Critical Reasoning

Type 1a Supernovae, caused by the detonation of matter accreted onto white dwarf stars, explode with a highly predictable brightness. Since the brightness of these explosions fades over distance in a higly predictable way, scientists have long used images measuring the brightness of type 1a supernovae to determine the distance to distant galaxies.

Which of the following discoveries, if true would most jeopardize scientist' reliance on images of type 1a supernovae as tools for measuring distances to distances to distant galaxies?

• A. Models explaining the causes of type 1a supernovae are altered to include an updated understanding of the role played by carbon fusion.
  B. Type 2 supernovae are discovered to be even more dramatically variable in their brightness than was previously thought.
  C. Large clouds of interstellar dust and ionized hydrogen can absorb the light emitted by the type 1a supernovae.
  D. Some supernovae exhibit very unusual spectral classifications and changes in brightness, and do not fit into the existing categories.
  E. A new telescope is able to measure the brightness of several thousand type 1a supernovae with an unprecedented level of precision.

IMO D

sivaelectric wrote:Type 1a Supernovae, caused by the detonation of matter accreted onto white dwarf stars, explode with a highly predictable brightness. Since the brightness of these explosions fades over distance in a higly predictable way, scientists have long used images measuring the brightness of type 1a supernovae to determine the distance to distant galaxies.

Which of the following discoveries, if true would most jeopardize scientist' reliance on images of type 1a supernovae as tools for measuring distances to distances to distant galaxies?

• A. Models explaining the causes of type 1a supernovae are altered to include an updated understanding of the role played by carbon fusion.
  B. Type 2 supernovae are discovered to be even more dramatically variable in their brightness than was previously thought.
  C. Large clouds of interstellar dust and ionized hydrogen can absorb the light emitted by the type 1a supernovae.
  D. Some supernovae exhibit very unusual spectral classifications and changes in brightness, and do not fit into the existing categories.
  E. A new telescope is able to measure the brightness of several thousand type 1a supernovae with an unprecedented level of precision.

it has to be C..!!

Yes it has to be C...why???

brightness of these explosions fades over distance in a higly predictable way,

If the light get absorbed no fading and hence no idea of distance

IMO C

It is asked to weaken this: "brightness of type 1a supernovae determines the distances to distant galaxies"

In choice C, for the reason that the large clouds absorb the light emitted by type 1, brightness is not a reliable tool to measure the distance.

A:we do not care about causes of the type 1- out of scope
B:variablity of brightness does not solve our problem
C:Correct
D:It does not talk about which type 1,2,3...?
E:New telescope thing is irrelevant. Also it is a vague meaning : able to...