Question: what do alien rainbows look like? If water in earth’s atmosphere refracts the full visible spectrum, what colors would we see in the clouds and raindrops of other planets? For example, sulfurbows on Venus, or methanebows on Titan?
Just a random guess but since the visible spectrum is the same everywhere for humans we'd be seeing the same ? As it splits the white light from the sun which is made of UV IR and visible light... Just that the length of the waves would be split differently I guess
This is more a perception thing. Eyes in an atmosphere evolve to specialize on the wavelengths that are not reflected/absorbed before they can reach the eye. distinguishing UV or red from green is often not as important as just seeing sharper or better at night. many insect eyes can see more in the UV, and flower patterns are stronger in UV and rainbows on earth have weak UV light in them.
Hey Fraser, kind of a followup question from this week's question about James Webb imaging planets from other nearby solar systems. Is it possible to use Webb for closeup images of bodies in OUR solar system - like getting high res shots of Io and Titan and objects in the Kupier belt?
The thought that the universe might be finite is strangely terrifying to me. I try to wrap my mind around this concept but it just won't work. Infinity is everything but what does it mean if there is a limit to everything? There should be a beyond, but there might not be one. Mind bending.
With regard to multiple sightings of the same ‘object’. Aren’t we in fact seeing exactly that when we study the CMB fluctuations, as we believe these areas later developed into substantial features and groups of objects in the present day universe? In effect, we’re looking past what we observe now in the physical, to the proto-matter from which they developed?
The protomatter that developed where the currently visible CMB originated is still beyond the edge of the observable universe. Conversely, the CMB that originated at the location of currently observable matter has already passed us.
Fraser! So good to see you again! A question for you: looking at Venus with the naked eye, tonight, it occurred to me for the first time that I could make out a crescent. Am I just confusing it with the 'twinkle' effect?
maybe it is possible? I've seen Venus' crescent only via my MAK102. but it is already (with respect to us) under not the worst angle and close-ish distance of a little more than 128 Tm (86% AU) and +~32 km/s speed
Hey Fraser, Here a bit of a weird question: Would it be possible to do a new project like the international space station, where they would develop a space big ship into space? I would imagne something like this: Start with some modules, use them as a space station at first, hook more modules over time together and in the end convert the space station into a space craft and fly away with it and explore the solar system with it.
Question: With regards to gravitational lensing, if you had two galaxies aligned in series such that their focal points overlapped would you be able to discern that a source of light from behind the more distant galaxy was in fact so or would it be indistinguishable from a source at the focal point of the nearest galaxy.
Regarding the hypothetical planet orbiting in a Lagrange point. I think it would be cool with an Earth size planet in a horseshoe orbit around the 2nd star in double star system.
Follow up question to the question Could we see the same galaxy multiple time, the part you talked about gravitational lensing what version of the 4 that we see would be the real version that we would be seen on earth without gravitational lensing, if we had a larg enough telescope to resolve it?
Funny story. I watch your show here on the you tubes and see you talk about "metallic hydrogen" at the center of Jupiter. My wife teaches 6th grade science and she just rolls her eyes when I try to tell her about the extremes of what gravity and pressure can do to basic elements.
You should consider interviewing a couple of friends of mine, Ken Roy and Martha Knowles. Both are founders of the Interstellar Research Group (originally Tennessee Valley Interstellar Workshop)
The photons from the Andromeda that reached us one billion years ago have passed us long time ago, actually one billion years ago, the moment is only seen once, and we have to be there to see it
every time a new hubble deep field is done, it is being analyzed for large scale patterns, to lean about (constrains of) the curvature of the (local/visible) universe. So far, the visible universe is VERY flat and it is VERY pattern-free. Thee are no repetitions besides some local disturbances of spacetime (black hole lensing)
I’ve been wanting the first question answered for years now. It seems obvious now. You seeing the photons produced at that time. If you could wait 10 billion years for the galaxy to age then you will see it’s 10 billion year old galaxy. The farther the galaxy the younger the photons compared to the origin universe creation. Waiting will also move that galaxy progressively to another point from you reference as the university expands.
Back to Einstein GR Theory, about two different perspective between a man in the car and a man in the roadside. In reality, galaxies move in way too fast that we cant imagine
@@hafashanum39 ?? This doesn't make sense. Proof by contradiction: If you have one galaxy at a distance of 10 billion light years, and say for arguments sake you observe the same galaxy at 8 billion light years. Take the simple formula D = Vt, and solve for V. Since it has taken 10 billion years for the galaxy to move 2 billion light years (10 bly - 8bly), you arrive at a velocity of .2 light years travelled per year. Or if my maths is correct, 20% the speed of light. Galaxies simply do not travel that fast. QED.
Q/A: Follow up. What if the universe has a really strange, yet finite topography...is it possible we could see the same galaxy over & over? Could it explain dark matter?
I would like to see that too but if it was launched like New Horizons (passed by Pluto in 2015), which was the fastest launch from Earth so far, it would take about 30 years to reach Sedna. Same for Eris that I would also like a probe to.
Hi Fraser... Patron here. Over time, have we ever observed galaxies moving as in seeing them actually rotate around their SMBH or do they seem frozen in time due to their size and our limited records?
We can detect their motion because of the wavelength of their light, but we can't actually track their movements. It's only when the objects are much closer, like stars, that we can detect their movement.
Hi Fraser, A question. What do you think of nuclear-pulse ships that use miniature nuclear explosives as propellant? It would shorten the trip to Mars, Jupiter, and Saturn enormously. Politics be damned! Another question. What do you think about space habitats like Kalpana 1 and O'Neill Cylinders?
Fraser, for us city dwellers, can you show some pictures that approximately match what you would see in the sky in a place with perfect viewing conditions?
When you have spoken about interstellar human travel, you have mentioned the fact that if you launch a rocket today, it'll be surpassed by a rocket developed before the first rocket would reach it's target. And, I don't remember the timeline, that it would be better to wait for more technology to come about so this doesn't happen. Having said all that, scaling it back a bit... with all of the delays with the James Webb telescope, wouldn't it almost be better to just scrap it and implement tech from today, vs when JWST was developed? Hey, I'm hopeful the it'll launch in December as "scheduled"...
Red shift. It seems when explained, we’re told about light ‘stretching’ to lower frequencies as the universe expands. Okay I’m good with that. But when we talk of how far away an object appears to be, there seems to be an assumption that this degree of red shift is constant. I have an issue here, as surely the degree of red shift will change with the rate of expansion, which we’re told is accelerating? Have I got something wrong here?
It means red-shift vs distance would be a curve rather than a straight line, but could still be used to calculate one given the other. It would be worse if the rate of expansion wasn't the same in all places.
Voyager 1's position in Earth's sky at 12h UTC on 30 September 2021 was ρ = 154.3483751 AU α = 17h 12m 38.15s δ = +12° 09′ 21.2″ That's very near the border between Hercules and Ophiuchus, about 4° west of Rasalhague. Its distance from the sun at the same time was 154.01 AU.
Question: if the universe is expanding, the earth rotating around the sun and the milky way - does it mean we are always in NEW spot in space? And.. this is crazy... time travel might have happened but the travelers died in the vacuum of space (or inside star)?
Hi Fraser, love what you do! I have a somewhat obscure question, say if NASA or some other space agency proposed a sample return mission from titan similar to the mars sample return expected in the next couple years, would it be possible to make a launch vehicle capable of lifting off from titan? Would the atmosphere be too dense to be able to achieve orbit from the surface? Could the high concentration of methane in titan's atmosphere trigger some sort of explosion if we tried to use a chemical rocket in the lower atmosphere of titan?
But the objects move. If it moved in space faster than the light of it travels to us, then we could see it at multiple points of time and space. At least, that's what I would think. Would this be a possibility, Fraser?
Hi Fraser, not related to this topic but do you have any insight as to the process to refurbish the Dragon capsule. We've all seen closeups of the capsule after it was put on the recovery ship. Are those outer layers completely replaced or are they cleaned in some manner?
Hey, Fraser! I know that the ISS is getting old. But, how much would it cost to replace modules, until it is rejuvenated? If they didn't make any upgrades, would the modules be cheaper than when they were first attached?
Hi Fraser, stupid question - reflecting telescopes have the secondary mirror, which is in the way of the light going into the telescopes main mirror. how come there is no dark patch in the field of view?
Titan would probably have a "permafrost" problem. Just like when homes are built on permafrost in the north, the heat from the habitat would cause the ground to thaw. Hopefully you could find some bedrock to build on otherwise you are going to sink.
Maybe build on stilts like the station at the South Pole? It gradually sinks but that is because of snow accumulation so they have to jack it up sometimes.
What do you think of SpaceX, Blue Origin, and Virgin Galactic, users not being called, "Astronauts"? Should they come up with a new term? What if SpaceX sends people to Mars; would they just be called, "People who just happen to be located around Mars"?
Q: if the so called 'dark matter' exist, and in abundance, as we are told, how come it is not slowing us down, by creating 'friction' when we are swishing trough the universe? Does it have the same speed and direction as us, or is it passing straight through us?
Well, that depends on what (if anything!?) Dark Matter turns out to be. If it is what is speculated to be, a particle (or class of particles) that only interact gravitationally, as observations seem to suggest, then there will be no friction, as such, only gravitational effects. i.e. no electromagnetic interactions which is what would supply the kind of friction that occurs in normal matter, such as gas or dust clouds. Remember we are also ploughing through neutrinos all the time, and they only (so far as we know) interact through the weak force. They must have some mass though, due to neutrino oscillation, and consequently there should be SOME gravitational force on them or from them, but no-one has yet pinned down what that mass actually is. But until we get a better handle on what exactly dark matter is, (and of course to some, IF it exists at all) it's pretty difficult to speculate on how it affects us!
@@timbeaton5045 - yes, the gravitational attraction should make the earth suck dark matter from the universe like a vacuum cleaner, especially since there is more dark matter than light matter, how come we are not a black hole already?
@@doncarlodivargas5497 OK, I'm guessing that as DM would have no friction, as hypothesised, then particles of DM would move towards the centre of the earth and straight through... it basically won't clump to gather as normal baryonic matter would. Nothing apart from gravity to hold them together. None of the electrostatic forces to bind them strongly enough (if at all). That's why the hypothesis is that DM forms halos round galaxies, but aren't :vacuumed up" as you asked. It would only be loosely bound by gravitation, and the particles won't appreciably add to the mass of the earth, or any large body with a large gravitational well.
Hey I think you misunderstood the question. I think the answer to his question is "yes". If we see a galaxy 12 billion light years away we are seeing it as it was say a billion years after the big bang. Today, is there not a location that is currently receiving the light that left that galaxy 12 billion years after the big bang? If not, then where are the photons that left the galaxy 12 billion years ago? Are they not still traveling and landing on some planet as we speak? Thanks.
how big would a telescope have to be to see a star in the Andromeda Galaxy? because isn't it true that every Exoplanet or star system we have observed has been in our Milky Way???
We see small stars orbiting large stars, planets orbiting stars, and moons orbiting planets. Why do we not see even smaller objects orbiting around moons?
Our own moon has a few orbiters going around it. OK, they're human-made... It's probably unlikely to get random rocks into stable orbits around a moon in a moon-planet-star system.
12:08 “Lots of clever engineers working for NASA, working for SpaceX, working for... Blue Origin...” Hahahahahahahahahahahahaha Blue Origin aaaaaaahahahahahahaha Thanks that was a good laugh!!
On titan we also burn hydrocarbons with oxygen for heat like cooking and even operate engines to produce electricity,but we would need to produce oxygen
For a barbecue on Titan you have to bring the oxygen :-) Edit: I think in reality the methane concentration in the atmosphere of Titan is to low to set fire to but I'd be wiling to try.
This is likely gibberish but is it possible that time on the earth is reversed versus the rest of the universe so the universe is really collapsing and slowing down but we perceive it as the opposite...
Imagine the universe is actually infinite. The observable is not. Can you get the same galaxy a billion years different in time in different areas of the sky? Yes, if you assume the local geometry is sufficiently curved. We could be in a saddle shaped universe. On the large scale, the geometry is flat, but for us, who can only know the local volume, the geometry is NOT typical. It doesn't have to be. We assume it is typical merely because that is the easiest way to model the unknown. But a group of humans growing up in a chasm might assume the rest of the planet does not exist, and only the chasm exists, or that hypothetical other beings must also live in a chasm. The idea of a plain must be very strange to such a people. I am hardly an expert in this field. Perhaps someone with better qualifications will see some flaw. But yes, it seems to me that you could have the same galaxy at very different points in the sky, although the problem then would be if you could see it, as the faintness increases with distance the photons have to travel, and redshifting, and of course the evolution of the galaxy might make it unrecognisable. Perhaps we should point a very bright torch at the sky and wait to see if it shines back. Dash dash dot dash?
Pro tip. Backgrounds shouldn’t distract from your face. I’m guessing…better if this background is upside down in some way? with your head being up in the flat black and the geologic stuff down low. Maybe think ‘interesting patterns low, and subtle stuff up high’??
In videos of gravitational lensing, light curves around an object and always aligns straightish again. Is it possible light bending around an object could actually ping off at a right angle, meaning the light is not coming from the direction we see it?
Just like a regular lens the lens has to be in between the object and you. I expect a photon can turn 90 degrees by swinging by close to a black hole but it might get lost among the light from the accretion disk there.
@@zapfanzapfan This idea fascinates me. Is it possible we could see rare moments of light, where bent light comes into our view, maybe for a fraction of a second 🤔
If you ever interview Elon you can tell us all to send the most interesting, best questions regarding space exploration - I think it would make for a REALLY good, innovative interview.
Ex President of Greenpeace Patrick Moore, said during an interview with Chris Williamson that Jupiter’s gravity had an effect of Earths axial cycle. Is that nonsense?
Jupiter is tugging on us and at least effects the eccentricity of Earth's orbit. I think Jupiter effects Mars's axis tilt (Mars has no large stabilizing Moon) which can vary a lot more than that of Earth.
3:00 I like this hall of mirrors idea. Maybe thats' how our memory works? When we remember ourselves doing stuff last week, maybe we look out & see last week. So let's say we were selling bibles. The light from us selling bibles moved away from us & travelled through some sort of hyperspace but the universe's finite so the light does the pac-man thing & then reaches us this week.
@@doncarlodivargas5497 It's like pacman: pacman goes to the left of the screen & he comes out of the right of the screen. So no mirror is required. You need a finite universe with no boundaries. Maybe a donut. I once took acid & walked into a tower block about 20 stories high. At the top of the stairs we found metal bats that belonged to a gang. Sometimes people would get their legs broken. We took them with us. It was a dangerous situation so we got in the lift. In a panic, all the buttons in the lift got pressed so the lift stopped at every floor. The doors opened & there was a mirror on every floor + a mirror in the lift behind us so we'd see a thousand acid-distorted copies of ourselves standing there with metal bats. Over & over & over again Anyway the point is the 1000s of reflected copies could correspond to how we can access memories of 1000s of moments in our life. Maybe the space has no size or it's lift-size
@Pelvic Yucca - our mind are structured for gathering food and looking out for danger, probably far earlier than as humans, probably are we unable to understand what is not intuitive
@Pelvic Yucca - that fear and our compulsion may be why we are here today, and not in the stomach of an animal, but also why we can not understand the concept of infinity and nothing and such
Question: what do alien rainbows look like? If water in earth’s atmosphere refracts the full visible spectrum, what colors would we see in the clouds and raindrops of other planets? For example, sulfurbows on Venus, or methanebows on Titan?
Just a random guess but since the visible spectrum is the same everywhere for humans we'd be seeing the same ? As it splits the white light from the sun which is made of UV IR and visible light... Just that the length of the waves would be split differently I guess
This is more a perception thing.
Eyes in an atmosphere evolve to specialize on the wavelengths that are not reflected/absorbed before they can reach the eye. distinguishing UV or red from green is often not as important as just seeing sharper or better at night.
many insect eyes can see more in the UV, and flower patterns are stronger in UV and rainbows on earth have weak UV light in them.
Great video as always Fraser! Super interesting
Dear Fraser, great to see you back!
Hey Fraser, kind of a followup question from this week's question about James Webb imaging planets from other nearby solar systems. Is it possible to use Webb for closeup images of bodies in OUR solar system - like getting high res shots of Io and Titan and objects in the Kupier belt?
Ok, now that is a green screen... right... right?
Nah...he's moved to the moon.
@@donsample1002 ah, my bad... that makes more sense.
The thought that the universe might be finite is strangely terrifying to me. I try to wrap my mind around this concept but it just won't work. Infinity is everything but what does it mean if there is a limit to everything? There should be a beyond, but there might not be one. Mind bending.
With regard to multiple sightings of the same ‘object’.
Aren’t we in fact seeing exactly that when we study the CMB fluctuations, as we believe these areas later developed into substantial features and groups of objects in the present day universe?
In effect, we’re looking past what we observe now in the physical, to the proto-matter from which they developed?
The protomatter that developed where the currently visible CMB originated is still beyond the edge of the observable universe.
Conversely, the CMB that originated at the location of currently observable matter has already passed us.
Fraser! So good to see you again! A question for you: looking at Venus with the naked eye, tonight, it occurred to me for the first time that I could make out a crescent. Am I just confusing it with the 'twinkle' effect?
I've seen the crescent through binoculars. Good power binoculars, but I have seen it. You probably did too.
I have seen crescent of Venus with the naked eye.
maybe it is possible? I've seen Venus' crescent only via my MAK102.
but it is already (with respect to us) under not the worst angle and close-ish distance of a little more than 128 Tm (86% AU) and +~32 km/s speed
Hey Fraser, Here a bit of a weird question: Would it be possible to do a new project like the international space station, where they would develop a space big ship into space? I would imagne something like this: Start with some modules, use them as a space station at first, hook more modules over time together and in the end convert the space station into a space craft and fly away with it and explore the solar system with it.
Hey Fraser, what planet or moon do you think is next in line for major exploration after Mars and why? Thanks to you and your team. Love the show!
I love the first question.
Question: With regards to gravitational lensing, if you had two galaxies aligned in series such that their focal points overlapped would you be able to discern that a source of light from behind the more distant galaxy was in fact so or would it be indistinguishable from a source at the focal point of the nearest galaxy.
Hi Fraser, what are your predictions for the next NASA planetary decadal survey?
Regarding the hypothetical planet orbiting in a Lagrange point. I think it would be cool with an Earth size planet in a horseshoe orbit around the 2nd star in double star system.
there was a problem with the toilet, I forget exactly what it was, but space x is working on a fix.
Follow up question to the question Could we see the same galaxy multiple time, the part you talked about gravitational lensing what version of the 4 that we see would be the real version that we would be seen on earth without gravitational lensing, if we had a larg enough telescope to resolve it?
Funny story. I watch your show here on the you tubes and see you talk about "metallic hydrogen" at the center of Jupiter. My wife teaches 6th grade science and she just rolls her eyes when I try to tell her about the extremes of what gravity and pressure can do to basic elements.
I think talking about it in class could definitely inspire some kid to want to learn more just because it sounds so cool :-)
Best info you provide.....
I miss the topic videos. Can we get an update on the Parker solar probe?
You should consider interviewing a couple of friends of mine, Ken Roy and Martha Knowles. Both are founders of the Interstellar Research Group (originally Tennessee Valley Interstellar Workshop)
Voyager 1's hyperbolic excess speed, relative to the solar system, is 16593.6 m/s. It will be one light year from Earth in the year 20038.
The photons from the Andromeda that reached us one billion years ago have passed us long time ago, actually one billion years ago, the moment is only seen once, and we have to be there to see it
every time a new hubble deep field is done, it is being analyzed for large scale patterns, to lean about (constrains of) the curvature of the (local/visible) universe.
So far, the visible universe is VERY flat and it is VERY pattern-free. Thee are no repetitions besides some local disturbances of spacetime (black hole lensing)
Why Hubble instead of for example VLT?
I’ve been wanting the first question answered for years now. It seems obvious now. You seeing the photons produced at that time. If you could wait 10 billion years for the galaxy to age then you will see it’s 10 billion year old galaxy. The farther the galaxy the younger the photons compared to the origin universe creation. Waiting will also move that galaxy progressively to another point from you reference as the university expands.
Also, galaxies and the like don't move fast enough for them to be in two temporal locations.
Back to Einstein GR Theory, about two different perspective between a man in the car and a man in the roadside.
In reality, galaxies move in way too fast that we cant imagine
@@hafashanum39 ?? This doesn't make sense. Proof by contradiction: If you have one galaxy at a distance of 10 billion light years, and say for arguments sake you observe the same galaxy at 8 billion light years. Take the simple formula D = Vt, and solve for V. Since it has taken 10 billion years for the galaxy to move 2 billion light years (10 bly - 8bly), you arrive at a velocity of .2 light years travelled per year. Or if my maths is correct, 20% the speed of light. Galaxies simply do not travel that fast.
QED.
"If that's Shaky"... B-roll shows the shake test. You guys having fun. 😄
I like adding little things like that :D
Question: Hey Fraser, if black holes evaporate, does that make black holes a volatile substance?
Can we laser beam the voyagers 1 and 2 with lasers to make them go faster ?
Hey Fraser. Weird question but just how common is salt in the universe? Thank you so much for all the great content.
Q/A: Follow up. What if the universe has a really strange, yet finite topography...is it possible we could see the same galaxy over & over? Could it explain dark matter?
Why hasn't NASA planned any missions for Sedna yet? It's a mysterious object that would probably reveal some really cool discoveries
I would like to see that too but if it was launched like New Horizons (passed by Pluto in 2015), which was the fastest launch from Earth so far, it would take about 30 years to reach Sedna. Same for Eris that I would also like a probe to.
Here Nasa don't have funding to look at Titan mission and you want Sedna?😆
@@SJ-cl4wq sorry i offended you by asking a question, i hope your feelings aren't shattered
@@garunixreborn2416 I was more concerned with such over expectations.
Hi Fraser... Patron here. Over time, have we ever observed galaxies moving as in seeing them actually rotate around their SMBH or do they seem frozen in time due to their size and our limited records?
We can detect their motion because of the wavelength of their light, but we can't actually track their movements. It's only when the objects are much closer, like stars, that we can detect their movement.
Hi Fraser, A question. What do you think of nuclear-pulse ships that use miniature nuclear explosives as propellant? It would shorten the trip to Mars, Jupiter, and Saturn enormously. Politics be damned!
Another question. What do you think about space habitats like Kalpana 1 and O'Neill Cylinders?
Hello Fraser Caín . I hace a question , is it posible to use the radiation of space to actívate a thorium reactor for space ships ?
Fraser, for us city dwellers, can you show some pictures that approximately match what you would see in the sky in a place with perfect viewing conditions?
When you have spoken about interstellar human travel, you have mentioned the fact that if you launch a rocket today, it'll be surpassed by a rocket developed before the first rocket would reach it's target. And, I don't remember the timeline, that it would be better to wait for more technology to come about so this doesn't happen. Having said all that, scaling it back a bit... with all of the delays with the James Webb telescope, wouldn't it almost be better to just scrap it and implement tech from today, vs when JWST was developed?
Hey, I'm hopeful the it'll launch in December as "scheduled"...
Red shift. It seems when explained, we’re told about light ‘stretching’ to lower frequencies as the universe expands. Okay I’m good with that.
But when we talk of how far away an object appears to be, there seems to be an assumption that this degree of red shift is constant. I have an issue here, as surely the degree of red shift will change with the rate of expansion, which we’re told is accelerating?
Have I got something wrong here?
It means red-shift vs distance would be a curve rather than a straight line, but could still be used to calculate one given the other.
It would be worse if the rate of expansion wasn't the same in all places.
Voyager 1's position in Earth's sky at 12h UTC on 30 September 2021 was
ρ = 154.3483751 AU
α = 17h 12m 38.15s
δ = +12° 09′ 21.2″
That's very near the border between Hercules and Ophiuchus, about 4° west of Rasalhague. Its distance from the sun at the same time was 154.01 AU.
Question: if the universe is expanding, the earth rotating around the sun and the milky way - does it mean we are always in NEW spot in space? And.. this is crazy... time travel might have happened but the travelers died in the vacuum of space (or inside star)?
Hi Fraser, love what you do! I have a somewhat obscure question, say if NASA or some other space agency proposed a sample return mission from titan similar to the mars sample return expected in the next couple years, would it be possible to make a launch vehicle capable of lifting off from titan? Would the atmosphere be too dense to be able to achieve orbit from the surface? Could the high concentration of methane in titan's atmosphere trigger some sort of explosion if we tried to use a chemical rocket in the lower atmosphere of titan?
But the objects move. If it moved in space faster than the light of it travels to us, then we could see it at multiple points of time and space. At least, that's what I would think. Would this be a possibility, Fraser?
Fraser, which five bodies in the solar system do you consider most worthy of having a mission send to explore them further?
Yes! A solar system spanning starlink network!!!
With LIGO, how do they tell between bigger collisions further away and smaller collisions closer?
Hi Fraser, not related to this topic but do you have any insight as to the process to refurbish the Dragon capsule. We've all seen closeups of the capsule after it was put on the recovery ship. Are those outer layers completely replaced or are they cleaned in some manner?
Hey, Fraser! I know that the ISS is getting old. But, how much would it cost to replace modules, until it is rejuvenated? If they didn't make any upgrades, would the modules be cheaper than when they were first attached?
Hi Fraser, stupid question - reflecting telescopes have the secondary mirror, which is in the way of the light going into the telescopes main mirror. how come there is no dark patch in the field of view?
Titan would probably have a "permafrost" problem. Just like when homes are built on permafrost in the north, the heat from the habitat would cause the ground to thaw. Hopefully you could find some bedrock to build on otherwise you are going to sink.
Maybe build on stilts like the station at the South Pole? It gradually sinks but that is because of snow accumulation so they have to jack it up sometimes.
What do you think of SpaceX, Blue Origin, and Virgin Galactic, users not being called, "Astronauts"? Should they come up with a new term? What if SpaceX sends people to Mars; would they just be called, "People who just happen to be located around Mars"?
What is the very final form of matter before a gravitational collapse?
Pretty sure nuclear saltwater rockets would have similar performance to the ships in the expanse, its just incredibly dangerous, and radioactive.
Q: if the so called 'dark matter' exist, and in abundance, as we are told, how come it is not slowing us down, by creating 'friction' when we are swishing trough the universe? Does it have the same speed and direction as us, or is it passing straight through us?
Well, that depends on what (if anything!?) Dark Matter turns out to be. If it is what is speculated to be, a particle (or class of particles) that only interact gravitationally, as observations seem to suggest, then there will be no friction, as such, only gravitational effects. i.e. no electromagnetic interactions which is what would supply the kind of friction that occurs in normal matter, such as gas or dust clouds. Remember we are also ploughing through neutrinos all the time, and they only (so far as we know) interact through the weak force. They must have some mass though, due to neutrino oscillation, and consequently there should be SOME gravitational force on them or from them, but no-one has yet pinned down what that mass actually is.
But until we get a better handle on what exactly dark matter is, (and of course to some, IF it exists at all) it's pretty difficult to speculate on how it affects us!
@@timbeaton5045 - yes, the gravitational attraction should make the earth suck dark matter from the universe like a vacuum cleaner, especially since there is more dark matter than light matter, how come we are not a black hole already?
@@doncarlodivargas5497 OK, I'm guessing that as DM would have no friction, as hypothesised, then particles of DM would move towards the centre of the earth and straight through... it basically won't clump to gather as normal baryonic matter would. Nothing apart from gravity to hold them together. None of the electrostatic forces to bind them strongly enough (if at all).
That's why the hypothesis is that DM forms halos round galaxies, but aren't :vacuumed up" as you asked. It would only be loosely bound by gravitation, and the particles won't appreciably add to the mass of the earth, or any large body with a large gravitational well.
Hey I think you misunderstood the question. I think the answer to his question is "yes". If we see a galaxy 12 billion light years away we are seeing it as it was say a billion years after the big bang. Today, is there not a location that is currently receiving the light that left that galaxy 12 billion years after the big bang? If not, then where are the photons that left the galaxy 12 billion years ago? Are they not still traveling and landing on some planet as we speak? Thanks.
Hi, Fraser. Question: Do the Voyagers revolve around the Sun as they leave the Solar system?
No, they have escape velocity from the Sun in roughly the direction of the Sun's direction of travel in the galaxy.
how big would a telescope have to be to see a star in the Andromeda Galaxy? because isn't it true that every Exoplanet or star system we have observed has been in our Milky Way???
We see small stars orbiting large stars, planets orbiting stars, and moons orbiting planets. Why do we not see even smaller objects orbiting around moons?
Our own moon has a few orbiters going around it.
OK, they're human-made...
It's probably unlikely to get random rocks into stable orbits around a moon in a moon-planet-star system.
Hi Fraser,why is titan rich in hydrocarbons?
12:08 “Lots of clever engineers working for NASA, working for SpaceX, working for... Blue Origin...”
Hahahahahahahahahahahahaha Blue Origin aaaaaaahahahahahahaha
Thanks that was a good laugh!!
poor bezos he wants to be a space cowboy but we all know the real space cowboy is elon
On titan we also burn hydrocarbons with oxygen for heat like cooking and even operate engines to produce electricity,but we would need to produce oxygen
For a barbecue on Titan you have to bring the oxygen :-)
Edit: I think in reality the methane concentration in the atmosphere of Titan is to low to set fire to but I'd be wiling to try.
This is likely gibberish but is it possible that time on the earth is reversed versus the rest of the universe so the universe is really collapsing and slowing down but we perceive it as the opposite...
Imagine the universe is actually infinite. The observable is not. Can you get the same galaxy a billion years different in time in different areas of the sky?
Yes, if you assume the local geometry is sufficiently curved. We could be in a saddle shaped universe. On the large scale, the geometry is flat, but for us, who can only know the local volume, the geometry is NOT typical.
It doesn't have to be. We assume it is typical merely because that is the easiest way to model the unknown. But a group of humans growing up in a chasm might assume the rest of the planet does not exist, and only the chasm exists, or that hypothetical other beings must also live in a chasm.
The idea of a plain must be very strange to such a people.
I am hardly an expert in this field. Perhaps someone with better qualifications will see some flaw.
But yes, it seems to me that you could have the same galaxy at very different points in the sky, although the problem then would be if you could see it, as the faintness increases with distance the photons have to travel, and redshifting, and of course the evolution of the galaxy might make it unrecognisable.
Perhaps we should point a very bright torch at the sky and wait to see if it shines back. Dash dash dot dash?
Pro tip. Backgrounds shouldn’t distract from your face.
I’m guessing…better if this background is upside down in some way? with your head being up in the flat black and the geologic stuff down low.
Maybe think ‘interesting patterns low, and subtle stuff up high’??
I also have a doubt that can we see a same galaxy many times in different moment in time
In videos of gravitational lensing, light curves around an object and always aligns straightish again. Is it possible light bending around an object could actually ping off at a right angle, meaning the light is not coming from the direction we see it?
Just like a regular lens the lens has to be in between the object and you.
I expect a photon can turn 90 degrees by swinging by close to a black hole but it might get lost among the light from the accretion disk there.
@@zapfanzapfan This idea fascinates me. Is it possible we could see rare moments of light, where bent light comes into our view, maybe for a fraction of a second 🤔
a statement I use all the time.
The Anti Vax/Anti-Science/Anti-Tech people exist today because of
Vaccines, Science and Technology.
question: frasier cain and scott manley get in a drunken bar fight. what are they arguing about & who wins?
Einstein's ring
If you ever interview Elon you can tell us all to send the most interesting, best questions regarding space exploration - I think it would make for a REALLY good, innovative interview.
Fraser Cain I think is not limited to Mars and space travel to Mars.
He will get bore within 5 minutes with an interview with Elon Musk.
What proof is there that says we live in a spiral galaxy
Ex President of Greenpeace Patrick Moore, said during an interview with Chris Williamson that Jupiter’s gravity had an effect of Earths axial cycle.
Is that nonsense?
Jupiter is tugging on us and at least effects the eccentricity of Earth's orbit. I think Jupiter effects Mars's axis tilt (Mars has no large stabilizing Moon) which can vary a lot more than that of Earth.
The centre of mass of our solar system moves, it's not even always within the sun, and most of that movement is because of Jupiter.
EIEIO
Love your first answer, that universe IS finite. Many dumb scientits out there say it otherway ❤❤❤❤❤
I'm not saying it is. I'm saying, it could be. But it also could be infinite.
That doesn't sound right. If you can see something as it was 1 billion years ago, you should be able to see something as it was 12 billion years ago.
You'd have to move 11bn LY in zero time to see both perspectives.
3:00 I like this hall of mirrors idea. Maybe thats' how our memory works? When we remember ourselves doing stuff last week, maybe we look out & see last week. So let's say we were selling bibles. The light from us selling bibles moved away from us & travelled through some sort of hyperspace but the universe's finite so the light does the pac-man thing & then reaches us this week.
The light from us selling bibles cross the whole universe and back again in one week? And who did put up that mirror at the end of the universe?
@@doncarlodivargas5497 It's like pacman: pacman goes to the left of the screen & he comes out of the right of the screen. So no mirror is required. You need a finite universe with no boundaries. Maybe a donut.
I once took acid & walked into a tower block about 20 stories high. At the top of the stairs we found metal bats that belonged to a gang. Sometimes people would get their legs broken. We took them with us. It was a dangerous situation so we got in the lift. In a panic, all the buttons in the lift got pressed so the lift stopped at every floor. The doors opened & there was a mirror on every floor + a mirror in the lift behind us so we'd see a thousand acid-distorted copies of ourselves standing there with metal bats. Over & over & over again
Anyway the point is the 1000s of reflected copies could correspond to how we can access memories of 1000s of moments in our life. Maybe the space has no size or it's lift-size
@Pelvic Yucca - our mind are structured for gathering food and looking out for danger, probably far earlier than as humans, probably are we unable to understand what is not intuitive
@Pelvic Yucca - that fear and our compulsion may be why we are here today, and not in the stomach of an animal, but also why we can not understand the concept of infinity and nothing and such
FAKE! Fraser clearly is not in space next to an astroid and using a green screen! Caught you! 😂
What causes Jupiter's intense radiation field?
Question: Around the time when the Earth was a snowball, do we have any idea what was happening on Mars?