Saturday, March 21, 2015

Cosmic Speed Bumps

Daedalus Project (British Interplanetary Society)
In the late 70s the British Interplanetary Society conducted a feasibility study (called Daedalus) for an unmanned interstellar space craft powered by nuclear reactions and designed to achieve speeds close to that of light itself (approximately 10% of c). The Daedalus study inspired a movie proposal in the 80s that would dramatize NAFAL (nearly as fast as light) travel to other star systems for which I was hired as a science advisor. This film proposal, to be directed by Ken Jenkins and Dixie Quinlin was named the
Ken Jenkins
Fictional Starbow Project Itinerary

Starbow Project after an optical illusion produced by NAFAL travel in which for the inhabitants of the ship, the stars seem to form a rainbow-colored band centered around the direction of travel -- the so-called "starbow". Part of my job was to calculate what the starbow would actually look like. The movie was to be an animated cartoon of a round-trip voyage from Earth to two stars on which a successor to the Hubble telescope had detected signatures of life. These two stars formed an equilateral triangle with Earth with sides equal to about 10 light-years. Thus a round-trip voyage at near-light speed would take about 30 years.

However our propulsion system was so advanced (perhaps based on the hypothetical Woodward Effect) that Einstein's relativity effect reduced the subjective travel time by a "gamma factor" of two.
This means that the 30-year round-trip time as seen from Earth would only seem like 15 years to the space travelers themselves.

The quantity gamma ( = γ) is equal to one at slow speeds and gets higher as the ship's velocity approaches the speed of light. At 87% of c, gamma = 2. Gamma is a direct measure of relativistic effects. Not only does time rate on board ship decrease by a factor of gamma, the mass of the ship increases by a factor of gamma. Perceived lengths decrease by the gamma factor (the so-called Lorentz Contraction) and the shape and color of the star bow illusion depends directly on gamma.

In our movie, a planet around the first star is discovered to have primitive forms of life. And on the way to the second star the aliens show up.

I was reminded of the Starbow Project (which floundered due to lack of cash) upon reading a recent paper by Yurtsever & Wilkinson in which they calculate the effect of outside objects on a space craft traveling at near-light speeds (large gamma). For example, Y&W calculate that for a modest speed of gamma = 2, a baseball-sized object weighing 150 grams will possess an impact energy of 36 Megatons. Even a tiny grain of cosmic dust can produce a massive explosion.

If we suppose that our ship can detect and deflect sizable objects, the next problem is the impact of atoms of hydrogen (protons). As far as protons go, it is as if the ship had been placed in a gigantic particle accelerator such as the Large Hadron Collider. At a gamma of 1.3, these protons produce pions when striking the matter of the hull. And at a gamma of 9.1, these protons produce anti-protons upon impact, both of which will shower the inhabitants with radiation.

These sorts of cosmic speed bumps never seemed to bother Captain Picard and the crew of the Star Ship Enterprise. I suppose all these nasty particles are taken care of by the Enterprise's "deflector shields".

Once we have solved the problem of matter drifting into the path of our interstellar ship, the next cosmic speed bump is made of light. The universe is flooded with cosmic background radiation which has been red-shifted by the expansion of the universe into the microwave range. Now our speedy little starship is going to blue-shift that harmless microwave radiation into dangerous X-rays and gamma radiation.

The large-scale production of killer radiation from the cosmic radio background takes place at very high gammas of 100 million or so. At such high speeds, the ship experiences this cosmic light as a kind of thick molasses which tends to slow the ship down. But at speeds lower than that at which the cosmic background becomes viscous and deadly, we are treated to a cosmic light show.

When our ship is traveling at a gamma of 700, the cosmic background becomes visible as a dim red glow in the forward direction. As our speed increases to a gamma of 1400, the cosmic background becomes a rainbow ring which gradually expands leaving a dark central hole filled with frequencies of light higher than the eye can see. As the speed increases, this cosmic starbow expands, then narrows and contracts.

Perhaps someday we will learn to change our bodies into an immaterial form of being that can travel thru the cosmos at any speed less than the speed of light. If we are still able to perceive color in the old familiar way, then Yurtsever and Wilkinson will have gone there before us -- they have calculated the shapes and the colors of the cosmic starbows that such future immaterial beings will perceive.

Starbows produced by cosmic background radiation

Thursday, March 12, 2015

Terry Pratchett (1948-2015)

Sir Terry being knighted by Queen Elizabeth: Feb 18, 2009
Sir Terry Pratchett died today at 66 with a cat in his lap, surrounded by his family. He was the author of more than 40 books about Discworld, a far funnier place than Larry Niven's classic Ringworld. (Ringworld is serious physics--held together by gravity and engineering; Discworld is serious parody, held together by magic -- and by Pratchett's unique brand of levity.) Although Pratchett's work  is consistently amusing, I also always feel a bit wiser after reading his stuff. I never met the man, but my nephew, Mark Herbert, while attending a science fiction convention in Memphis, TN, found himself at a party drinking beer and singing songs with Pratchett from the repertoire of Steeleye Span, Terry's favorite music group.

Here are a few Pratchett quotes for your edification.

If you don’t turn your life into a story, you just become a part of someone else’s story.

They say a little knowledge is a dangerous thing, but it's not one half so bad as a lot of ignorance.

The pen is mightier than the sword if the sword is very short, and the pen is very sharp.

Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it.

I think perhaps the most important problem is that we are trying to understand the fundamental workings of the universe via a language devised for telling one another where the best fruit is.

Sometimes it is better to light a flamethrower than curse the darkness.

I mean, I wouldn't pay more than a couple of quid to see me, and I'm me.

It is often said that before you die your life passes before your eyes. It is in fact true. It's called living.


Sir Terry Pratchett has brought joy to millions of souls. He will be missed.

Sunday, February 22, 2015

Altered State

by Bill Tavis at


When it first comes on
It feels odd 
To experience universe
From just one point of view
To navigate spacetime
In just one mind and body.

When it first comes on
It seems odd
To make one place in cosmos special
To feel one moment -- now -- is real.

When it first comes on
It seems strong
To be kicked out of eternity into time
To feel suddenly ignorant and helpless
To be gripped by strange laws
Not of my own making.

When it first comes on
It feels wrong
Not to be connected to All of You
Not to experience the ever-present
Schoolyard playfulness of sentient pals.

When it first comes on
It feels long
More then twenty thousand nights
I've switched off self and still come back.
Did I fail to read the warning on the box top?
Is this the fabled Nightmare Trip
That never ends?

Friday, February 6, 2015

The Quantum Olympics

Selection of molecules which show quantum interference in matter-wave interferometers. (Graphic by Sandra Eibenberger.)
At the beginning of the 20th century, one of the biggest problems in physics was to understand the interaction between matter and light. Today we possess an impressively broad and detailed knowledge of matter-light interactions expressed in the language of quantum theory.

In 1900, it was generally believed that light was made of waves and that matter was made of particles. This belief was shattered when Albert Einstein (better known for his relativity theories) showed that light in some situations acted like a particle. Einstein's particles of light were christened "photons". Later in the century, Louis de Broglie, the French prince who became a physicist, proposed that particles should possess wave properties. And de Broglie was able to calculate the supposed wavelength of the electron (the lightest of the known particles). He submitted this proposal for his PhD thesis at the Sorbonne. His professors were prepared to reject his thesis on the grounds of preposterousness. But through the intervention of Einstein the prince was awarded his degree which was crowned a few years later by a Nobel Prize when some American physicists at Bell Labs measured the wavelength of the electron which was precisely the value that de Broglie had predicted using his "preposterous" theory.

De Broglie's wave theory of matter predicts that every piece of matter possesses frequency, wavelength and "phase" (whatever these quantities might mean). Not only electrons, but protons, cats, bicycles and you yourself possess wave properties. The catch is that the more massive a particle gets, the smaller the particle's de Broglie wavelength. Hence it becomes more difficult to experimentally demonstrate a particle's wave properties as its mass gets larger.

Enter the Quantum Olympics. Open only to experimental quantum physics. What is the biggest (most massive) particle whose wave properties you can demonstrate in the laboratory?

The electron was the first to show its waviness, later the neutron -- almost 2000 times more massive than the electron -- was shown to be a wave. In the 1990s several large atoms such as Helium, Iodine and Sodium vapors were shown to possess wave properties. And in 1999, someone in Vienna succeeded in diffracting a buckyball -- a soccer-ball-shaped molecule consisting of 60 Carbon atoms.

A Talbot Carpet demonstrating near-field interference from multiple slits
Recently, spectacularly impressive records have been set in the Quantum Olympics. Using a novel matter-wave detection technique developed by John Clauser (of Bell's Theorem fame) called Talbot-Lau interferometry, experimenters from Vienna, Basel and Duisburg-Essen have demonstrated high-contrast quantum interference for a remarkable assortment of complex and increasingly massive molecules culminating with the current winner of Olympic Gold -- molecule "m" shown above.

The 2015 Olympic champ is a "functionalized porphyrin" with atomic formula:

C(284) H(190) F(320) N(4) S(12)

Congratulations to the assortment of clever physicists who showed that this assortment of increasingly massive particles behave like waves as well as like particles.

As admirable as these experiments might seem to the ordinary person, they seem even more remarkable, even impossible to the average physicist. These experiments seem impossible on the face of it because wave interference is a very delicate affair, requiring stability and coherence over large times and distances (compared to the sizes of these atoms). Although it might be possible to observe interference with atoms with very little structure, it should be impossible to do so for buckyballs and especially impossible for the grotesquely complicated molecules pictured above.

The reason that such experiments should be impossible is that these complex molecules are not rigid objects but possess hundreds of degrees of rotational, vibrational and conformational freedom. They are turning, vibrating, bending in hundreds of different ways. Certainly the waves associated with such a busy, buzzing, bendable object could never be moving coherently long enough to form a clean high-contrast Talbot Carpet such as the figure above in green. So goes the conventional wisdom.

But the conventional wisdom is wrong.

It can be shown (by quantum calculations) that as long as the internal motion of the molecule (no matter how grotesque this motion) is UNCORRELATED with the external trajectory of the molecule, then this internal motion will not destroy the coherence of the external motion. Hence these delicate experiments can even be carried out at room temperature when the internal motion of the molecule is as complicated as Times Square on New Year's Eve. However as the temperature is raised and the internal motion becomes hot enough to emit photons, photons that can perturb the molecule's external motion, then coherence is lost and the molecule's wave properties become impossible to detect.

This intrinsic decoupling of internal motions from the external motions of a complex object reminds me of a similarly engaging problem in theoretical physics: How do cats always manage to land on their feet when dropped?

It would seem impossible for a cat to turn over in midair because of conservation of angular momentum. And whatever could the cat push against to begin its spin? Like the busy, buzzing, bendable molecules, a cat's internal motion is completely decoupled from the trajectory of its center of mass. Yet it turns (as Galileo might have said). The cat turns. And lands on its feet. All without violating a single law of physics. Clever cat.

The Falling Cat Problem (from an illustration in the journal Nature 1894)

Saturday, January 10, 2015

Dangerous Candy

Dangerous candy: conjectured tomography

Hey little girl
Hey little boy
Lend me your ears.
And responsible grown-ups too.
This may be the most important news
You and your loved ones ever will hear.

There's a new candy going round
Made in physics labs.

Don't even look at it!
Its color is produced by
Triple-conjugated poly-peptides.

Just looking at this candy
Will pop the retinas of your eyes
Into 3 quantum states at once:
What you'll experience
Thru your triple-entangled retinas
Makes the Schrödinger Cat state
Look like Hello Kitty.

Don't look at this candy
Unless you're prepared to peek
Into hidden dimensions
No human has ever imagined.
Don't look at this candy
Unless you're prepared to see
Into the hearts and minds
Of the people around you
In ways you never dreamt possible.

If you've already looked
Stop right there.

Little girls, little boys,
Responsible grown-ups.

Don't touch this candy!
Its surface is made of layers
Of room-temperature interfering plasmons
That will jack your body directly into
What some scientists call the "Unified Field"
And what others describe as:
"Really weird shit
Outside the realm of science."

Little boys, little girls,
Responsible grown-ups.

Don't touch this candy
Unless you're prepared
To be swept away
Into the deep quantum currents
That make the stars shine
And hold the world together.

Don't touch this candy
Unless you're prepared
To knowingly experience
The warm invisible tentacles
That connect us to all living things
And to every particle of matter.

If you've already touched
Stop right there.

Little girls, little boys,
Responsible grown-ups.

Don't put this candy into your mouth!
This candy was made
By the same folks
Who work and play on a first-name basis
With quarks, gluons and the Higgs boson.

Little boys, little girls,
Responsible grown-ups.

Don't put this candy into your mouth.
Don't taste this candy with your lips and tongue
Don't chew up and swallow
This miracle of modern physics.

Little girls, little boys,
Responsible grown-ups.

Don't take this miracle
Into your body.

Fruitful Nature (photo by August O'Connor)

Monday, December 29, 2014

Verse & Universe

Happy New Year 2015 !

Browsing through the Capitola Library on Christmas Eve, I came across a real gem. It's a big anthology of poetry about science and math called Verse & Universe. The poetry is mainly by non-scientists, taking the material of science as their inspiration. John Updike's justly famous poem about neutrinos is included but none of my own verse -- not even the eminently anthologizable Physics For Beginners. I am enjoying this big book in small bursts as if eating a box of chocolates. Reading this anthology is a good way for a scientist to begin the New Year, to appreciate so many fresh new perspectives on the craft of doing science. So far, having gobbled up only about 40 pages of the 300 plus in the box, my most favorite poem is one by Serbian-American Charles Simic which I reprint here:


Most ancient Metaphysics, (poor Metaphysics!)
All decked up in imitation jewelry.
We went for a stroll, arm in arm, 
                                 smooching in public
Despite the difference in age.

It's still the 19th century, she whispered.
We were in a knife-fighting neighborhood
Among some rundown relics 
                      of the Industrial Revolution.
Just a little further, she assured me.
In the back of a certain candy store 
                                 only she knew about,
The customers were engrossed in 
              the Phenomenology of the Spirit.

It's long past midnight, my dove, my angel!
We'd better be careful, I thought.
There were young hoods on street corners
With crosses and iron studs 
                           on their leather jackets.
They all looked like they'd read Darwin 
                             and that madman Pavlov,
And were about to ask for a light.

Thursday, December 11, 2014

No Torture Please

Alan Dershowitz, Harvard law professor


"Harvard law professor Alan Dershowitz 
OKs torture in USA" -- New York Times

Torture Dershowitz, not me
I'll tell you all I know
Of freedom-hating terrorists
And poisoned H2O.

Here's what I'll say if tortured
So you can skip the rack
No shock machines: I'll spill the beans
And never answer back.

I'll finger all conspirators
Turn in my mom and fadda
Don't torture me -- here's what you need:
Al Dershowitz is al Qeadda.

Could lawyer's guise conceal a spy?
Is Al the man behind our troubles?
Is Dershowitz the terrorist
That turned our Towers into rubble?

At first he will deny the charges
But the truth is near at hand
For Harvard profs respond to torture
More smartly than the common man.

He'll confess to kissing Satan
While his testicles are fryin'
Al engineered the Holocaust
And wrote the Protocols of Zion.

Torture Dershowitz, not me
Barbarism's not my diet.
Is Dershowitz so fond of torture?
Then let him be the first to try it.

Sunday, December 7, 2014

Abduction by Aliens

Dr Future Show at
Allan and Sun Lundell (also known as Doctor and Mrs Future) host a radio show every Tuesday in which they interview folks working (and playing) at the edge of science, technology and consciousness. A few days ago they convened a Conclave of Mad/Glad Scientists at a secret beach house location in Rio Del Mar, CA. Most of the scientists invited to the Conclave had appeared on the Dr Future Show and included people demonstrating Russian hand-held electro-vibratory healing devices, brain stimulating machines, light-pattern projectors; people claiming channeled and otherwise inspired visions of the future and reports from Amazon explorers concerning ayahuasca-mediated connections to the Mind of Nature. Musicians, singers (including the remarkable Caroluna) and splendidly-inventive cooks added spice to the Mad/Glad Conclave.

Nick Herbert attended mainly as a spectator, expecting at most to be goaded into battle against some champion of the Catastrophic Anthropogenic Global Warming (CAGW) hypothesis of which he had recently expressed his reasons for skepticism over the airwaves on the Dr Future Show.

But instead, during a break in the stream of speakers, Nick was called to the stage and asked to do whatever he pleased. He obliged by recounting his Abduction by Aliens story which was captured by Dr Future on video and posted on YouTube.

Later, away from the food, the drink and the music, away from the buzzy touch of the Russian healing machine, away from the rushing buzz of the responsive audience and presenters, Nick and Al slipped outside, walked across the sand, took off their shoes and renewed their age-old connection with the sea.

Tuesday, November 25, 2014

The New Physicality

June Jordan (1936-2002)

Poem Number Two on Bell's Theorem
Or the New Physicality of Long Distance Love

There is no chance that we will fall apart
There is no chance
There are no parts.

----June Jordan

June Jordan's marvelous little poem is one more piece of art inspired by Bell's Theorem. Just in time for the Queen's College exhibit in Belfast, Ireland which closes Nov 30: Action at a Distance: The Life and Legacy of John Stewart Bell.

Thursday, November 20, 2014

Salvia Divinorum


it starts suddenly with a circle

circular motion

a sense of movement

going counterclockwise

and it feels 

it feels like it comes

out of my mouth

out of my forehead

the left side of my face

a scatter pattern

a pattern

a scatter

left to right

a pull and circularity

around me above me 

from me

inside a huge room

a cathedral

I am both

the inside and the outside

and I don't know

I don't know how

I don't know how to


or swim

through this space

and I keep thinking

its growing

growing out of my face

out of my body


out of my body

and wondering

where my body


I want to relax

just wonder

at the beauty

of it all

and part of me 

is saying

where am I

not as in what is this place

where is this place


where is my body

because its 

pure consciousness


any physical sense

and I feel like I

should be inside

this space I've created






and this time it is pastel green

but another time it was

pink luminescent light

and its made of


its made of

my face my body


over & over & over & over &

like a patchwork 

or finely woven fabric

and it would be peaceful

except for me


where my body's gone

and if it will ever come back

or will I ever find my way back

so I let go and swim and

it's huge

it's vast

it's cavernous

and afterwards

there is this 

deep profound

sense of


because I couldn't 



this place I have always

wanted to be

this place I have always

looked for

-- by Laura Pendell

Salvia Divinorum from Erowid