I can count on one hand the number of UA-cam videos I watch from beginning to end. This is one of those channels. Great conversation for a Sunday morning coffee.
In q&a 76 you address the question on whether something can be completely still in space. Your answer was that you can't be completely still relative to other objects because there's always something to compare to. What if you don't care about other objects, but just to space itself? The map of Kanilea and how galaxies and Galaxy clusters are moving in space suggests that there are speeds that are not relative to other objects but to space itself. So imagine you could come to a complete stop relative to space itself. I imagine the expansion of SpaceTime would in itself distance you from objects just by the space between you and them getting larger, also objects with an absolute speed >0 would swoosh past you like if you're on the side of the road watching cars go by. Now imagine two completely stopped objects close to each other. Will they still affect each other in terms of gravity? Will the expansion of spacetime cancel out their gravital effect or perhaps will they slowly separate from each other but don't affect anything that has a absolute speed? So, is there a thing as absolute speed =0 relative to space, even if we can't measure it yet? And which properties would a body have on its surroundings at absolute speed =0?
Hi, Fraser! A question on JWST: how compromised is the design due to bandwidth starvation for being on L2 rather than LEO? (Eg. does it impact resolution, the amount of images, both?) And could you do an interview on the Deep Space Network and on generally increasing bandwith for science missions? Thanks!!!
@@Релёкс84 gravity is sill a theory. Why still a theory after so long? When a theory is proven, it’s no longer a theory, it becomes fact. Question everything.
@@Richardrefund 1. who was talking about theories? why do you bring this up? 2. please look up the scientific definition of the word "theory" 3. what even is your point?
0:50 the game Elite Dangerous gives you the opportunity to land on planets all across the galaxy and the sky always changes relative to your position. You can go catch voyager in its actual location if you like
But Elite was set in the year ~ 3200 ish. Elite: Frontier was set about 100 years later. I think Elite: Dangerous is set somewhere around the 3400s, during the second Thargoid invasion. edit - So you'd have to cover roughly 1,200 years of Voyager's flight path to be able to come upon it.
@@allbymys3lf831 Yeah, I was active during the first race to SagA. Never made it there myself, despite having everything I would have needed to make the long distance flight.
@@Raz.C i remember when I finished fully optimizing my anaconda for jump distance. After all that flying around and planet hopping to every damn engineer and crystal site, the last thing I wanted to do was leave the bubble Preparing for my first colonia trip soon but I may just take my krait so I can blow it up when I'm done and skip the trip back
Imagine, if you will, a cupcake made from whole wheat flour, leavened with baking soda and cream of tartar, with flavors from Ceylon cinnamon, maple syrup, and a mashed-up banana, baked at 400 degrees Fahrenheit for 16 minutes, so they're fluffy and moist. Now imagine that you eat the cupcake with whipped cream on each bite, which is chased by espresso.
@@frasercain You know how Isaac Arthur always recommends that you get a snack before settling down to watch his latest video? I think that this is an especially good snack to have while watching your videos.
18:34 The Big Bang analogy I like that the universe is the surface of a balloon that inflated (and is inflating). The radius of the balloon represents time. Inside the balloon is the past. The outside is the future. The center of the balloon is the Big Bang.
In the center of the milkyway number of star visible would increase with the cube of density, so if the average distance between stars is 1/5 than in the our neighborhood you will see 125 more stars of the same magnitude than on the earth, but because of the lighter sky low luminosity stars(5th and 6th aparent magnitude) cannot be seen with the naked eye , assuming that you have the same distribution of stars by classes like near solar system.
For the past two Q & As (or maybe in one of the other recent videos) you have talked about the rate of expansion in the universe. As related to inflation though, don't we "know" that the rate of expansion was at one time faster? And have we made any progress to the force that led to inflation?
? Hi Frazier ! I have always heard that Hubble discovered the expansion of the universe using Cepheid variables .how exactly did that work? What makes them special Thanks again Paul
Q. for Fraser: If we launch JWST this year, how much time do you think will pass until we get it operational and get the data, first data? Thank you, regards from Montenegro! Great work, been following you for years.
according to this en.m.wikipedia.org/wiki/Timeline_of_the_James_Webb_Space_Telescope it will reach its final orbit 1month after launch. it will already have deployed all the equipment until then. launch is on 31st of october, so I'd expect it to be operational end of November. Maybe wait some days for actual pictures.. 乁| ･ 〰 ･ |ㄏ
@@georgplaz Thanks! In the meantime, Dr. Becky made an interview with one of the astronomers who is working on JWST, and , listen to this, if everything goes right, we should wait at least for 6 months, shoot... Check it out yrself: ua-cam.com/video/O9ZlqWp7620/v-deo.html and the whole interview: ua-cam.com/video/IzFa5Vg40Qc/v-deo.html Really appreciate your effort to help me out, regards from Montenegro!
Hi Fraser, I have a question. Do you think advances in AI might push the limits of after the fact interferometry into shorter wavelengths? It feels like matching up signals in progressively more complicated ways might be the sort of thing they could excel at. Thanks for all your work 🙂
Great video have often thought about what the night sky would look like at different locations And at the centre of the milkyway I thought it would look like Coruscant 😂
Hey Fraser! Been a fan since many years back! I have a question about magnetars. I heard they can strip you of all your electrons. How close would you have to be for that to happen, and what would it look like to suffer such a fate? Also, the idea of our solar system being disturbed by a brown dwarf is scary. Do we know where the closest ones are?
I don't think that other launch companies are unaware of Starship. There are a number arguments as to why they may not be as worried. 1: Superheavy hasn't flown it has not heat shield. At current rate of progress it is 2-3 years away from a reusability demonstration and further away from commercial launch. 2: When Elon talks cost he normally means some future state, price to build Starship will still be ~$1-2 million per tonne (same as aircraft or Falcon 9), they will have a finite lifespan likely in the 10-30 launches range and it will be years before the lifespan can be extended commercially as some failures will manifest in flight so expanding the lifetime will be a trial and error process. 3: SpaceX still have a fixed cost of employing all their people and maintaining their sites, even mega constellations don't need that many flights so the fixed cost per launch will still be there. 4: Starlink revenue will likely dominate the launch business but that may end up with antitrust enforcement if they cross subsidise launch pricing. 5: It may well be that Rocket Labs much lower fixed costs and lower cost to manufacture the Neutron mean that their cost per flight is lower even with a second stage being thrown away, especially if that second stage is relatively cheap. 6: Science missions need an un-recoverable upper stage anyway unless they are going to a return location for Starship. 7: I don't doubt that most of the rivals have a recoverable upper stage in some form of preliminary design, but they aren't going to release them until they actually recover a first stage.
Question: Given the current "crisis" in cosmology with the Hubble constant, and the possibility that the expansion of the Universe may fluctuate-wouldn't this also potentially affect the speed of light? Considering the speed of light constant is based on a static and unchanging vacuum state.
Hey Fraser! On Earth the vegetation is mostly green due to how chlorophyl absorbs and reflects light. What color would vegetation most likely be on a planet with 1.141 Earth masses orbiting a white dwarf star at 4.5 AU (not tidally locked)?
Question: In a telescope whose primary mirror is made using multiple hexagons, does each hexagon have the same shape? Are they flat or do they have any curvature?
You can make them the same, and have a spherical mirror. But this gives spherical aberration. So generally the hexagons are different, but from symmetries, a few can be the same.
Question: If what causes time dilation is acceleration, not speed; if I teleport to a ship traveling close to the speed of light, but without acceleration, will I not experience time dilation relative to my previous location?
Question: In regards to interferometry in space, how would you deal with the fact that the telescopes are moving? It isn't possible to have 'perfect' orbits that keep them exactly a certain distance apart, is it?
NASA and Spacex. It's not just the money and the customer-supplier relationship. Also super important is all the technical and experience transfer that has taken place between NASA and Spacex. To use a plant breeding analogy, it's an example of hybrid vigour. The relationship is symbiotic, good for both parties. What Spacex has given NASA besides cheaper prices is a reminder of what the spirit of Apollo was like back in the day.
Hey there Fraser, my man! So, without overly cueing up the X-Files theme song in the background, what do you think of this possible explanation for the Fermi Paradox: Time Travel! What if every single advanced hyper-technological focused civilization (like ours) simply innocently advances and stumbles along, all while mainly exploring/hunting for ever more new rich-inducing efficient energy-access... and then what if such research always makes it clear that at those higher-energy levels time-travel is indeed possible... Then who could resist?! Seriously if I gave you a time machine... don't tell me you wouldn't be tempted to use it, from everything from a little bit of a selfish lottery win for you and your family, to much more innocent/poetic re-explorations of your past life, and past historic life. All of which eventually leading to a major self-annhilating-time-paradox-feed-back-loop, of stepping on a butterfly while also inadvertently killing your great-great-great-grandfather at the same time?! If the only way to higher-energy usage involves the realization of time-travel, then that might be the answer? Involving vast galaxy-spanning empires that once arose, but then self-cancelled themselves out, when they began messing with time travel... maybe?
Hi Fraser! What are your thoughts on the habitability of Venus? Either balloon cities high in the atmosphere (when would we even get the tech for that?), or removing enough CO2 so that it’s no longer a 900 degree greenhouse (when would we have the tech for that, since we can’t do it on our own planet with even less CO2?)?
Hey Fraser. Is the ISS tidally locked with Earth? Does it orient itself along its path? Or is it always facing the same direction relative to the solar system no matter where it's at in its orbit around Earth? Cheers!
And don't forget Starlink. Space X will be self sustaining once Starlink is fully operational. They'll have tourism, satellite launches for military and private organizations, and Starlink customers to keep them going even if NASA cut ties completely. But with NASA then they also have the Artemis contract and all the ISS stuff. But people often forget or underestimate how critical Starlink is to the survival is Space X.
I feel like just saying "we're alone" isn't a great explanation. For me, it just leads to the next question of "why" we are alone. Why did life form here and nowhere else?
We are getting excited about reusing a booster for the 10th time. Aircraft fly 10000s of times and yet fuel STILL isn't the biggest cost. Even if starship pulls off reentry, which it hasn't. Doesn't need to go on a GIANT gantry robot to fix the heat shield between launches (Space shuttle anyone). Now add boosters that land on converted drilling Rigs in the ocean (aircraft don't need extra runways in the middle of the ocean!) that are going to be free to maintain? Why do you think these were sold so cheap? People who believe that starship will be "just the cost of fuel" are dreaming. Unless you have a full payload bay, it won't be the cheaper launcher.
The speed of light confuses me in regards to predicting solar eclipses. Not so much in the modern era, but hundreds of years ago, astronomers were able to predict eclipses fairly well, not knowing the speed of light. The travel time from the sun is 8 minutes, and from the moon, under 2 seconds. I can see modern computers being able to predict eclipses knowing exact distances from the moon and sun, and knowing the speed of light. How did astronomers figure it out 2000 or 3000 years ago?
If you had, as you say, a telescope at both the North and South poles for interferometry, what % or band of the sky would they actually be able to both see? I'm guessing a pretty small section, possibly zero if you think about it...
The Hubble Space Telescope is still getting mentioned in having played a vital role in recent discoveries. If it is such a fantastic machine, why didn't we build a second one to make twice as much telescope time available for astronomers in the 30 years since its launch? Building a copy should me much less expensive and faster, without the need to develop new technologies.
I think regarding the question about the Big Bang, even if the universe wasn't infinite at its inception then the material that the Earth was made out of was part of the massively compressed material that was at that point (which is a bit untrue as the Earth has metals that can only have been made in stars, supernovae), so you can't look back to where that point is, because that point is everywhere in the universe now. You could say that even though every part of the universe was at that point and moved (or the space it was in was stretched) and so there must be one point that didn't move. Assuming that is what is meant then I don't know how you'd do that (or even what the point of doing that would be), it might even be outside of what is the visible universe now and so can never be seen. I know the "stretching" of space-time and so the speed at which the universe is expanding its faster than the speed of light, but I still don't think you can look back and see where you've come from all I just don't think it's possible.
Ideally, Mars needs more gravity, an atmosphere and a magnetosphere to be habitable. If we gently crashed the moons of Jupiter and Saturn into Mars could it be a place we could live?
Re - Asteroids vs Nukes The reason nukes are so devastating on earth is because of the shockwave they produce. They do this by superheating the atmosphere. The key word to notice here is "atmosphere." An asteroid has no atmosphere (for the most part). A nuke exploding on the surface of an asteroid, or in the centre of an asteroid would do little more than generate heat. That's it. Just a big flash of light and heat (and radiation). A chemical explosion which utilises expanding gasses from the exploding chemicals themselves would be far more effective at damaging an asteroid. In point of fact, nuking an asteroid may have precisely the opposite effect of that intended: Instead of blowing it apart, since there's no shockwave created, the intense heat generated by the nuke would melt large parts of the asteroid, making it molten, and then causing the cooling rock to form together far more solidly than they would normally be held together. Instead of having an asteroid resembling a loosely-held together mudball, nuking it would turn it into a hardened volcanic rock. Sending even more nukes would just cause more of the asteroid to melt, only to eventually solidify upon cooling.
Q: Where can I find a graph showing the time dilation vs % of c, so I can see things like how fast you have to be going to reach Proxima Centauri within the traveler's lifetime?
@@Релёкс84 Thanks! However, my Excel's gamma() function is broken (read: I don't math). So, anyone up to drawing a graph for me? :D Such a plot would be very cool to look at and imagine possibilities.
question: is there a sweat-spot for gravitation waves (like the time the whole universe was ~+18c;) - where you are not instantly blasted to bits or irradiated to death or very boring and painful, but short-lived super-hero-mutation, by whatever the hell created the gravitational waves in the first place. But still feel them not by giant 4km arms that squeeze quantum light into other words that I don't understand, to register movement by a fraction of proton size... I mean to get the "whoa?!" feel that a magnitude 2 earthquake gives you? ;) Or if you feel anything, congratulations, here come the gamma rays, enjoy your last, here it was...?;)
About alien life, i think life with an open sky (like us ) is very rare, 'cause of radiations, meteorites, etc... but it might be necessary for technological civilisation. Maybe life in liquid water under a sheet of ice is the norm. Go discover fire under water :D.
Hey Frasier, my son wants to know what would happen if the earth were in the sun. This made me wonder: what would happen if a rogue exoplanet hurtled into our star system and collided with the sun? Something earth-sized. Would the heavy elements of the planet sink into the core and cause the star to undergo a big change, like in that episode of stargate sg-1? Or would it simply be destroyed by the power of the sun?
Could the Oortcloud be a big web of astroids/comets in-between all the stars? Could it be very big and massive enough to explain at least a part of Dark Matter? Edit... I think not but it was just a thought. :-)
RAUG recently modified their Ariane 5 fairing for NASA's more stringent pressurization requirements for the upcoming JWST launch. Now they have experienced fairing separation anomalies on the last two flights, resulting in excessive vibration. Ariane 5 flights are currently on hold until the problem is resolved. JWST is third in line. Guess what. It's launch is going to be delayed.
Given the amount of planets in the universe, it doesn't really matter how small the odds are for microbes to evolve on any specific planet, and you still get a chance for life on many planets that is basically 1. 10^25 is a really big number.
Some more recent studies do indicate that multicellularity has likely evolved several times on Earth. The last common ancestor of plants and animals was most likely a single celled eucaryote. Maybe this changes a variable in your Drake Equation? www.sciencemag.org/news/2018/06/momentous-transition-multicellular-life-may-not-have-been-so-hard-after-all
0:43..."5 pm Pacific Time and I'll answer your questions"...erm...LOL....no you won't. Look a the number of questions below that were answered - about 1 in 100. Take the money and run, buddy.
FYI, I can't find a single reference that agrees with your pronunciation of "globular". Maybe you're the first, and will someday be credited with originating this variant. :)
The Universe is only infinite if you assume the Big Bang occurred inside another existing cosmos. The BB theory doesnt require there to be anything outside of our Universe. So the theory and everything we currently know says that our Universe is finite and always will be.
I can't exactly wrap my head around the fact that you believe we're the only advanced civilization in the universe. I assume you understand probability and mathematics, and while I totally get that we are technically the only "one" we see, in what world can you think we're the only civilization out there? I love your channel and watch everything you post, but I can't help but cringe every time you make a comment like that. You attempt to explain yourself by saying "life may be really, really rare" ...uhmmm...ok, sure, it could be rare. So is a triple-play, but it still happens. The universe may be more or less endless, man. And IF microbial life is possible elsewhere, saying intelligent life doesn't exist anywhere else is absurd...just my opinion. Throughout human history, we believed we had "discovered" everything that was out there on Earth, and we continued to explore and find new life & civilizations. To think the universe, which is far more vast, is any different, is short-sided. We haven't even landed another human being on another PLANET... proposing that we are the only intelligent life in the countless trillions of unexplored planets doesn't seem, in any way, rational to me.
The key to my argument is that an advanced civilization will eventually send self-replicating robot spacecraft to other stars, visiting the Milky Way at an exponential rate. No matter which corner the civilization originates, it can "colonize" the entire galaxy in a couple million years.
@@frasercain btw i love you Fraser, i just enjoy debate/discourse. I feel it's a big assumption to think that's what an advanced civilization would do. Just because we think of ourselves as a colonizing species, doesn't necessarily mean others would act in the same manner. Who knows what their intentions would be, but sending out robots to millions of dusty planets may be unnecessary if they have found other ways to fulfill their resources/needs/etc.
Unless it's full of white blood cells (ie, failing liver, jaundice, etc.) as your body over produces "attack" cells. Hope this helps your dilemma because you should seek medical attention immediately if your poo isn't brown! ;O)-
I can count on one hand the number of UA-cam videos I watch from beginning to end. This is one of those channels. Great conversation for a Sunday morning coffee.
In q&a 76 you address the question on whether something can be completely still in space. Your answer was that you can't be completely still relative to other objects because there's always something to compare to. What if you don't care about other objects, but just to space itself?
The map of Kanilea and how galaxies and Galaxy clusters are moving in space suggests that there are speeds that are not relative to other objects but to space itself.
So imagine you could come to a complete stop relative to space itself. I imagine the expansion of SpaceTime would in itself distance you from objects just by the space between you and them getting larger, also objects with an absolute speed >0 would swoosh past you like if you're on the side of the road watching cars go by.
Now imagine two completely stopped objects close to each other. Will they still affect each other in terms of gravity? Will the expansion of spacetime cancel out their gravital effect or perhaps will they slowly separate from each other but don't affect anything that has a absolute speed?
So, is there a thing as absolute speed =0 relative to space, even if we can't measure it yet? And which properties would a body have on its surroundings at absolute speed =0?
Love your channel.
What is the difference between Astronomy, Astrophysics and Cosmology? Which field do you count yourself towards most?
Hi, Fraser! A question on JWST: how compromised is the design due to bandwidth starvation for being on L2 rather than LEO? (Eg. does it impact resolution, the amount of images, both?) And could you do an interview on the Deep Space Network and on generally increasing bandwith for science missions? Thanks!!!
? Is it possible for a meteor to nearly match Earth's orbital velocity and impact at low speed resulting in a mountain instead of crater?
Cool question
No, it's not possible. No matter how slowly a meteor comes in, the Earth's gravity will accelerate it to at least 11km/s
@@Релёкс84 Well there ya go lol. Cool question, and cool answer.
@@Релёкс84 gravity is sill a theory. Why still a theory after so long? When a theory is proven, it’s no longer a theory, it becomes fact. Question everything.
@@Richardrefund
1. who was talking about theories? why do you bring this up?
2. please look up the scientific definition of the word "theory"
3. what even is your point?
0:50 the game Elite Dangerous gives you the opportunity to land on planets all across the galaxy and the sky always changes relative to your position. You can go catch voyager in its actual location if you like
But Elite was set in the year ~ 3200 ish. Elite: Frontier was set about 100 years later. I think Elite: Dangerous is set somewhere around the 3400s, during the second Thargoid invasion.
edit - So you'd have to cover roughly 1,200 years of Voyager's flight path to be able to come upon it.
@@Raz.C 3307, it won't show the current star field, but the density of stars near SagA* is mind bending. Really worth a view
@@allbymys3lf831
Yeah, I was active during the first race to SagA. Never made it there myself, despite having everything I would have needed to make the long distance flight.
@@Raz.C i remember when I finished fully optimizing my anaconda for jump distance. After all that flying around and planet hopping to every damn engineer and crystal site, the last thing I wanted to do was leave the bubble
Preparing for my first colonia trip soon but I may just take my krait so I can blow it up when I'm done and skip the trip back
@@Raz.C as for voyager, there is a way to locate it using the starfield for navigation
Imagine, if you will, a cupcake made from whole wheat flour, leavened with baking soda and cream of tartar, with flavors from Ceylon cinnamon, maple syrup, and a mashed-up banana, baked at 400 degrees Fahrenheit for 16 minutes, so they're fluffy and moist. Now imagine that you eat the cupcake with whipped cream on each bite, which is chased by espresso.
Wait, what's the astronomy connection? Is this to replace the raisin bread analogy?
@@frasercain You know how Isaac Arthur always recommends that you get a snack before settling down to watch his latest video? I think that this is an especially good snack to have while watching your videos.
@@Jenab7 I am so confused
"That's just my opinion man"
Lol Big Lebowski reference!
@Helio Toxin he's out of his element
I am curious if you don't think life exists elsewhere in the universe, what makes us so special
18:34 The Big Bang analogy I like that the universe is the surface of a balloon that inflated (and is inflating). The radius of the balloon represents time. Inside the balloon is the past. The outside is the future. The center of the balloon is the Big Bang.
In the center of the milkyway number of star visible would increase with the cube of density, so if the average distance between stars is 1/5 than in the our neighborhood you will see 125 more stars of the same magnitude than on the earth, but because of the lighter sky low luminosity stars(5th and 6th aparent magnitude) cannot be seen with the naked eye , assuming that you have the same distribution of stars by classes like near solar system.
For the past two Q & As (or maybe in one of the other recent videos) you have talked about the rate of expansion in the universe. As related to inflation though, don't we "know" that the rate of expansion was at one time faster? And have we made any progress to the force that led to inflation?
? Hi Frazier ! I have always heard that Hubble discovered the expansion of the universe using Cepheid variables .how exactly did that work? What makes them special
Thanks again
Paul
Q. for Fraser: If we launch JWST this year, how much time do you think will pass until we get it operational and get the data, first data?
Thank you, regards from Montenegro! Great work, been following you for years.
according to this en.m.wikipedia.org/wiki/Timeline_of_the_James_Webb_Space_Telescope
it will reach its final orbit 1month after launch. it will already have deployed all the equipment until then. launch is on 31st of october, so I'd expect it to be operational end of November. Maybe wait some days for actual pictures..
乁| ･ 〰 ･ |ㄏ
@@georgplaz Thanks! In the meantime, Dr. Becky made an interview with one of the astronomers who is working on JWST, and , listen to this, if everything goes right, we should wait at least for 6 months, shoot... Check it out yrself: ua-cam.com/video/O9ZlqWp7620/v-deo.html and the whole interview: ua-cam.com/video/IzFa5Vg40Qc/v-deo.html Really appreciate your effort to help me out, regards from Montenegro!
That was the answer I was aiming for, thank you Fraser!
A one-way trip to Antarctica...said initially (I think) without irony. kinda made my hour.
Hi Fraser, I have a question. Do you think advances in AI might push the limits of after the fact interferometry into shorter wavelengths? It feels like matching up signals in progressively more complicated ways might be the sort of thing they could excel at. Thanks for all your work 🙂
Curious - why can't the Perseverance cams not able to track full flights of Ingenuity? Thanks
Great video have often thought about what the night sky would look like at different locations
And at the centre of the milkyway I thought it would look like Coruscant 😂
Hey Fraser! Been a fan since many years back! I have a question about magnetars. I heard they can strip you of all your electrons. How close would you have to be for that to happen, and what would it look like to suffer such a fate?
Also, the idea of our solar system being disturbed by a brown dwarf is scary. Do we know where the closest ones are?
I don't think that other launch companies are unaware of Starship. There are a number arguments as to why they may not be as worried. 1: Superheavy hasn't flown it has not heat shield. At current rate of progress it is 2-3 years away from a reusability demonstration and further away from commercial launch. 2: When Elon talks cost he normally means some future state, price to build Starship will still be ~$1-2 million per tonne (same as aircraft or Falcon 9), they will have a finite lifespan likely in the 10-30 launches range and it will be years before the lifespan can be extended commercially as some failures will manifest in flight so expanding the lifetime will be a trial and error process. 3: SpaceX still have a fixed cost of employing all their people and maintaining their sites, even mega constellations don't need that many flights so the fixed cost per launch will still be there. 4: Starlink revenue will likely dominate the launch business but that may end up with antitrust enforcement if they cross subsidise launch pricing. 5: It may well be that Rocket Labs much lower fixed costs and lower cost to manufacture the Neutron mean that their cost per flight is lower even with a second stage being thrown away, especially if that second stage is relatively cheap. 6: Science missions need an un-recoverable upper stage anyway unless they are going to a return location for Starship. 7: I don't doubt that most of the rivals have a recoverable upper stage in some form of preliminary design, but they aren't going to release them until they actually recover a first stage.
Question: Given the current "crisis" in cosmology with the Hubble constant, and the possibility that the expansion of the Universe may fluctuate-wouldn't this also potentially affect the speed of light? Considering the speed of light constant is based on a static and unchanging vacuum state.
Amazing episode
Hey Fraser! On Earth the vegetation is mostly green due to how chlorophyl absorbs and reflects light. What color would vegetation most likely be on a planet with 1.141 Earth masses orbiting a white dwarf star at 4.5 AU (not tidally locked)?
If stars' Oort clouds overlap, are we really just talking about general interstellar material that hasn't gotten drawn close to a star yet?
Please do a video about the next New Horizons (Pluto) probe that we are all going to witness: BepiColombo exploring the planet Mercury in 2025!
Question: In a telescope whose primary mirror is made using multiple hexagons, does each hexagon have the same shape? Are they flat or do they have any curvature?
You can make them the same, and have a spherical mirror. But this gives spherical aberration. So generally the hexagons are different, but from symmetries, a few can be the same.
Question: If what causes time dilation is acceleration, not speed; if I teleport to a ship traveling close to the speed of light, but without acceleration, will I not experience time dilation relative to my previous location?
@Helio Toxin But without acceleration, what does it mean to be moving? From my point of view, it would be an observer left on Earth that is moving!
Question: In regards to interferometry in space, how would you deal with the fact that the telescopes are moving? It isn't possible to have 'perfect' orbits that keep them exactly a certain distance apart, is it?
My son and I have a question - have the planets in our solar system ever been all in alignment? That is, all lined up on one side of the sun. Thanks!
NASA and Spacex. It's not just the money and the customer-supplier relationship. Also super important is all the technical and experience transfer that has taken place between NASA and Spacex. To use a plant breeding analogy, it's an example of hybrid vigour. The relationship is symbiotic, good for both parties. What Spacex has given NASA besides cheaper prices is a reminder of what the spirit of Apollo was like back in the day.
Hey there Fraser, my man!
So, without overly cueing up the X-Files theme song in the background, what do you think of this possible explanation for the Fermi Paradox: Time Travel!
What if every single advanced hyper-technological focused civilization (like ours) simply innocently advances and stumbles along, all while mainly exploring/hunting for ever more new rich-inducing efficient energy-access... and then what if such research always makes it clear that at those higher-energy levels time-travel is indeed possible...
Then who could resist?! Seriously if I gave you a time machine... don't tell me you wouldn't be tempted to use it, from everything from a little bit of a selfish lottery win for you and your family, to much more innocent/poetic re-explorations of your past life, and past historic life.
All of which eventually leading to a major self-annhilating-time-paradox-feed-back-loop, of stepping on a butterfly while also inadvertently killing your great-great-great-grandfather at the same time?!
If the only way to higher-energy usage involves the realization of time-travel, then that might be the answer? Involving vast galaxy-spanning empires that once arose, but then self-cancelled themselves out, when they began messing with time travel... maybe?
Hi Fraser! What are your thoughts on the habitability of Venus? Either balloon cities high in the atmosphere (when would we even get the tech for that?), or removing enough CO2 so that it’s no longer a 900 degree greenhouse (when would we have the tech for that, since we can’t do it on our own planet with even less CO2?)?
Hey Fraser. Is the ISS tidally locked with Earth? Does it orient itself along its path? Or is it always facing the same direction relative to the solar system no matter where it's at in its orbit around Earth? Cheers!
And don't forget Starlink. Space X will be self sustaining once Starlink is fully operational. They'll have tourism, satellite launches for military and private organizations, and Starlink customers to keep them going even if NASA cut ties completely. But with NASA then they also have the Artemis contract and all the ISS stuff. But people often forget or underestimate how critical Starlink is to the survival is Space X.
Are there examples of planets orbiting their sun in an atypical fashion? Ex. perpendicular to the others, or in the opposite direction
I feel like just saying "we're alone" isn't a great explanation. For me, it just leads to the next question of "why" we are alone. Why did life form here and nowhere else?
Isn't it very helpful to having half scale of starship ( starship mini ) for planetary explorations?
We are getting excited about reusing a booster for the 10th time. Aircraft fly 10000s of times and yet fuel STILL isn't the biggest cost. Even if starship pulls off reentry, which it hasn't. Doesn't need to go on a GIANT gantry robot to fix the heat shield between launches (Space shuttle anyone). Now add boosters that land on converted drilling Rigs in the ocean (aircraft don't need extra runways in the middle of the ocean!) that are going to be free to maintain? Why do you think these were sold so cheap? People who believe that starship will be "just the cost of fuel" are dreaming. Unless you have a full payload bay, it won't be the cheaper launcher.
Q: Can Oort Clouds overlap? If Two stars is closer to each other, can their Oort Clouds interfere / overlap?
The speed of light confuses me in regards to predicting solar eclipses. Not so much in the modern era, but hundreds of years ago, astronomers were able to predict eclipses fairly well, not knowing the speed of light. The travel time from the sun is 8 minutes, and from the moon, under 2 seconds. I can see modern computers being able to predict eclipses knowing exact distances from the moon and sun, and knowing the speed of light. How did astronomers figure it out 2000 or 3000 years ago?
If you had, as you say, a telescope at both the North and South poles for interferometry, what % or band of the sky would they actually be able to both see? I'm guessing a pretty small section, possibly zero if you think about it...
Should Arecibo be rebuilt? Should a bigger/better one be constricted or is it antiquated technology and there's no real reason to rebuild it?
The Hubble Space Telescope is still getting mentioned in having played a vital role in recent discoveries. If it is such a fantastic machine, why didn't we build a second one to make twice as much telescope time available for astronomers in the 30 years since its launch?
Building a copy should me much less expensive and faster, without the need to develop new technologies.
The Nancy grace roman telescope will be able to the the job of 100 Hubble's. I believe we should continue to push our capabilities
I think regarding the question about the Big Bang, even if the universe wasn't infinite at its inception then the material that the Earth was made out of was part of the massively compressed material that was at that point (which is a bit untrue as the Earth has metals that can only have been made in stars, supernovae), so you can't look back to where that point is, because that point is everywhere in the universe now.
You could say that even though every part of the universe was at that point and moved (or the space it was in was stretched) and so there must be one point that didn't move. Assuming that is what is meant then I don't know how you'd do that (or even what the point of doing that would be), it might even be outside of what is the visible universe now and so can never be seen.
I know the "stretching" of space-time and so the speed at which the universe is expanding its faster than the speed of light, but I still don't think you can look back and see where you've come from all I just don't think it's possible.
Ideally, Mars needs more gravity, an atmosphere and a magnetosphere to be habitable. If we gently crashed the moons of Jupiter and Saturn into Mars could it be a place we could live?
Nice one
How small would an earth mass black hole be?
@@tauceti8060 8.87 millimetres. Source: www.omnicalculator.com/physics/schwarzschild-radius
Why is the moon getting further away from the Earth?
How do we know it's the universe which is expanding and not the elementary particles which are shrinking?
Re - Asteroids vs Nukes
The reason nukes are so devastating on earth is because of the shockwave they produce. They do this by superheating the atmosphere. The key word to notice here is "atmosphere." An asteroid has no atmosphere (for the most part). A nuke exploding on the surface of an asteroid, or in the centre of an asteroid would do little more than generate heat. That's it. Just a big flash of light and heat (and radiation). A chemical explosion which utilises expanding gasses from the exploding chemicals themselves would be far more effective at damaging an asteroid. In point of fact, nuking an asteroid may have precisely the opposite effect of that intended:
Instead of blowing it apart, since there's no shockwave created, the intense heat generated by the nuke would melt large parts of the asteroid, making it molten, and then causing the cooling rock to form together far more solidly than they would normally be held together. Instead of having an asteroid resembling a loosely-held together mudball, nuking it would turn it into a hardened volcanic rock. Sending even more nukes would just cause more of the asteroid to melt, only to eventually solidify upon cooling.
2:36 I've read that as a kid, great memory of it.
It made me respect Church a little bit more as a Atheist.
Do space agencies use general relativity to calculate spacecraft trajectories, or is Newtonian mechanics accurate enough?
Q: Where can I find a graph showing the time dilation vs % of c, so I can see things like how fast you have to be going to reach Proxima Centauri within the traveler's lifetime?
Wikipedia: Time Dilation. Looks like 0.5c gives time boost of about +20%, 0.9c around +130%, 0.995c around +900%.
@@leopoldroos1704 ohhh nice, I wonder if there's a formula to plot the line. I'll check it out thank you!
@@taqyon of course there is a formula: gamma(v) = 1/sqrt(1-(v/c)²)
@@Релёкс84 Thanks! However, my Excel's gamma() function is broken (read: I don't math). So, anyone up to drawing a graph for me? :D Such a plot would be very cool to look at and imagine possibilities.
@@taqyon You'll find such a graph on the relevant wikipedia page: en.wikipedia.org/wiki/Lorentz_factor#/media/File:Lorentz_factor.svg
question: is there a sweat-spot for gravitation waves (like the time the whole universe was ~+18c;) - where you are not instantly blasted to bits or irradiated to death or very boring and painful, but short-lived super-hero-mutation, by whatever the hell created the gravitational waves in the first place. But still feel them not by giant 4km arms that squeeze quantum light into other words that I don't understand, to register movement by a fraction of proton size... I mean to get the "whoa?!" feel that a magnitude 2 earthquake gives you? ;) Or if you feel anything, congratulations, here come the gamma rays, enjoy your last, here it was...?;)
Giant Olmec head Fraser Cain strikes again.
About alien life, i think life with an open sky (like us ) is very rare, 'cause of radiations, meteorites, etc... but it might be necessary for technological civilisation. Maybe life in liquid water under a sheet of ice is the norm. Go discover fire under water :D.
Has there been any updates to or plans to try to resolve the so-called axis of evil?
Hey Frasier, my son wants to know what would happen if the earth were in the sun. This made me wonder: what would happen if a rogue exoplanet hurtled into our star system and collided with the sun? Something earth-sized. Would the heavy elements of the planet sink into the core and cause the star to undergo a big change, like in that episode of stargate sg-1? Or would it simply be destroyed by the power of the sun?
It would just get gobbled up, no problem.
Could the Oortcloud be a big web of astroids/comets in-between all the stars?
Could it be very big and massive enough to explain at least a part of Dark Matter?
Edit... I think not but it was just a thought. :-)
Can you change your greenscreen? "Fraiser's den" is getting old. I vote for Endor again.
It's not Star Wars. It's Stargate.
👍👍👍
What happened to the Guide to Space?
RAUG recently modified their Ariane 5 fairing for NASA's more stringent pressurization requirements for the upcoming JWST launch. Now they have experienced fairing separation anomalies on the last two flights, resulting in excessive vibration. Ariane 5 flights are currently on hold until the problem is resolved. JWST is third in line. Guess what. It's launch is going to be delayed.
I give microbial life elsewhere in the universe greater odds than JWST successfully completing it's mission.
Given the amount of planets in the universe, it doesn't really matter how small the odds are for microbes to evolve on any specific planet, and you still get a chance for life on many planets that is basically 1.
10^25 is a really big number.
No life in the universe!? Maybe not the galaxy but an infinite universe must have life.
A telescope the size of Earth, in theory has already been done and we have a picture of a black hole as a result. ;O)-
The size of the Earth's orbit, not the Earth.
@@frasercain ahh, got it. That detail slipped my mind. ;O)-
Some more recent studies do indicate that multicellularity has likely evolved several times on Earth. The last common ancestor of plants and animals was most likely a single celled eucaryote.
Maybe this changes a variable in your Drake Equation?
www.sciencemag.org/news/2018/06/momentous-transition-multicellular-life-may-not-have-been-so-hard-after-all
what if you made like a nuclear bunker buster to stab an asteroid, then blow it up?
0:43..."5 pm Pacific Time and I'll answer your questions"...erm...LOL....no you won't. Look a the number of questions below that were answered - about 1 in 100. Take the money and run, buddy.
L3 and L4 points are interesting, but nobody seems interested in them.
FYI, I can't find a single reference that agrees with your pronunciation of "globular". Maybe you're the first, and will someday be credited with originating this variant. :)
This is an age old argument. David Dickinson eventually found that my pronunciation was also correct, and so I doubled down on it.
Dyson swarm from the inside, space telescope from the outside.
Can really nuclear missiles able to fly into space and go hit an astroid ?
So, maybe we don´t see the aliens because they are the size of ants flying around in tiny adorable space ships? Makes sense. Take that Fermi.
If the Big Bang is an expansion, Should it be called The Expanse?
Get Elon Musk on for an interview.
People read too much into the fact that microbes popped up early in earth's history IMO
against asteroids,,,,, hit it wit ha nuke, then hit the cloud with a casaba howitzer
Wow the fuckin chicoms are copying and undoubtedly stealing tech from starship? Im shooketh
The Universe is only infinite if you assume the Big Bang occurred inside another existing cosmos. The BB theory doesnt require there to be anything outside of our Universe. So the theory and everything we currently know says that our Universe is finite and always will be.
I can't exactly wrap my head around the fact that you believe we're the only advanced civilization in the universe. I assume you understand probability and mathematics, and while I totally get that we are technically the only "one" we see, in what world can you think we're the only civilization out there? I love your channel and watch everything you post, but I can't help but cringe every time you make a comment like that.
You attempt to explain yourself by saying "life may be really, really rare" ...uhmmm...ok, sure, it could be rare. So is a triple-play, but it still happens. The universe may be more or less endless, man. And IF microbial life is possible elsewhere, saying intelligent life doesn't exist anywhere else is absurd...just my opinion.
Throughout human history, we believed we had "discovered" everything that was out there on Earth, and we continued to explore and find new life & civilizations. To think the universe, which is far more vast, is any different, is short-sided. We haven't even landed another human being on another PLANET... proposing that we are the only intelligent life in the countless trillions of unexplored planets doesn't seem, in any way, rational to me.
The key to my argument is that an advanced civilization will eventually send self-replicating robot spacecraft to other stars, visiting the Milky Way at an exponential rate. No matter which corner the civilization originates, it can "colonize" the entire galaxy in a couple million years.
@@frasercain btw i love you Fraser, i just enjoy debate/discourse. I feel it's a big assumption to think that's what an advanced civilization would do. Just because we think of ourselves as a colonizing species, doesn't necessarily mean others would act in the same manner. Who knows what their intentions would be, but sending out robots to millions of dusty planets may be unnecessary if they have found other ways to fulfill their resources/needs/etc.
My question: why is poo usually brown?
Not an astronomy question. Maybe talk to a biologist?
Old blood cells. Watch chubbyemu
Unless it's full of white blood cells (ie, failing liver, jaundice, etc.) as your body over produces "attack" cells.
Hope this helps your dilemma because you should seek medical attention immediately if your poo isn't brown! ;O)-
took 7 days to post a video? you need to fire the editor
No, I just release it a week after the show.