One of the latest images from the James Webb Space Telescope depicts a cosmic collision-Stephan's Quintet is a visual grouping of five interacting galaxies, two of which are actively colliding, swapping gas, dust and stars in the process and even creating a shockwave! See here: www.nasa.gov/webbfirstimages
That first question was amazing. I have always wondered if photons didn't experience time but I never thought to take it to that level. Wow. It also kind of fits in with Fermat's principle of least time, which just never ceases to amaze me.
Neil has mentioned multiple times throughout ST that a photon doesn't experience time. But wondering if a photon knows its destination 13.5 billion years into the future is kind of a cool concept. We step outside and feel the warmth of the Sun, but the photon that just hit your face was 100,000 to 1,000,000 years in the making deep inside the Sun. Once it manages to escape the Sun's layers, it immediately knows where you will be eight minutes in its future (8 light minutes to reach you), but while that knowledge is instantaneous to the photon, we still have to travel through space and time for eight minutes for the photon to get there. Add to that relativity, which I'm not smart enough to speak about, but I've done the calculations to account for the expansion of space over great distances (negligible for a photon from the Sun). So does that mean we are where we are supposed to be because a photon emitted was meant to collide there? Personally I don't think so lol but it's a cool thought.
First time I've seen Dr. Tyson pause and think like that, those were some good questions!!! The world wouldn't be the same with out these great videos. And the videos aren't as funny unless Mr. Nice is on there too. Thanks for what y'all do!
It is a good question, and the "experiencing time all at once" perspective of the photon reminds me of a Feynman story. In 1940, John Wheeler called Richard Feynman one day because he had a profound thought. He said, “Feynman, I know why all electrons have the same charge and the same mass” “Why?” “Because, they are all the same electron!”. (I believe this relates to the "experiencing all time at once" thought, I could be wrong) Feynman said he got the idea that positrons could simply be represented as electrons going from the future to the past in a back section of their world lines from this conversation. source: Richard P. Feynman's Nobel Lecture, December 11, 1965 The Development of the Space-Time View of Quantum Electrodynamics
If you stop and think about it you will come to realize that nothing is predestined, it just happens when you experience it. Be thankfull you have the intellegence to appreciate it.
Hey, Dr. Tyson and Mr. Nice.. I'm new to this community but I've recently discovered a personalized strength and hope within science, and your videos sort of fortify that. So I just wanted to say thanks for what you do! Y'all give greatness to the world.
🙋🏿♂️Thanks Dr. Tyson and Lord Nice for another brainy cool video.😎👍🏿 ❓Quick question, is there anyway to convert spent fuel rods into batteries or convert the remaining radioactive energy into a productive power source for?❓
Unfortunately, radioactivity is not convertible to electricity. The spent fuel rods went beyond their capacity to become critical and sustain that reaction. The rods go from emitting gamma rays to beta radiation, which is useless in terms of energy recovery. Well, not so useless, but you need tons of it to become relevant.
@@parintelebaiazid80 I have no science qualifications, but it seems IMPOSSIBLE that there is no combination of chemicals, metals or substances which may harness half-life radioactivity productively.🔋 💡If not by electricity production, than something!🤷🏿♂️
Chuck can NEVER be replaced ! NEIL your the reason why I'm fascinated about the universe and in my short life stay optimistic in the virtues of Artificial Intelligence, Wars, Epidemics, Armageddons, or whatever the Earth and it's far and near distant neighborhood will have in store for all. You 2 are the chocolate-chip to my ice creme when I want to mentally wind down and look up into the skys and think of endless possibilities. Gracias
I taught chem and bio for 36 yrs. Questions were/are key to inquiry. Inquiry is itself key to promoting thinking. Experimentation as inquiry promotes higher level thinking. Neil, your explanations and discussions stimulate curiosity, and I hope, longtime learning. We achieve success if we create longtime learners, and scientific thinkers.
The answer to Tucker's question was actually the best explanation of The Twin Paradox I have ever heard, this is the time it clicked and I understood it rather than accepted it!!!
That first photon/predestination question is so interesting!! Do we also consider the photon’s predestined collision in terms of the perceived usefulness of its destination? If they land on living plant mater, they ultimately serve the purpose of sustaining the earths biome in a way, no? The same can be said if that photon hits plankton in the open ocean. 🤔
I can watch theses all day, as long as chuck is on, i just have this channel on a loop in my house. only channel i feel safe having my kid listening to by accident.
The comic character that Dr Tyson mentioned is Fred Fleming (Dark Matter). He was a short-time Flash villain in DC's Legends comics. He was only around for 2 or 3 issues.
Hey Dr. Tyson, do you guys podcast?? I'd LOVE to get the chance to even be as honored to just get to sit in chat with you explaining everthingness. I can tell your mind is set right. That movie "Limitless" was a great example for explaining time because time in a value of a different relm is obviously different for the one who controls time in all. Love the show. Love the content sir. ❤🤘🏽 Ps my Grandfather's name is Fred 😄
Celestial banging 😂, now if my professor taught like that,I might I have working in NASA right now .i love this show 😂❤ thank you for the knowledge and wonderful content.
Dear Dr. Tayson, dear Shack. I can't wait for the show to go back to it's original filming format with both of you in the same room in the museum. I understand that this video conference format is due to social distancing necessity. But I'm afraid that it will stay like this forever. I hope I'm wrong. I miss the old conversation with a direct interaction. Keep up with the good work. Best Regards
Question 1 answer: the photon DOES travel... it not feeling time just means it does not decay. So it does still travel and has ability to hit something else. It's not predetermined.
You are handwaving here. Photon 'travels' and 'has ability to hit something else' from your perspective, or from the perspective of a temporal being. The point of the question was, from a non temporal being's perspective, the photon is already at the destination when created. There's no travel. It's created as a vector in space, with a starting point, a destination and a direction. It's a very insightful question and you have to dig a lot deeper to explain why its interaction is not predetermined.
My take on Light Sabers is that it is high energy plasma confined by a magnetic field and those fields have changing polarities so they will always be a point where they repel each other.
I am curious on if you were to be in the ring of light of the blackhole and without being sucked in, how the light would look like, would it be blinding or would it be a sped up remind of all the previous objects that the light originally came from
Nice that they jump directly into the questions. Sometimes with other guests on the show, they take 15 minutes of rambling before getting to the topic and questions. Thank you.
that first question about the photon is interesting, it's born in an instant, and travels for eternity before hitting something, all while experiencing no time. Is a photon predetermined to have hit your eyeball though? no, because it's entire existance was darkness, so it had no awareness of your eye until it had reached there. and now y'all got me Personifying particals....great Also keep in mind that photons ARE subject to gravity. so here a photon is not even knowing it's own existance or travel for thousands of years when suddenly it gets pulled in a different direction by a black hole, or sun, or planet, moon etc... constantly getting yanked back and forth until finally coming to a stop and experiencing time for the first moment
@@shanecombs1993 I thought (and hoped) the same way back when. I liked the romantic/poetic nature it allowed for infinite death and rebirth. By the way, that hypothesis is referred to as "the big crunch" unforunutatley it has largely been rejected in favor of "the heat death" based on the universe expanding (and speeding up) greater than the force of gravity. Still I don't see why blackholes couldn't trigger the creation of new universes. There is the hypothesis of black holes that they emit radiation (look up hawking radiation) and if they didn't consume matter for long enough could revert to their state before being a blackhole.... it's way above me. so is the thing about blackholes being wormholes through time and space into the past..... Anyways, still hold the idea that blackholes themselves could be trigger events for the creation of new universes outside our own, and multiverse theory allows for multiple universes existing like a froth of bubbles, even while they expand and push on other universes, they never interact of affect one another.
The pictures of the James Webb telescope has many 6 pointed stars. What causes that? Is it something to do with the hexagonal mirrors on the telescope?
Don Lane was a US singer and personality that settled in Australia and became a very popular TV host. Died in Sydney 2009 with an Alzheimer's related illness. He had a number of successful shows.
34:47 Ice merging. So in space, in a vacuum, Astraunauts found out the hard way that bare metal will cold-weld to bare metal in vacuum. It seems possible that in a vacuum a flat plane of ice might merge with a flat plane of ice if they are pressed together.
exactly. Increase in pressure increases the melting point, not the opposite which the question suggests. A drop in pressure might however change a solid to a liquid, thereby increasing the chance for a cold-welding.
As Leibniz put it: “If an ontological theory implies the existence of two scenarios that are empirically indistinguishable in principle but ontologically distinct ... then the ontological theory should be rejected and replaced with one relative to which the two scenarios are ontologically identical.” In other words, if a theory describes two situations as being distinct, and yet also implies that there is no conceivable way, empirically, to tell them apart, then that theory contains some superfluous and arbitrary elements that ought to be removed. Leibniz’s prescription is, of course, widely accepted by most physicists today. The idea exerted a powerful influence over later thinkers, including Poincaré and Einstein, and helped lead to the theories of special and general relativity. And this idea, Spekkens suggests, may still hold further value for questions at the frontiers of today’s physics. Leibniz’s correspondent Clarke objected to his view, suggesting an exception. A man riding inside a boat, he argued, may not detect its motion, yet that motion is obviously real enough. Leibniz countered that such motion is real because it can be detected by someone, even if it isn’t actually detected in some particular case. “Motion does not indeed depend upon being observed,” he wrote, “but it does depend upon being possible to be observed ... when there is no change that can be observed, there is no change at all.” In this, Leibniz was arguing against prevailing ideas of the time, and against Newton, who conceived of space and time in absolute terms. “I have said more than once,” Leibniz wrote, “that I hold space to be something merely relative.” Einstein, of course, followed Leibniz’s principle when he noticed that the equations of electricity and magnetism make no reference to any absolute sense of motion, but only to relative motion. A conducting wire moving through the field of a magnet seems like a distinct situation from a magnet moving past a stationary wire. Yet the two situations are in fact empirically identical, and should, Einstein concluded, be considered as such. Demanding as much leads to the Lorentz transformation as the proper way to link descriptions in reference frames in relative motion. From this, one finds a host of highly counter-intuitive effects, including time dilation. Einstein again followed Leibniz on his way to general relativity. In this case, the indistinguishability of two distinct situations - a body at rest in the absence of a gravitational field, or in free fall within a field - implied the impossibility of referring to any concept of absolute acceleration. In a 1922 lecture, Einstein recalled the moment of his discovery: “The breakthrough came suddenly one day. I was sitting on a chair in my patent office in Bern. Suddenly the thought struck me: If a man falls freely, he would not feel his own weight. I was taken aback. This simple thought experiment made a deep impression on me. This led me to the theory of gravity.” 🆒️
Leibniz now mostly inhabits scientific history books, his ideas receiving scant attention in actual research. And yet, Spekkens argues, Leibniz’s principle concerning indistinguishability may be as useful as ever, especially when confronting foundational issues in physics. Consider the interpretation of quantum theory, where theorists remain separated into two opposing groups, loosely associated with the terms realism and empiricism. Although Leibniz’s principle can’t offer any way to unify the two groups, Spekkens argues, it might help them focus their attention on the most important issues dividing them, where progress might be made. For example, one particular interpretation comes in the form of so-called pilot-wave theories, in which electrons and other particles follow precise but highly non-classical trajectories under the influence of a quantum potential, which produces the wave-like nature of quantum dynamics. These theories demonstrate by explicit example that nothing in quantum physics prohibits thinking about particles moving along well-defined trajectories. But the theory does require the existence of some absolute rest frame, while also implying that this frame can never be detected. Many other aspects of such theories also remain unconstrained by empirical data. Hence, one might take Leibniz’s principle as coming down against such theories. On the other hand, Spekkens points out, Leibniz’s principle demands that distinct states be, in Leibniz’s own words, “empirically indistinguishable in principle,” and achieving such certainty is not easy. If several states appear indistinguishable now, future experiments might turn up measurable differences between them. So a proponent of the pilot-wave approach might agree with Leibniz’s principle, but still reject its application just yet. The aim of research, from this point of view, ought to be to seek out such evidence, or at least envision the conditions under which it might be obtained. And in this sense, Spekkens notes, Leibniz’s principle also offers some criticism of theorists from the empirical school, who object to pilot-wave or other realist interpretations of quantum theory for containing unmeasurable quantities. It implies, as he puts it, that the empiricists’ “set of mental tools is too impoverished.” After all, progress in physics often requires imagination, and creative exploration of possible distinguishing features that have not yet been measured, or even thought to exist. Progress requires scientists to “entertain ontological hypotheses, expressed with concepts that are not defined purely in terms of empirical phenomena.” Science thrives on the essential tension existing at the boundary between empirical observation and unconstrained imagination. Incredibly, Leibniz perceived that more than 300 years ago.
14:41 The name Lord Nice was looking for was Frederick (Fred) Fleming (AKA Dark Matter) DC Super Villain. Neil is right. 22:05 Actually Don Lane was an American born entertainer who was a popular TV Host here in Australia from the mid 1960's - til the mid 1990's. So it's possible you knew of him, as he did perform in the US on and off in the early 60's and in the early 70's.
@@RealDealDude Thanks. I assume you may of known of the 'Don Lane' i speak of. If not you can you tube him in action with his best friend Burt Newton. Both have now passed on and both were legends of Australian TV.
Also I'd like to quote Richard Dawkins, from a short essay called 'The Real Romance In The Stars' It's ostensibly about the fraudulent nature of astrology and how it cheapens the majesty of astronomy. But it contains a mention of a collision of epic scale and sends shivers down my spine, while getting me a little choked up tbh. _The sun, when you see it, is only eight minutes ago. But look through a large telescope at the sombrero Galaxy and you are seeing a trillion suns as they were when your tailed ancestors peered shyly through the canopy and India collided with Asia to raise the Himalayas. A collision on a larger scale, between two galaxies in Stephan's Quintet, is shown to us at a time when on Earth dinosaurs were dawning and the trilobites fresh dead._
Another fascinating episode, gentlemen! Thank you very much. And thanks for the folks who sent in these excellent questions! However... When listening to your answers, some fresh, related questions came to mind: - About photons: Light that reaches us from very remote galaxies is red-shifted, right? Because, a) those galaxies are moving away from us at significant fractions of the speed of light. But also b) the space traversed by the photon on its way to us is expanding. Is it possible that, through the combined effects of a & b, photons travelling inward from galaxies on the Hubble Horizon (which is itself moving away from us at the speed of light) are red-shifted to a _negative_ wavelength??? Or would they get 'stuck' when their stretched wavelength hits infinity? Could this be the source of Dark Energy? - Dark Matter: I believe there is _no_ Dark Matter. Dark Gravity is a much better term, yes. That has been observed in various ways. I propose that Dark Gravity is simply gravity leaking into our universe from _other universes._ Call it 'Foreign Gravity'. This would explain a lot, would it not? The distribution of matter, of mass, in potentially a vast number of other universes, would influence the distribution of matter in our universe in exactly the same way we see 'Dark Matter' do. Also the mystery of the Coma Cluster, where two galaxies collided head-on, a 'while' ago, and we can observe how the visible matter clearly and strongly interacted, slowing the two galaxies down. But the 'Dark Matter' does not seem to have slowed down by quite so much. This would make sense if the two corresponding clouds of 'Dark Matter' are in _different_ other universes. No direct / strong gravitational interaction between them, in that case, only the much weaker inter-universal gravitational interaction of this 'Foreign Gravity'. And, if the 'Fecund Universe' theory proves to be right, that is, every black hole that is created in our universe is also the birth, the big bang, of a 'child' universe, then through the weak inter-universe gravitational interaction, the child-universe would to some extent inherit the distribution of matter from its parent-universe. - Phobos & Deimos are also orbiting Mars in the 'wrong' direction. They are clearly captured asteroids. Should we keep calling bodies like these moons? Not sure... - Particles from Meteorite Impacts: But... Wait... Light is created in such an event. Photons are particles, right? Sort of... But even if those don't count, what about alpha- or beta-radiation? Particles for sure. But i guess those are not _created_ by the impact. They already exist, in some form, on the surface or in the meteorite, and are then just released, ejected, emitted, by the impact-energy.
The first question is very brilliant. If considering the Many World interpretation of quantum mechanics, u standing up and photon hitting ur eye is one world and u not standing up and photon not missing the eye and hitting something else is another world. All these worlds happen to present and are real and u just happen to be in one of that (or u r experiencing one of it) As per Copenhagen interpretation, photon's path is the superposition of all such paths and when ur eyes(or any other thing) measures the photon, it collapses to one of those paths.
Chuck you might be surprised by what a kid would ask. When I was 9 I was reading university level texts on astronomy. I didn't know the calculus but I understood the concepts.
You talk about bending the fabric of time and space. We say the sun makes a big dip in this fabric which causes the planets to orbit. That black holes cause so much bending of this fabric that they affect time. We associate this and orbiting with gravity. Mass affects how much gravity they exert. We leaned the Higgs Boson is a wave in the Higgs Field that gives everything mass. Do you see where I'm going with this? If space and time are so intrinsically linked, are they waves in their own fields? In the same field?
About ice cubes - you cannot merge them, but... if you touch them for a sufficient time and blow at them - ice will melt under the heat energy from your breath and then will refreeze (for a time of course) as one ice cube.
Light sabres aren't lasers, though. They're plasma beams hemmed in by a force field. It's the force fields that bounce off each other, and the plasma that makes them glow.
@ApocalypseOfSpoons Not everything is named after its defining characteristics. People see the light, that's what they call them. They're not sabres either, or do you see a curved blade? Also remember that the term 'force' is already taken. Recall the famous Jedi equation? Force equals midichloreans times caffeine squared (F=mc²).
Can we make an analogy about the photon that goes from the star to your eye like a sleeping person ? The person can be moved anywhere and wake up in different places while sleeping. But when the person wakes up, he doesn't "feel" the time that has passed, because of the speed. So basically he just awakes at the destination in a "fraction". Wouldn't this be an analogy ? so basically the photon does not "feel" the time...because of his speed, the time is standing still, for it. For someone who is sleeping on a car compared to the driver, the driver drives 2 hours, and the person sleeping feels like he traveled in an instant.
A not so much related question to today's topic. But one that pops up in my mind sometimes. Why do all the moons in our solar system (and beyond) have been given names, except our own moon.
@@avistryfe4534 Yes i do believe there were some cultures that did named our moon in the past. It would be nice if our scientists of today would come up with a name for our most important Satellite and make it official. It almost feels like our moon is not worthy enough to carry it's own official name. 😟🥲 Professor de Grasse Tyson would be the perfect person to do so in my opinion.
20:00 I wonder if that's why fusion can happen more easily at very high temperature. The nucleons would be going at such a high speed their internals would be ticking slow enough to interact with.
5:28 Photon takes a path through just space dimension (with speed of causality) and we take a path through space and time (mostly through time with speed of causality). We both end up at the same event in spacetime but through different paths!
The speed of light through diamond reminds me of a favourite story from my youth (yeah, a long time ago) about 'slow glass' called Light of Other Days, and its sequels, by Bob Shaw. Potentially wonderful material, someone should make it
They should cover the Webb telescope information...can't wait for those pictures. Positive vibes from New Hampshire, remember to be kind to each other and yourself during these trying times
The photons perspective on time is merely different from our perspective on time, we're not experiencing two different realities. If there were an object that experienced time slower than us and light, it would still experience the same outcome and reality as everyone else that's experiencing time faster or not at all. Between us, the slower object, and the photon, we all share the same reality and outcome just perceived from different time scales. When you swat at a fly and it disappears that doesn't mean that when it lands on your shoulder it was determinism, you and the fly just perceive things differently. To you it's a blur, but to it you're barely moving at all. You both arrive at the same reality.
re: tucker - hey guys i was contemplating the issue of time slowing down and us being unaware in our reference frame.. what if we 'run out' of time or experience an absence of time somehow.. would our reference frame continue infinitely .. or say for like a year of regular time til we get over our little speed bump?
So if two black holes are orbiting each other, there are gravitational waves coming off the edges. Is the gravitational center perfectly still like the eye of a storm or is it continuously spinning like a disk sander?
This avocado conversation brought up an interesting point that I am very curious about. I know you mentioned putting lemon on it, however if you keep the seed in 1/2 of the avocado it was significantly longer from going bad. I want to know why this is. Also if you throw the seed from the avocado into the guacamole it keeps it fresher longer.🤯
The thing is that the photon was not just emitted "X million years ago", it was emitted "X million years ago X million light years away". And "X million years ago X million light years away" is not in the past, it is "now" as it could not be observed here before now. This comes from the fast the c is not the speed of light, it is the speed of causality propagating in space.
Another way to see it: Right before the photon hit the eye of the observer on Earth, from the point of view of the observer, the photon doesn't exist yet i.e. it still wasn't emitted. That's because the photon and the point from which it is emitted on a distant star aren't in the past light cone of the observer. In a way they aren't yet in the observable universe of the observer. Therefore the observer isn't influenced by them and as far as the observer could know they do not exist, yet. At the precise moment the photon hits the eye of the observer, the photon , the path it took and its emission point all enter in the light cone of the observer.
Sorry for repeating myself and for being off topic but I have a question. How do we know the Big Bang was the beginning of the universe and not just the beginning of our galaxy?
@@jonnym4670 I have had this idea that each galaxy was formed by its own independent Big Bang, I knew about Cosmic Background Radiation and the mapping; I just wondered how to tell that the Big Bang was kicked off somewhere else and not at the center of out galaxy. Is it just from tracking objects are in a red and blue shift and following those back to a point of origin?
So I have heard of cold welding, in which two pieces of metal (either the same or alike in grain structure) can be fused in a vacuum using no heat. This is supposedly because Earth's atmosphere provides an oxidizing layer between pieces of metal which requires heat to break it down in order for the metals to fuse, however this oxidizing layer is not present within a vacuum and the grain structures of the metal can align in such a way that they fuse with ease. With this knowledge, I believe that in a vacuum at just under freezing temperatures, with the correct pressure applied (to support, Dr. Tyson and Lord Nice have discussed the melting properties of ice under pressure in previous episodes), two pieces of ice may very well have he capacity to fuse or "cold weld" together. Thoughts?
If you take two sheets of pure gold foil and press them together the atoms will intermingle and weld the sheets together. In the right conditions you can get materials to combine at their atomic edge.
For Chuck…. Your amazing. Carl Sagan and Ann Druyan collaborated and produced an amazing book titled “Shadows of Forgotten Ancestors” Love your work! Neil? You ok too 😂
One of the latest images from the James Webb Space Telescope depicts a cosmic collision-Stephan's Quintet is a visual grouping of five interacting galaxies, two of which are actively colliding, swapping gas, dust and stars in the process and even creating a shockwave!
See here: www.nasa.gov/webbfirstimages
Something on my brain: If we potentially live in an "unstable" condition ... are black holes just the universe trying to "correct" itself?
Does light function to create linear space time flow by somehow organizing mass in consistent ways?
@@BWEPS some day all the light will fade from the universe and we will be left with nothing but dead stars the goth phase
@@josephmatuszak3855 no my unstable wife's unitability cancels out the universes unitability
We need an episode on recent transgressions!
Thanks!
That first question was amazing. I have always wondered if photons didn't experience time but I never thought to take it to that level. Wow. It also kind of fits in with Fermat's principle of least time, which just never ceases to amaze me.
Neil clearly wasn't ready for Chuck to throw down a max-stoner question right outta the gate...
Neil has mentioned multiple times throughout ST that a photon doesn't experience time. But wondering if a photon knows its destination 13.5 billion years into the future is kind of a cool concept. We step outside and feel the warmth of the Sun, but the photon that just hit your face was 100,000 to 1,000,000 years in the making deep inside the Sun. Once it manages to escape the Sun's layers, it immediately knows where you will be eight minutes in its future (8 light minutes to reach you), but while that knowledge is instantaneous to the photon, we still have to travel through space and time for eight minutes for the photon to get there. Add to that relativity, which I'm not smart enough to speak about, but I've done the calculations to account for the expansion of space over great distances (negligible for a photon from the Sun). So does that mean we are where we are supposed to be because a photon emitted was meant to collide there? Personally I don't think so lol but it's a cool thought.
This question was discussed on Through the Wormhole w/ Morgan Freeman. I believe they concluded that these interactions are predetermined.
Sooooo did photons come into existence when they can be seen, or explained? Or they were always there?
@@heofonumheo3174 photons did not show up untill it was cold enough for them to break away . There was no light so there was no photon.
First time I've seen Dr. Tyson pause and think like that, those were some good questions!!!
The world wouldn't be the same with out these great videos.
And the videos aren't as funny unless Mr. Nice is on there too.
Thanks for what y'all do!
Hawking died from it!
It is a good question, and the "experiencing time all at once" perspective of the photon reminds me of a Feynman story. In 1940, John Wheeler called Richard Feynman one day because he had a profound thought. He said, “Feynman, I know why all electrons have the same charge and the same mass” “Why?” “Because, they are all the same electron!”.
(I believe this relates to the "experiencing all time at once" thought, I could be wrong)
Feynman said he got the idea that positrons could simply be represented as electrons going from the future to the past in a back section of their world lines from this conversation.
source: Richard P. Feynman's Nobel Lecture, December 11, 1965
The Development of the Space-Time View of Quantum Electrodynamics
All I can say is Chuck makes this two times more fun for me he is Dr. Chuck
Thanks for this kind comment!
I think you have to remember that the photons perspective is instant destination but it actually takes a long time to travel long distances
That photon and the pre-destined discussion was DEEEEP. Now I can't stop thinking about it.
Let me help you. Stop!
nah nva stop eva make a cloud chamber
If you stop and think about it you will come to realize that nothing is predestined, it just happens when you experience it. Be thankfull you have the intellegence to appreciate it.
Same
Agreed. Was listening just before sleeping, but now it's stuck haha
Chuck, is fxckin awesome, I'm so glad he can be a part of this. He always has the perfect color commentary.
It’s beautiful to see my favorite actor and my favorite space professor ...🎉I appreciate life from this view....
Hey Neil & Chuck, its Levi ive been a fan for years!!! Keep up the great work. Cant wait to see what's in store for this one
Hey, Dr. Tyson and Mr. Nice.. I'm new to this community but I've recently discovered a personalized strength and hope within science, and your videos sort of fortify that. So I just wanted to say thanks for what you do! Y'all give greatness to the world.
✨“I am susettable to flattery”✨
"Lord Nice"
🙋🏿♂️Thanks Dr. Tyson and Lord Nice for another brainy cool video.😎👍🏿
❓Quick question, is there anyway to convert spent fuel rods into batteries or convert the remaining radioactive energy into a productive power source for?❓
Unfortunately, radioactivity is not convertible to electricity. The spent fuel rods went beyond their capacity to become critical and sustain that reaction. The rods go from emitting gamma rays to beta radiation, which is useless in terms of energy recovery. Well, not so useless, but you need tons of it to become relevant.
@@parintelebaiazid80 is there no substance that reacts to beta radiation which may excite electrons ?
@@philandeswilliams1975 i don't think there is, but whoever discovers or invents it will surely win a Nobel Prize!
@@parintelebaiazid80 I have no science qualifications, but it seems IMPOSSIBLE that there is no combination of chemicals, metals or substances which may harness half-life radioactivity productively.🔋
💡If not by electricity production, than something!🤷🏿♂️
@@philandeswilliams1975 i agree completely my friend, it's just a matter of time!
Hi professors, very interesting learning from you, recommendation to Neil. Don't be afraid of the microphone, get closer! Please.
Superb first question! Would love to get a follow-up on this by Neil.
Hey guys thanks for answering my question and making me a game show host! I knew I had the right stuff. Lol
Chuck can NEVER be replaced ! NEIL your the reason why I'm fascinated about the universe and in my short life stay optimistic in the virtues of Artificial Intelligence, Wars, Epidemics, Armageddons, or whatever the Earth and it's far and near distant neighborhood will have in store for all. You 2 are the chocolate-chip to my ice creme when I want to mentally wind down and look up into the skys and think of endless possibilities. Gracias
latino chuck was absolutely hilarious hahahaha
I taught chem and bio for 36 yrs. Questions were/are key to inquiry. Inquiry is itself key to promoting thinking. Experimentation as inquiry promotes higher level thinking. Neil, your explanations and discussions stimulate curiosity, and I hope, longtime learning. We achieve success if we create longtime learners, and scientific thinkers.
We couldn't do that without Chuck! :)
Gotta have chuck here, we love you Chuck
great show, volume need to be up thx.the best
The answer to Tucker's question was actually the best explanation of The Twin Paradox I have ever heard, this is the time it clicked and I understood it rather than accepted it!!!
I love the content that Dr Tyson shares on this show, but more than anything, I LOVE watching Neil and Chuck just cutting up! ❤
That first photon/predestination question is so interesting!! Do we also consider the photon’s predestined collision in terms of the perceived usefulness of its destination? If they land on living plant mater, they ultimately serve the purpose of sustaining the earths biome in a way, no? The same can be said if that photon hits plankton in the open ocean. 🤔
I can watch theses all day, as long as chuck is on, i just have this channel on a loop in my house. only channel i feel safe having my kid listening to by accident.
Another great explain video guys, audio Very low through.
The comic character that Dr Tyson mentioned is Fred Fleming (Dark Matter). He was a short-time Flash villain in DC's Legends comics. He was only around for 2 or 3 issues.
There was also a comic series by Dark Horse Comics called Dark Matter, too. 🙂
Yep, a kind of anti-hero, really, as he thought he was avenging the death of his parents.
It's so fun to watch Neil and Chuck cuttin' up
Hey Dr. Tyson, do you guys podcast?? I'd LOVE to get the chance to even be as honored to just get to sit in chat with you explaining everthingness.
I can tell your mind is set right. That movie "Limitless" was a great example for explaining time because time in a value of a different relm is obviously different for the one who controls time in all. Love the show. Love the content sir. ❤🤘🏽
Ps my Grandfather's name is Fred 😄
Celestial banging 😂, now if my professor taught like that,I might I have working in NASA right now .i love this show 😂❤ thank you for the knowledge and wonderful content.
Dear Dr. Tayson, dear Shack.
I can't wait for the show to go back to it's original filming format with both of you in the same room in the museum.
I understand that this video conference format is due to social distancing necessity. But I'm afraid that it will stay like this forever. I hope I'm wrong. I miss the old conversation with a direct interaction.
Keep up with the good work.
Best Regards
We're all proud of you Chuck!
Always a pleasure listening to you guys…thank you!
Amo esses Caras! - love these guys!
Saudações do Brasil! - Greetings from Brazil!
This is one of ya'lls best works... So grateful how a new telescope awakens us!
These two are a national treasure
NBC really dropped the ball with you. I was enjoying learning what you had to say about JWST could you do a video on that please?
@Sky ohhh please do not
Question 1 answer: the photon DOES travel... it not feeling time just means it does not decay. So it does still travel and has ability to hit something else. It's not predetermined.
You are handwaving here. Photon 'travels' and 'has ability to hit something else' from your perspective, or from the perspective of a temporal being. The point of the question was, from a non temporal being's perspective, the photon is already at the destination when created. There's no travel. It's created as a vector in space, with a starting point, a destination and a direction. It's a very insightful question and you have to dig a lot deeper to explain why its interaction is not predetermined.
Neil and Chuck, you're awesome!
Also high. 😊
Really good video, you two, as always. Thanks for bringing us science in a very pleasing way. 🙂👍🏼 You're appreciated! ❤️❤️
I need Janna Levin on here more often ESPECIALLY on blackhole conversations!
Please master the audio, I need to turn the volume up like crazy on your videos
Just got done watching this video and I am ready for more!
My take on Light Sabers is that it is high energy plasma confined by a magnetic field and those fields have changing polarities so they will always be a point where they repel each other.
These discussions are delightful! Best regards from a fellow New Yorker. Art
Hope we have an update on the 1st question!! Please keep remind Neil until we have a video on this issue ❤
super quite audio
Edit- Chuck gets pretty loud compared to Neil so they may have turned the audio down because of that.
And am I high or does everything seemed slowed down as well 🤨
@@EazyE11 Chuck seemed very low energy today
Quite what? Quite _quiet,_ perhaps?
🙄
Excellent podcast but deserves better mic audio
I am curious on if you were to be in the ring of light of the blackhole and without being sucked in, how the light would look like, would it be blinding or would it be a sped up remind of all the previous objects that the light originally came from
This was a very quiet episode. Had to have the volumes maxed out.
Yeah,Whats up with that?
Nice that they jump directly into the questions. Sometimes with other guests on the show, they take 15 minutes of rambling before getting to the topic and questions. Thank you.
Often, what you call "rambling" contains damned interesting information. A shame you let it go in one ear and out the other. 😕
that first question about the photon is interesting, it's born in an instant, and travels for eternity before hitting something, all while experiencing no time. Is a photon predetermined to have hit your eyeball though? no, because it's entire existance was darkness, so it had no awareness of your eye until it had reached there. and now y'all got me Personifying particals....great
Also keep in mind that photons ARE subject to gravity. so here a photon is not even knowing it's own existance or travel for thousands of years when suddenly it gets pulled in a different direction by a black hole, or sun, or planet, moon etc... constantly getting yanked back and forth until finally coming to a stop and experiencing time for the first moment
Well, you're not the only one personifying *particles* (not particals) here, after this. 😄
@@shanecombs1993 I thought (and hoped) the same way back when. I liked the romantic/poetic nature it allowed for infinite death and rebirth.
By the way, that hypothesis is referred to as "the big crunch" unforunutatley it has largely been rejected in favor of "the heat death" based on the universe expanding (and speeding up) greater than the force of gravity.
Still I don't see why blackholes couldn't trigger the creation of new universes. There is the hypothesis of black holes that they emit radiation (look up hawking radiation) and if they didn't consume matter for long enough could revert to their state before being a blackhole.... it's way above me. so is the thing about blackholes being wormholes through time and space into the past.....
Anyways, still hold the idea that blackholes themselves could be trigger events for the creation of new universes outside our own, and multiverse theory allows for multiple universes existing like a froth of bubbles, even while they expand and push on other universes, they never interact of affect one another.
Oh my gosh I'm so glad I subscribe to you guys not only do you learn but you guys are funny and you make me laugh
I didn't know about the lemon juice preserving the avocado, but leaving the pit in preserves it as well.
The pictures of the James Webb telescope has many 6 pointed stars. What causes that? Is it something to do with the hexagonal mirrors on the telescope?
Don Lane was a US singer and personality that settled in Australia and became a very popular TV host. Died in Sydney 2009 with an Alzheimer's related illness. He had a number of successful shows.
34:47 Ice merging. So in space, in a vacuum, Astraunauts found out the hard way that bare metal will cold-weld to bare metal in vacuum. It seems possible that in a vacuum a flat plane of ice might merge with a flat plane of ice if they are pressed together.
exactly. Increase in pressure increases the melting point, not the opposite which the question suggests. A drop in pressure might however change a solid to a liquid, thereby increasing the chance for a cold-welding.
As Leibniz put it: “If an ontological theory implies the existence of two scenarios that are empirically indistinguishable in principle but ontologically distinct ... then the ontological theory should be rejected and replaced with one relative to which the two scenarios are ontologically identical.”
In other words, if a theory describes two situations as being distinct, and yet also implies that there is no conceivable way, empirically, to tell them apart, then that theory contains some superfluous and arbitrary elements that ought to be removed.
Leibniz’s prescription is, of course, widely accepted by most physicists today. The idea exerted a powerful influence over later thinkers, including Poincaré and Einstein, and helped lead to the theories of special and general relativity. And this idea, Spekkens suggests, may still hold further value for questions at the frontiers of today’s physics.
Leibniz’s correspondent
Clarke objected to his view, suggesting an exception. A man riding inside a boat, he argued, may not detect its motion, yet that motion is obviously real enough. Leibniz countered that such motion is real because it can be detected by someone, even if it isn’t actually detected in some particular case. “Motion does not indeed depend upon being observed,” he wrote, “but it does depend upon being possible to be observed ... when there is no change that can be observed, there is no change at all.”
In this, Leibniz was arguing against prevailing ideas of the time, and against Newton, who conceived of space and time in absolute terms. “I have said more than once,” Leibniz wrote, “that I hold space to be something merely relative.”
Einstein, of course, followed Leibniz’s principle when he noticed that the equations of electricity and magnetism make no reference to any absolute sense of motion, but only to relative motion. A conducting wire moving through the field of a magnet seems like a distinct situation from a magnet moving past a stationary wire. Yet the two situations are in fact empirically identical, and should, Einstein concluded, be considered as such. Demanding as much leads to the Lorentz transformation as the proper way to link descriptions in reference frames in relative motion. From this, one finds a host of highly counter-intuitive effects, including time dilation.
Einstein again followed Leibniz on his way to general relativity. In this case, the indistinguishability of two distinct situations - a body at rest in the absence of a gravitational field, or in free fall within a field - implied the impossibility of referring to any concept of absolute acceleration. In a 1922
lecture, Einstein recalled the moment of his discovery: “The breakthrough came suddenly one day. I was sitting on a chair in my patent office in Bern. Suddenly the thought struck me: If a man falls freely, he would not feel his own weight. I was taken aback. This simple thought experiment made a deep impression on me. This led me to the theory of gravity.” 🆒️
Leibniz now mostly inhabits scientific history books, his ideas receiving scant attention in actual research. And yet, Spekkens argues, Leibniz’s principle concerning indistinguishability may be as useful as ever, especially when confronting foundational issues in physics. Consider the interpretation of quantum theory, where theorists remain separated into two opposing groups, loosely associated with the terms realism and empiricism. Although Leibniz’s principle can’t offer any way to unify the two groups, Spekkens argues, it might help them focus their attention on the most important issues dividing them, where progress might be made.
For example, one particular interpretation comes in the form of so-called pilot-wave theories, in which electrons and other particles follow precise but highly non-classical trajectories under the influence of a quantum potential, which produces the wave-like nature of quantum dynamics. These theories demonstrate by explicit example that nothing in quantum physics prohibits thinking about particles moving along well-defined trajectories. But the theory does require the existence of some absolute rest frame, while also implying that this frame can never be detected. Many other aspects of such theories also remain unconstrained by empirical data. Hence, one might take Leibniz’s principle as coming down against such theories.
On the other hand, Spekkens points out, Leibniz’s principle demands that distinct states be, in Leibniz’s own words, “empirically indistinguishable in principle,” and achieving such certainty is not easy. If several states appear indistinguishable now, future experiments might turn up measurable differences between them. So a proponent of the pilot-wave approach might agree with Leibniz’s principle, but still reject its application just yet. The aim of research, from this point of view, ought to be to seek out such evidence, or at least envision the conditions under which it might be obtained.
And in this sense, Spekkens notes, Leibniz’s principle also offers some criticism of
theorists from the empirical school, who object to pilot-wave or other realist interpretations of quantum theory for containing unmeasurable quantities. It implies, as he puts it, that the empiricists’ “set of mental tools is too impoverished.”
After all, progress in physics often requires imagination, and creative exploration of possible distinguishing features that have not yet been measured, or even thought to exist. Progress requires scientists to “entertain ontological hypotheses, expressed with concepts that are not defined purely in terms of empirical phenomena.”
Science thrives on the essential tension existing at the boundary between empirical observation and unconstrained imagination. Incredibly, Leibniz perceived that more than 300 years ago.
14:41 The name Lord Nice was looking for was Frederick (Fred) Fleming (AKA Dark Matter) DC Super Villain. Neil is right.
22:05 Actually Don Lane was an American born entertainer who was a popular TV Host here in Australia from the mid 1960's - til the mid 1990's.
So it's possible you knew of him, as he did perform in the US on and off in the early 60's and in the early 70's.
Love this. It was my question.
@@RealDealDude Thanks. I assume you may of known of the 'Don Lane' i speak of.
If not you can you tube him in action with his best friend Burt Newton. Both have now passed on and both were legends of Australian TV.
Also I'd like to quote Richard Dawkins, from a short essay called 'The Real Romance In The Stars' It's ostensibly about the fraudulent nature of astrology and how it cheapens the majesty of astronomy. But it contains a mention of a collision of epic scale and sends shivers down my spine, while getting me a little choked up tbh.
_The sun, when you see it, is only eight minutes ago. But look through a large telescope at the sombrero Galaxy and you are seeing a trillion suns as they were when your tailed ancestors peered shyly through the canopy and India collided with Asia to raise the Himalayas. A collision on a larger scale, between two galaxies in Stephan's Quintet, is shown to us at a time when on Earth dinosaurs were dawning and the trilobites fresh dead._
Looks like something I want to find, with that bit!
Another fascinating episode, gentlemen! Thank you very much. And thanks for the folks who sent in these excellent questions!
However... When listening to your answers, some fresh, related questions came to mind:
- About photons: Light that reaches us from very remote galaxies is red-shifted, right? Because, a) those galaxies are moving away from us at significant fractions of the speed of light. But also b) the space traversed by the photon on its way to us is expanding. Is it possible that, through the combined effects of a & b, photons travelling inward from galaxies on the Hubble Horizon (which is itself moving away from us at the speed of light) are red-shifted to a _negative_ wavelength??? Or would they get 'stuck' when their stretched wavelength hits infinity? Could this be the source of Dark Energy?
- Dark Matter: I believe there is _no_ Dark Matter. Dark Gravity is a much better term, yes. That has been observed in various ways. I propose that Dark Gravity is simply gravity leaking into our universe from _other universes._ Call it 'Foreign Gravity'. This would explain a lot, would it not? The distribution of matter, of mass, in potentially a vast number of other universes, would influence the distribution of matter in our universe in exactly the same way we see 'Dark Matter' do. Also the mystery of the Coma Cluster, where two galaxies collided head-on, a 'while' ago, and we can observe how the visible matter clearly and strongly interacted, slowing the two galaxies down. But the 'Dark Matter' does not seem to have slowed down by quite so much. This would make sense if the two corresponding clouds of 'Dark Matter' are in _different_ other universes. No direct / strong gravitational interaction between them, in that case, only the much weaker inter-universal gravitational interaction of this 'Foreign Gravity'.
And, if the 'Fecund Universe' theory proves to be right, that is, every black hole that is created in our universe is also the birth, the big bang, of a 'child' universe, then through the weak inter-universe gravitational interaction, the child-universe would to some extent inherit the distribution of matter from its parent-universe.
- Phobos & Deimos are also orbiting Mars in the 'wrong' direction. They are clearly captured asteroids. Should we keep calling bodies like these moons? Not sure...
- Particles from Meteorite Impacts: But... Wait... Light is created in such an event. Photons are particles, right? Sort of... But even if those don't count, what about alpha- or beta-radiation? Particles for sure. But i guess those are not _created_ by the impact. They already exist, in some form, on the surface or in the meteorite, and are then just released, ejected, emitted, by the impact-energy.
love this show. you both would be great in the uk. you banter like us brits.
Time particles-thoughts pixels. Great q and a.
The first question is very brilliant. If considering the Many World interpretation of quantum mechanics, u standing up and photon hitting ur eye is one world and u not standing up and photon not missing the eye and hitting something else is another world. All these worlds happen to present and are real and u just happen to be in one of that (or u r experiencing one of it)
As per Copenhagen interpretation, photon's path is the superposition of all such paths and when ur eyes(or any other thing) measures the photon, it collapses to one of those paths.
Chuck you might be surprised by what a kid would ask. When I was 9 I was reading university level texts on astronomy. I didn't know the calculus but I understood the concepts.
You talk about bending the fabric of time and space.
We say the sun makes a big dip in this fabric which causes the planets to orbit.
That black holes cause so much bending of this fabric that they affect time.
We associate this and orbiting with gravity.
Mass affects how much gravity they exert.
We leaned the Higgs Boson is a wave in the Higgs Field that gives everything mass.
Do you see where I'm going with this?
If space and time are so intrinsically linked, are they waves in their own fields? In the same field?
I live for these knowledge-packed cosmic queries editions! 🥳 Greetings from Kenya
Neil and Chuck for 2024!
For what
Don Lane was a late night TV host in Australia who was originally from the USA. He was big in Australia in the 70s & 80s
Really great questions on this episode 😎
I enjoy these so much!
Every time I think this may be safe I say boring or simple, it turns out to be one of the better episodes I’ve seen.
Everytime I watch this I learn something new. I did not know about the people watching the dark side of the moon looking for impacts. Ty Neil. ;O)-
“Einstein was a badass.” LOVE it! 🙏🏻
About ice cubes - you cannot merge them, but... if you touch them for a sufficient time and blow at them - ice will melt under the heat energy from your breath and then will refreeze (for a time of course) as one ice cube.
Light sabres aren't lasers, though. They're plasma beams hemmed in by a force field. It's the force fields that bounce off each other, and the plasma that makes them glow.
* * cough *_NERD!_* cough * *
@ApocalypseOfSpoons Not everything is named after its defining characteristics. People see the light, that's what they call them. They're not sabres either, or do you see a curved blade? Also remember that the term 'force' is already taken.
Recall the famous Jedi equation? Force equals midichloreans times caffeine squared (F=mc²).
Can we make an analogy about the photon that goes from the star to your eye like a sleeping person ? The person can be moved anywhere and wake up in different places while sleeping. But when the person wakes up, he doesn't "feel" the time that has passed, because of the speed. So basically he just awakes at the destination in a "fraction". Wouldn't this be an analogy ? so basically the photon does not "feel" the time...because of his speed, the time is standing still, for it. For someone who is sleeping on a car compared to the driver, the driver drives 2 hours, and the person sleeping feels like he traveled in an instant.
A not so much related question to today's topic. But one that pops up in my mind sometimes. Why do all the moons in our solar system (and beyond) have been given names, except our own moon.
I believe it has had names. But outside of science.
@@avistryfe4534 Yes i do believe there were some cultures that did named our moon in the past.
It would be nice if our scientists of today would come up with a name for our most important Satellite and make it official.
It almost feels like our moon is not worthy enough to carry it's own official name. 😟🥲
Professor de Grasse Tyson would be the perfect person to do so in my opinion.
As a Mexican, c'mon Chuck! Let's be friends!
Bruh i found out why it matter dawg 😄
the movie is "In Time" and it is with Amanda Seyfried
20:00 I wonder if that's why fusion can happen more easily at very high temperature. The nucleons would be going at such a high speed their internals would be ticking slow enough to interact with.
Could you guys do a video on the library or babel
Sound is low please turn it up haha
5:28 Photon takes a path through just space dimension (with speed of causality) and we take a path through space and time (mostly through time with speed of causality). We both end up at the same event in spacetime but through different paths!
The speed of light through diamond reminds me of a favourite story from my youth (yeah, a long time ago) about 'slow glass' called Light of Other Days, and its sequels, by Bob Shaw. Potentially wonderful material, someone should make it
Hey Chuck! Hey Neil! This stuff is great!
When will there be a 4th season for Cosmos ??? :)
They should cover the Webb telescope information...can't wait for those pictures. Positive vibes from New Hampshire, remember to be kind to each other and yourself during these trying times
The photons perspective on time is merely different from our perspective on time, we're not experiencing two different realities. If there were an object that experienced time slower than us and light, it would still experience the same outcome and reality as everyone else that's experiencing time faster or not at all. Between us, the slower object, and the photon, we all share the same reality and outcome just perceived from different time scales. When you swat at a fly and it disappears that doesn't mean that when it lands on your shoulder it was determinism, you and the fly just perceive things differently. To you it's a blur, but to it you're barely moving at all. You both arrive at the same reality.
Dude! the first one was a realy good question.
Can you please do a new episode explaining the recent telescope images? NBC was not letting you shine.
I noticed that too and yes I agree I'd love to hear more on that
re: tucker - hey guys i was contemplating the issue of time slowing down and us being unaware in our reference frame.. what if we 'run out' of time or experience an absence of time somehow.. would our reference frame continue infinitely .. or say for like a year of regular time til we get over our little speed bump?
Please correct audio again lol, the audio from the Set Intro STARTALK Logo, should not be 80% Higher than audio from Neil and Chuck lol.
So if two black holes are orbiting each other, there are gravitational waves coming off the edges. Is the gravitational center perfectly still like the eye of a storm or is it continuously spinning like a disk sander?
This avocado conversation brought up an interesting point that I am very curious about. I know you mentioned putting lemon on it, however if you keep the seed in 1/2 of the avocado it was significantly longer from going bad. I want to know why this is. Also if you throw the seed from the avocado into the guacamole it keeps it fresher longer.🤯
The thing is that the photon was not just emitted "X million years ago", it was emitted "X million years ago X million light years away".
And "X million years ago X million light years away" is not in the past, it is "now" as it could not be observed here before now.
This comes from the fast the c is not the speed of light, it is the speed of causality propagating in space.
Another way to see it:
Right before the photon hit the eye of the observer on Earth, from the point of view of the observer, the photon doesn't exist yet i.e. it still wasn't emitted.
That's because the photon and the point from which it is emitted on a distant star aren't in the past light cone of the observer. In a way they aren't yet in the observable universe of the observer.
Therefore the observer isn't influenced by them and as far as the observer could know they do not exist, yet.
At the precise moment the photon hits the eye of the observer, the photon , the path it took and its emission point all enter in the light cone of the observer.
Sorry for repeating myself and for being off topic but I have a question.
How do we know the Big Bang was the beginning of the universe and not just the beginning of our galaxy?
they have a map of the background radiation left over from the big bang
@@jonnym4670 I have had this idea that each galaxy was formed by its own independent Big Bang, I knew about Cosmic Background Radiation and the mapping; I just wondered how to tell that the Big Bang was kicked off somewhere else and not at the center of out galaxy. Is it just from tracking objects are in a red and blue shift and following those back to a point of origin?
So I have heard of cold welding, in which two pieces of metal (either the same or alike in grain structure) can be fused in a vacuum using no heat. This is supposedly because Earth's atmosphere provides an oxidizing layer between pieces of metal which requires heat to break it down in order for the metals to fuse, however this oxidizing layer is not present within a vacuum and the grain structures of the metal can align in such a way that they fuse with ease. With this knowledge, I believe that in a vacuum at just under freezing temperatures, with the correct pressure applied (to support, Dr. Tyson and Lord Nice have discussed the melting properties of ice under pressure in previous episodes), two pieces of ice may very well have he capacity to fuse or "cold weld" together. Thoughts?
If you take two sheets of pure gold foil and press them together the atoms will intermingle and weld the sheets together. In the right conditions you can get materials to combine at their atomic edge.
Older Aussies watching will know that Don Lane was an American-born talk show host and singer in Australia in the 60s and 70s.
Dr Neil and lord Chuck
Simply the Best
Cosmic collisions at Louisville palace! June9th! I was there! Great show
Love how Neil reminds me that I have no soul so often! Keep it up guys ❤
For Chuck…. Your amazing. Carl Sagan and Ann Druyan collaborated and produced an amazing book titled “Shadows of Forgotten Ancestors”
Love your work! Neil? You ok too 😂
Best show today 👏🏼