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Distance ladder uses successive methods to measure cosmic distances: parallax (nearby), Cepheids (galaxies), supernovae (clusters), Hubble (universe).

ଷ୍ଟେପ୍-ଷ୍ଟେପ୍ ଗାଇଡ୍ |

  1. 1Measure parallax for nearby stars
  2. 2Use Cepheid variables to calibrate nearby galaxies
  3. 3Extend to distant supernovae
  4. 4Apply Hubble law to universe

ସମାଧାନ ହୋଇଥିବା ଉଦାହରଣ

ଇନପୁଟ୍
Distant galaxy
ଫଳ
Distance 100 Mpc using multi-rung method
Each rung calibrates next

ଏଡ଼ାଇବା ଯୋଗ୍ୟ ସାଧାରଣ ଭୁଲ

  • Neglecting rung calibration errors (accumulate)
  • Using inconsistent Hubble constant

ବାରମ୍ବାର ଜିଜ୍ଞାସା

Why not direct measurement?

Angular sizes too small; need successive calibrations.

ସେଟିଂ