Re: Vehicles... I'd think the real challenge isn't structure, but thermals and chemistry and abrasion. Lunar regolith would tear the crap out of motors, bearings, hinges, anything that rubs on anything, and Martian soil chemistry has a bunch of perchlorates that could do interesting things over time (chlorine being the chemical equivalent of that guy that starts fights in bars). Temperature fluctuations on Mars aren't as bad as on the Moon, but still something to think about. Also... maintenance. No Jiffy lube on Luna (yet)! Whatever breaks up there has to be fixed up there with what was brought with it; whatever regular maintenance must be done is done by the people and the parts they already have. Send Toyota Hilux trucks. You can't kill 'em.
Because of moon dust there was an idea having the EVA suits hanging on the outside and you step into the suit from the inside never bringing the suit inside. Is that still the plan?
It is probably the most sensible idea, but from what I have seen it is not currently being pursued. The are having enough trouble getting new EVA suits made as it is, ILC Dover bowed out of their contract for unknown reasons.
Hebridan is my favorite question. Concerning changing the direction of the Earth's rotation: You can do that now. Go to Australasia, or New Zealand, or South Africa, or Argentina.
He forgot that if the earth rotated in the opposite direction at the same speed, the length of the day would be different, and the number of days in a year would also be different.
First time listener to the channel here, loved the video! One comment regarding difficulty of falling past the event horizon of a black hole- I believe the question may have been referring to difficulty crossing the ergosphere. In an ideal, non-rotating (Kerr) black hole, this does not apply. But in the universe, all real black holes are rotating due to the conservation of angular momentum. This produces a new horizon above the event horizon known as the ergosphere, where spacetime is essentially pulled around the black hole rather than into it, where where matter can still escape. This results in a region where matter falling in is accelerated to near the speed of light before being ejected back into space. This is the mechanism that energizes accretion disks. Because of this massive increase in energy, it actually becomes difficult for matter to travel through the ergosphere and past the event horizon.
_"For the void hushes every voice except to the speaker himself [...] And I have heard it said that if it were not thus, the roaring of the suns would deafen the universe."_ ~ Gene Wolfe, _The Urth of the New Sun_
As far as the xhulak question is concerned the big factor is actually about who you're talking to. If you're talking to an astronomer they'll tell you we have 8 planets. If you're talking to a geologist they're going to say 125 (or more) . I would then tend to find that then it comes down to *why* you're asking - is your interest related to further astronomical research, or something of a planetary Science question. A plumber and a farmer can both tell you what "plumb" is. But that's answers won't have anything to do with each other
Fraser, Great advice about _not_ using UA-cam’s algorithm. It’s gotten worse over the tears and I’d say about 90% of the recommendations it gives me are bad. So, that’s why I subscribe and check the Community tab at least weekly.
There's an extension that puts your subsciptions as the home page and removes the recommended videos. I've used it for years. I think its called Remove UA-cam Suggestion.
Belote: If you want an exact simulation of this, just pretend north is south and south is north and it would yield the exact same result. The spin direction all depends on how you name your poles.
For some reason, you saying "aaa" translated- to my mind- as Anti-Aircraft Artillery. Even though we don't have "AAA" in Australia, well we do, but we call it something else entirely... But even though "AAA" doesn't mean anything in Australia, while Americans would immediately recognise it as roadside assistance, I do understand that it represents some popular U.S. roadside assistance company (ie- I'm not entirely ignorant of the association).
Concerning Goronak, I believe the question was not one of time dilation but one of angular momentum, radiation pressure, and the last parsec problem. Mass falling into a black hole can encounter a lot of different problems getting in. Gases falling in bump into each other heat up, cause radiation to press outward, and limit the rate at which matter can get close. Angular momentum of objects in orbit around a black hole have to be shed in some way for the objects to lose orbital altitude. Other black holes have a lot of trouble losing this extra angular momentum when they get down to the last parsec of separation, as gravitational wave energy isn't strong enough to carry energy away fast enough for them to merge.
I’m afraid the Galileo Leaning Tower of Pisa story is most likely apocryphal. Though there’s no consensus between historians or mathematicians, many from both backgrounds think Galileo’s experiment was thought experiment where he imagined dropping bricks or blocks of the same shape with, perhaps, a single brick versus two others stacked on each other dropped from an equal height. I’m under the impression the stacking was to keep the wind profile of each as close as possible. There was a drop test done, I believe somewhere else in Europe, by if not a contemporary of Galileo someone near him in time.
Also I think the question was less about removing the mass from the earth and more about using it as reaction mass (maybe with some kind of orbital mass driver). That's how I took it anyway.
Thanks Fraser for another great episode! - In regards to the last question concerning global warming... rather than move the earths orbit, couldn't you put a large object between the earth and the sun that acts as an adjustable blind/shade?
I don't feel that Pluto was demoted as much as it was reclassified into a more appropriate category. Now instead of being the smallest body in its classification, it is the biggest in its classification. It even has a whole class of objects nicknamed after it -- plutoids. How cool is that for Pluto?
Re- moon cars/ Mars cars I suspect the question was asking- "Assuming some point in the future where we have cities on Mars and the moon, what would the cars on the roads of those cities look like?" Otherwise, he'd just be asking about what Lunokhod/ Perseverance look like and we have pictures of those...
The density of the universe after the big bang was of course enormously large (not a near vacuum until after the first few seconds) and it was expanding at near the speed of light.
“Astronomers say they have heard the sound of a black hole singing. And what it is singing, and perhaps has been singing for more than two billion years, they say, is B flat -- a B flat 57 octaves lower than middle C.” Could the Big Bang have a sound frequency or musical note associated with it?
@ We can calculate the frequency of a Bb note that is 57 octaves lower than middle C by using the following formula: N(O) = log(fu/fL)/log(2). fu = upper frequency fL = lower frequency N(O)=number of octaves So the frequency is very very very tiny: in fact equal to f = 466.2/(1O^189.4) hz Roughly 187 orders of magnitude smaller than 1 hz. Need a special Sub woofer for that Bb bass note and extremely sensitive ears 😁 (We are talking about the hum from a Black hole rather than the big bang sound) 200,000 light years is approximately 10^20 metres.
Alaris: Sound waves can travel in any medium with enough density. In the early universe, during the Big Bang and shortlly after the universe was a plasma. So - Sound could travel through this medium and we have evidence for this in the distribution of galaxies.This is evidence of what has been termed "Baryonic Acoustic Oscillations", which is not a sound as we would imagine, in spite of the word "Acoustic" being part of the name. Rather the distribution of the galaxies in a wave-like formation when they settled in position after the "sound Wave" stopped moving as tyhe density of the stellar medium dropped below a certain level and true space became transparent.
Realistically, It would be more practical to use plutonium as a source of heat for thermocouples to generate power. 50 years later, Voyager is still working.
"They appear to pause on the event horizon before they slowly fade away" aka, their splat mark takes a while to disappear. no one is 'landing' on the event horizon.
Re - Space Debris Couldn't you send up a tall, wide sheet of metal, possibly with a thick kevlar cushion on either side, straight up about 1,000 km, such that it has an effective orbital velocity of zero. Any debris in orbit would strike the sheet of metal (and kevlar) and possibly vaporise or embed itself in the metal sheet (or in the kevlar)... Ideally, you'd only want to encounter the small bits of debris, so that the metal sheet isn't obliterated. You don't want to add more debris, after all. But since the sheet isn't achieving orbit, you don't need to keep track of it. It'll just go straight up and then come straight back down again. How thick would such a sheet of metal need to be for such a "sky-sweeper" to be feasible- so that it would stop most of the space debris smacking into it, rather than having them slice right through it?
How do planets with no moons capture their first moon or asteroid? Assuming one is flying past the planet in an hyperbolic orbit, what could cause it to decelerate at periapsis to get captured into elliptical/circular orbit without the aid of a third body (another previously captured moon)?
In the early solar system, it would be all the gas and dust that still lingers around that would cause drag and slow objects down to get them captured around planets... Once all the gas and dust are gone this process would become much more rare, objects on hyperbolic trajectories would simply keep flying past and not get captured.
If undisturbed, will New Horizons ever encounter another Star? Based on its current trajectory, is it heading towards any known star systems? Something I've been curious about. Hoping either Fraser or someone in this comment section can answer this question for me, I'm genuinely curious
About the sound of the big bang: Another way to see it -- The universe probably wasn't made up of mostly space, but mostly of hot stuff, and is probably best thought of a some kind of fluid. It's simply innacurate to consider it an extension of our currently mostly empty universe... & sapce....
Last week you answered my question about the spin of the Earth helping launch into space. Thank you. As a follow up, could there be such a planet with more gravity that a spin is absolutely necessary for the species to launch into orbit? Or that they could only launch from an area around the equator? I think you mentioned before that a species would be homebound if the gravity was too great to overcome.
Regrading the evaporation of black holes, what is the maximum energy particles/photons a regular black hole reaches in the final moment before it dissappear? If it from infrared, to gamma rays and so on there has to be a standard maximum wavelength it reaches, right?
Does Planet Spin Matter?!!? :D Yes.... What a great question! No spin would be cataclysmic for earth.... Reversing the earth's spin would be cataclysmic for most countries and population centers (even if done gradually). An earth like planet with reverse spin would have mostly reversed weather patterns which would make life interesting for the farmer colonists! :)
I was thinking about your answer to the black holes decreasing in size with mass, and that a black hole with a weight of 10,000,000 tonnes would be only an atom wide. If the black hole became smaller than this, wouldnt it start to be subject to certain quantum effects. If so, what would this mean to the black hole. Could the probability of areas inside the event horizon staying inside the event horizon go down too? Thanks as always for these fantastic videos.
By blasting off rockets from the surface of the Earth isnt the thrust of the rocket also either increasing or decreasing the Earths spin? Will this eventually be a problem if enough rockets blast off into space?
We can approximate the earth as a solid sphere of matter, meaning its moment of inertia "I" is (2/5) M R^2 The angular frequency w is 2pi/(1day) The angular momentum is then L = I w = roughly 7x10^33 J s Imagine an extreme scenario: we take 1000 starship super heavy boosters and attached them to the equator pointing counter to the rotation of the planet, and kept them constantly fed with propellant. Also assume the atmosphere has no effect. There are 33,000 Raptor engines each applying 2.75MN to the earth at a radius of 6350km The rate of change of angular momentum of a body is equal to the total torque. Dividing 7x10^33 Js by the total torque gives a total stopping time of 385 million years. And aside from a few test fires here and there, we're mostly letting our rockets go once we light them, so they actually have very little effect on our rotational angular momentum. So I think we're good for a while.
It's a fun question, but most launches eventually return to Earth and restore the momentum they took (minus whatever propellant escaped Earth). Only launches that forever leave Earth matter. You'd have to eject a significant percentage of Earth's mass to change the rotation. Digging the entire surface of the Earth down a few hundred miles and launching that into deep space might do it.
"They're not going to get into a car accident on the moon" I wouldn't be so sure. I think you are underestimating our propensity for getting in car accidents. Even if we only ever put two cars on the moon, it will only be a matter of time before they hit each other.
Wouldn’t an orbiter with an aerogel type material configured in a large sail be sufficient to capture those thousands of minute particles? Dozens of small probes could probably deorbit a majority of the larger objects.
Before watching I think a black hole will always be a black hole, let's see if my guess is right hehe - yay my guess is correct 😅 Also the sound of 2 black holes merging was translated into a sound we can understand audibly i remember seeing that. Isnt earth pair shaped and not completely round?
Hi Fraser, I've got a question I'd adore an answer to. With Silo season 2 coming out staring Friday I've been rewatchng season 1. In episode 5 one of the characters points out that there are lights in the sky from the viewport, and notes they move. What constellations are shown in the viewport do you know? :)
If you observe an extremely close object under a high enough magnification, wouldn’t you be able to observe it in “real time” vs in the past when observing an extremely distant object?
Honestly there is no logical reason why the number of planets orbiting our sun must be a small number. Pluto being classified as a Dwarf Planet does not stop it being a planet, its just a more specific designation - it literally says planet after 'Dwarf'. But people seem to forget that for... reasons.
Is the milky way's core or the core of other similar galaxies as dense as globular clusters? Since they are said to be the core from older galaxies, were they arranged like that from the begining and that's how all galaxies cores look like?
I've understood that tiny wormholes exist in accordance with general relativity, but can't be normally traversed. Could we somehow "squeeze" or wink the wormhole mouth to send morse messages instantly across lightyears?
Asuria... What is the maximum theoretical naturally occurring temperature? Where did/could this happen? Can we exceed that temperature artificially, in the same sense that the "coldest place in the universe" is in labs here on Earth that go below natural minimums?
I believe there is, I cant remember exactly what it is but it is related to E=MC^2. When the energy density of a given volume gets high enough particles will be created taking some of that energy with them; more energy creates more massive particles. We are probing these boundaries with our particle accelerators but I do not think we can get to the energy densities you would reach if you could go backwards in time to arbitrarily close the Big Bang (like millionths of a picosecond).
Mortician here w/a bit of a morbid Q. What's the plan for somebody dying on the 1st peopled Mars mission? Wouldn't burial on Mars mean eventual contamination?
Belote: Hang on, I went to a planet that spun the other way once, and time went backwards! (according to my sundial, anyway - it didn't feel much different)
When and how did astronomers discover that the Milky Way is a barred spiral galaxy? On a side note, I know we can’t take a picture of our own galaxy since we’re in it. Is there a good image I could show my students to represent what it should look like rather than the nonbarred pictures that are out there?
Hey Fraser and hello everyone from the community, I have a question. Is there a limit to the payload that can be carried to space using a single stage rocket? I assume at some point the weight of the fuel will be so much that the rocket cannot lift off from the pad. Is there a formula or something for that? Can anyone provide some example?
I still can't wrap my mind around the CMB and how we are able to see it.. So everything that makes up the earth was there at the big bang, and then space expanded and stuff clumped together to make us and our galaxy..So the dust we're made of expanded out and away but the CMB light just stayed at the edges of the whole expanding universe? Like if our matter was somewhere there weren't we a part of this first "light" in a sense? So wasn't the light also expanding with us? Like why is it still there? So the photons are just still constantly being emitted from the big bang and travelling 13 billion years from back then and back there to right now and right here? If you can make sense of all that and just dumb it down for me that would be great! Also red and blue shift gets thrown around a lot I don't fully understand that either.. Thank you!
Regarding "Chulak" question I wonder had life and humans evolved on a moon around a gas giant, how would that civilization name things. Clearly the gas giant has to be part of their religion and myths, being literally in the sky, but then the sun, and other moons, and other planets, would also occupy some space in the minds of the civilization, leading to different arguments, perhaps what is a sun? what is a moon?
I'm writing a medieval vampire novel that takes place on the Moon. How well do you think horses would do on the Moon? I think they would touch the ground three times and be going fast enough to splatter.
Edura: why do the lasers need to be in space? surely we can build stronger lasers here on earth. you are not in orbit with the debris you want to remove either way.
You said you'd "provide a link in the show notes" to Peter Kohl's blog. What is the "Show Notes"? Where is it? I'm trying to find his blog and google is useless.
Doesn't crossing the equator make the Earth seem like it is rotating the other direction? This depends on your frame of reference. Facing the North Pole, East is to your right. Facing the South Pole, East is to your left.
Not really, but maybe somehow? The sun will still rise in the east and set in the west, but it will go over the northern sky over noon, not the south. And the stars look different. As someone living on the northern hemisphere I always think how weird it is that I know the stars in the southern hemisphere better then in the northern hemisphere, because in europe I hardly ever see them. In the middle of my Megacity, I have to not only deal with light polution, but also 79% average cloud coverage. That´s why I never care about meteorite showers or eclipses or whatever. They are behind the clouds every single time anyways. That isn´t really related to your question, but this rant needed to get out of the system.... Sorry
@@AndreasPeters-r3e East is an arbitrary label that was developed in Europe. It is to the left if you look at the North Pole. If the definition for East had been developed in Australia, while looking at the nearest pole (South), it would be the mirror opposite, i.e.: it would be what we call West. Most people think of North as the top of the world, but I've seen maps in Australia with Antarctica on top. These make the point that the reference frame is arbitrary. There are two poles on a spinning sphere. One pole is just as good as the other. A storm moving left-to-right viewed from the North, is moving right-to-left if viewed from the South.
There will not be solar panels beyond the Jupiter system. The weight of the solar power system at saturn would be over 50% of the craft. That ratio would be rejected by every countries mission assessment committee. The cutoff presently is 20%.
In space, no-one can hear you make... whatever noise the Sun makes. I don't know what noise that is, on account of not being able to hear it, but if you make it, no-one will be able to hear you, so don't! Or do, I guess, it doesn't really matter.
A planet that spins "backwards"..... Yeah, just turn around 180° and your on a planet spinning "backwards". If you have a planet spinning against it's orbit around it's star, or against the rotation of the star or against the orbit of its moon, then there would be a difference in how long it takes the planet to become tidal locked. There would be a difference in how long the moon and sun stay in the sky each day also but that difference would be seconds per day and likely have no effect.
I'm ok with Dwarf Planets, but I don't think the debate is over with moons, because I don't think every tiny bit of Ice in Saturn's rings for example should be called a moon. 1. A Moon should have a stable orbit around a planet that will last for a reasonable period of time. Whether that's 1,000, 10,000, 100,000 or 1 Million years can be debated. But certainly not objects that will be lost within a year or two, let alone weeks. 2. A Moon should be large enough to form an approximate sphere. 3. If its too small for that but still has a significant size, say 10km, then its a Dwarf Moon. Re. Phobos and Deimos. 4. 1-10km Diameter is a Moonlet. 5. Below 1km its just a minor satellite.
i agree with your sentiment but youre making the same mistake as they did: making phobos a 'dwarf moon' means it has the word moon in the category and yet is NOT a moon, since here moons would be rounded. 'dwarf moon' like 'dwarf planet' implies its a type of moon/planet. instead i would use the word moonlet for anything thats bigish but not round in orbit around a planet, which includes phobos. instead i say: Planet: anything big n round but not shiny Star: big round and shiny Moon: a planet in orbit of a planet Moonlet: asteroid in orbit of a planet Asteroid: anything bigish but not round [[Planetar: big round and shinyish where the surface is dominated by convection rather than wind]] (this may or may not be a new useful category between planet and star) therefore dwarf planets and moons are a type of planet.
I have heard the larger more geologically complex moons described as 'worlds' by scientists that study them and their evolution. Before the arrival of the Pioneer and Voyager probes there was a general assumption that all moons would be mostly like our own Moon or Mercury, even if the material they were made out of different. We expected cold, cratered and dead places that were all boringly similar. Now it seems like almost every one is interesting and unique in its own way, even out to Pluto and Charon. It seems like the more we look and investigate, the more interesting they get.
@@sudazima People get so hung up on Pluto not being a planet just because it got a more specific description. Its really not much different than using the terms giant planet or gas giant/ice giant. Personally I kind of liked Issacs Asimov's term 'Mesoplanet' for everything between say the sizes of Ceres and Mercury and wish they had gone for that.
If something falls into a black hole and is later released as Hawking radiation, how much time passed from the perspective of that object between going in and coming out? Or is the premise of this question nonsense?
I do not understand where the temperature in space after the big bang came from? We learn in school the temperature is atoms moving, but inside the "big bang" there can be no movement? And then no temperature?
Are you talking about the CMB? That was after the BB, by about 380 000 years. The radiation arose because that is where the temperature became low enough for the ionised gas (plasma) created in the BB to recombine to form neutral atoms. That causes a certain type of radiation, and that is what we see as the CMB. Of course, the wavelengths at which the CMB was initaially produced have been lengthened considerably due to the expansion of space in the meantime. Which is why we now see it at ~ 2.7 K.
if you can look into space and “see the past” due to being millions of lightyears away and time dilation, is there any possible or theoretical way to reverse that and see the future? any theory connecting to white holes? (basically time travel but instead of bringing ourselves to the future it’s moreso just perceiving it) I hope this reaches u!
Not that we know of. It's like hearing things after they happen because of the speed of sound. Could there be a way to hear things before they happen? Probably not.
40:20 "don't let your media consumption be dictated to you by an algorithm" - fully agree :)
Re: Vehicles... I'd think the real challenge isn't structure, but thermals and chemistry and abrasion. Lunar regolith would tear the crap out of motors, bearings, hinges, anything that rubs on anything, and Martian soil chemistry has a bunch of perchlorates that could do interesting things over time (chlorine being the chemical equivalent of that guy that starts fights in bars). Temperature fluctuations on Mars aren't as bad as on the Moon, but still something to think about.
Also... maintenance. No Jiffy lube on Luna (yet)! Whatever breaks up there has to be fixed up there with what was brought with it; whatever regular maintenance must be done is done by the people and the parts they already have.
Send Toyota Hilux trucks. You can't kill 'em.
Because of moon dust there was an idea having the EVA suits hanging on the outside and you step into the suit from the inside never bringing the suit inside. Is that still the plan?
Probably yes, i see no other viable solution to keep the dust away from the astronauts.
It is probably the most sensible idea, but from what I have seen it is not currently being pursued. The are having enough trouble getting new EVA suits made as it is, ILC Dover bowed out of their contract for unknown reasons.
Hebridan is my favorite question.
Concerning changing the direction of the Earth's rotation: You can do that now. Go to Australasia, or New Zealand, or South Africa, or Argentina.
He forgot that if the earth rotated in the opposite direction at the same speed, the length of the day would be different, and the number of days in a year would also be different.
@@FLPhotoCatcher By a very, very small margin...
Thanks for answering my question Fraser! I hadn't thought of lasers being used for space junk aswell, definitely another dual purpose opportunity.
First time listener to the channel here, loved the video! One comment regarding difficulty of falling past the event horizon of a black hole- I believe the question may have been referring to difficulty crossing the ergosphere. In an ideal, non-rotating (Kerr) black hole, this does not apply. But in the universe, all real black holes are rotating due to the conservation of angular momentum. This produces a new horizon above the event horizon known as the ergosphere, where spacetime is essentially pulled around the black hole rather than into it, where where matter can still escape. This results in a region where matter falling in is accelerated to near the speed of light before being ejected back into space. This is the mechanism that energizes accretion disks. Because of this massive increase in energy, it actually becomes difficult for matter to travel through the ergosphere and past the event horizon.
_"For the void hushes every voice except to the speaker himself [...] And I have heard it said that if it were not thus, the roaring of the suns would deafen the universe."_
~ Gene Wolfe, _The Urth of the New Sun_
in space no-one can hear you scream.
As far as the xhulak question is concerned the big factor is actually about who you're talking to. If you're talking to an astronomer they'll tell you we have 8 planets. If you're talking to a geologist they're going to say 125 (or more) . I would then tend to find that then it comes down to *why* you're asking - is your interest related to further astronomical research, or something of a planetary Science question.
A plumber and a farmer can both tell you what "plumb" is. But that's answers won't have anything to do with each other
Thanks Fraser!! I'll be watching the lives again from now on, it's been a few months hiatus. Love your channel!!!!!!
Awesome content, expressed in a captivating way, thank you, Fraser.
Fraser,
Great advice about _not_ using UA-cam’s algorithm. It’s gotten worse over the tears and I’d say about 90% of the recommendations it gives me are bad. So, that’s why I subscribe and check the Community tab at least weekly.
There's an extension that puts your subsciptions as the home page and removes the recommended videos. I've used it for years. I think its called Remove UA-cam Suggestion.
@@birdbrainiac Awesome-thank you!
Wow! Thank you!
Belote: If you want an exact simulation of this, just pretend north is south and south is north and it would yield the exact same result. The spin direction all depends on how you name your poles.
when driving On mars, they should stick to the roads and out of the rocky terrain cause it will take AAA forever to get there
For some reason, you saying "aaa" translated- to my mind- as Anti-Aircraft Artillery.
Even though we don't have "AAA" in Australia, well we do, but we call it something else entirely... But even though "AAA" doesn't mean anything in Australia, while Americans would immediately recognise it as roadside assistance, I do understand that it represents some popular U.S. roadside assistance company (ie- I'm not entirely ignorant of the association).
Can you show us the best images we have of Titan's surface? What are the best hints of possible life being found there?
Asuria Thank you for another, as always, great video!
Love the thumbnail!!! 😂
Concerning Goronak, I believe the question was not one of time dilation but one of angular momentum, radiation pressure, and the last parsec problem. Mass falling into a black hole can encounter a lot of different problems getting in. Gases falling in bump into each other heat up, cause radiation to press outward, and limit the rate at which matter can get close. Angular momentum of objects in orbit around a black hole have to be shed in some way for the objects to lose orbital altitude. Other black holes have a lot of trouble losing this extra angular momentum when they get down to the last parsec of separation, as gravitational wave energy isn't strong enough to carry energy away fast enough for them to merge.
That's what I thought it meant. 👍
Yeah, Fraser seemed to miss the question, or at least could of explored the concepts more.
@@Beldizar great comment 🙂
So informative
I’m afraid the Galileo Leaning Tower of Pisa story is most likely apocryphal. Though there’s no consensus between historians or mathematicians, many from both backgrounds think Galileo’s experiment was thought experiment where he imagined dropping bricks or blocks of the same shape with, perhaps, a single brick versus two others stacked on each other dropped from an equal height. I’m under the impression the stacking was to keep the wind profile of each as close as possible.
There was a drop test done, I believe somewhere else in Europe, by if not a contemporary of Galileo someone near him in time.
Also I think the question was less about removing the mass from the earth and more about using it as reaction mass (maybe with some kind of orbital mass driver). That's how I took it anyway.
Asuria!
Thanks Fraser for another great episode! - In regards to the last question concerning global warming... rather than move the earths orbit, couldn't you put a large object between the earth and the sun that acts as an adjustable blind/shade?
I don't feel that Pluto was demoted as much as it was reclassified into a more appropriate category. Now instead of being the smallest body in its classification, it is the biggest in its classification. It even has a whole class of objects nicknamed after it -- plutoids. How cool is that for Pluto?
Such a great show
27:04 absolutely! Great idea
the more and more i hear about the black holes, the more i believe our universe is inside one.
Re- moon cars/ Mars cars
I suspect the question was asking-
"Assuming some point in the future where we have cities on Mars and the moon, what would the cars on the roads of those cities look like?"
Otherwise, he'd just be asking about what Lunokhod/ Perseverance look like and we have pictures of those...
The density of the universe after the big bang was of course enormously large (not a near vacuum until after the first few seconds) and it was expanding at near the speed of light.
“Astronomers say they have heard the sound of a black hole singing. And what it is singing, and perhaps has been singing for more than two billion years, they say, is B flat -- a B flat 57 octaves lower than middle C.”
Could the Big Bang have a sound frequency or musical note associated with it?
If understood it correctly, he said the sound waves were 200,000 light years long, I believe that would be the frequency. I could be mistaken though.
@
We can calculate the frequency of a Bb note that is 57 octaves lower than middle C by using the following formula:
N(O) = log(fu/fL)/log(2).
fu = upper frequency
fL = lower frequency
N(O)=number of octaves
So the frequency is very very very tiny: in fact equal to
f = 466.2/(1O^189.4) hz
Roughly 187 orders of magnitude smaller than 1 hz.
Need a special Sub woofer for that Bb bass note and extremely sensitive ears
😁
(We are talking about the hum from a Black hole rather than the big bang sound)
200,000 light years is approximately 10^20 metres.
New episode happy day
Alaris: Sound waves can travel in any medium with enough density. In the early universe, during the Big Bang and shortlly after the universe was a plasma. So - Sound could travel through this medium and we have evidence for this in the distribution of galaxies.This is evidence of what has been termed "Baryonic Acoustic Oscillations", which is not a sound as we would imagine, in spite of the word "Acoustic" being part of the name. Rather the distribution of the galaxies in a wave-like formation when they settled in position after the "sound Wave" stopped moving as tyhe density of the stellar medium dropped below a certain level and true space became transparent.
Intersting channel, thank you
Realistically, It would be more practical to use plutonium as a source of heat for thermocouples to generate power. 50 years later, Voyager is still working.
Question: moving the earth with asteroids is awesome. Is there a way we could change the axial tilt? Would there be any benefit to doing so?
Fav:
Ardena
"They appear to pause on the event horizon before they slowly fade away"
aka, their splat mark takes a while to disappear. no one is 'landing' on the event horizon.
6:06 what about Planck energy?? There should be a minimum size that the black hole cannot emit further quanta.
Re - Space Debris
Couldn't you send up a tall, wide sheet of metal, possibly with a thick kevlar cushion on either side, straight up about 1,000 km, such that it has an effective orbital velocity of zero. Any debris in orbit would strike the sheet of metal (and kevlar) and possibly vaporise or embed itself in the metal sheet (or in the kevlar)...
Ideally, you'd only want to encounter the small bits of debris, so that the metal sheet isn't obliterated. You don't want to add more debris, after all. But since the sheet isn't achieving orbit, you don't need to keep track of it. It'll just go straight up and then come straight back down again.
How thick would such a sheet of metal need to be for such a "sky-sweeper" to be feasible- so that it would stop most of the space debris smacking into it, rather than having them slice right through it?
How do planets with no moons capture their first moon or asteroid? Assuming one is flying past the planet in an hyperbolic orbit, what could cause it to decelerate at periapsis to get captured into elliptical/circular orbit without the aid of a third body (another previously captured moon)?
In the early solar system, it would be all the gas and dust that still lingers around that would cause drag and slow objects down to get them captured around planets... Once all the gas and dust are gone this process would become much more rare, objects on hyperbolic trajectories would simply keep flying past and not get captured.
I like the idea of a campervan for the next visitors to Mars!
If undisturbed, will New Horizons ever encounter another Star? Based on its current trajectory, is it heading towards any known star systems? Something I've been curious about. Hoping either Fraser or someone in this comment section can answer this question for me, I'm genuinely curious
I recently wondered, assuming you could get within a kilometer of it, how loud the sun is.....explosions, roars, and winds beyond my imagination.
I’ll you use a laser to push a Sail or use a sails laser to push off from an object? Or a bridge of objects stretching out into space .
About the sound of the big bang:
Another way to see it -- The universe probably wasn't made up of mostly space, but mostly of hot stuff, and is probably best thought of a some kind of fluid. It's simply innacurate to consider it an extension of our currently mostly empty universe... & sapce....
Last week you answered my question about the spin of the Earth helping launch into space. Thank you. As a follow up, could there be such a planet with more gravity that a spin is absolutely necessary for the species to launch into orbit? Or that they could only launch from an area around the equator? I think you mentioned before that a species would be homebound if the gravity was too great to overcome.
Regrading the evaporation of black holes, what is the maximum energy particles/photons a regular black hole reaches in the final moment before it dissappear? If it from infrared, to gamma rays and so on there has to be a standard maximum wavelength it reaches, right?
I wonder if there are tiny primordial black holes still around, that are moving at relativistic speeds so only a few million years have passed to them
Cartego. But I'm a huge fan of science and cars
Does Planet Spin Matter?!!? :D
Yes.... What a great question!
No spin would be cataclysmic for earth....
Reversing the earth's spin would be cataclysmic for most countries and population centers (even if done gradually).
An earth like planet with reverse spin would have mostly reversed weather patterns which would make life interesting for the farmer colonists! :)
Cartego
I was thinking about your answer to the black holes decreasing in size with mass, and that a black hole with a weight of 10,000,000 tonnes would be only an atom wide. If the black hole became smaller than this, wouldnt it start to be subject to certain quantum effects. If so, what would this mean to the black hole. Could the probability of areas inside the event horizon staying inside the event horizon go down too? Thanks as always for these fantastic videos.
Planet is simple. If it's spherical, and the main body it orbits is a star, it's a planet
By blasting off rockets from the surface of the Earth isnt the thrust of the rocket also either increasing or decreasing the Earths spin?
Will this eventually be a problem if enough rockets blast off into space?
We can approximate the earth as a solid sphere of matter, meaning its moment of inertia "I" is (2/5) M R^2
The angular frequency w is 2pi/(1day)
The angular momentum is then
L = I w = roughly 7x10^33 J s
Imagine an extreme scenario: we take 1000 starship super heavy boosters and attached them to the equator pointing counter to the rotation of the planet, and kept them constantly fed with propellant. Also assume the atmosphere has no effect.
There are 33,000 Raptor engines each applying 2.75MN to the earth at a radius of 6350km
The rate of change of angular momentum of a body is equal to the total torque.
Dividing 7x10^33 Js by the total torque gives a total stopping time of 385 million years.
And aside from a few test fires here and there, we're mostly letting our rockets go once we light them, so they actually have very little effect on our rotational angular momentum.
So I think we're good for a while.
It's a fun question, but most launches eventually return to Earth and restore the momentum they took (minus whatever propellant escaped Earth). Only launches that forever leave Earth matter. You'd have to eject a significant percentage of Earth's mass to change the rotation. Digging the entire surface of the Earth down a few hundred miles and launching that into deep space might do it.
Fraser in the House!
Question: What would happen if a gamma ray burst hit earth? What would the damage be?
"They're not going to get into a car accident on the moon"
I wouldn't be so sure. I think you are underestimating our propensity for getting in car accidents. Even if we only ever put two cars on the moon, it will only be a matter of time before they hit each other.
Oh no! It did not have the Q&A at the bottom. I almost mistook for any other Fraser Cain video that I was going to watch anyway.
Wouldn’t an orbiter with an aerogel type material configured in a large sail be sufficient to capture those thousands of minute particles? Dozens of small probes could probably deorbit a majority of the larger objects.
What is the state of matter at the singularity of a black hole. Is it sub-quark material or even a lower state?
Before watching I think a black hole will always be a black hole, let's see if my guess is right hehe - yay my guess is correct 😅
Also the sound of 2 black holes merging was translated into a sound we can understand audibly i remember seeing that.
Isnt earth pair shaped and not completely round?
Hi Fraser, I've got a question I'd adore an answer to. With Silo season 2 coming out staring Friday I've been rewatchng season 1. In episode 5 one of the characters points out that there are lights in the sky from the viewport, and notes they move. What constellations are shown in the viewport do you know? :)
There is only one acceptable answer to, "how loud was the big bang?" Yes.
12:56 people in Australia experience opposite spin from US
If you observe an extremely close object under a high enough magnification, wouldn’t you be able to observe it in “real time” vs in the past when observing an extremely distant object?
Honestly there is no logical reason why the number of planets orbiting our sun must be a small number. Pluto being classified as a Dwarf Planet does not stop it being a planet, its just a more specific designation - it literally says planet after 'Dwarf'. But people seem to forget that for... reasons.
Ardena. I've wondered that my self.
Is the milky way's core or the core of other similar galaxies as dense as globular clusters? Since they are said to be the core from older galaxies, were they arranged like that from the begining and that's how all galaxies cores look like?
I've understood that tiny wormholes exist in accordance with general relativity, but can't be normally traversed. Could we somehow "squeeze" or wink the wormhole mouth to send morse messages instantly across lightyears?
Asuria...
What is the maximum theoretical naturally occurring temperature? Where did/could this happen? Can we exceed that temperature artificially, in the same sense that the "coldest place in the universe" is in labs here on Earth that go below natural minimums?
I believe there is, I cant remember exactly what it is but it is related to E=MC^2. When the energy density of a given volume gets high enough particles will be created taking some of that energy with them; more energy creates more massive particles. We are probing these boundaries with our particle accelerators but I do not think we can get to the energy densities you would reach if you could go backwards in time to arbitrarily close the Big Bang (like millionths of a picosecond).
Mortician here w/a bit of a morbid Q. What's the plan for somebody dying on the 1st peopled Mars mission? Wouldn't burial on Mars mean eventual contamination?
Belote: Hang on, I went to a planet that spun the other way once, and time went backwards! (according to my sundial, anyway - it didn't feel much different)
When and how did astronomers discover that the Milky Way is a barred spiral galaxy?
On a side note, I know we can’t take a picture of our own galaxy since we’re in it. Is there a good image I could show my students to represent what it should look like rather than the nonbarred pictures that are out there?
...except we've never actually observed Hawking Radiation
Hey Fraser and hello everyone from the community,
I have a question. Is there a limit to the payload that can be carried to space using a single stage rocket? I assume at some point the weight of the fuel will be so much that the rocket cannot lift off from the pad. Is there a formula or something for that? Can anyone provide some example?
I still can't wrap my mind around the CMB and how we are able to see it.. So everything that makes up the earth was there at the big bang, and then space expanded and stuff clumped together to make us and our galaxy..So the dust we're made of expanded out and away but the CMB light just stayed at the edges of the whole expanding universe? Like if our matter was somewhere there weren't we a part of this first "light" in a sense? So wasn't the light also expanding with us? Like why is it still there? So the photons are just still constantly being emitted from the big bang and travelling 13 billion years from back then and back there to right now and right here? If you can make sense of all that and just dumb it down for me that would be great! Also red and blue shift gets thrown around a lot I don't fully understand that either.. Thank you!
Regarding "Chulak" question
I wonder had life and humans evolved on a moon around a gas giant, how would that civilization name things. Clearly the gas giant has to be part of their religion and myths, being literally in the sky, but then the sun, and other moons, and other planets, would also occupy some space in the minds of the civilization, leading to different arguments, perhaps what is a sun? what is a moon?
If there was a golf ball sized event horizon over a tiny singularity, will it eat me if I poke it?
I'm writing a medieval vampire novel that takes place on the Moon. How well do you think horses would do on the Moon? I think they would touch the ground three times and be going fast enough to splatter.
They wouldn't be able to run flat out like they do on earth because they would loose their balance.
To push hard off the ground, you need to be pulled down hard into it first - they'd mostly teeter around and fall over, like astronauts do at first.
@@Rob-eg8qc Not to mention being out of breath XD
@@LoricSwift very good point. Designing a space suit for a horse could prove difficult to make due to having the 4 legs and the long face.
@@Rob-eg8qc I would love to see some designs for that honestly!
Edura: why do the lasers need to be in space? surely we can build stronger lasers here on earth. you are not in orbit with the debris you want to remove either way.
You can’t send any information out of a black hole. But can you send information IN to a space ship that have entered say a very big black hole?
what IS the maximum gamma radiation temperature?
You said you'd "provide a link in the show notes" to Peter Kohl's blog. What is the "Show Notes"? Where is it? I'm trying to find his blog and google is useless.
It's the description under the video
@hive_indicator318 the link isn't there
Doesn't crossing the equator make the Earth seem like it is rotating the other direction? This depends on your frame of reference. Facing the North Pole, East is to your right. Facing the South Pole, East is to your left.
Not really, but maybe somehow? The sun will still rise in the east and set in the west, but it will go over the northern sky over noon, not the south. And the stars look different.
As someone living on the northern hemisphere I always think how weird it is that I know the stars in the southern hemisphere better then in the northern hemisphere, because in europe I hardly ever see them. In the middle of my Megacity, I have to not only deal with light polution, but also 79% average cloud coverage. That´s why I never care about meteorite showers or eclipses or whatever. They are behind the clouds every single time anyways.
That isn´t really related to your question, but this rant needed to get out of the system.... Sorry
@@AndreasPeters-r3e East is an arbitrary label that was developed in Europe. It is to the left if you look at the North Pole. If the definition for East had been developed in Australia, while looking at the nearest pole (South), it would be the mirror opposite, i.e.: it would be what we call West.
Most people think of North as the top of the world, but I've seen maps in Australia with Antarctica on top. These make the point that the reference frame is arbitrary. There are two poles on a spinning sphere. One pole is just as good as the other. A storm moving left-to-right viewed from the North, is moving right-to-left if viewed from the South.
There will not be solar panels beyond the Jupiter system.
The weight of the solar power system at saturn would be over 50% of the craft.
That ratio would be rejected by every countries mission assessment committee.
The cutoff presently is 20%.
In space, no-one can hear you make... whatever noise the Sun makes. I don't know what noise that is, on account of not being able to hear it, but if you make it, no-one will be able to hear you, so don't!
Or do, I guess, it doesn't really matter.
Ardena
Why don't we have more mission using radioisotope thermoelectric generators? Doesn't it increases complexity and cost to have these huge solar panels?
11:04 when is your next EC update,
A planet that spins "backwards"..... Yeah, just turn around 180° and your on a planet spinning "backwards". If you have a planet spinning against it's orbit around it's star, or against the rotation of the star or against the orbit of its moon, then there would be a difference in how long it takes the planet to become tidal locked. There would be a difference in how long the moon and sun stay in the sky each day also but that difference would be seconds per day and likely have no effect.
Alaris
Edora
I'm ok with Dwarf Planets, but I don't think the debate is over with moons, because I don't think every tiny bit of Ice in Saturn's rings for example should be called a moon.
1. A Moon should have a stable orbit around a planet that will last for a reasonable period of time. Whether that's 1,000, 10,000, 100,000 or 1 Million years can be debated. But certainly not objects that will be lost within a year or two, let alone weeks.
2. A Moon should be large enough to form an approximate sphere.
3. If its too small for that but still has a significant size, say 10km, then its a Dwarf Moon. Re. Phobos and Deimos.
4. 1-10km Diameter is a Moonlet.
5. Below 1km its just a minor satellite.
i agree with your sentiment but youre making the same mistake as they did:
making phobos a 'dwarf moon' means it has the word moon in the category and yet is NOT a moon, since here moons would be rounded. 'dwarf moon' like 'dwarf planet' implies its a type of moon/planet. instead i would use the word moonlet for anything thats bigish but not round in orbit around a planet, which includes phobos.
instead i say:
Planet: anything big n round but not shiny
Star: big round and shiny
Moon: a planet in orbit of a planet
Moonlet: asteroid in orbit of a planet
Asteroid: anything bigish but not round
[[Planetar: big round and shinyish where the surface is dominated by convection rather than wind]] (this may or may not be a new useful category between planet and star)
therefore dwarf planets and moons are a type of planet.
I have heard the larger more geologically complex moons described as 'worlds' by scientists that study them and their evolution. Before the arrival of the Pioneer and Voyager probes there was a general assumption that all moons would be mostly like our own Moon or Mercury, even if the material they were made out of different. We expected cold, cratered and dead places that were all boringly similar. Now it seems like almost every one is interesting and unique in its own way, even out to Pluto and Charon. It seems like the more we look and investigate, the more interesting they get.
@@sudazima People get so hung up on Pluto not being a planet just because it got a more specific description. Its really not much different than using the terms giant planet or gas giant/ice giant. Personally I kind of liked Issacs Asimov's term 'Mesoplanet' for everything between say the sizes of Ceres and Mercury and wish they had gone for that.
As Titan has lakes of methane ,and rains methane, could you set it on fire by striking a match?
is there the technology to see radio waves? could be a way to find aliens.
If something falls into a black hole and is later released as Hawking radiation, how much time passed from the perspective of that object between going in and coming out? Or is the premise of this question nonsense?
I do not understand where the temperature in space after the big bang came from? We learn in school the temperature is atoms moving, but inside the "big bang" there can be no movement? And then no temperature?
Are you talking about the CMB? That was after the BB, by about 380 000 years. The radiation arose because that is where the temperature became low enough for the ionised gas (plasma) created in the BB to recombine to form neutral atoms. That causes a certain type of radiation, and that is what we see as the CMB. Of course, the wavelengths at which the CMB was initaially produced have been lengthened considerably due to the expansion of space in the meantime. Which is why we now see it at ~ 2.7 K.
m struggling to find where to submit questions on mobile, coukd anyone give me directions?
You just did it
oh cool!!! i’ll submit mine right now then :]
if you can look into space and “see the past” due to being millions of lightyears away and time dilation, is there any possible or theoretical way to reverse that and see the future? any theory connecting to white holes? (basically time travel but instead of bringing ourselves to the future it’s moreso just perceiving it) I hope this reaches u!
Not that we know of. It's like hearing things after they happen because of the speed of sound. Could there be a way to hear things before they happen? Probably not.
Im in for a misión to Enceladus
2 hours, unless the power goes out.
28:38 unless there is a photo wall
Definitely not smooth
I really like the orbit picture with Lagrange clouds at 34:45. nice!