I find it very
Fascinating
Yeah, very good, very well done
It touches, I was also laughing at some parts
Episode 74: Hubble and Heaven's Carousel
Presented by DR J aka Dr Joe Liske
Over its lifetime
Hubble has inspired new thinking about the Universe
and contributed to more fields within physics and astronomy than we could ever have imagined.
But, Hubble has also become an icon of discovery,
of human achievement, and of culture.
And, has been the inspiration for artistic work that goes beyond the science.
Creations of art and sound.
Creations like Tim Otto Roth's Heaven's Carousel,
premiered in March 2014 at the fourth Hubble Space Telescope Conference at the Accademia dei Lincei in Rome.
What's the point?
Well, you see it glowing but finally you will see, or will hear, that there are sounds coming out.
So, what I am doing, I am translating light physics
into acoustics.
So imagine, that's the simple experiment of the Heaven's Carousel,
you hear the stars, the galaxies, up on there.
Tim Otto Roth has used sound to interpret the light that Hubble collects when it looks at the stars.
This allows us to explore the physics of light with our ears,
and follows an ancient tradition of linking music to astronomy.
Two and a half thousand years ago
the Pythagorean speculated about a connection between planetary motions,
and the small numbered ratios that describe musical harmonies.
These ratios form the foundation of Western music,
and the mathematics of this Harmony of the Spheres
was even used by the renowned astronomer Johannes Kepler.
More recently, in the 1800's,
Christian Doppler wondered whether the effect that he observed in stars,
and which would later bare his name,
could be demonstrated with sound.
And so it was.
First, using a brass band on an open railway wagon.
And then, later, by the Heaven's Carousel.
The Doppler Effect
causes a shift in the observed wavelength of radiation
if the source of the radiation and the observer are in motion,
relative to each another.
Now, in this simulation we have a light source moving to the right.
So, to Alice, sitting on the right, the source appears bluer
because the wavelengths are compressed
but Bob, on the left, sees redder light because the wavelengths are stretched.
The light is blue- or red-shifted
The same thing happens to sound.
As the train with the brass band passed the audience, they would have heard the pitch changing,
from higher, to lower.
Just because I could not afford a whole brass band sitting for days or weeks on a carousel and turning around,
I just took loudspeakers playing sine waves.
At the centre of the Heaven's Carousel
the pitch of the tones is constant and no Doppler Effect is heard.
The thirty six speakers circle overhead,
and neither approach, nor recede from your ears.
As you move out from the centre the effect becomes steadily stronger.
Each new position brings a new perspective,
and a different set of pitches can be heard,
changing with the changes in direction of the speakers.
Wavelengths are stretched as the speakers recede,
and compressed as they approach.
The Doppler Shift explains what we see in the local Universe,
when objects are moving away from or towards us.
This is one way that astronomers have detected exoplanets orbiting nearby stars.
But, this effect also has a cosmological cousin.
A form of redshift that allowed Hubble's namesake,
Edwin Hubble,
to discover, in the 1920's, that the Universe is expanding.
A discovery that revolutionised our thinking about the cosmos.
Space itself is stretched as the Universe expands.
And, stretched with it, are the wavelengths of light from distant galaxies.
The more distant a galaxy,
the more its light waves are stretched as they travel across the Universe,
and the redder its light appears.
This is the cosmological redshift.
Now clearly the cosmological redshift is somehow connected with distance.
But the exact relation between the two depends on how the Universe expanded in the past.
Astronomers have studied this relationship using far away exploding stars,
called supernovae.
By comparing their redshifts with Hubble's observations of their actual distances,
they discovered that the Universe began accelerating round about six billion years ago.
Now, this came as quite a shock,
because, after all, the combined gravitational pull of all the matter in the Universe
should in fact slow down the expansion of the Universe.
Why it is instead speeding up,
is one of the biggest mysteries in contemporary physics.
To the cosmologist acceleration offers insight into the age and fate of the Universe
and perhaps an echo of the prior growth spurt called inflation.
But it seems only natural that new knowledge evokes feelings and feelings are communicated better by art than by science.
This incredible dynamic sculpture created by Tim Otto Roth
channels some of those feelings about the accelerating Universe.
Important themes are related to the discovery are echoed in the piece.
Blue shifts and red shifts.
Isotropy and Homogeneity.
Our inability to see the strings directing the action.
The struggle to perceive depth in the Universe. Are just a few.
And I'm sure you will have and will find many more.
Hubble has shown us the Universe
and the Heaven's Carousel has transformed these red and blue shifts
into a moving fabric of speakers and sound.
The expansion of the Universe
played out in a concert of sound and light.
At times, these sources of sound are telling us through their pitch that they are moving away from us.
Leaving the same clues that planets around distant stars leave
for today's astronomers.
And at other times,
A high pitch and dazzling ice blue
transitions to a deep red
and a pitch almost too low to hear.
Making us feel like an observer of cosmic time.
Listening as the Universe expands,
and its contents accelerate away from us.
Hubblecast is produced by ESA/Hubble at the European Southern Observatory in Germany.
The Hubble mission is a project of international cooperation between NASA and the European Space Agency.
Transcription by ESO; translation by —