Scientists have caught fast-moving hydrogen atoms—the keys to countless biological and chemical reactions—in action.
A team led by researchers at the Department of Energy’s SLAC National Accelerator Laboratory and Stanford University used ultrafast electron diffraction (UED) to record the motion of hydrogen atoms within ammonia molecules. Others had theorized they could track hydrogen atoms with electron diffraction, but until now nobody had done the experiment successfully.
The results, published in Physical Review Letters, leverage the strengths of high-energy Megaelectronvolt (MeV) electrons for studying hydrogen atoms and proton transfers, in which the singular proton that makes up the nucleus of a hydrogen atom moves from one molecule to another.
WASHINGTON, Oct 6 (Reuters) — Since beginning operations last year, the James Webb Space Telescope has provided an astonishing glimpse of the early history of our universe, spotting a collection of galaxies dating to the enigmatic epoch called cosmic dawn.
But the existence of what appear to be massive and mature galaxies during the universe’s infancy defied expectations — too big and too soon. That left scientists scrambling for an explanation while questioning the basic tenets of cosmology, the science of the origin and development of the universe. A new study may resolve the mystery without ripping up the textbooks.
The researchers used sophisticated computer simulations to model how the earliest galaxies evolved. These indicated that star formation unfolded differently in these galaxies in the first few hundred million years after the Big Bang event 13.8 billion years ago that initiated the universe than it does in large galaxies like our Milky Way populating the cosmos today.
American physicist, John Wheeler (1911−2008), made seminal contributions to the theories of quantum gravity and nuclear fission, but is best known for coining the term ‘black holes’. A keen teacher and mentor, he was also a key figure in the Manhattan Project. [Listener: Ken Ford]
TRANSCRIPT: I knew the stories about Gödel being concerned always about his health. I knew from his friend Oscar Morgenstern how Gödel would never take a pills prescription from his doctor without getting out a big medical book and studying up on that pill himself to make sure that it was okay. But I didn’t realize how far his dreams went, because I had failed to resonate to a talk he gave in 1945 at the symposium held in honor of Einstein’s birthday. In that talk Gödel had described what he called a Rotating Universe, a universe where all the galaxies turn the same way, and where the geometry is such that you keep on going living your life and you come round and come back and can live it over again; ‘Closed Time-like Line’ was the magic phrase to describe it. So you didn’t have to worry about the pill because you come back and live your life all over again. Well, after I’d introduced the two I said “Professor Gödel, we’d like to know what the relation is between the great Heisenberg Principle of Uncertainty or Indeterminism; and your famous proof that every significant mathematical system contains theorems which cannot be proven, your theorem of Unprovable Propositions.” Well, he didn’t want to talk about that. It turned out that later that he had walked and talked enough with Einstein to dismiss quantum theory. He didn’t believe quantum[theory]. All he wanted to know is what we were going to say in our book about the rotating universe that he had described. Well actually, we weren’t saying anything. Well, this bothered him and he wanted to know what the evidence is today, at that moment, about whether galaxies do rotate in the same way. We said we hadn’t studied it. Well it turned out that he himself had taken out the great Hubble atlas of the galaxies and page after page had opened it up and looked at each galaxy, determined the direction of its axis. He made a statistics of these numbers and found there was no preferred direction of rotation, so they couldn’t all be rotating in the same way.
The most widely used machine learning algorithms were designed by humans and thus are hindered by our cognitive biases and limitations. Can we also construct meta-learning algorithms that can learn better learning algorithms so that our self-improving AIs have no limits other than those inherited from computability and physics? This question has been a main driver of my research since I wrote a thesis on it in 1987. In the past decade, it has become a driver of many other people’s research as well. Here I summarize our work starting in 1994 on meta-reinforcement learning with self-modifying policies in a single lifelong trial, and — since 2003 — mathematically optimal meta-learning through the self-referential Gödel Machine. This talk was previously presented at meta-learning workshops at ICML 2020 and NeurIPS 2021. Many additional publications on meta-learning can be found at https://people.idsia.ch/~juergen/metalearning.html.
Jürgen Schmidhuber. Director, AI Initiative, KAUST Scientific Director of the Swiss AI Lab IDSIA Co-Founder & Chief Scientist, NNAISENSE http://www.idsia.ch/~juergen/blog.html.
This video discusses what it would mean to live forever or to have a greatly expanded lifespan. Would we inevitably grow bored with existence? Why do we even want to live longer?
We also discuss the philosophy of the Ship of Theseus as it applies to mind upload or body transfer. If you transfer your mind to a new body, are you still the same person? We conclude that the answer is yes if and only if you experience no discontinuities in consciousness.
Finally, we discuss a few different ways that new bodies might be formed as technology advances. Digital avatars and robotic bodies are just a few of the possibilities.
