What Was the Temperature of the Universe When a Typical

question 39

Multiple Choice

What was the temperature of the universe when a typical CMB photon was no longer able to spontaneously create an electron and positron pair? Note that a photon has an energy equal to E = hc/λ,the CMB at any point in time has a blackbody spectrum that peaks at a wavelength λ_peak = (2900 μm K) /T,and the mass of a single electron is 9 × 10⁻³¹ kg.

• A)2000 K
• B)400,000 K
• C)2 million K
• D)40 million K
• E)2 billion K

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Definitions:

Rescission

The revocation, cancellation, or repeal of a contract, returning the parties involved to their positions before the contract was made.

Contract of Adhesion

A standard-form contract prepared by one party to be signed by another party in a position of weaker bargaining power, often not negotiable.

Fraudulent Misrepresentation

The act of intentionally providing false information with the aim of deceiving another party, often to induce them into a contract.

Mutual Mistake

A misunderstanding shared by both parties involved in a contract, leading to a misalignment in agreement terms.