Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: cosmology – Page 2

Blazar Ton 599’s complex variability investigated by long-term observations

Using the Whole Earth Blazar Telescope (WEBT), an international team of astronomers have performed long-term photometric observations of a luminous blazar known as Ton 599. Results of the observations, published in the Astronomy & Astrophysics journal, shed more light on the optical variability of this object.

Blazars are very compact quasi-stellar objects (quasars) associated with supermassive black holes (SMBHs) at the centers of active, giant elliptical galaxies. They are the most luminous and extreme subclass of active galactic nuclei (AGNs). The characteristic features of blazars are highly collimated relativistic jets oriented very close to our line of sight.

Based on their optical emission properties, astronomers generally divide blazars into two classes: flat-spectrum radio quasars (FSRQs) that feature prominent and broad optical emission lines, and BL Lacertae objects (BL Lacs), which do not.

What if Dark Energy Doesn’t Exist? New Theory Could Rewrite Cosmic Expansion

The rapid acceleration of the universe’s expansion continues to challenge our understanding of fundamental physics. Why the universe is expanding faster and faster remains one of the most intriguing open questions in modern physics. Current theories cannot fully account for this behavior using th

Cosmic rays from a nearby supernova may help explain Earth-like planets

How common are Earth-like planets in the universe? When I started working on supernova explosions, I never imagined that my research would eventually lead me to ask a question about the origin of Earth-like planets. Yet that is exactly where it brought me.

For decades, planetary scientists have believed that the early solar system was enriched with short-lived radioactive elements—such as aluminum-26—by a nearby supernova. These radioactive elements played a crucial role in forming water-depleted rocky planets such as Earth. Their decay heated young planetesimals, causing them to lose much of their originally accreted water and other volatile materials.

There was just one problem that kept bothering me.

Physicists & Philosophers debunk The Fine Tuning Argument

The Fine-Tuning Argument is often seen as the best argument for the existence of God. Here we have assembled some of the world’s top physicists and philosophers to offer a reply. Not every critic of the argument comes from the same perspective. Some doubt there is a problem to be solved whilst others agree it is a genuine problem but think there are better solutions than the God hypothesis. Some like the multiverse and anthropics other don’t. We have tried to represent these different approaches and so it should be taken as given, that not all of the talking heads agree with each other. Nevertheless, they all share the view that the fine-tuning argument for God does not work. Nor are all the objectors atheist, Hans Halvorson offers what we think is a strong theological objection to the argument. This film does not try to argue that God doesn’t exist only that the fine-tuning argument is not a good reason to believe in God. Most of the footage was filmed exclusively for this film with some clips being re-used from our Before the Big Bang series, which can be viewed here: • Before the Big Bang 5: The No Boundary Pro… All of the critics of the fine tuning argument that appear were sent a draft of the film more than a month before release and asked for any objections either to their appearance, the narration or any other aspect of the film. No objections were raised, and many replies were extremely positive and encouraging. A timeline of the subjects covered is below:
(We define God as a perfect Omni immaterial mind as for example modern Christians and Muslims advocate, there are other conceptions of God which our video does not address).
Just to be clear, this is a polemical film arguing against the fine tuning argument.

Timecodes.

0:00 Introduction.
4:11 The universe as a roll of the dice.
6:15 what is probability?
7:28 probability problems.
9:25 measure problem.
15:45 deceptive probabilities.
20:23 the flatness problem.
22:14 counterfactuals versus probabilities.
23:59 fine tuning versus God.
37:02 necessity.
38:53 multiverse and anthropics.
47:34 Boltzmann brains.
49:45 Entropy.
52:45 Cosmological Natural Selection.
59:10 conclusion.

Study unveils the dual nature of a young stellar object

Astronomers from the Aryabhatta Research Institute of Observational Sciences (ARIES) in India and elsewhere have conducted a long-term photometric and spectroscopic study of a young stellar object known as V1180 Cassiopeiae. Results of the study, published December 23 on the arXiv preprint server, unveil the dual nature of this object.

Young stellar objects (YSOs) are stars in the early stages of evolution; in particular, protostars and pre-main sequence (PMS) stars. They are usually observed embedded in dense molecular clumps, environments containing plenty of molecular gas and interstellar dust.

Given that episodic accretion processes occur in YSOs, these objects may experience accretion-driven outbursts. Astronomers usually divide such events into EX Lup (also known as EXors) and FU Ori outbursts (or FUors). EXors are a few magnitudes in amplitude, and last from a few months to one or two years. FUors are more extreme and rare as they can be up to 5–6 magnitudes in amplitude and last from decades to even centuries.

The origin of space time matter and everything

On the Same Origin of Spacetime, Matter, and Everything https://lnkd.in/gCs9XBzx What if space, time, matter, gravity, dark matter, and dark energy all come from one thing: quantum entanglement? 1. Reality starts as a quantum state (not spacetime) In EWOG, the universe does **not** begin with space and time. It begins with a single quantum state: |Ψ⟩ ∈ No coordinates No distances No clocks Only quantum information. ➡ Spacetime appears later. 2. Geometry is quantum, not classical Spacetime is not a background — it is made of operators: ĝ_μν, R̂_μν, R̂ What we experience as classical spacetime is just the **average**: g_μν = ⟨ ĝ_μν ⟩ Intuition: Spacetime is a *shadow* cast by quantum entanglement. 3.

Finding runaway stars to help map dark matter in the Milky Way

Hypervelocity stars have, since the 1920s, been an important tool that allows astronomers to study the properties of the Milky Way galaxy, such as its gravitational potential and the distribution of matter. Now astronomers from China have made a large-volume search for hypervelocity stars by utilizing a special class of stars known for their distinct, regular, predictable pulsation behavior that makes them useful as distance indicators.

Their research is published in The Astrophysical Journal.

The escape velocity of any planet, star or galaxy is the velocity required for a mass, leaving the object’s surface, to coast completely and exactly out of the planet’s gravitational well, going to infinity. Earth’s escape velocity is 11.2 kilometers per second (km/s).

Searching for light dark matter by tracking its direction with quantum sensors

Dark matter is an elusive type of matter that does not emit, absorb or reflect light, interacting very weakly with ordinary matter. These characteristics make it impossible to detect using conventional technologies used by physicists to study matter particles.

As it has never been observed before, the exact composition of dark matter remains unknown. One proposed theory is that this elusive type of matter is comprised of light particles with very small masses, below 1 eV (electronvolt), which behave more like waves than particles.

Researchers at the University of Tokyo and Chuo University recently explored the possibility of searching for sub-GeV dark matter using quantum sensors, advanced systems that rely on quantum mechanical effects to detect extremely weak signals.

/* */