I am 62 years old and lived through the entire course of our space-faring heritage. It is one of those things in life that pleases me beyond words. NASA has published countless pictures of actual spacecraft in both Earth orbit and lunar orbit. There is an entire catalog of the Gemini 6 and 7 rendezvous, as well as catalogs of spacecraft photos during the Apollo missions as the Command/Service Module was separated from the Lunar Module, each able to take pictures of the other. However, one of my favorite picture sets is from the Apollo 12 mission, which landed literally within walking distance of the Surveyor lunar probe - absolutely stunning. All of these wonderful images are public domain and can be found with even a cursory Google search. Of course, as the saying goes, "There are none so blind as those who will not see". If you're inclined to believe everything NASA does is fake, then these phenomenal pics won't change your mind. Another great segment, Fraser. As always, thanks so much for sharing. Steve
Exactly right. Pictures can all be faked. With enough effort you can fake entire movies. But then why would you? The benefits we already have from space activities like weather satellites, GPS, satellite TV, satellite phones... can't be faked. The mental gymnastics to dismiss photographs are easy. The mental gymnastics to dismiss GPS, satellite TV, satellite phones are way harder. There's an amatuer rocketeer who's keen to launch himself to see if his flat-Earth beliefs are true. I expect, if he survives his trip, he will come back with his beliefs confirmed in his own mind. If he sees evidence of a spherical Earth he will likely construct some elaborate conspiracy of a holographic dome and Illuminati & lizard people. Conspiracy theorists will go to crazy ends to defend their investment in their theories.
Metal Gear: "People dont trust NASA cuz NASA gives & gave them plenty of reasons not to." Pure, unadulterated hogwash. *Virtually* no one who lived through the 50's, 60's and 70's disbelieved that NASA indeed accomplished the feats as transcribed in history. There has been an infinitesimal rise in those who disbelieve virtually everything in the generations since, culminating in a slightly larger group of crackpot, conspiracy theorists in the millennial generation. Why? I haven't a clue. Perhaps there are just too many distractions available today to allow some of the more effervescent among them to focus on facts. Perhaps they're all just that much smarter than the rest of us and see things the rest of us just miss. Perhaps it's all that GMO that's rearranging their DNA and retarding their synaptic spark. Or, perhaps they prefer to live in their own make-believe world, where they can dismiss the facts and insert their own set. Regardless, I'll forever hold in reverence the achievements of NASA through the Mercury, Gemini and Apollo missions. I'll also forever applaud the exploits of that hallowed gentleman, Buzz Aldrin, the second human to set foot on the moon, and the first moonwalker to punch one of these naysayers square in the nose when arrogantly confronted. Well done, Buzz. Well done. Steve
Metal Gear Yeah, experts aught to know more than everyone else... that's what makes them experts. If they knew only as much as everyone else they'd just be... everyone else. I want to see the sciences populated by the best and brightest. I want a handfull of people pushing the frontiers of knowledge. I'm perfectly ok with not knowing everything about everything and trusting in experts to know their specialty. I'm ok if a particular expert sucks at everything outside their field of expertise.
The only way I know of to simulate "annotations" is to add them to the Closed Captions, or make a separate CC commentary Track. (There is a Board Game Play through Channel that does the latter, where they use a separate CC track to point out all the mistakes they made during gameplay, or to clarify the rules.)
Fraser, would we be able to detect our own radio and tv signals at our closest star Proxima Centauri at 4 light years away? Or would we have trouble detecting them.
Nothing like a 'Big Rip' to dip your toe in the pool of existential nihilism. Just in the time for the holiday season ! Thanks again citizen Cain. May you be free of snowstorms ( buwhahaha ) and checking the BCHydro Outage Page first thing in the morning !
15:00 I always think of a big centrifuge you could lie in to be under 1g while you sleep to help keeping your bones in check. We could do this on the moon/mars too.
Amy on "Vintage Space" makes annotations on her videos if she has made a mistake. This saves her time from having to reshoot the scene, especially if she discovers the error during final production. I don't make videos, but people who do make corrections to what they say all the time.
22 Billion years until a possible “Big Rip” doesn’t sound very long. I’m used to hearing about red dwarfs that will last 100 Trillion years or something like that. 22 Billion doesn’t sound like much at all compared to the timespans you mentioned in your “How to Save the Sun” video. :( I hope dark energy isn’t accelerating.
It won't happen. Everything that is gravitationally bound like the local cluster will merge which is Andromeda, Milky Way and a few smaller dwarf galaxies but everything outside that group will just be too far away and we'll never meet. The reason Big Rip won't happen is bc the vacuum has uniform density that is the energy in 1m^3 is the same everywhere in space. Even if you created more space it's energy in m^3 is lower than the gravitational attraction. Which means there will be more space between those galaxy clusters but they won't meet. Check Ethan Siegel, a PHD physicist that regularly blogs about space stuff, he talks a ton about it and he can explain it better than I can.
Poor Fraser gave in to the flat boys, you can actually see 50 shades of red on that melon. Fraser you have done so well ignoring the trolls for the most part but over the last month or so, you have acknowledge them. Be careful they multiply like Tribbles.
On the video request for spacecraft in space I'd point to Gemini rendezvous missions (VI and VII?), and many Dragon/Progress missions to ISS. You can often see them on the live broadcast from the ISS.
Thanks for the correction. I was waiting for you to correct that. People make mistakes, and you admit & correct yours. Love your ethics & your channel. Peace.
On the topic of photos ... plenty of images from various manned missions out there as well. Anything from russian and american manned flight (especially those involving rendezvous), great footage of hubble maintenance, etc etc etc.
On my other travel channel I put up a "card" at the mistake. It doesn't stop people from noting my mistake but it at least has the correction popping up when I talk.
Pictures of spacecraft: There are many pictures of the ISS, the Hubble Telescope and shuttles that were taken from nearby spacecraft. Here is one of Discovery taken from the ISS: i.telegraph.co.uk/multimedia/archive/01374/shuttle-station_1374726i.jpg
SpaceX often has brief videos when they detach probes and capsules after launch as well. Admittedly you don't tend to see all to much or for very long as they tend to quickly drift out of view, but it's something. Here's an image from one of those, spacenews.com/wp-content/uploads/2015/12/falcon-deploys-11th-orbcomm-satellite-2015-12-21.jpg You occasionally can find images of this kind from other launchers as well. So there certainly should be a fair number of images to find if one but knows what to look for.
This question made my brain hurt. People who think they are smarter than everybody else but don't even get that you need a camera to take pictures. God damn.
4:48 ... but technically we aren't crashing into each other right? Technically aren't we moving towards a common center in the galactic cluster? From the models I've seen it looks like we are moving much faster towards the center of the cluster than we are towards Andromeda. There's no doubt we will collide, but most of the 3d galaxy collision models seem to focus on a head-on type of encounter. Technically it's more like a freeway onramp merger from what I've seen in the more recent mapings of our galactic region. I forget where I saw the model of the galactic cluster recently. Sorry, it might have even been here. I'm a bit spacey after just leaving the hospital from practically the world's worst case of the flu.
Regarding binary galaxies, the tidal forces are indeed the main issue. But you can have a very small galaxy orbiting a very large galaxy for considerable time. Think Magellanic clouds, or just globular clusters. There are small enough that they can survive many orbits around the big galaxy and still keep reasonably together as long as they stay far away from dense regions.
What if black holes are the counterweight to the expansion of space , so what if black holes are preventing a big rip in an ever expanding space. If there is new Blackholes created by merging galaxy superclusters or Deaths of supermassive stars , space can expand forever. Just a thought.
How far can something orbit out without it leaving the solar system? Does it matter how close the solar system is to its nearest neighbor (ie, it might be so close to escape from the solar system that it could get 'sucked out' by the gravity of our neighbor)?
I have a question it concerns our sun. The sun has been converting Hydrogen to Helium for approx. 4.5 - 5 billion years. Due to solar winds, light,and mass ejections, is it possible to guess-a-mate how much mass the sun has lost? Has this mass loss effected it's gravity to any great amount or is to little to cause any changes to the solar system?
William Bays According to Wikipedia the sun has already lost about .01% of its mass to solar wind. The sun is expected to get bigger and hotter in its old age so it may lose around .1% of its mass just to solar wind. Then there's mass-energy loss due to fusion and e=mc2 which is roughly three times as much as the solar wind. All told the sun will likely have shed .4% of its mass by the time it dies.
I would have thought it was more. I always thought there would be more loss due to mass to energy conversion and radiations. Protons loss to light, electrons loss to EM and charged particles. I don't count H to He conversions because a pound of H or a pound of He is still a pound. Of course minus any mass loss to the conversion process itself.
Once we understand gravity as well as we understand electromagnetism, using centripetal acceleration to evoke gravity would go the way of gaslamps when the lightbulb was invented. Further still, compare the first lightbulb to modern supercomputers. I can't even imagine what the "supercomputer" equivalent of gravitational technology would be/used for.
So to protect Mars from solar wind we'd have to install some sort of a shield at Mars - Sun lagrange point. But if we do so, won't the planet be in an eternal eclipse? How would we ever get plants to grow on Mars if it's constantly in a shade of whatever we use to cover it up from solar wind?
No, for that it should be huge. For there to be an eclipse like on earth with the moon, once in a while on a small portion of the planet, it should be more than 6000 km in diameter. To plunge mars into a constant night, it should be more than 230 000 km in diameter... Please someone ceck my numbers (which are rounded) to see if there is no error. To calculate that is not very difficult, all you need are these data and a little elementary geometry: - mars-L1 distance : 1x10^6 km - mars-sun distance : 228x10^6 km - The sun's diameter : 1.4X10^6 km - for the scond number you must also have Mars diameter : 7.2x10^3 km.
Fraser, Your Venus 'snow' scenario might work as an alien conquest technique. Set up a sun shield in space to cool Earth until most life freezes. Remove shield and let the planet re-heat. Then invade with little resistance. Not that I'm trying to conquer Earth but... thanks for the suggestion!
SpaceX had a live feed a couple of months ago where they deployed something like 12 satellites into orbit. You can clearly see them fading off into the distance behind the rocket. Really cool stuff.
Fraser, to that person that wanted to see pictures of spacecraft in space, there are plenty of pictures of gemini 6 & 7 as they were flying in formation after they rendezvoused back in December of 1965. And there are various pictures of Gemini docking targets taken from Gemini spacecraft too. Still that person still won't believe it, but they are there.
the big rip entails the universe's expansion accelerating so much that the universe reaches the point where all distances within it become infinite, right? if that's the case then I'm quite curious what we'll see when the curtain gets pulled back. Secondary question: would it be possible to have an entirely airborne ecosystem evolve on/in Jupiter or Saturn? tertiary question: wait, why was the surface of Mars grey at 20:28?
You'd be getting torn apart at the atomic level, so you might be a little busy to appreciate exactly what's going on. The airborne idea is a cool one, and that's also being considered over on Venus.
How do we know ancient Mars had water like we see in so many renders? The polar caps wouldn’t provide enough water to completely cover the planet, would it?
From the Kazmir effect experiment, since there's a force that pushes the plates together, then where does the energy that pushes those plates come from? Surely it can't be made from nothing, which would violate conservation of energy?
Fun4uitstrue Think of it like potential energy, the plates are pushed together by the kashmir effect. The same amount of potential energy released from letting the plates approach each other, is also necessary to take them apart. It's just like a regular pressure differential!
Regarding Oumuamua, technically any such pass around the Sun is a slingshot "maneuver", regardless whether it gains or loses speed. And it seems to have gained some energy to me, though it's rough guess - it came very roughly from the direction in which Sun is traveling around the Milky Way, and it left roughly that way too. So whatever it was lacking in motion at that direction, it gained that amount. It did not gain anywhere near the speed to leave Milky Way and it would not even if it left in the most convenient direction, i.e. towards Cygnus constellation. With 230 km/s Sun's orbital speed, about 30 km/s on top of it is nowhere near enough - you'd need to leave Sun at about 100 km/s excess velocity in the right direction to achieve that.
Question: Do you think it would be possible that the SpaceX Big Falcon Rocket could help to build a base on Titan? There are oceans of methane for fuel and there is ice for oxidiser. Could a base be built there after we have one on Mars, or is it just too cold and dark on Saturn's largest moon?
They do, but stuff gets wedged behind junk, floats out. In Endurance, Scott mentions how he found a water bottle from an astronaut who hadn't been there for 3 years behind a pipe when he was working on a water filter. Pretty amazing, actually.
If black holes only get bigger whatever you throw at them, why do virtual particles cause black holes to evaporate and not just make it bigger and bigger ?
The crux of the issue is how the problem is usually explained. In this case, the particle pairs are _virtual_ (rather than 'real') up until one of them escapes. Once that happens the escaping particle is no longer 'virtual', but real. Since real matter/energy can neither be created nor destroyed, in this case (via _exceedingly_ complicated mathematical theory) the mass of the particle is drawn from the black hole, leaving it that much smaller than before. In other words, think of it like the escaping particle were 'real' & the captured particle were 'unreal'. (This still isn't right, but it's better than the particle/anti-particle image, imo.) Because they were BOTH virtual (i.e. 'unreal') to start with, the escaping particle always becomes 'real' with all the rights & responsibilities of a genuine particle in space-time, while the captured particle always subtracts an equal amount of 'real' particle mass/energy from the BH. The actual picture involves something called the Unruh Effect, & I can't do that justice in YT comments. Look for "The Black Hole Death Problem" by Physics Girl on YT (th-cam.com/video/ADM4oxBCkVk/w-d-xo.html ) for the best SIMPLE explanation I've seen on the matter, & hopefully that'll uncomplicate things... you know... _slightly._ Black holes are weird, you guys. ^_^
Great point: If we were to cool Venus as Fraser suggests, but do so _without_ reducing the amount of atmosphere/air pressure, then yes: the CO2 at or near Venus' surface would likely reach a point where it becomes a super-critical fluid, then an actual liquid below ~32 C. It's points like this that the terraforming engineers will absolutely need to consider when planning out their order of operations. ^_^
Regarding our future descendants going to a higher gravity planet, I've always envisioned that we would have a rotating generation ship that would very slowly increase the rate of rotation so each generation would be born into a slightly higher gravity. This would, of course, assume that we have a good idea what the destination planet's mass/volume is.
Edit: Omuamua was not “huge” as I claim below. I apologize for incorrectly claiming so. Q: The interstellar asteroid was huge and came in very fast and pretty close to Earth. What is the danger to Earth of collisions from interstellar asteroids? If the recent visitor had been on a collision course with Earth, how would it compare to the dinosaur-killer impact? Bigger? Smaller? How does knowing that these interstellar asteroids exist change our risk calculations for asteroid impacts? Seems like these are an entirely newly discovered class of threat to Earth that was alway present, but we didn’t know about. Could you speak about that?
The chances are slimmer than you winning the lottery. Imagine firing a bullet in a general direction of Washington D.C. and hitting the P.O.T.U.S. Nearly an impossibility.
Pha Q EDIT2: In the following comment, I assert that Omuamua was 10km long. It is not. It is closer to 230m to 300m in length, vs the 10,000m I claimed. My conclusion that this particular space rock would have been an extinction-level event is therefore falsified as one another commenter kindly pointed out. However, there were certainly many more asteroids that missed the earth than hit it during the age of dinosaurs. That this particular one wasn’t as dangerous as I thought in no way changes our level of risk from whatever it actually is, despite the human tendency to incorrectly assume so. End of EDIT2. Wouldn’t a better analogy be more like blanketing all of Maryland edge to edge with a random distribution of guns and artillery ranging in size from from BB guns to those massive canons that shoot tactical nukes, and then continuously firing them all in random directions for a year with infinite ammo and no breakdowns. What are the odds that at least one shell will hit the White House over the course of a year? 5 years? Ten? The chance of any single asteroid hitting us are tiny, but there are an unknown number big enough to do damage and we don’t know where they are. The fact that Omuamua didn’t hit Earth might (speculation) be within the margin of error of the Casimir effect for the duration it was warmed by the sun. It was a dinosaur-killer that we didn’t see until after closest approach. That last sentence should send chills up your spine and make you want to call your representatives to have them increase NASA funding. I repeat: This was a dinosaur-killer-sized asteroid (~10km cigar of rock traveling fast) that came within 60 lunar orbits of Earth (if I recall correctly) and we didn’t see it until after it would have hit us. Even if we had seen it, there wouldn’t have been a damn thing we could do about it even if we saw it a year in advance because our preparedness is so poor. I am alive writing this and you are alive and reading this right now because of dumb (orbital mechanics) luck, and I for one am immensely uncomfortable with that state of affairs. Our luck will run out, and it only takes one. We need to make space rock defense a budget priority. It’s not just asteroids in stable orbits anymore. Long-period comets and now we know that blind “interstellar snipers” could take us out with little warning. We were ALWAYS at risk from these things and we simply didn’t know it. NOW WE KNOW, and we need to turn that knowledge into defense. Call your representatives and ask about space rock preparedness. Talk to people, turn it into a conversation. Beware of falling (space) rocks. Edit: To clarify, I’ve always thought our preparedness level was abysmal, but learning about this new ongoing danger has caused me to become more outspoken.
The dinosaur impactor is estimated to have been 10km in diameter. Oumaumau is estimated to be about 300 meters along its longest length, so about 3% in diameter. Volume and roughly the mass would go as the cube of the diameter so it would be .003% the volume and mass of the dinosaur impactor. Oumaumau would have struck Earth at 2 or 3 times the velocity and energy increases with the square of the velocity, so a total energy about .01% that of the dino killer. Enough for a decent crater or tsunami, maybe a degree or two of global cooling for a year or two, but far from an extinction level event. Had it struck a major population center it could easily kill a few million people, but the odds of that are fantastically small.
Lenard Segnitz My apologies. I thought I had read that Omuamua was 10km long but that is wrong. I have have not checked your math but I have verified your input numbers are valid. Omuamua was not an extinction level event as I claimed if your math and impact speed estimate is correct, which it sounds like it is. That said, there really is no upper limit on the incoming velocity of an interstellar object on a hyperbolic trajectory. We ought not assume an upper limit on risk levels based on a single data point. I thank you for your thoughtful and considerate correction.
I think Isaac Arthur said that if you try to separate quarks it creates more out of nowhere. So the final ending of the big rip could be a huge release of energy?
We discovered Oumuamua when it was leaving the solar system, after passing at it's closest point to earth, so probably not. Even if we did get lucky and discovered one like Oumuamua heading to us, it would probably be moving just way to fast for us plan and launch something that would divert it in time. That's just my thoughts anyways :)
One-time interstellar visitors suffer from short lead-times and short observation arcs. To peg down a decent orbit for an object it helps to have repeated observations over months or years. Oumuamua was in and out of the inner solar system in the time we needed to peg down its orbit. Deflection is best done early and often. It's possible that Bennu and Apophis will be subjected to deflection projects each with a good decade of advanced notice. To have a significant effect on Oumuamua we would have needed an accurate observation arc starting when it was still 30+ AU out from the sun. That's a tall order even for objects a thousand times bigger. The nice thing about interstellar threats is that they only get one crack at being a threat. Oumuamua is gone, done, never to be a threat to Earth ever again. I'm much more worried about Earth-crossing objects that get a crack at being a collision threat every year or two. Other than being a scientific curiosity Oumaumau is really not very interesting. At best we might get a pixel or two, or if we invest a ton of money we could get a New Horizon-type of probe to fly by it. Earth-crossing asteroids are potential mining sites that could significantly change the human presence in space. Bennu and Apophis are not only collision threats but potential hardware stores.
Hey Fraser, I was thinking on the feasability of the hyperloop and it came to my mind. Could you layer vacuum tubes, one with full vacuum inside one with higer pressure inside one with even higher pressure and so on to minimize force on each individual tube. There must be something wrong with this but I can't figure it out. So please tell me why this won't work.
I'm sure you could, but it would require much more engineering. I'm assuming engineers have done the calculations and decided the structure that'll work best for a hyperloop. If you had multiple loops in the same area, it might make sense to house them in a larger lower pressure structure?
Regarding seeing a picture of actual spacecraft in space, go to the Space-X youtube channel and find one of their videos where they launch a rocket to deploy multiple communications satelites. They did this for Iridium for example. If you skip to the end where they depoly the satelites you'll be able to see the satelite as well as Earth. If you look closely you can see multiple satelites in relation to each other, it's pretty cool.
Search for "Gemini spaceships in space". The Gemini missions had a few with 2 ships together to practice docking. Really cool pictures, some that include astronauts while spacewalking.
Gravity assist slingshot maneuver definitely applies to Oumoumoua and solar system which are both in orbit around the galactic barycenter. Oumoumoua and solar system have mutually altered their galactic orbits.
Question: Fraser will the JWST be able to observe details of stellar "surfaces" ? There is so much hype about the possibility of observing or at least characterizing exoplanet atmospheres. It would seem that in comparison it would be easier to observe activity on a star's surface, the equivalent to sun spots, coronal-mass ejections, flares, etc..Thanks
Hubble and ground based telescopes can already see the surface of red giants, so I can see JWST taking those observations to the next level. It's an infrared telescope, so much better at looking at really cool stuff.
Not physically, but just as Earth has an escape velocity, so too does every collection of mass... the galaxy & its DM halo included. Google reports that in our vicinity the galactic escape velocity is ~540 kilometers per second, so if you can get moving faster than that, you'll be on an escape trajectory, despite the DM halo.
Alaskan Ballistics Although we aren't sure what DM is physically composed of, we can say for sure that it doesn't form a solid shield-like "wall" around the galaxy, a la the original Star Trek's edge of the galaxy energy barrier, so it's probably not an issue. =D
R.Instro okay so don't take my spaceship through the actual physical dark matter hard parts... Gotcha, avoid those since we can't detect them, get through the tight spots
Hey, Fraiser, awesome show. I was listening to a description by Leonard Susskind of bubbles of new spacetime, whole new universes, can form within our own universe. it got me wondering, is it possible that the CMB cold spot is one of these expanding universes?
Hi Fraser Which video of yours do you think would be the best to show how awesome your channel is? I have just recently discovered your channel, your videos are amazing! I am learning so much from it, never been so interested in space before. I would sometimes try to send it to some of my friends, but I have unfortunately never succeeding in gaining u another subscriber. Do you have a "best" video that can act as a good intro to your channel that I can try to send to my friends? Thanks for all the great work!
Hey Fraser, had a question: Would stars in a very near orbit to the supermassive black hole at the center of the galaxy with insanely fast orbital speeds experience time dilation compared to us on the outer arms? Or a more general question: What frame of reference for speed determines how time dilation is experienced (do whole star systems experience time at a different rate?)
When a comet is on a parabolic orbit, it's in the process of getting captured by the Sun. But a hyperbolic is on an escape velocity out of the Solar System.
It's a measure of eccentricity. 0 eccentricity is a perfectly circular orbit. Between 0 and 1 is anything gravitationally bound to the sun in a near-circular or highly elliptical orbit. Exactly 1 is a parabolic orbit which signifies an object that "fell" from a nearly motionless point with respect to the sun and is bound to go back out to a motionless point. Everthing above 1 is hyperbolic and is gravitationally unbound to the sun. Everything we observe is elliptical or hyperbolic (which is technically elliptical too). Exactly 0 and exactly 1 are pretty much mathematically impossible. There is no such thing as an orbit which isn't a conic cross-section. You need artificial thrusters to pull off an octogonal or hexagonal path through the solar system.
Fraser cain- good video am really enjoying you QA videos. Have question- i know its only gonna be a to guess, but since are universe is speeding up as it rotates, what do you believe making it speed up/going to. My 2 guesses are 1 we are in a solid enclosure. Easyest/shortest way to describe it is the MIB theory. 2 there is a giant invisible bouble kinda like the Van Allen belt (stationary or expanding not sure) around are universe that pulling everything toward it. Then past that emptiness/nothing.
Hi Fraser, happy holidays! I'm not sure if you answered this one already, but when it comes to space colonization: do you prefer large space stations or planetary settlements?
It would be the first extra-solar object found within the solar system, but it isn't the first non-stellar extra-solar object directly imaged. A number of exoplanets have been directly observed in the past decade.
Two galaxies can indeed orbit each other, if they do so at a separation that is large compared to their physical size. Each galaxy needs to be beyond the tidal disruption radius of the other galaxy (conventionally, at least three times the Hill radius).
when talking of the big rip, estimates on the affects of dark matter were used but recently there have been info and even arguments online about dark matter not being proven and theories falling apart, could you perhaps do a more down to earth explanation of what has happened in the community and the meaning of it all...also on the matter of waste floating in the space station why dont they use a series of low powered vacume cleaners to draw the particals in,just a thought..
You can also find lots of pictures and videos of satellites being launched from the shuttle cargo bay, Hubble while being serviced, cargo and crew capsules docking and leaving the ISS and Mir, Agena upper stages photographed from Gemini capsules...
Lets say that we would send a probe to another star system and assume we can keep it alive during the journey, would we be able to and do we actually have the technology to plan a flight path in interstellar space? Like we do when sending a probe to another planet and would it be able to navigate? I get the images of Voyager passing Jupiter and beyond in my head so would we be able to predict where a star system is and where it should be when the probe reach its destination?
Why don’t we continuously send spacecrafts to orbit the sun and get a gravitational slingshot to go to other planets in the solar system? Wouldn’t it be faster since the suns orbital speed is 200km/s which will reach Uranus and Neptune much quicker
My limited understanding of gravitational slingshotting is it only works when the object you're trying to slingshot off of is moving in the general direction that you're trying to go. For example. If you were trying to get to a planet and another planet was "on the way" and moving in the same direction, as you approach the "another" planet, it will start to gravitationally pull you towards itself, which so happens to also be towards the target planet. The Sun isn't really moving towards any other planets, it's relatively motionless. The Sun is moving 200km/s relative to the Milkyway, so you could in theory, sap some of that movement. But we kind of are already as we originate from within the solar system. The Earth is moving 30km/s relative to the Sun. The Earth is moving 200km/s+-30km/s relative to the Milkyway. I want to say that slingshotting is only applicable to two objects that are not already gravatationally bound. The Oberth effect still applies, making thrust based acceleration more efficient nearer the Sun.
It's an interesting question, since the Oort cloud is a supposedly a bubble rather than a disc, direction doesn't mean too much? The speed could be explained by a binary pair orbiting each other, when one of them is involved in a collision the other is propelled away at high velocity?
I've heard scientist's say: 'If you were to remove all matter from the universe except for say, two basket balls and placed them at opposite ends of the known universe.. they would attract and eventually collide..' Is this true? What about the expansion rate of the universe? Wouldn't there be a certain distance at which the expansion rate would overcome this gravity? If so, how far away would a 16oz object have to be from an identical 16 oz object for this to happen or is that not how it works?
When we talk about the size of black holes, do we talk about the size of the event horizon? Because thats all we can observe, right? We can calculate the mass, but do we know how big a black hole really is? If we do, how can we observe the size?
A while ago in one of your Q & A shows you said that Jupiter had a chance of kicking out Mercury and maybe just maybe Earth in billions of years, so you said we should mine away the outer planets. But doesn't Jupiter act as a shield from asteroids and comets to Earth, sucking in all those dangerous objects?
There are plenty of pictures of spacecraft taken before/after docking with the ISS, and probably Skylab and MIR too. Here's some now: www.space.com/11899-photos-shuttle-endeavour-space-station-nasa-gallery.html
Hey Fraser, How about listening through your vids 'before' posting it? Just to check for errors? You seem to be right on top of your errors, but 'slightly' too late. My Dad ALWAYS does this with his texts. Seems to me, just a quick proof read would solve the problem. Maybe not, but just an idea that I'm throughing out there. Peace Fraser! Love your channel. Don't take this the wrong way. Many people love your channel, myself included. Keep up the GREAT space info work! PEACE!
One of the problems is that it's super hard to notice you're own typos and errors. I do listen after and fix issues. AND Chad catches mistakes that I've made.
I love this channel and I have a question. I am looking for a great book about physics/astronomy or anything about science. Which books do you recommend? I have read the astrophysics for people in a hurry so I am looking for something similar to this. Thx!
How are galaxies moving away faster than the speed of light? Objects with mass can't travel faster or equal to light, right? Or it's because a galaxy is moving in our opposite direction? I didn't understand how this works.
WiperHunter well right now space is not expanding faster than the speed of light. Every bit of space is expanding and at a much slower rate than that, but over a large enough distance the accumulated rate of expansion between two points would amount to them moving away at a speed faster than light.
Hey Fraser, I just watched your video on Oumuamua. I'm curious, are we at the point where we could capture an asteroid and put it into our own orbit for longer term studies? How hard would this be and would this adversely affect the Earth?
I am 62 years old and lived through the entire course of our space-faring heritage. It is one of those things in life that pleases me beyond words. NASA has published countless pictures of actual spacecraft in both Earth orbit and lunar orbit. There is an entire catalog of the Gemini 6 and 7 rendezvous, as well as catalogs of spacecraft photos during the Apollo missions as the Command/Service Module was separated from the Lunar Module, each able to take pictures of the other. However, one of my favorite picture sets is from the Apollo 12 mission, which landed literally within walking distance of the Surveyor lunar probe - absolutely stunning. All of these wonderful images are public domain and can be found with even a cursory Google search.
Of course, as the saying goes, "There are none so blind as those who will not see". If you're inclined to believe everything NASA does is fake, then these phenomenal pics won't change your mind.
Another great segment, Fraser. As always, thanks so much for sharing.
Steve
Well said!!!
Exactly right.
Pictures can all be faked. With enough effort you can fake entire movies. But then why would you?
The benefits we already have from space activities like weather satellites, GPS, satellite TV, satellite phones... can't be faked. The mental gymnastics to dismiss photographs are easy. The mental gymnastics to dismiss GPS, satellite TV, satellite phones are way harder.
There's an amatuer rocketeer who's keen to launch himself to see if his flat-Earth beliefs are true. I expect, if he survives his trip, he will come back with his beliefs confirmed in his own mind. If he sees evidence of a spherical Earth he will likely construct some elaborate conspiracy of a holographic dome and Illuminati & lizard people. Conspiracy theorists will go to crazy ends to defend their investment in their theories.
Metal Gear Not everything is wrong. But you are.
Metal Gear: "People dont trust NASA cuz NASA gives & gave them plenty of reasons not to."
Pure, unadulterated hogwash. *Virtually* no one who lived through the 50's, 60's and 70's disbelieved that NASA indeed accomplished the feats as transcribed in history. There has been an infinitesimal rise in those who disbelieve virtually everything in the generations since, culminating in a slightly larger group of crackpot, conspiracy theorists in the millennial generation. Why? I haven't a clue. Perhaps there are just too many distractions available today to allow some of the more effervescent among them to focus on facts. Perhaps they're all just that much smarter than the rest of us and see things the rest of us just miss. Perhaps it's all that GMO that's rearranging their DNA and retarding their synaptic spark. Or, perhaps they prefer to live in their own make-believe world, where they can dismiss the facts and insert their own set.
Regardless, I'll forever hold in reverence the achievements of NASA through the Mercury, Gemini and Apollo missions. I'll also forever applaud the exploits of that hallowed gentleman, Buzz Aldrin, the second human to set foot on the moon, and the first moonwalker to punch one of these naysayers square in the nose when arrogantly confronted. Well done, Buzz. Well done.
Steve
Metal Gear Yeah, experts aught to know more than everyone else... that's what makes them experts. If they knew only as much as everyone else they'd just be... everyone else.
I want to see the sciences populated by the best and brightest. I want a handfull of people pushing the frontiers of knowledge. I'm perfectly ok with not knowing everything about everything and trusting in experts to know their specialty. I'm ok if a particular expert sucks at everything outside their field of expertise.
The only way I know of to simulate "annotations" is to add them to the Closed Captions, or make a separate CC commentary Track. (There is a Board Game Play through Channel that does the latter, where they use a separate CC track to point out all the mistakes they made during gameplay, or to clarify the rules.)
Fraser Cain and PBS Spacetime, how can television even compete?
They seem to be doing pretty well so far. :-) They did Cosmos and Planet Earth...
Fraser, would we be able to detect our own radio and tv signals at our closest star Proxima Centauri at 4 light years away? Or would we have trouble detecting them.
Great job, humility, care a lot to what you are talking!
Thanks for watching!
Nothing like a 'Big Rip' to dip your toe in the pool of existential nihilism. Just in the time for the holiday season ! Thanks again citizen Cain. May you be free of snowstorms ( buwhahaha ) and checking the BCHydro Outage Page first thing in the morning !
For All the cool info you put out, one mistake is forgivable, maybe more than one. Lol... Thanks for the cool video
15:00 I always think of a big centrifuge you could lie in to be under 1g while you sleep to help keeping your bones in check. We could do this on the moon/mars too.
Fraser you are a legend! love these vids!
Thanks a lot!
Amy on "Vintage Space" makes annotations on her videos if she has made a mistake. This saves her time from having to reshoot the scene, especially if she discovers the error during final production. I don't make videos, but people who do make corrections to what they say all the time.
We can't use annotations any more, that's what I used to do too. :-(
22 Billion years until a possible “Big Rip” doesn’t sound very long. I’m used to hearing about red dwarfs that will last 100 Trillion years or something like that. 22 Billion doesn’t sound like much at all compared to the timespans you mentioned in your “How to Save the Sun” video. :( I hope dark energy isn’t accelerating.
Brian Smith I'm also curious about this!
It won't happen. Everything that is gravitationally bound like the local cluster will merge which is Andromeda, Milky Way and a few smaller dwarf galaxies but everything outside that group will just be too far away and we'll never meet. The reason Big Rip won't happen is bc the vacuum has uniform density that is the energy in 1m^3 is the same everywhere in space. Even if you created more space it's energy in m^3 is lower than the gravitational attraction. Which means there will be more space between those galaxy clusters but they won't meet. Check Ethan Siegel, a PHD physicist that regularly blogs about space stuff, he talks a ton about it and he can explain it better than I can.
Poor Fraser gave in to the flat boys, you can actually see 50 shades of red on that melon. Fraser you have done so well ignoring the trolls for the most part but over the last month or so, you have acknowledge them. Be careful they multiply like Tribbles.
I didn't really have doubt on space stuff but those pictures amazed me, thank you!
On the video request for spacecraft in space I'd point to Gemini rendezvous missions (VI and VII?), and many Dragon/Progress missions to ISS. You can often see them on the live broadcast from the ISS.
The big rip will happen next time i eat some taco bell. I make the house shake
RuggedALAN 👏👏👏 perfect timing on that one lol. I actually laughed out loud.
Thanks for the correction. I was waiting for you to correct that. People make mistakes, and you admit & correct yours. Love your ethics & your channel.
Peace.
Thanks! Like I said, wasn't the first, won't be the last. :-)
On the topic of photos ... plenty of images from various manned missions out there as well. Anything from russian and american manned flight (especially those involving rendezvous), great footage of hubble maintenance, etc etc etc.
Yeah, I found so many cool pictures that I'm doing a whole episode on them.
On my other travel channel I put up a "card" at the mistake. It doesn't stop people from noting my mistake but it at least has the correction popping up when I talk.
Yeah, I think that's probably the best solution. And then I can link to a quick video or Community page to mention the mistake.
Pictures of spacecraft: There are many pictures of the ISS, the Hubble Telescope and shuttles that were taken from nearby spacecraft. Here is one of Discovery taken from the ISS: i.telegraph.co.uk/multimedia/archive/01374/shuttle-station_1374726i.jpg
I LOVE those pictures. This whole question got me inspired to do a special episode just about cool pictures of spacecraft... from space.
SpaceX often has brief videos when they detach probes and capsules after launch as well. Admittedly you don't tend to see all to much or for very long as they tend to quickly drift out of view, but it's something. Here's an image from one of those, spacenews.com/wp-content/uploads/2015/12/falcon-deploys-11th-orbcomm-satellite-2015-12-21.jpg
You occasionally can find images of this kind from other launchers as well. So there certainly should be a fair number of images to find if one but knows what to look for.
This question made my brain hurt. People who think they are smarter than everybody else but don't even get that you need a camera to take pictures. God damn.
4:48 ... but technically we aren't crashing into each other right? Technically aren't we moving towards a common center in the galactic cluster? From the models I've seen it looks like we are moving much faster towards the center of the cluster than we are towards Andromeda. There's no doubt we will collide, but most of the 3d galaxy collision models seem to focus on a head-on type of encounter. Technically it's more like a freeway onramp merger from what I've seen in the more recent mapings of our galactic region.
I forget where I saw the model of the galactic cluster recently. Sorry, it might have even been here. I'm a bit spacey after just leaving the hospital from practically the world's worst case of the flu.
Regarding binary galaxies, the tidal forces are indeed the main issue. But you can have a very small galaxy orbiting a very large galaxy for considerable time. Think Magellanic clouds, or just globular clusters. There are small enough that they can survive many orbits around the big galaxy and still keep reasonably together as long as they stay far away from dense regions.
What if black holes are the counterweight to the expansion of space , so what if black holes are preventing a big rip in an ever expanding space. If there is new Blackholes created by merging galaxy superclusters or Deaths of supermassive stars , space can expand forever. Just a thought.
How far can something orbit out without it leaving the solar system? Does it matter how close the solar system is to its nearest neighbor (ie, it might be so close to escape from the solar system that it could get 'sucked out' by the gravity of our neighbor)?
I have a question it concerns our sun. The sun has been converting Hydrogen to Helium for approx. 4.5 - 5 billion years. Due to solar winds, light,and mass ejections, is it possible to guess-a-mate how much mass the sun has lost? Has this mass loss effected it's gravity to any great amount or is to little to cause any changes to the solar system?
William Bays According to Wikipedia the sun has already lost about .01% of its mass to solar wind. The sun is expected to get bigger and hotter in its old age so it may lose around .1% of its mass just to solar wind.
Then there's mass-energy loss due to fusion and e=mc2 which is roughly three times as much as the solar wind. All told the sun will likely have shed .4% of its mass by the time it dies.
I would have thought it was more. I always thought there would be more loss due to mass to energy conversion and radiations. Protons loss to light, electrons loss to EM and charged particles. I don't count H to He conversions because a pound of H or a pound of He is still a pound. Of course minus any mass loss to the conversion process itself.
Once we understand gravity as well as we understand electromagnetism, using centripetal acceleration to evoke gravity would go the way of gaslamps when the lightbulb was invented. Further still, compare the first lightbulb to modern supercomputers. I can't even imagine what the "supercomputer" equivalent of gravitational technology would be/used for.
Question:
What are the different ways we can provide Mars with a magnetosphere?
So to protect Mars from solar wind we'd have to install some sort of a shield at Mars - Sun lagrange point. But if we do so, won't the planet be in an eternal eclipse? How would we ever get plants to grow on Mars if it's constantly in a shade of whatever we use to cover it up from solar wind?
No, for that it should be huge. For there to be an eclipse like on earth with the moon, once in a while on a small portion of the planet, it should be more than 6000 km in diameter. To plunge mars into a constant night, it should be more than 230 000 km in diameter... Please someone ceck my numbers (which are rounded) to see if there is no error.
To calculate that is not very difficult, all you need are these data and a little elementary geometry:
- mars-L1 distance : 1x10^6 km
- mars-sun distance : 228x10^6 km
- The sun's diameter : 1.4X10^6 km
- for the scond number you must also have Mars diameter : 7.2x10^3 km.
Fraser, Your Venus 'snow' scenario might work as an alien conquest technique. Set up a sun shield in space to cool Earth until most life freezes. Remove shield and let the planet re-heat. Then invade with little resistance. Not that I'm trying to conquer Earth but... thanks for the suggestion!
Great Video well Informed an no worries mistakes happen. Keep up the great work as always
So basically Oumuamua is one of my ships from KSP that went too far away and it is now performing a gravity assist with Earth. Nice.
Those poor Kerbals...
SpaceX had a live feed a couple of months ago where they deployed something like 12 satellites into orbit. You can clearly see them fading off into the distance behind the rocket. Really cool stuff.
Fraser, to that person that wanted to see pictures of spacecraft in space, there are plenty of pictures of gemini 6 & 7 as they were flying in formation after they rendezvoused back in December of 1965. And there are various pictures of Gemini docking targets taken from Gemini spacecraft too. Still that person still won't believe it, but they are there.
Yeah, I was so inspired that I'm doing a bigger episode on this topic and I've got some Gemini photos to show.
the big rip entails the universe's expansion accelerating so much that the universe reaches the point where all distances within it become infinite, right? if that's the case then I'm quite curious what we'll see when the curtain gets pulled back.
Secondary question: would it be possible to have an entirely airborne ecosystem evolve on/in Jupiter or Saturn?
tertiary question: wait, why was the surface of Mars grey at 20:28?
You'd be getting torn apart at the atomic level, so you might be a little busy to appreciate exactly what's going on. The airborne idea is a cool one, and that's also being considered over on Venus.
Maybe you could try do something with the info cards to notify of corrections
I was thinking of that, making a "mistake" info card, and then link to an unlisted video explaining the correction.
You had me smiling at the end there. selfie sticks 😂 that’s comedy
bad boy Cain, dropping knowledge bombs again/ love it
How do we know ancient Mars had water like we see in so many renders? The polar caps wouldn’t provide enough water to completely cover the planet, would it?
What do you use to shave your head?
Clippers? I haven't gone the full razor yet. :-)
Fraser Cain me too... Full razor burns
From the Kazmir effect experiment, since there's a force that pushes the plates together, then where does the energy that pushes those plates come from? Surely it can't be made from nothing, which would violate conservation of energy?
Fun4uitstrue
Think of it like potential energy, the plates are pushed together by the kashmir effect. The same amount of potential energy released from letting the plates approach each other, is also necessary to take them apart. It's just like a regular pressure differential!
Question:
Can Project Breakthrough Starshot send probes to ʻOumuamua to take pictures?
Share your music playlist.
With some decent binoculars (don't need a telescope) you can make out the ISS. You can see it's shape and the solar panels. It's real.
These subjects are just mind blowing, insane
Thanks, I'm glad you enjoyed it.
on the suit what about a suit with resistive servos making the user work harder to get resistance?
Regarding Oumuamua, technically any such pass around the Sun is a slingshot "maneuver", regardless whether it gains or loses speed. And it seems to have gained some energy to me, though it's rough guess - it came very roughly from the direction in which Sun is traveling around the Milky Way, and it left roughly that way too. So whatever it was lacking in motion at that direction, it gained that amount. It did not gain anywhere near the speed to leave Milky Way and it would not even if it left in the most convenient direction, i.e. towards Cygnus constellation. With 230 km/s Sun's orbital speed, about 30 km/s on top of it is nowhere near enough - you'd need to leave Sun at about 100 km/s excess velocity in the right direction to achieve that.
Question:
Do you think it would be possible that the SpaceX Big Falcon Rocket could help to build a base on Titan? There are oceans of methane for fuel and there is ice for oxidiser. Could a base be built there after we have one on Mars, or is it just too cold and dark on Saturn's largest moon?
The BFR could take cargos to Titan. If we did decide to build a base, that would be the machine to do it.
i find the length of this video more appropriate
You like the longer format?
yea
What! There is crap floating around the space station? Don't they have air filters?
They do, but stuff gets wedged behind junk, floats out. In Endurance, Scott mentions how he found a water bottle from an astronaut who hadn't been there for 3 years behind a pipe when he was working on a water filter. Pretty amazing, actually.
If black holes only get bigger whatever you throw at them, why do virtual particles cause black holes to evaporate and not just make it bigger and bigger ?
The crux of the issue is how the problem is usually explained. In this case, the particle pairs are _virtual_ (rather than 'real') up until one of them escapes. Once that happens the escaping particle is no longer 'virtual', but real. Since real matter/energy can neither be created nor destroyed, in this case (via _exceedingly_ complicated mathematical theory) the mass of the particle is drawn from the black hole, leaving it that much smaller than before.
In other words, think of it like the escaping particle were 'real' & the captured particle were 'unreal'. (This still isn't right, but it's better than the particle/anti-particle image, imo.) Because they were BOTH virtual (i.e. 'unreal') to start with, the escaping particle always becomes 'real' with all the rights & responsibilities of a genuine particle in space-time, while the captured particle always subtracts an equal amount of 'real' particle mass/energy from the BH.
The actual picture involves something called the Unruh Effect, & I can't do that justice in YT comments. Look for "The Black Hole Death Problem" by Physics Girl on YT (th-cam.com/video/ADM4oxBCkVk/w-d-xo.html ) for the best SIMPLE explanation I've seen on the matter, & hopefully that'll uncomplicate things... you know... _slightly._ Black holes are weird, you guys. ^_^
Why doesn't the Carbon Dioxide of Venus just condense into a liquid Carbon Dioxide ocean ?
Great point: If we were to cool Venus as Fraser suggests, but do so _without_ reducing the amount of atmosphere/air pressure, then yes: the CO2 at or near Venus' surface would likely reach a point where it becomes a super-critical fluid, then an actual liquid below ~32 C. It's points like this that the terraforming engineers will absolutely need to consider when planning out their order of operations. ^_^
Regarding our future descendants going to a higher gravity planet, I've always envisioned that we would have a rotating generation ship that would very slowly increase the rate of rotation so each generation would be born into a slightly higher gravity. This would, of course, assume that we have a good idea what the destination planet's mass/volume is.
You could take all that Carbon Dioxide from Venus and give it to Mars. Tera-forming two planets in one go.
Blave Kaiser but thats alot of money to do. And alot of carbon dioxide to transport. It would take decades and beyond trillions
Edit: Omuamua was not “huge” as I claim below. I apologize for incorrectly claiming so.
Q: The interstellar asteroid was huge and came in very fast and pretty close to Earth. What is the danger to Earth of collisions from interstellar asteroids? If the recent visitor had been on a collision course with Earth, how would it compare to the dinosaur-killer impact? Bigger? Smaller? How does knowing that these interstellar asteroids exist change our risk calculations for asteroid impacts? Seems like these are an entirely newly discovered class of threat to Earth that was alway present, but we didn’t know about. Could you speak about that?
The chances are slimmer than you winning the lottery.
Imagine firing a bullet in a general direction of Washington D.C. and hitting the P.O.T.U.S.
Nearly an impossibility.
Pha Q
EDIT2: In the following comment, I assert that Omuamua was 10km long. It is not. It is closer to 230m to 300m in length, vs the 10,000m I claimed. My conclusion that this particular space rock would have been an extinction-level event is therefore falsified as one another commenter kindly pointed out. However, there were certainly many more asteroids that missed the earth than hit it during the age of dinosaurs. That this particular one wasn’t as dangerous as I thought in no way changes our level of risk from whatever it actually is, despite the human tendency to incorrectly assume so. End of EDIT2.
Wouldn’t a better analogy be more like blanketing all of Maryland edge to edge with a random distribution of guns and artillery ranging in size from from BB guns to those massive canons that shoot tactical nukes, and then continuously firing them all in random directions for a year with infinite ammo and no breakdowns. What are the odds that at least one shell will hit the White House over the course of a year? 5 years? Ten?
The chance of any single asteroid hitting us are tiny, but there are an unknown number big enough to do damage and we don’t know where they are.
The fact that Omuamua didn’t hit Earth might (speculation) be within the margin of error of the Casimir effect for the duration it was warmed by the sun. It was a dinosaur-killer that we didn’t see until after closest approach. That last sentence should send chills up your spine and make you want to call your representatives to have them increase NASA funding.
I repeat: This was a dinosaur-killer-sized asteroid (~10km cigar of rock traveling fast) that came within 60 lunar orbits of Earth (if I recall correctly) and we didn’t see it until after it would have hit us. Even if we had seen it, there wouldn’t have been a damn thing we could do about it even if we saw it a year in advance because our preparedness is so poor.
I am alive writing this and you are alive and reading this right now because of dumb (orbital mechanics) luck, and I for one am immensely uncomfortable with that state of affairs.
Our luck will run out, and it only takes one. We need to make space rock defense a budget priority. It’s not just asteroids in stable orbits anymore. Long-period comets and now we know that blind “interstellar snipers” could take us out with little warning.
We were ALWAYS at risk from these things and we simply didn’t know it. NOW WE KNOW, and we need to turn that knowledge into defense.
Call your representatives and ask about space rock preparedness. Talk to people, turn it into a conversation.
Beware of falling (space) rocks.
Edit: To clarify, I’ve always thought our preparedness level was abysmal, but learning about this new ongoing danger has caused me to become more outspoken.
+Brian Smith: Even a blind squirrel can get lucky and find a nut.
The dinosaur impactor is estimated to have been 10km in diameter. Oumaumau is estimated to be about 300 meters along its longest length, so about 3% in diameter. Volume and roughly the mass would go as the cube of the diameter so it would be .003% the volume and mass of the dinosaur impactor. Oumaumau would have struck Earth at 2 or 3 times the velocity and energy increases with the square of the velocity, so a total energy about .01% that of the dino killer. Enough for a decent crater or tsunami, maybe a degree or two of global cooling for a year or two, but far from an extinction level event. Had it struck a major population center it could easily kill a few million people, but the odds of that are fantastically small.
Lenard Segnitz My apologies. I thought I had read that Omuamua was 10km long but that is wrong. I have have not checked your math but I have verified your input numbers are valid. Omuamua was not an extinction level event as I claimed if your math and impact speed estimate is correct, which it sounds like it is.
That said, there really is no upper limit on the incoming velocity of an interstellar object on a hyperbolic trajectory. We ought not assume an upper limit on risk levels based on a single data point.
I thank you for your thoughtful and considerate correction.
I think Isaac Arthur said that if you try to separate quarks it creates more out of nowhere. So the final ending of the big rip could be a huge release of energy?
Would we be able to do anything to stop an interstellar asteroid like Oumuamua from hitting the earth
We discovered Oumuamua when it was leaving the solar system, after passing at it's closest point to earth, so probably not. Even if we did get lucky and discovered one like Oumuamua heading to us, it would probably be moving just way to fast for us plan and launch something that would divert it in time. That's just my thoughts anyways :)
One-time interstellar visitors suffer from short lead-times and short observation arcs. To peg down a decent orbit for an object it helps to have repeated observations over months or years. Oumuamua was in and out of the inner solar system in the time we needed to peg down its orbit.
Deflection is best done early and often. It's possible that Bennu and Apophis will be subjected to deflection projects each with a good decade of advanced notice. To have a significant effect on Oumuamua we would have needed an accurate observation arc starting when it was still 30+ AU out from the sun. That's a tall order even for objects a thousand times bigger.
The nice thing about interstellar threats is that they only get one crack at being a threat. Oumuamua is gone, done, never to be a threat to Earth ever again. I'm much more worried about Earth-crossing objects that get a crack at being a collision threat every year or two.
Other than being a scientific curiosity Oumaumau is really not very interesting. At best we might get a pixel or two, or if we invest a ton of money we could get a New Horizon-type of probe to fly by it. Earth-crossing asteroids are potential mining sites that could significantly change the human presence in space. Bennu and Apophis are not only collision threats but potential hardware stores.
Hey Fraser, I was thinking on the feasability of the hyperloop and it came to my mind. Could you layer vacuum tubes, one with full vacuum inside one with higer pressure inside one with even higher pressure and so on to minimize force on each individual tube. There must be something wrong with this but I can't figure it out. So please tell me why this won't work.
I'm sure you could, but it would require much more engineering. I'm assuming engineers have done the calculations and decided the structure that'll work best for a hyperloop. If you had multiple loops in the same area, it might make sense to house them in a larger lower pressure structure?
Hey Fraser love the channel question I work offshore so threw the naked eye when you look up how far are you able to see ??
Regarding seeing a picture of actual spacecraft in space, go to the Space-X youtube channel and find one of their videos where they launch a rocket to deploy multiple communications satelites. They did this for Iridium for example. If you skip to the end where they depoly the satelites you'll be able to see the satelite as well as Earth. If you look closely you can see multiple satelites in relation to each other, it's pretty cool.
What i would do is pin a comment on the video comment section with the time mark and the correction
I'll warn people in advance that I've probably made mistakes and so they'll know to look.
Search for "Gemini spaceships in space". The Gemini missions had a few with 2 ships together to practice docking. Really cool pictures, some that include astronauts while spacewalking.
Gravity assist slingshot maneuver definitely applies to Oumoumoua and solar system which are both in orbit around the galactic barycenter. Oumoumoua and solar system have mutually altered their galactic orbits.
Question: Fraser will the JWST be able to observe details of stellar "surfaces" ? There is so much hype about the possibility of observing or at least characterizing exoplanet atmospheres. It would seem that in comparison it would be easier to observe activity on a star's surface, the equivalent to sun spots, coronal-mass ejections, flares, etc..Thanks
Hubble and ground based telescopes can already see the surface of red giants, so I can see JWST taking those observations to the next level. It's an infrared telescope, so much better at looking at really cool stuff.
If I separate a pair of quarks will it release energy when new quarks appear for the separated ones?
So would the dark matter halo prevent us from leaving the galaxy in any form?
Not physically, but just as Earth has an escape velocity, so too does every collection of mass... the galaxy & its DM halo included. Google reports that in our vicinity the galactic escape velocity is ~540 kilometers per second, so if you can get moving faster than that, you'll be on an escape trajectory, despite the DM halo.
R.Instro but would you crash into it in your space craft?
Alaskan Ballistics Although we aren't sure what DM is physically composed of, we can say for sure that it doesn't form a solid shield-like "wall" around the galaxy, a la the original Star Trek's edge of the galaxy energy barrier, so it's probably not an issue. =D
R.Instro okay so don't take my spaceship through the actual physical dark matter hard parts... Gotcha, avoid those since we can't detect them, get through the tight spots
Totally hooking, not trying to subs like a smart butt
Hey, Fraiser, awesome show. I was listening to a description by Leonard Susskind of bubbles of new spacetime, whole new universes, can form within our own universe. it got me wondering, is it possible that the CMB cold spot is one of these expanding universes?
Are you planning on making a video about radiotelescopes?
Hi Fraser
Which video of yours do you think would be the best to show how awesome your channel is?
I have just recently discovered your channel, your videos are amazing! I am learning so much from it, never been so interested in space before.
I would sometimes try to send it to some of my friends, but I have unfortunately never succeeding in gaining u another subscriber.
Do you have a "best" video that can act as a good intro to your channel that I can try to send to my friends?
Thanks for all the great work!
Thanks a lot!
People seem to enjoy this one: th-cam.com/video/7x0RpGa_IXA/w-d-xo.html
@@frasercain Thank you!
did you get a new high def camera? The graphics on this ep is off the charts!
Hey Fraser, what is the biggest star discovered so far and where is it located? How massive can stars actually get?
Hey Fraser, had a question: Would stars in a very near orbit to the supermassive black hole at the center of the galaxy with insanely fast orbital speeds experience time dilation compared to us on the outer arms? Or a more general question: What frame of reference for speed determines how time dilation is experienced (do whole star systems experience time at a different rate?)
You mentioned that the interstellar asteroid had a hyperbolic orbit. Why is that? Why is it hyperbolic and not parabolic, or heck, even semi circular?
When a comet is on a parabolic orbit, it's in the process of getting captured by the Sun. But a hyperbolic is on an escape velocity out of the Solar System.
It's a measure of eccentricity. 0 eccentricity is a perfectly circular orbit. Between 0 and 1 is anything gravitationally bound to the sun in a near-circular or highly elliptical orbit. Exactly 1 is a parabolic orbit which signifies an object that "fell" from a nearly motionless point with respect to the sun and is bound to go back out to a motionless point. Everthing above 1 is hyperbolic and is gravitationally unbound to the sun.
Everything we observe is elliptical or hyperbolic (which is technically elliptical too). Exactly 0 and exactly 1 are pretty much mathematically impossible.
There is no such thing as an orbit which isn't a conic cross-section. You need artificial thrusters to pull off an octogonal or hexagonal path through the solar system.
Watched this on Patreon. I watch here for the comments.
I hope you were justly rewarded. In fact. Just to reward this even further, I'll release a new blooper reel.
How many dimensions does a photon experience?
Fraser cain- good video am really enjoying you QA videos. Have question- i know its only gonna be a to guess, but since are universe is speeding up as it rotates, what do you believe making it speed up/going to. My 2 guesses are 1 we are in a solid enclosure. Easyest/shortest way to describe it is the MIB theory. 2 there is a giant invisible bouble kinda like the Van Allen belt (stationary or expanding not sure) around are universe that pulling everything toward it. Then past that emptiness/nothing.
Hi Fraser, happy holidays! I'm not sure if you answered this one already, but when it comes to space colonization: do you prefer large space stations or planetary settlements?
I'm for space stations, personally.
What type of orbit would be required to permanently place a sun shade between a planet and the sun?
What is a wall calendar? Is that a phone app?
Is Oumuamua the first recorded known instance of a non stellar object from outside the solar system being directly imaged?
It would be the first extra-solar object found within the solar system, but it isn't the first non-stellar extra-solar object directly imaged. A number of exoplanets have been directly observed in the past decade.
Two galaxies can indeed orbit each other, if they do so at a separation that is large compared to their physical size. Each galaxy needs to be beyond the tidal disruption radius of the other galaxy (conventionally, at least three times the Hill radius).
when talking of the big rip, estimates on the affects of dark matter were used but recently there have been info and even arguments online about dark matter not being proven and theories falling apart, could you perhaps do a more down to earth explanation of what has happened in the community and the meaning of it all...also on the matter of waste floating in the space station why dont they use a series of low powered vacume cleaners to draw the particals in,just a thought..
You can also find lots of pictures and videos of satellites being launched from the shuttle cargo bay, Hubble while being serviced, cargo and crew capsules docking and leaving the ISS and Mir, Agena upper stages photographed from Gemini capsules...
If you were on a planet with more gravity, would it be harder to breathe?
Lets say that we would send a probe to another star system and assume we can keep it alive during the journey, would we be able to and do we actually have the technology to plan a flight path in interstellar space? Like we do when sending a probe to another planet and would it be able to navigate? I get the images of Voyager passing Jupiter and beyond in my head so would we be able to predict where a star system is and where it should be when the probe reach its destination?
You're always rugged up in your videos! You must live someplace cold. Toasty warm here in Australia, come visit!
I'm going to be visiting in July 2018. :-)
Why don’t we continuously send spacecrafts to orbit the sun and get a gravitational slingshot to go to other planets in the solar system? Wouldn’t it be faster since the suns orbital speed is 200km/s which will reach Uranus and Neptune much quicker
My limited understanding of gravitational slingshotting is it only works when the object you're trying to slingshot off of is moving in the general direction that you're trying to go. For example. If you were trying to get to a planet and another planet was "on the way" and moving in the same direction, as you approach the "another" planet, it will start to gravitationally pull you towards itself, which so happens to also be towards the target planet.
The Sun isn't really moving towards any other planets, it's relatively motionless. The Sun is moving 200km/s relative to the Milkyway, so you could in theory, sap some of that movement. But we kind of are already as we originate from within the solar system. The Earth is moving 30km/s relative to the Sun. The Earth is moving 200km/s+-30km/s relative to the Milkyway.
I want to say that slingshotting is only applicable to two objects that are not already gravatationally bound. The Oberth effect still applies, making thrust based acceleration more efficient nearer the Sun.
With regards to the dust and small particles floating around the ISS, couldn't most of these be removed by electrostatic filtration?
How can we distinguish asteroids that are from out of the Solar System opposed to those coming in from the Oort Cloud?
colinp2238 I'd think it would be due to the ovjects speed and the direction it came from
It's an interesting question, since the Oort cloud is a supposedly a bubble rather than a disc, direction doesn't mean too much?
The speed could be explained by a binary pair orbiting each other, when one of them is involved in a collision the other is propelled away at high velocity?
Only by the trajectory right now. Until we can actually get up close and sample them, we can't determine when and how they formed.
I've heard scientist's say: 'If you were to remove all matter from the universe except for say, two basket balls and placed them at opposite ends of the known universe.. they would attract and eventually collide..'
Is this true? What about the expansion rate of the universe? Wouldn't there be a certain distance at which the expansion rate would overcome this gravity? If so, how far away would a 16oz object have to be from an identical 16 oz object for this to happen or is that not how it works?
I love your channel! Thanks!
Fraser, I’m saddened that you have made a whole video about me.
When we talk about the size of black holes, do we talk about the size of the event horizon? Because thats all we can observe, right? We can calculate the mass, but do we know how big a black hole really is? If we do, how can we observe the size?
A while ago in one of your Q & A shows you said that Jupiter had a chance of kicking out Mercury and maybe just maybe Earth in billions of years, so you said we should mine away the outer planets. But doesn't Jupiter act as a shield from asteroids and comets to Earth, sucking in all those dangerous objects?
We did a video on the "guardian Jupiter" theory here: th-cam.com/video/J9cQdpoNY4M/w-d-xo.html
There are plenty of pictures of spacecraft taken before/after docking with the ISS, and probably Skylab and MIR too. Here's some now: www.space.com/11899-photos-shuttle-endeavour-space-station-nasa-gallery.html
Hey Fraser,
How about listening through your vids 'before' posting it?
Just to check for errors?
You seem to be right on top of your errors, but 'slightly' too late. My Dad ALWAYS does this with his texts. Seems to me, just a quick proof read would solve the problem.
Maybe not, but just an idea that I'm throughing out there. Peace Fraser! Love your channel.
Don't take this the wrong way.
Many people love your channel, myself included.
Keep up the GREAT space info work!
PEACE!
One of the problems is that it's super hard to notice you're own typos and errors. I do listen after and fix issues. AND Chad catches mistakes that I've made.
Proud of your dad. But he made one error to. YOU! heheheheeh
Q: Solar sails seem really brittle. How can/will engineers compensate for high speed collisions with dust and small meteorites?
I love this channel and I have a question. I am looking for a great book about physics/astronomy or anything about science. Which books do you recommend? I have read the astrophysics for people in a hurry so I am looking for something similar to this. Thx!
How are galaxies moving away faster than the speed of light? Objects with mass can't travel faster or equal to light, right?
Or it's because a galaxy is moving in our opposite direction?
I didn't understand how this works.
Here's an episode for you: th-cam.com/video/vsT2b-dR9uI/w-d-xo.html
Fraser Cain thanks :)
Matheus Barreto
Not the galaxies. Space is expanding faster than the speed of light.
WiperHunter well right now space is not expanding faster than the speed of light. Every bit of space is expanding and at a much slower rate than that, but over a large enough distance the accumulated rate of expansion between two points would amount to them moving away at a speed faster than light.
No information can move through space faster than light, but there is no known or theoretical speed limit to how fast space can move or expand.
Hey Fraser, I just watched your video on Oumuamua. I'm curious, are we at the point where we could capture an asteroid and put it into our own orbit for longer term studies? How hard would this be and would this adversely affect the Earth?
There are photographs of the satellites launched by the shuttle in the 80's.
Hi Fraser you mentioned that Venus lost all it's hydrogen a long time ago but that can't be true if there is sulphuric acid in Venus atmosphere.
Some of the hydrogen was locked away with the available sulphur since it's very reactive, but the rest is long gone.