Siegel — Why Hubble Will Never see the First Stars

The reason is, the Universe becomes transparent to optical light at times between 500-to-700 million years of age, with the most distant known galaxy existing in a rare “pocket” where the Universe is transparent at only 400 million years old. But various estimates for the time of formation of the very first stars, at redshifts of 20, 30 and 50, correspond to ages of the Universe of 177 million, 98 million and 46 million years, respectively. Even if the Universe were transparent to begin with, the wavelengths of light we’d look for — that strong Lyman-α emission line at 121.567 nanometers (UV light) — will be redshifted to wavelengths of 2,553 nm, 3,769 nm or 6,200 nm, depending on how early these stars formed.

Ethan Siegel — Why Hubble Will Never see the First Stars

Image by Eurritimia

Burt Likko

Pseudonymous Portlander. Homebrewer. Atheist. Recovering Republican. Recovering Catholic. Recovering divorcé. Editor-in-Chief Emeritus of Ordinary Times. Relapsed Lawyer, admitted to practice law (under his real name) in California and Oregon. On Twitter, to his frequent regret, at @burtlikko. House Likko's Words: Scite Verum. Colite Iusticia. Vivere Con Gaudium.

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8 Responses

  1. Oscar Gordon says:

    Whenever I read about the latest thing Astronomers have seen, I have to do a little mental reminder that they are really looking back in time, and what we see is quite possibly no longer there.

    In Larry Niven’s Ringworld, there is a subplot that the center of the Milky Way has exploded and it’s a growing concern, but not terribly so, because the shock wave from the explosion that will wipe everything out will take 25,000 years to reach known space.

    • no longer there

      Whatever that means, relativistically speaking 🙂

    • J_A says:

      And now, for something completely different (but very similar)

      Dogs, and other animals with a highly developed olfactory sense, “see” (smell) the world differently than us. They can “see” backwards in time to what was there before, and not just what it’s there now, and can “see” al their surrounds at the same time.

      Every once in a while I think this could be great material to write a story truly from a dog’s POV, in which the dog relies more on smell and sound to explain his world and his actions

      (famous New Yorker cartoon: one dog to another, who looks a bit cross with the first: “It doesn’t matter he’s a jerk, of course I smelled his ass. It’s the polite thing to do”)

      And re Ringworld, the wave is actually an important thing

  2. I took the liberty of fixing the HTML for the spacial characters.