WHAT POWERED
THE BIG BANG?
WHAT HAPPENS
AT THE EDGE
OF A BLACK HOLE?
WHAT IS
DARK ENERGY?
National Aeronautics and
Space Administration
Presented by Dr. James Lochner (USRA & NASA/GSFC)
BEYOND EINSTEIN
Beyond Einstein
• Einstein’s Predictions
• Expanding Universe
• Black Holes
• Dark Energy
• Evidence for those predictions
• Lingering Questions …
• What Powered the Big Bang?
• What Happens at the Edge of a Black Hole?
• What is Dark Energy?
•
… And How We’ll Answer them
• LISA
• Constellation-X
• Implications for Your Students
BEYOND EINSTEIN
Einstein & Our Universe
Einstein changed the way we think of the universe:
• The speed of light is the ultimate speed limit.
• Time passes more slowly for observers traveling at high
speeds or near a massive body.
• Light rays can be bent passing near a massive body.
Einstein’s theories also made three startling predictions:
• The expansion of the Universe (from a big bang)
• Black Holes
• Cosmological Constant
(acting against pull of gravity)
These predictions have been confirmed by observations.
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Evidence for the Expanding Universe
•
We know about Expanding Universe &
Big Bang from:
•
•
•
•
Hubble’s discovery of red-shifted
galaxies.
Penzias & Wilson discovery of 3 K
background.
Abundances of the light elements.
Big Bang alone doesn’t quite produce
the universe we see.
• Inflation produces a flat universe.
• A growth spurt that stretches sub-atomic scales to
astronomical scales.
• Produces the fluctuations that lead to galaxies.
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Evidence for Black Holes
• Black holes in 3 flavors
• Stellar (5 - 15 solar masses)
o Evident in X-ray Binary Systems
• Massive (Million solar masses)
o In center of galaxies
• Intermediate (Thousand solar masses)
o Within galaxies, but not in center
• Abundant Observations and Evidence
• We measure masses (e.g from binary systems).
• We observe radiation from gaseous disks surrounding the
black hole.
• We see effects of strong gravity on nearby matter.
o First evidence for frame dragging and black hole rotation.
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Evidence for Dark Energy
 Dark Energy revealed itself in a survey of
supernovae in the late 1990’s.
 We can use certain types of supernovae to
determine distances to galaxies.
 We then compare those distances with the
galaxy’s velocity.
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1. Create a White Dwarf
A dying star becomes a white dwarf.
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2. Dump more mass onto it
The white dwarf strips gas from its stellar companion….
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3. Until it explodes
….and uses it to become a hydrogen bomb. Bang!
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4. Observe it in a distant galaxy
The explosion is as bright as an entire galaxy of stars….
…..and can be seen in galaxies across the universe.
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Redshift
Evidence for Dark Energy
SN Ia are more distant than expected.
Spacetime has expanded more than
expected.
Distance via SN Ia
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Dark Energy and the Universe
Flatness
of Universe
and
amount
of known
We
do not know
what 95%
of the
universe
is made of!
matter (and dark matter) means dark energy
makes up 70% of the Universe
BEYOND EINSTEIN
Completing Einstein’s Legacy
Einstein’s legacy is incomplete, his theory fails to explain the
underlying physics of the very phenomena his work predicted
BIG BANG
What powered the Big Bang?
BLACK HOLES
What happens at the edge of a Black Hole?
DARK ENERGY
What is the mysterious Dark Energy pulling
the Universe apart?
BEYOND EINSTEIN
What Powered the Big Bang?
What Powered the Big Bang?
Gravitational Waves Can Escape from
Earliest Moments of the Big Bang
Inflation
(Big Bang plus
10-34 Seconds)
Big Bang plus
300,000 Years
light
Now
gravitational waves
Big Bang plus
14 Billion Years
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What Powered the Big Bang?
Gravitational waves coming from
Inflation period and from “phase transitions”
may be detected directly.
• Free quarks becoming bound into protons, neutrons, etc
• Decoupling of the Electroweak and Strong forces
Wavelength of the Gravitational Waves gives size of
Universe at that time.
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Sources of Gravitational Waves
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• Black holes orbiting each other generate gravitational
waves.
• Merging black holes also generate gravitational
waves.
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Catching a Gravitational Wave
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Laser Interferometer Space Antenna (LISA)
Joint ESA-NASA project
LISA uses a laser based Michelson
interferometer to monitor the
separation between proof masses in
separate spacecraft.
• Three spacecraft separated by 5 million km.
• Each spacecraft includes two freely falling test masses.
• Distance changes measured with precision of 4 ppm
RMS over 100 seconds.
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What Happens at the Edge of a Black
Hole?
Black holes are ubiquitous in the Universe
Close to a black hole event horizon,
extreme distortions of space & time
predicted by Einstein can be observed
Chandra Deep Image
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What Happens at the Edge of a Black
Hole?
• Japan-US ASCA satellite studied iron gas orbiting near
the event horizon of a black hole.
• Iron line emission exhibits a distortion due to motion of
gas and strong gravitational effects near the black
hole.
• Line profile provides a probe of regions near black
hole.
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are needed to see this picture.
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Measuring Black Holes via Spectroscopy
• Better determination of black hole parameters by
studying individual blobs falling into event horizon.
• Measure effects of black hole spin on nearby spacetime.
• Study intermediate size black holes.
• Growth of supermassive black holes early in the
universe.
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Constellation-X
A fleet of 4 X-ray Telescopes to perform high
resolution spectroscopy on faint x-ray sources
• Each telescope 10 meter focal length.
• 4 telescopes increase the light collection area.
• Launched on two Delta rockets.
• Placed at L2 point (4x distance to moon)
• 4 - 10 year lifetime.
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Constellation-X: Achieving High
Resolution Spectroscopy
X-ray Microcalorimeter Spectrometer:
Measure the heat from an x-ray to determine the
x-ray’s energy.
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Resolution of 4 ev for a 6 kev x-ray
energy. (25x-100x better than current
sensitivity.)
BEYOND EINSTEIN
What is the Dark Energy?
Einstein introduced the Cosmological Constant to explain what was
then thought to be a static Universe, “my biggest mistake . . . ”
Empty space has energy. It’s
gravitational effect pushes the
universe apart.
Need a form of energy that is elastic:
• Vacuum energy (= Cosmol. Const.)
• But it’s effect may be too large
• Quintessence (particle field)
Astronomical Tools: Surveillance & Interrogation
• Measure expansion via fluctuations in CMB.
• Measure expansion via more SN and clusters of
galaxies.
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Constellation-X and Dark Energy
• Dark Energy with Galaxy Clusters
- Compare Distance with redshift to measure history of
expansion of the universe.
- Examine the growth of structure in the universe.
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Realizing Science Beyond Einstein
Three inter-linked components that work together:
1. Einstein Great Observatories providing breakthrough
increases in capabilities to address all Beyond
Einstein science:
• LISA: Gravitational waves from merging black holes and the
early Universe.
• Constellation-X: Spectroscopy close to the event horizon of
black holes and place constraints on dark side of the Universe.
2. Einstein Probes to address focused science
objectives:
• Determine the amount and nature of the Dark Energy.
• Search for the signature of inflation in the microwave
background via gravitational waves.
• Take a census of Black Holes of all sizes in the Universe.
3. A technology program, theoretical studies and an
education program to inspire future generations of
scientists and engineers towards the vision:
• Directly detect the gravitational waves emitted during the
Big Bang.
• Image and resolve the event horizon of a Black Hole.
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Image a Black Hole!
Hubble, Chandra, and other observatories
are showing black holes are common place
in the Universe.
HST Image
M87
0.1 arc sec resolution
Black holes provide a unique laboratory
to test Einstein’s theory of gravity.
Black Hole Imager
0.1 micro arc sec resolution
4-8 m arc sec
A future black hole imager with a resolution
one million times Hubble will observe the
effects Einstein predicted.
X-ray emission from close to the event
horizon provides a powerful probe.
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Observe the Big Bang
• Detect the gravitational waves from the earliest
moments after the Big Bang.
• Provides a direct view of the formation of space
and time.
• Big Bang Observer will also detect mergers of
neutron stars and black holes, giving the rate of
expansion of the universe through time.
BEYOND EINSTEIN
Beyond Einstein Timeline
BEYOND EINSTEIN
The Story of “Beyond Einstein”
• Science is an endless frontier
• Einstein changed our way of thinking about the universe,
but we are going beyond that.
• Science is a search for answers
• Nature of science inquiry
• Science as a process and as a human endeavor.
• When we do not know the answers, we work on
phrasing the questions.
• We push the envelope of what we know.
• We push the envelope of our technology.
BEYOND EINSTEIN
The 21st Century
How did the Universe
begin? Does time
have beginning & an
end? Does space
have edges? The
questions are as old
as human curiosity.
But the answers have
always seemed
beyond the reach of
science. . .
until now!
BEYOND EINSTEIN
BEYOND EINSTEIN
Einstein Probes
Three focused missions, each designed to address a
single high priority science question:
 Dark Energy Probe
• Determine amount of dark energy, and whether it changes.
• Ex. Search for large numbers of Type Ia supernovae.
 Inflation Probe
• Map polarization of Microwave Background to search for
signature of gravitational waves from the Big Bang.
 Black Hole Finder Probe
• Take census of black holes in the universe
• Ex. Use wide-field X-ray telescope