đš The Biggest Problem in Physics (Cosmological Constant) https://lnkd.in/gt7tEpJw â Problem: Why is the Universe accelerating⊠and why is the value so unbelievably small? Observations (supernovae, CMB, BAO) show: đ The expansion is accelerating đ This requires a cosmological constant Î From Einsteinâs equation: Î = 8ÏG Ï_Î đł But hereâs the crisis: Quantum physics predicts vacuum energy: Ï_vac â M_Pl⎠But observations give: Ï_Î â 10â»ÂčÂČâ° M_Pl⎠đ„ Thatâs a mismatch of 120 orders of magnitude This is called the cosmological constant problem đ§ Standard thinking fails because: We assume: đ Energy fills space uniformly đ Î comes from summing quantum fluctuations Ï_vac = (1/V) ÎŁ (Âœ âÏâ) But this diverges â way too large â đĄ A different perspective (EWOG insight): Instead of asking: đ âWhat is the energy of empty space?â Ask: đ âWhat is the geometry of the Universe?
These individuals consistently perform on memory tests at levels similar to people at least 30 years younger, challenging the long-standing belief that cognitive decline is unavoidable with age.
Over decades of research, scientists have noticed some lifestyle and personality traits that set SuperAgers apart from their peers, including being highly social and outgoing. Still, the most surprising discoveries have come from examining their brains. âItâs really what weâve found in their brains thatâs been so earth-shattering for us,â said Dr. Sandra Weintraub, a professor of psychiatry and behavioral sciences and neurology at Northwestern University Feinberg School of Medicine.
By identifying both biological and behavioral patterns linked to SuperAging, researchers hope to develop new approaches to strengthen cognitive resilience and reduce the risk of Alzheimerâs disease and other forms of dementia.
During cell division, faithful chromosome segregation is ensured by the mitotic spindle. van Toorn et al. uncovered that Cdk1-mediated phosphorylation of the dynein-activating adaptor NuMA promotes the timely assembly of dynein/dynactin/NuMA complexes, essential for correct mitotic progression and genome integrity.
0:00 Origins of complex life on Earth 1:00 Gathaagudu or Shark Bay and its stromatolites 2:10 Archae and why they matter â formation of eukaryotes 3:30 Asgard archaea 4:40 Study tries to grow complex life 5:40 What was done and why it matters 7:30 Additional research on where this started 9:35 Implications and conclusions.
Enjoy and please subscribe.
Bitcoin/Ethereum to spare? Donate them here to help this channel grow! bc1qnkl3nk0zt7w0xzrgur9pnkcduj7a3xxllcn7d4 or ETH: 0x60f088B10b03115405d313f964BeA93eF0Bd3DbF
Get MagellanTV here: https://try.magellantv.com/arvinash and get an exclusive offer for our viewers: an extended, month-long trial, FREE. MagellanTV has the largest and best collection of Science content anywhere, including Space, Physics, Technology, Nature, Mind and Body, and a growing collection of 4K. This new streaming service has 3,000 great documentaries. Check out our personal recommendation and MagellanTVâs exclusive playlists: https://www.magellantv.com/genres/sciâŠ
The gauge bosons of the standard model of particle physics are responsible for 3 of the 4 known forces in the universe. A force is conferred is through the exchange of virtual bosons. So for example in electromagnetism, an exchange of virtual photons results in an exchange of momentum which results in two like charges repelling each other.
Gravity is missing from this picture because in General relativity, gravity is not a force, but is a curvature of space-time. The problem is that stars and planets are made of molecules, atoms and radiation. And the forces that hold the atoms together are due to discrete units of virtual particles. It is the exchange or swapping of these virtual bosons that holds or breaks up atoms and molecules.
Quantum mechanics conflicts with general relativity, because QM treats every thing as being discrete, and GR treats everything as being continuous. We need a theory that combines the two because we live in one reality, not two different realities.
This is why most physicists believe General relativity is incomplete. Why canât quantum mechanics be the one that is incomplete? Of the 4 fundamental forces, 3 have very robust quantum mechanical theories. Only gravity lacks a quantum description. Quantum mechanics also has almost all of classical physics within in its limits. Classical physics like general relativity, does not have quantum effects. We have learned is that Quantum physics is the fundamental language of reality.
One way to quantize gravity is to quantize space-time itself. This is what loop quantum gravity or LQG does. It shows that the fabric of space-time is not continuous, but is made up of discrete quanta, like the pixels on a TV screen. This is different than string theory, because in string theory, space is the background or the canvas, on which strings vibrate.
Following reports of recurring DRM checks, Sony clarifies that digital games only require a single online verification to confirm ownership in a new statement.
The transitions of hydrogen molecules embedded in a crystal depend on the surroundingsâa behavior that could be used to tailor molecular quantum dynamics.
In quantum physics, we often learn that the rules governing a system are set by its symmetry. These rulesâknown as selection rulesâdetermine which transitions between quantum states are allowed and which are forbidden. For example, rotational symmetry constrains how an atomâs angular momentum can change. But what if those rules are not fixed? A recent study of hydrogen (H2)âone of the simplest molecules in natureâshowed that the allowed pathways between quantum states are determined not solely by the moleculeâs internal symmetry but also by its surroundings. By embedding hydrogen molecules in different crystalline environments, Nathan McLane and colleagues from the University of Maryland, College Park, have demonstrated that the symmetry of the host material can selectively enable or suppress nuclear-spin transitions [1]. In doing so, the team revealed that quantum dynamics is not just an intrinsic propertyâit can be shaped by the environment.
H2 is one of the simplest systems for exploring quantum behavior. Its two identical protons can align their spins in two different ways: In so-called orthohydrogen the nuclear spins are parallel, whereas in parahydrogen they are antiparallel. Although this difference is subtle, it leads to markedly different physical properties for the two forms. Crucially, transitions between them are highly constrained: In an isolated hydrogen molecule, the overall wave function is symmetric under exchange of the two protons, and this exchange symmetry forbids direct conversion between ortho and para states [2]. This restriction makes H2 a textbook example of how symmetry governs quantum dynamics.
