the tools. hot question of galileo’s time what’s at the centre: earth or sun?
TRANSCRIPT
The tools
Hot question of Galileo’s time
•what’s at the centre: earth or sun?
Sun-centered universeGalileo’s observations. 1. The Moon’s
surface
Moon not a perfect “heavenly body”
Sun-centered universeGalileo’s observations. 2. Jupiter’s
moons
Jupiter has moons!> there are things that do not orbit the Earth!
Sun-centered universeGalileo’s observations. 3. Phases of
Venus
Venus has phases, just like the MoonAttributed them to Venus’ motion around the Sun
Copernicus is right!Earth is not at the centre!
Hot questions of recent time
•how do stars work?
•how are chemical elements made?
•how big is the universe?
•what are “spiral nebulae”?
•what are quasars?
•are there planets around other stars?
•...
Better tools got us the answers
Hot questions of today and tomorrow
1.how do planets form?
2.how do stars form?
3.how do galaxies form?
4.what were the first objects to form after the Big Bang?
•To address these questions, we need great tools
•What makes a great tool?
Three things that count
1.sharpness of image
•resolve structure - get into the details 2.wavelength coverage
•go after different physical processes in the same object
3.ability to collect lots of light
•go after faint objects •lots of detail on brighter objects
from the ground from space
1.sharpness of image
•resolve structure - get into the details 2.wavelength coverage
•go after different physical processes in the same object
3.ability to collect lots of light
•go after faint objects •lots of detail on brighter objects
Three things that count
M31CO and optical
M81: starlight & dust
1.sharpness of image
•resolve structure - get into the details 2.wavelength coverage
•go after different physical processes in the same object
3.ability to collect lots of light
•go after faint objects •lots of detail on brighter objects
Three things that count
Bigger is better
10m diameter
5mm diameter
The eye vs Keck
eye Keck advantage
photons/sec entering “instrument” : π(5/2 mm)2 π(10/2 m)2 4,000,000 x
of these, actually detected: ~1% ~90% 90 x
persistence (Integration time): < 1 sec >1 hr 3600 x
bottom line: ~1.3x1012 x
How do we go about it?
1.size
2.location, location location
Bigger is better
10m diameter
5mm diameter
How do we go about it?
1.size
2.location, location location
Location, location, location
•important for sharpness of image•clarity of atmoshpere (“seeing”)•or no atmosphere at all
•ability to detect different wavelengths
•Earth’s atmosphere absorbs light (esp. bad at IR)
•so... get above the atmoshpere
from the ground from space
Hot questions of today and tomorrow
1.how do planets form?
2.how do stars form?
3.how do galaxies form?
4.when did the first structures (galaxies, stars...) form in the universe?
The future(A Canadian perspective)
• ALMA (2010)
• JWST (2014)
• TMT (2018 ? )
Three world-class telescopes
for Canada
ALMA(Atacama Large Millimetre
Array)
radio interferometer consisting of 64 12m antennas
ALMA(Atacama Large Millimetre
Array)• at 5000m elevation in the Atacama
desert (Chile)
• location minimizes water vapour in the atmosphere
ALMA(Atacama Large Millimetre
Array)• Capabilities:
• star formation in the early Universe:
• heat emission from dust in distant galaxies
• molecular (cold) gas in distant galaxies
• very high spatial resolution = study internal structures
• large collecting area = high sensitivity
JWST(James Webb Space Telescope)
Next generation space telescope (successor to Hubble)with a 6.5m segmented mirror
2.8m diameter6.5m (equivalent) diameter
JWST(James Webb Space Telescope)
• Capabilities:
• infrared (heat) observations from space
• very high spatial resolution:
• study structural details of distant galaxies
• search for planets around other stars
• large collecting area = very sensitive
TMT(Thirty Meter Telescope)
Extremely large optical telescope with adaptive optics
• 30-m diameter (duh!)
• 3x bigger diameter than Keck => 9 times more collecting area
• Capabilities:
• huge mirror: extreme light-gathering power
• adaptive optics: resolve very fine details or small separations
• extremely complementary to JWST
TMT(Thirty Meter Telescope)
• ALMA (2010)
• JWST (2014)
• TMT (2018 ? )
Three world-class telescopes
for Canada
