  The mystery object appeared to be moving at 4 times the speed of light (which is, of course, quite impossible according to the standard model of the universe.  Newscientist.com offered the following explanation (of sorts) for the mystery object’s perceived velocity:

Such apparent “superluminal” motion has been seen before in high-speed jets of material squirted out by some black holes. The stuff in these jets is moving towards us at a slight angle and travelling at a fair fraction of the speed of light, and the effects of relativity produce a kind of optical illusion that makes the motion appear superluminal.

At present, the best explanation astronomers have for the mystery is that it is some sort of microquasar or black hole which is interacting in an unusual way with the tumultuous mass within a starburst cluster.  At present, the mystery is unexplained.

A super-dramatic before-and-after animation/photo of the type Ia supernova in M82

However, at present, M82 is doing entirely different things which have captured the attention of the international astronomy community.  On January 21^st, 2014, Steve Fossey and a group of his students at University College London spotted a colossal explosion within M82.  The event was quickly identified as a type Ia supernova, a bright and consistently energetic star explosion which occurs in binary stars where at least one star is a white dwarf (the dead, but energetic fragment of a larger star).   CBS News explains the phenomenon and its historical significance:

[When a] white dwarf siphons off too much mass from its companion star, a runaway nuclear reaction begins inside the dead star, leading to a brilliant supernova. Because Type Ia supernovas are believed to shine with equal brightness at their peaks, they are used as “standard candles” to measure distances the universe.

The supernova in M82 is the nearest supernova of its type observed since Supernova 1987A was spotted in February 1987 in the Large Magellanic Cloud (the dwarf galaxy which is companion to the Milky Way).  Telescopes around Earth are turning towards Ursa Major (where M82 is located in the sky).  Although the supernova is big news here, it is a very stale story in M82 where this all happened 12 million years ago.

An Artist’s Conception of a Type Ia Supernova

Brown Dwarfs

Between giant planets and small stars exists a bizarre class of heavenly objects known as brown dwarfs. Brown dwarfs are not massive enough to fuse hydrogen elements together as do main sequence stars like the sun, however brown dwarfs larger than 13 Jovian masses are believed to fuse deuterium atoms and large brown dwarfs (65 Jovian masses and up) are believed to fuse lithium.  Since brown dwarfs can be very much like planets or like stars, there is a specific definition to describe the objects: a brown dwarf must have experienced some sort of nuclear fusion as a result of mass and temperature, however it cannot have fused all of its lithium (or it is considered a star or stellar fragment).  A stellar physicist reading this blog might object that medium and large stars have some lithium present in their outer atmosphere, or that a very young white dwarf could still have some unused lithium present, or even that an old heavy brown dwarf could have fused all of its lithium.  That physicist would be correct: she deserves some cookies and a pat on the head for poking holes in unnecessarily simple definitions.

Various Classifications of Brown Dwarfs

Brown dwarfs were theorized to exist in the 1960s, but no astronomer managed to discover one until 1988 when a team of University of California astronomers who were studying white dwarfs found a bizarrely cool red spectral signature for a faint companion to the star GD 165.  Since then many brown dwarfs have been discovered and sorted into the major types M, L, T, and Y.  They occupy a strange ambiguous area at the bottom of the Hertzsprung-Russell diagram—objects which are luminous and massive in comparison to everything else but tiny and dim compared to real stars.

There are some planets which are known to orbit brown dwarfs and there also brown dwarfs known to orbit true stars.  It is beginning to seem that there a great many brown dwarfs out there: perhaps they are as numerous as true stars (or maybe they are even more common than that).  Since they are hard to detect, scientists do not have a very accurate assay of their frequency in the universe.  The question bears somewhat on our understanding of the universe–since a great deal of matter is  not accounted for.

An artist’s conception of a brown dwarf seem from a closely orbiting planet

My mind keeps returning to the fact that some brown dwarfs have planetary systems.  Imagine these melancholic twilight ice worlds forever orbiting a dim glow which will never blaze into a true sun.   It is a melancholy picture, but not without a certain beauty.

A Brown Dwarf with Planet and Moon (painting by Lynette Cook from fineartamerica.com)

The Fastest Manmade Object

NASA has recently released plans for a new ion thruster capable of propelling spacecraft to the astonishing speed of 90,000 miles per hour (the thruster is named NEXT–an unnecessarily clever acronym which is short for “NASA’s Evolutionary Xenon Thruster”). Reading about the thruster’s blazing speed made me wonder: what exactly is the fastest human-made item ever? The answer was not what I expected—or rather it was exactly what I expected, but it happened a long time ago.

NASA’s Helios 2 spaceprobe

To escape Earth’s gravitational pull, an object must already be traveling around 25,000 mph, so ICBMs and orbital space craft are fairly speedy anyway. Interplanetary probes are the fastest objects we humans have crafted, although they tend to obtain their velocity by means of using the gravity wells of planets or the sun to “sling” off at a higher velocity.  In 1976, NASA launched the solar probe Helios 2 to measure electromagnetic radiation emanating from the sun and to calculate solar magnetic fields.  The eccentric orbit of Helios 2 resulted in the craft reaching a top speed of 157,078 miles per hour. If the probe were running along the equator, it could whip around the Earth six and a third times during an episode of “The Bionic Woman” (or whatever other hour-long show was playing in 1976).

We’re probing the sun and voting for Carter: apparently that’s what’s happening…

Helios 2 has held the record for being the fastest man-made object since I was a toddler, but NASA has finally decided to rise to the challenge (since nobody else apparently has the know-how or the desire to push mankind forward).  Solar Probe Plus is a NASA mission planned for launch in 2018 which features a robot space probe which will travel to the outer corona of the sun (assuming feckless American lawmakers don’t scrap the mission). When the probe is closest to the sun it will be a mere 5.9 million kilometers (3.67 million miles) from the photosphere of the star and it will be traveling at a blistering 432,000 miles per hour.  The insane temperature and radiation which Solar Probe Plus will face at such proximity to the sun will necessitate that the speed demon robot must take shelter behind a carbon fiber reinforced carbon shield as it blasts through the outer corona at a fifteen hundredths the speed of light (it turns out light is still incomprehensibly fast compared to our very fastest things).

An artist’s conception of Solar Probe Plus (Credit: JHU/APL)

(Coincidentally, long time readers might wonder why I have abandoned my usual convention of citing measurement values in metric and then following them with U.S. customary measurements in parenthesis. The answer, alas, is laziness.  All of the sources about really fast things use miles per hour and I didn’t feel like converting.  If you are so inclined, you can easily convert to kilometers per hour (or parsecs per second, or whatever) using the internet.  Alternatively, you could write me an angry letter in French.)

90377 Sedna

Artist's Interpretation of Sedna (Credit: Gemini artwork by Jon Lomberg)

After the discovery of Pluto in 1930, there was a long hiatus in discovering objects of comparable size. Then in 2003, a team of astronomers led by Mike Brown of Caltech discovered a distant icy sphere which was quickly heralded as “the tenth planet.”  Mike Brown announced the discovery on his website along with his team’s rationale for naming the object.  He wrote “Our newly discovered object is the coldest most distant place known in the Solar System, so we feel it is appropriate to name it in honor of Sedna, the Inuit goddess of the sea, who is thought to live at the bottom of the frigid Arctic Ocean.

It turns out that Sedna is only one of many similar snowball-like planetoids beyond Neptune.  In fact, Ferrebeekeeper has already described the dwarf planet Eris (named after the Greek goddess of Strife) which is the largest currently known Kuiper belt object.  Sedna was the first to be discovered since Pluto and it sparked a debate about such objects which ultimately resulted in Pluto’s downgrade to dwarf planet.  Sedna also has some unique features which make it remarkable in its own right.

The orbit of Sedna (red) set against the orbits of Jupiter (orange), Saturn (yellow), Uranus (green), Neptune (blue), and Pluto (purple)

Sedna takes 11,400 years to complete its orbit around the sun and its bizarre highly elliptical orbit has given rise to much conjecture among astronomers.  Although some astronomers believe it was scattered into a skewed orbit by the gravitational influence of Neptune, other astronomers believe it originated in the inner Oort cloud and was never close enough to Neptune to be affected by the giant’s gravity.  Some scientists speculate that its lengthy orbit may have been caused by a passing star (perhaps from the sun’s birth cluster).  A few theorists have gone one step further and conjectured that Sedna is from a different solar system and was captured by our Sun billions of years ago.  A final school contends that Sedna is evidence of an unknown giant planet somewhere in the depths of space (!).

A photo of Sedna taken from a powerful telescope on Earth

We don’t know much about Sedna except that is probably 1,200–1,600 km in diameter and that its surface is extremely red.  After Mars, Sedna is one of the reddest astronomical objects in our solar system.  This color comes from the profusion of tholins covering the methane and nitrogen ice of which the little world is formed.  Tholins are large, complex organic molecules created by the interaction of ultraviolet light on methane and other simple hydrocarbons.  It is believed that early Earth (prior to obtaining an oxidizing atmosphere) was rich in Tholins and they are one of the precursors to the rise of life.