The highest-quality JWST spectra reveal that little red dots are young supermassive black holes shrouded in dense cocoons of ionized gas, where electron scattering, not Doppler motions, broadens their spectral lines.
Category: cosmology – Page 2
Is There A Simple Solution To The Fermi Paradox?
Use code PBS to get 15% off all Hoverpens and free shipping to most countries for the first 48 hours, 10% off after that. North America / UK / Australia / International: https://bit.ly/pbs_novium.
EU: https://bit.ly/pbs_noviumeu.
Around 2 billion years ago, life had plateaued in complexity, ruined the atmosphere, and was on the verge of self-annihilation. But then something strange and potentially extremely lucky happened that enabled endless new evolutionary paths. The first eukaryote cell was born. This may also explain why there are no aliens.
Patreon Interview with Dr. Matt Caplan.
• How Black Holes Feast — Patreon Interview…
Cool world episode: • the odds of life — THIS CHANGED MY MIND
Sign Up on Patreon to get access to the Space Time Discord!
/ pbsspacetime.
Check out the Space Time Merch Store.
Ghost Particles Interacting With Dark Matter Could Solve a Huge Cosmic Mystery
A new investigation of the early Universe led by Poland’s National Centre for Nuclear Research has just found that there may be an interaction between two of the most elusive components of the cosmos.
By combining different kinds of observations, cosmologists have shown that what we see is more easily explained if neutrinos, aka ‘ghost particles’, weakly interact with dark matter.
With a vexing certainty of three sigma, the signal isn’t strong enough to be definitive, but is also too strong to be a mere hint or noise in the data.
The Dark Halo That Never Lit Up
Galaxies announce themselves through the light of billions of stars, all embedded in vast clumps, or “halos,” of dark matter. But researchers may have spotted, for the first time, a starless halo of dark matter—containing only a gas cloud. The result was announced by Rachael Beaton of the Space Telescope Science Institute in Maryland at the meeting of the American Astronomical Society in Phoenix, Arizona. Using observations from the Hubble Space Telescope, Beaton and her collaborators showed that the object, known as Cloud-9, contains a negligible amount of stars [1]. “There is nothing like this that we have found so far in the Universe,” Beaton said in a press conference last week.
Cloud-9’s makeup—as inferred from radio and optical observations—would qualify it as the first example of a REionization-Limited H I Cloud (RELHIC), a starless dark matter halo filled with neutral hydrogen gas (H I). RELHICs are thought to be leftovers of dark matter clumps that couldn’t accrue a sufficient amount of gas to form stars, says the project’s principal investigator Alejandro Benítez-Llambay of the University of Milano-Bicocca in Italy. A RELHIC is “a tale of a failed galaxy,” he says.
Starless halos arise naturally within the standard paradigm of cosmology: the lambda cold dark matter (ΛCDM) model, where Λ refers to a “cosmological constant” that describes dark energy. According to ΛCDM, dark matter can cluster into halos that provide the gravitational backbone for galaxy formation. The model also predicts that there is a critical mass below which halos would be too small to ever form stars. Spotting unlit halos might sound hopeless, but simulations by Benítez-Llambay and collaborators in 2017 suggested that halos within a narrow mass range may exist as RELHICs (a term they coined) [2]. According to their calculations, RELHICs would have masses close to the critical value for galaxy formation. Crucially, the compact, hydrogen-filled cores of these objects provide a potential observational window, since hydrogen clouds have a characteristic radio emission.
The Many Worlds of the Quantum Multiverse
Decoherance which is why we are not aware of the universe splitting.
Is our universe a definitive single reality or is it merely one within an infinitely branching multiverse? Be sure to check out Physics Girl’s Dianna Cowern for more awesome science / physicsgirl.
Get your own Space Time tshirt at http://bit.ly/1QlzoBi.
Tweet at us! @pbsspacetime.
Facebook: facebook.com/pbsspacetime.
Email us! pbsspacetime [at] gmail [dot] com.
Comment on Reddit: / pbsspacetime.
Support us on Patreon! / pbsspacetime.
Help translate our videos! https://www.youtube.com/timedtext_cs_p… Copenhagen interpretation of quantum mechanics tells us that observation collapses a probability wave into a single definitive outcome, but this isn’t the only interpretation of quantum mechanics. The many worlds theory proposes that the wavefunction never actually collapses. The observer simply follows one of those many possible paths into their present reality while all the other paths continue on independent of the observer. Each of these paths branches off into an entirely different reality. In this episode Matt discusses the details of the many worlds theory and why it’s not so far-fetched to think that our reality is simply one of an infinite number of realities existing within space time. Links to sources: The Quantum Experiment that Broke Reality • The Quantum Experiment that Broke Reality… Hugh Everett’s Ph.D. Dissertation http://www-tc.pbs.org/wgbh/nova/manyw… Crazy Pool Vortex
• Crazy pool vortex Previous Episode
• The First Humans on Mars Written and hosted by Matt O’Dowd Produced by Rusty Ward Made by Kornhaber Brown (www.kornhaberbrown.com)
The Copenhagen interpretation of quantum mechanics tells us that observation collapses a probability wave into a single definitive outcome, but this isn’t the only interpretation of quantum mechanics. The many worlds theory proposes that the wavefunction never actually collapses. The observer simply follows one of those many possible paths into their present reality while all the other paths continue on independent of the observer. Each of these paths branches off into an entirely different reality. In this episode Matt discusses the details of the many worlds theory and why it’s not so far-fetched to think that our reality is simply one of an infinite number of realities existing within space time.
