Q&A 51: Could We See Ourselves in the Past? And more..

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Q&A 51: Could We See Ourselves in the Past? And more..

Рет қаралды 25,518

6 жыл бұрын

In this week's QA, I wonder if we could use the speed of light to see ourselves in the past, how the Mars rovers clean their solar panels, and if aliens would infect us with their bacteria and viruses.
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Team: Fraser Cain - @fcain / frasercain@gmail.com
Karla Thompson - @karlaii / / @karlathompson001
Chad Weber - weber.chad@gmail.com
Chloe Cain - Instagram: @chloegwen2001
Balázs Suhajda
Hi Fraser! We use massive cosmic bodies to bend light and magnify distant objects, soon using them to observe exoplanets and their atmospheres as they were long ago. I wonder if it could be possible to find rays of light that have left earth long ago and through the curvature of space end up returning to earth with high enough resolution to allow us to look back into the past. Is it completely out of the question?
path finder discovery
I want to know who dusts off the solor panels when it gets dusty an it probably does often due to those huge dust storms , hmmmmmm🤔??🙃🤓🤔🙄 ohh👽👾😱😨😍
Schnitzel Vonlichenmenutz
Imagine the virus’s and bacteria they may unintentionally bring. Could potentially be the end of all life on earth. Also, I hope they have a good immune system for our planetary virus’s and bacteria
Alpha Gusta
I notice that in some space launches that the space craft immediately starts to spin into another direction, I know some course correction is needed for different orbital planes and trajectories. But sometimes it seems like they turn 90 degrees.
Why dont they just build launch platforms in somewhat the correct direction?
Phil Metal
When the galaxies merge or slam together, would it be a slow event until things start smashing into each other? Or would some crazy gravity changes rip world's apart and it be a cataclysmic show? In your opinion would it be a galactic reset, would anything survive
CODELESS
Enjoy your videos and Q & A's : i was wondering, with this Mission of colonizing mars in the future, there are some ideas that the domes could have water in them to shield Radiation. How much water is needed to block radiation as in the thickness or width of water to block radiation. Thanks
XXCoder
I was wondering if it was possible to make "bed cylinders" that is partitioned into 2 sleeping areas. With some automatic counterbalancing for mass differences, it may be enough for sleeping in gravity for better health?
Jim Labbe
If super earths are more massive and have greater gravity wells, might that make space travel much more difficult for intelligent life? Put differently, if we could increase the mass of the earth at what point might it create a physical constraint on space travel?
Captain Ultimate
G'day from Down Under! I am a new subscriber and I am really enjoy your videos Fraser, so thanks for your knowledge and all your hard work. Would there be any point or benefit to launching a telescope into orbit around a planet in the outer solar system like neptune, or even pluto? Or are they too close in regards to current telescopes to really return any befit?
Matthew Kramer
Hello Fraser, quick question: How do you think our advances in Machine Learning, Reinforcement Learning and A.I in general will affect space missions in the near and distant future? Greetings Matthew
Jesse Dyball
Could you get two BFRs joined by long cables and have them spin?
Peter Granzeier
Do white dwarves have habitable zones?

Пікірлер: 528

@TheExoplanetsChannel 6 жыл бұрын

*I was kind of shocked while watching the movie 'déjà vu' when the FBI agent says something like 'when you look to a mirror, you are looking to the past, an old version of you, as it takes some time for the light to reflect you into the mirror and your brain process that info'*

@namelessfred8417 6 жыл бұрын

Well technically thats true but the light delay is only like 7 nanoseconds, far too quick for a human to appreciate. Still, that is a good reminder that everything we perceive is limited by our senses.

@frasercain 6 жыл бұрын

Yup, there's the time from the speed of light, and then the time for your neurons to fire.

@KrustyKlown 6 жыл бұрын

Everything we see, occurred in the past.... The average reaction time for humans is 0.25 seconds to a visual stimulus ... that is the time delay for your brain to process visual input and then construct the virtual reality in our brains that we perceive as reality. If ya have Amazon Prime . watch this neat series that explains this.... The Brain with David Eagleman Link: a.co/iO8L7n

@psychobartus 6 жыл бұрын

Yes guys, we (our sense of self as derived by our senses) live in the past.

@Deciverse 6 жыл бұрын

The Exoplanets Channel 80 milliseconds for the brain to process info and less than 7 nanoseconds for light to reflect to you about a meter away from your mirror.

@unvergebeneid 6 жыл бұрын

Of course, aliens might still put up giant space mirrors as a courtesy to other species so that they can study their own past ;)

@frasercain 6 жыл бұрын

That would be thoughtful of them.

@superfunbad 6 жыл бұрын

"Terrified. Horrified. Love." So true.

@frasercain 6 жыл бұрын

Isn't it always?

@StealthGamingFactory 6 жыл бұрын

Thank you for answering my question! Great channel you've got there :)

@frasercain 6 жыл бұрын

Thanks for asking it.

@sierravortec2629 6 жыл бұрын

Really enjoy these videos, look forward to them every week. Usually don’t comment, just had to say good job and keep it up! You’ve taught me a lot

@frasercain 6 жыл бұрын

Thanks a lot, I really appreciate it.

@camo733 6 жыл бұрын

hi Fraser,Love all the effort you and your team put in. I’d like to know....You always have a down to earth, happy and nice persona about you.How do you stay so positive?

@frasercain 6 жыл бұрын

I was probably just born that way. :-) Actually, my Mom set a really good example for me, I think. Always positive and kind to everyone she ever interacted with.

@RPKGameVids 6 жыл бұрын

This is one of my most favourite space channels.

@frasercain 6 жыл бұрын

Thanks a lot!

@chaunceyli367 6 жыл бұрын

RPKVids WOW, I literally watch your cubing vids!

@RPKGameVids 6 жыл бұрын

Lol!

@XTVPodcast2017 6 жыл бұрын

keep up the good work Fraser, greetings from Portugal!

@frasercain 6 жыл бұрын

Thanks a lot!

@BJBaye 6 жыл бұрын

Your answer about the rocket launches explains a gravity turn, but reading the question I believe what it was asking about was the roll program, given they were talking about the angle of the launch pad. To try to answer what I believe the question means: It is connected, of course. The roll is to line up the craft so the guidance computers can make gravity turn in the correct direction for the target inclination. (It's easier to control the craft with a 'roll to this angle and then pitch down' instead of 'calculate which direction is the correct one and pitch that way', especially when the rockets in question are not straight tubes and have more complicated aerodynamic profiles.) The reason some rockets need to roll so far, really, has to do with using new designs on old launch pads. For example, the space shuttle had to basically sit backwards on a launch pad designed for a Saturn V. (The roll in that case was also so that the antennas on the shuttle would face the earth.) Building a new launch pad would, however, be far too expensive and complicated just to skip a process that takes a few seconds at most. At least, that's my understanding. :-)

@frasercain 6 жыл бұрын

I thought that might also be the case, but then asking why they don't just point it at the place they're trying to go was what made me answer it that way.

@shadowxsm 6 жыл бұрын

I love your efforts to pronounce some of the names people have, that and the smiley faces :~) What's the most difficult name you've had to pronounce, in the fields of study or peoples names.

@frasercain 6 жыл бұрын

I struggle with them all equally. I ruin all the names with my hilarious Canadian accent.

@CarFreeSegnitz 6 жыл бұрын

I too highly recommend Kerbal Space Program. I learned tons about orbital dynamics... gravity turns, orbit inclination, catching up by lowering your orbit or raising your orbit to fall back, Hohmann Transfers, landing on Mun.

@frasercain 6 жыл бұрын

I learned more about orbital mechanics by playing KSP than I did from reporting on spaceflight for more than a decade.

@Threedog1963 6 жыл бұрын

I put KSP on my dinosaur computer and it locked up. Not the game, the computer. It did look interesting as it installed though. No, it's not a TRS-80. LOL

@theblackwiggle84 6 жыл бұрын

Universe Sandbox 2 is another great space physics simulator.

@horacefairview5349 6 жыл бұрын

It does lead to people having unrealistic expectations about sstos though.

@garyking4032 6 жыл бұрын

Just found your channel, so interesting! Thanks for sharing.

@frasercain 6 жыл бұрын

Thanks a lot, welcome aboard.

@violetskydiver7684 6 жыл бұрын

QnA: How do we know that the Andromeda galaxy still exists if it takes millions of years for it's light to reach us? Thanks for another great video, Fraser!

@gertinoss 6 жыл бұрын

So astronomers have found the first galaxy that doesn't contain any darkmatter. My question here is, how do the astronomers determine if a galaxy has darkmatter or not since you can't directly see it. How do we know that that particular galaxy has no darkmatter

@frasercain 6 жыл бұрын

They tracked the movements of globular clusters in the galaxy and determined that it's only the mass of just the stars that's pulling them around.

@psychobartus 6 жыл бұрын

We cant "see" air but we can detect its effects.

@Stoner9th 6 жыл бұрын

Another awesome video, Fraser!

@frasercain 6 жыл бұрын

Thanks!

@CarFreeSegnitz 6 жыл бұрын

Space telescope at Pluto: actually anywhere but in LEO would be a huge benefit. Hubble is hobbled by being right next to Earth blocking half the sky at all times and blinding it with reflected light. And IR observations are seriously undermined by Earth's glow. Hard to beat the servicability of Hubble though.

@frasercain 6 жыл бұрын

Yeah, that's why JWST is going to be so far away. But as you said, the serviceability is an issue.

@justinnielsen8756 6 жыл бұрын

He just got done talking about parasites at 5:00, and then he had a mosquito land on top of his head at 5:01

@frasercain 6 жыл бұрын

Who evolved in an arms race with us. This one had the edge on me.

@gotbread2 6 жыл бұрын

5:06 I think he is referring to the roll program that for example the space shuttle did? Launchpad is already build so the rocket, if orientation matters, has to roll shortly after launch.

@frasercain 6 жыл бұрын

I considered that, but it didn't exactly match the question

@HebaruSan 6 жыл бұрын

I think the rocket question was about "roll programs" executed just off the pad. Hence "Why don't they just build launch platforms in somewhat the correct direction". I believe the answer is that they would like to, but a.) different launches require different directions, and b.) they're also constrained by the infrastructure that moves the rocket to the pad.

@frasercain 6 жыл бұрын

I did consider that possibility, but it really seemed like they were wondering why they don't just shoot the rocket at the destination, instead of doing a big turn. But maybe they'll clarify it.

@AShrubbery 6 жыл бұрын

5:10 I think the question may have been about the rotation of the rocket, not the direction of travel. The rotation is because the rocket needs to turn in the direction that it needs to travel. It is way easier to rotate the rocket after launch than to make a launch platform that can rotate.

@frasercain 6 жыл бұрын

I considered that, but it really seemed like they were wondering why the rocket doesn't just go straight up to the target. If they do a followup I'll get more info.

@sjpugsie 6 жыл бұрын

Frasier is the man!!!

@frasercain 6 жыл бұрын

Thanks!

@markfrick3218 6 жыл бұрын

I like the idea of the spinning BFR's... I'd imagine you'd need to do a few modifications, such as hardening the structure to support the different loads, perhaps an add-on harness which can be assembled in space? You'd also probably want to mechanically dampen the vibrations of the cable. Station keeping burns may also be needed to maintain the correct angular momentum, and also things could get really scary if there was an engine or power failure.

@djmit44 6 жыл бұрын

Hi Fraser, My understanding is that dark matter tends to form a "halo" around galaxies, rather than being the same shape as the visible galaxy. Two questions: 1) if I'm wrong about that, can you explain how we think it is distributed?2) what does the distribution of dark matter in and around galaxies suggest about its characteristics?

@michaelgranzeier5300 6 жыл бұрын

Thank you! It sounds like it would be super awesome to visit a planet in the habitable zone of a white dwarf star! I wonder what it would look like.

@ugthefluffster 6 жыл бұрын

Hi! From Israel here. First of all, this is a fantastic channel. My question - If living on a planet with higher gravity makes space-faring super difficult, what about a planet with lower gravity? what is the theoretical lowest amount of gravity (due to planet size/mass) acceptable for sustaining life? And how would that affect space launches from that planet?

@frasercain 6 жыл бұрын

We don't know what the lowest gravity would be, especially if you evolved in it. But for humans, we can't perform tasks or walk around if it gets lower than about 20% gravity. But I'd assume you could have much much lower gravity. The problem is that a lower gravity world would have trouble holding onto its atmosphere.

@georgplaz 6 жыл бұрын

Hey Fraser. The atmosphere is one of the most energy consuming parts of a travel into space. Why don't we build launchpads on top of a massive balloon and start our rockets from the edge of the atmosphere? If the pads were reusable and technically advanced enough, couldn't we basically ditch the first stage on every flight or have increadibly massive payloads?

@frasercain 6 жыл бұрын

That's definitely been considered, it's just that there are a lot of moving parts, to build the launch platform and coordinate the launch from it. The reusable approach that SpaceX is taking seems to be the simplist.

@wsj1983 6 жыл бұрын

Hey, Fraser! About spacex BFR to Mars and BACK: What about how much water will be needed to make metane there and how much is available on Mars now? I mean it will be like a "fossil fuel" there. Won't water be a too valuable resource for the locals to be used in a returning ship?

@frasercain 6 жыл бұрын

It will be a valuable resource, but there are huge polar ice caps. Being able to return from Mars will also be a valuable resource, so they'll need to conserve the water.

@Legion_Victrix 6 жыл бұрын

@Fraiser Cain: Awesome show by the way. Star SO-2 was recently been confirmed single and able to prove (or not who knows) Einstein's theory when it zips around Sagitarius A. Will you make a dedicated show on this topic when it happens? Thanks again for the hard work and informations you give us on a regular basis. Cheers

@frasercain 6 жыл бұрын

Thanks! I'll definitely do a video on Sgr A* and the stuff around it. Especially since astronomers just discovered 10,000 black holes at the galactic core.

@NickPoeschek 6 жыл бұрын

You reading the emojis made me laugh so hard... :D

@frasercain 6 жыл бұрын

I thought that was fun. :-)

@philmetal9604 6 жыл бұрын

Thanks for answering my question, love the channel.

@frasercain 6 жыл бұрын

No problem, great questions. :-)

@philmetal9604 6 жыл бұрын

Fraser Cain do you think, with the likely hood that the first few Mars colonization missions will be 1 way trips and probably end with lost life, will they pull the plug? Or call it a necessary evil due to the nature of exploration.

@frasercain 6 жыл бұрын

I don't think they'll pull the plug, once there are people there, they'll need to keep sending more supplies, so I don't think they'll abandon the Mars colony unless everyone dies.

@agentnea 6 жыл бұрын

Hi Fraser! I've wondered a long time if we could use entangled particles to create interstellar communications? that way we wouldn't be bound by the speed of light or any limit, it'd be instantenous!

@frasercain 6 жыл бұрын

Unfortunately you can't do that. You still need to communicate the state of each particle at regular speed.

@AliMuhammadAli 6 жыл бұрын

Regarding the recent discovery of a galaxy with no or almost no dark matter. I read that they calculate the amount of dark matter based on the gravitational pole of the galaxy. and they know that based on the mass expected of the galaxy calculated by how far and bright the galaxy is. my question is simple .. how do we know a galaxy is far and brighter instead of it being near and dimmer! .. sometimes I feel lots of the announced discoveries about distant galaxies/stars are based on mere guesses!

@MasteringWoodwinds 6 жыл бұрын

I just watched a video from the Goddard Center about a galaxy that seems to have an unusually low amount of dark matter. In it, the presenter talks about "ultra-diffuse galaxies," and it got me wondering: what exactly is the definition of a galaxy and how do we identify these ultra-diffuse things as such?

@frasercain 6 жыл бұрын

They've only found one of these so far, so I'm not sure it's a category yet. Diffuse just by not having a lot of stuff in it.

@donsample1002 6 жыл бұрын

I think you missed the point of the "why do rockets turn? " question. It wasn't "Why do rockets pitch over to more horizontal flight after launch?" It was "Why do some rockets have to roll before they begin to pitch over? Why not just have them start out on the launch pad in the correct orientation to begin their pitch over without having to roll first?"

@frasercain 6 жыл бұрын

Maybe, and I considered that too, but it didn't seem like that was the question. Maybe they'll clarify their question again and I can answer this other interpretation.

@joefarah06 6 жыл бұрын

Hi Fraser, I have a question... if massive objects “warp” space time and affect its curvature does that mean the fabric of space/time has mass? If gravity is a force between 2 objects of mass then how does a massive object affect space unless space itself has mass? How does it pull on it and curve it?

@frasercain 6 жыл бұрын

No, it's just that mass bends space and impacts the passage of time. Why? Because that's what it seems to do.

@CUXOB2 6 жыл бұрын

Hey Fraser, if we for a limited number of times could visit any place in the universe , what would our destination priorities be to get maximum amount of science done? What do scientists really want to see up close?

@frasercain 6 жыл бұрын

Any place in the Universe? Wow, then they'd want to do close up observations of various objects that we don't have in the Solar System, like brown dwarfs, white dwarfs, neutron stars, magnetars, supernova remnants, etc. Very cool.

@Actual420Ninja 6 жыл бұрын

Hey Fraser great show as always. Im relatively new to the channel but i was wondering if youve ever talked about using different forms of stasis for manned interplanetary travel or even travel to other stars. My though process was if we mastered a form of stasis that also stopped or slowed ageing, then a small spinning centrifuge within a ship could provide enough gravity for the passengers. Also laying down would solve the problem of a centrifuge having more gravity and your feet than your head.

@frasercain 6 жыл бұрын

We talked about hibernation in this video: kzfaq.info/get/bejne/jMydgtGizZ_aqXU.html&list=PLbJ42wpShvml6Eg22WjWAR-6QUufHFh2v

@huffie00 6 жыл бұрын

I never get why someone downvotes. Always good explanations on this channel.

@frasercain 6 жыл бұрын

They hate questions or maybe answers? Perhaps they hate both.

@huffie00 6 жыл бұрын

Fraser Cain or mayby they dont like the answer they got. Anyways good video keep up the good work! Anyone dont agree with any video should leave a comment so a dialoge can be started instead of a dumb downvote

@frasercain 6 жыл бұрын

That would be awesome, if people want to have an actual dialog, I'm happy to answer.

@k0per1s 6 жыл бұрын

QUESTIONs. Question regarding warp drives, warping of space in general. If space warps around us, like in a gravity well, do we physically warp with the space ? If we bend with the space, then does our velocity "deform" too ? This all leads to, how can we use bending of space to travel faster ? And if we do not deform with space, how would a collision with the walls of a wormhole would look like, when the borders (as i understand )are, heavily deformed space ?

@KohuGaly 6 жыл бұрын

well, yes and no. If you have group of particles that experience no attractive/repulsive forces to each other (like particles of neutral gas), then yes, the relative positions of the particles will warp with the space. However, if you have particles bound with forces to each other, then the attractive/repulsive forces will respond to the changing relative position of the particles. Example, let's say you are in space and you are standing knee deep in some weird space anomaly that is contracting on the inside, but has absolutely no effect on the outside. You would feel a force pushing on your feet, while the rest of your body experieces weightlessness. Similar to how when you're standing knee deep in water, the water squeezes on your feet.

@ferusgratia 6 жыл бұрын

Hey Fraser! Thanks to all the work you and KZfaqrs like you do, I feel like I have a much better grasp of space and to some extent Cosmology. That said it's been a bit since I've had my mind blown by some new fact. I think I'm ready to delve into materials that would be hard to cover on KZfaq, but I don't think I'm ready for hardcore scientific journals. Do you know of any good "middle ground" resources? Thanks!

@frasercain 6 жыл бұрын

I try to attach those middle-ground videos as playlists to the end of all Guide to Space videos I do. I really like Starts With a Bang blog as more of a challenge. medium.com/starts-with-a-bang And then, of course, there are books. But you might also want to try some journals, they're not that bad. Start here: arxiv.org/list/astro-ph/new

@frasercain 6 жыл бұрын

Ooh, and astrobites: astrobites.org/

@gerpara 6 жыл бұрын

Hey Fraser, you said that we're close to the limit where rockets make sense, because above that "it's just not worth it anymore". Sure there are limits with gravity x100, but a couple times gravity would still be ok if you're drive to go to space, e. g. because you run out of space on your planet. Going to space for exploring is nice, but the long term goal is to get more space for people to live in. Someone coming from a planet with gravity x0.5 could say the same about our planet. So: The limit is where you can't physically achieve it anymore.

@frasercain 6 жыл бұрын

Right, and as I mentioned in the video, you'd need the mass of your entire planet to be rocket fuel to get you to space with 10g. So, just decide when it's too expensive.

@MrKrack-ri8ix 6 жыл бұрын

Hey Fraiser! I got a question. Since distant galaxies are moving away from us because of the expansion of space. And, let's say a galaxy 1 Megaparsec away is moving from us at the speed of about 70.6 km/sec. My Question: Is the expanding space 1 Megaparsec away expanding at 70.6 km/sec, or not? Or, is the distant galaxy the only one moving at that speed and not the expanding space?

@frasercain 6 жыл бұрын

yes, and if the galaxy is 2 megaparsecs away, then it's moving at 140 km/sec.

@MrKrack-ri8ix 6 жыл бұрын

Fraser Cain - But, if a galaxy is moving away from us at (let's say) 70.6 km/sec, does that mean the expanding space is expanding at the speed of 70.6 km/sec?

@Skizm6666 6 жыл бұрын

Hi Fraser. I know you get a lot of questions about Galaxy collisions but if say 2 stars did collide what would be the possible outcomes? A merger, a Supernova or maybe an emerging winner like Earth over Thea? Thanks for your time. Chris

@frasercain 6 жыл бұрын

Here's an older video for you: kzfaq.info/get/bejne/kNuTncx8x5ytgn0.html&index=302&list=PLbJ42wpShvml6Eg22WjWAR-6QUufHFh2v

@lordrenar666 6 жыл бұрын

To understand how getting shit in orbit works, play kerbal :)

@frasercain 6 жыл бұрын

All hail KSP. I've learned more about orbital mechanics from that game than I have from decades of being a space journalist.

@amicklich6729 6 жыл бұрын

If all the scientists are right in that everything in the universe is made of the same "stuff", it would stand to reason that viruses and bacteria in distant places evolve similarly. The environment plays the determining factor. So anything we might encounter could be scientifically broke down if we take into account the absolute utmost of extreme conditions the viruses and bacteria could have come from. That's taking extreme scientific to the next level, AND assuming we really understand what's out there entirely... Having said that - long live the explorer minded.

@frasercain 6 жыл бұрын

We'd assume they're made of the same basic building blocks, but we don't know if life on other worlds would even come up with the concept of DNA, or it would have some other way to replicate.

@amicklich6729 6 жыл бұрын

I get it. In a way I like the fact we don't quite grasp many, many things. Keeps a sense of wonder alive, and the possibilities out of our calculations.

@frasercain 6 жыл бұрын

We did a video on this topic here: kzfaq.info/get/bejne/nNufZtmI2bnIoY0.html&index=193&list=PLbJ42wpShvml6Eg22WjWAR-6QUufHFh2v

@bartp5987 6 жыл бұрын

KSP is in Humble Bundle now. Go get it! :D

@frasercain 6 жыл бұрын

I saw that. I'm signed up to the Monthly Bundle, so I'll have a spare copy to give away. :-)

@TheMsPetal 6 жыл бұрын

Hi Fraser, I just love your programs. Thank you so much! I'm not that knowledgeable about physics, so I have a question. Why was it so difficult for space agencies to pinpoint more precisely when and where Tiangong-1 would come down?

@frasercain 6 жыл бұрын

There are just too many factors involved. The thickness and density of the atmosphere, the way the space station was tumbling. All of that would change the entry location.

@TheMsPetal 6 жыл бұрын

Can you give a bit more detail?

@frasercain 6 жыл бұрын

Which part? Stand in a strong wind with a piece of cardboard. Hold it face on to the wind, and then hold it edge on to the wind and feel the difference in the force you experience.

@larrybeckham6652 6 жыл бұрын

From Wikipedia on the this subject: "The subsequent lifetime of white dwarfs is thought to be on the order of the lifetime of the proton, known to be at least 10^34-10^35 years". Did you hear you said 3 x 10^9 years?

@frasercain 6 жыл бұрын

No, I think I said that was how long it would take for them to cool down, not for how long it would take for them to decay.

@larrybeckham6652 6 жыл бұрын

Fair enough, I didn't read that as decay time (but a half-life). But from Wikipedia for Schools: "...few white dwarfs are observed with surface temperatures below 4,000 K, and one of the coolest so far observed, WD 0346+246, has a surface temperature of approximately 3,900 K. The reason for this is that, as the Universe's age is finite, there has not been time for white dwarfs to cool down below this temperature. The white dwarf luminosity function can therefore be used to find the time when stars started to form in a region; an estimate for the age of the Galactic disk found in this way is 8 billion years." Other sources as well state that no white dwarf has cooled down in the 13.8 billion herstory of this local universe. That said, you are still the best podcaster in this Solar System. And so responsive!

@NickPoeschek 6 жыл бұрын

Hi Fraser, thanks for all the work you and your team do on these videos. Question for you Fraser, do know what the practical weight limit is for putting things into orbit is? I was playing some Kerbal Space Program with the kids and we were curious how much an IRL Kerbal-style monstrosity could put into orbit if the cost and efficiency was not a factor. I know the rocket equation gives you diminishing returns as the weight of the rocket increases but is there actually a physical limit to the potential size of a rocket? Keep up the great work!

@maithem212 6 жыл бұрын

Fraser - lets say in an alternate universe, the governments of the world spent the same amount on space exploration as we do on on our military. The US alone will spend $886B in 2018 (declared budget); what can NASA do with that kind of money? will we only explore our solar system quicker and still never reach the stars?

@frasercain 6 жыл бұрын

Just multiply everything you see from NASA by about 40. 40 missions for every one mission we have today. It boggles the mind.

@horacefairview5349 6 жыл бұрын

Hi Fraser, I'm not sure if you've covered this yet (you've done so much already!). if we can measure the gravitational waves or colliding neutron stars, why can't we use precise gravitational measurements to detect/prove the existence of Planet X?

@frasercain 6 жыл бұрын

We can only use gravitational waves to detect the most extreme events in the Universe, like colliding black holes and neutron stars.

@johnathanmartin1504 6 жыл бұрын

I now realize that this means aliens are going to see me in that idiotic hot pink baseball cap I wore in the eighties! God damn it......

@frasercain 6 жыл бұрын

Only ones that are about 30 light-years from here.

@jameslucas6589 6 жыл бұрын

Well, I was just thinking about the long distant traveler, Voyager. I know it recently made one of its last maneuvers, what would that maneuver look like if one were to be sitting next to it. Would it be now a maneuver in total darkness? Could you even see the cray at all? I am assuming the engines were using a compressed gas such as nitrogen or some large molecule gas (to help prevent long term leakage; hydrogen would surely escape). If the engines use gas, it must be so cold that the gas must be in liquid form and heated by the craft to work. Would you not see the gas released? Or is there ignition? I once spoke to a retired JPL engineer who worked on one of these deep space craft. He said the craft was worked on in a room which was in a room which was in another room to prevent contamination of every possible type. Magnetic, dust, etc. Thanks, love the videos.

@frasercain 6 жыл бұрын

Thanks a lot. The spacecraft has thrusters that it can fire to change its orientation. If you were beside it, you'd see a puff of gas come out from its thrusters.

@MrKrack-ri8ix 6 жыл бұрын

Hey Fraiser! I got a question. Since planet Mercury is the color gray, how come in books they show Mercury as the color brown?

@frasercain 6 жыл бұрын

Color depends on what information they're trying to convey, what filters were used, what kind of wavelength of light was captured. Did you see this video? kzfaq.info/get/bejne/h5phm695yLHdhYE.html&list=PLbJ42wpShvml6Eg22WjWAR-6QUufHFh2v

@DarkJK 6 жыл бұрын

Q: One thing matter and dark matter share is that it creates or give rise to gravity (don’t know how to phrase that). Wouldn’t it be so that dark matter clumped together too like normal matter? Or is it immune to the gravity though it produce it? If not, shouldn’t there be like massive dense chunks of dark matter? Like invisible “dark stars” and planets? You see where I’m going with this? I really can’t seem to form my thoughts into good words I think.

@frasercain 6 жыл бұрын

It just seems like the dark matter particles are very small and don't bump into each other or clump together. You can have huge clouds of dark matter pass right through each other and not clump up.

@j0d13xxx 6 жыл бұрын

Question: Is, or will there be any way we could capture the excess co2 from our atmosphere, transport it to mars and release many payloads at once, in an attempt to warm the red planet, increase the atmospheric pressure, thus allowing any water ice to become liquid without evaporating? With the bonus of cleaning earth's air in the process? Many thanks in advance

@frasercain 6 жыл бұрын

It would be much better to sequester it here and use different methods to warm up Mars. Did you see this video? kzfaq.info/get/bejne/Y8d_etRz2ZmWon0.html&list=PLbJ42wpShvml6Eg22WjWAR-6QUufHFh2v

@1970jeffreyg 6 жыл бұрын

Hello Fraser,Since some white dwarfs and neutron stars have been found to spin at incredible speeds, I was wondering if they may come close to flinging anything off their equator, or even cancelling a significant fraction of their own tremendous gravity at the surface. Is this even possible within our laws of physics?

@frasercain 6 жыл бұрын

Neutron stars can't, but white dwarfs can spin so fast they can have an early death. Check this out: www.newscientist.com/article/dn23282-astrophile-dizzy-dwarf-star-will-spin-itself-to-death/

@c.augustin 6 жыл бұрын

Shielding with water - does this account for ice too? Easier to have ice than water in space, right? (Or perhaps not, but anyways. I read about the idea of ice as a shield for fast space travel to shield from micro-metorites and other debris.)

@frasercain 6 жыл бұрын

Yes, ice works the same as liquid water.

@joemclaughlin5661 6 жыл бұрын

I still don't understand what space is, the stuff between mass like stars and planets ? What does it look like up close ? And how can it grow ? Maybe it's endless and matter, the universe is just expanding in it ?

@frasercain 6 жыл бұрын

It's just less dense. If planets and stars are more dense, imagine less dense. We talk about that here: kzfaq.info/get/bejne/ZtWKltubnqzUpYk.html&list=PLbJ42wpShvml6Eg22WjWAR-6QUufHFh2v

@gradimirknezevic8554 6 жыл бұрын

Fraser, is it possible that there is no dark matter, but a bunch of small black holes all over the universe, influencing moving of everything? Maybe that weird galaxy without dark matter is just too old to have significant number of miniature black holes, or space over there is somehow restrictive for forming of such black holes.

@frasercain 6 жыл бұрын

This is one of the possibilities proposed for dark matter, but not many astrophysicists really consider it serious any more.

@ChrisClark31415 6 жыл бұрын

I've always envisioned a bunch of BFR style launches to send massive water tanks into space. They are then attached to a central cylindrical habitat module to provide both fresh water and protection from radiation. Bonus points if the entire structure rotates to provide artificial gravity. 🚀

@ReinholdOtto 6 жыл бұрын

Question: We know that the intergalactic medium in galaxy clusters is very hot, millions of K, emitting X-Rays; recently I learned that even our galaxy is embedded in that sort of medium, even though the local group is comparatively small as galaxy clusters go. How does that fit to what they say about space being very cold (only a few degrees due to the cosmic background radiation)? Does that intergalactic heat relate in any meaningful way to what we perceive as heat every day?

@frasercain 6 жыл бұрын

These regions are very hot, in that the individual particles are releasing photons of high energy, but they're incredibly diffuse. So, if you flew through that area, it would still seem incredibly cold because of its low density.

@ReinholdOtto 6 жыл бұрын

Would the gamma radiation affect me?

@frasercain 6 жыл бұрын

There are all kinds of terrible radiation while you're out in deep space.

@miguelakira 6 жыл бұрын

Would it be possible to make a gravitational push on the entire solar system in order to use the entire system to move across space in a specific direction, say, close enough to another star? Like a ginormous interstellar motorhome.

@massimookissed1023 6 жыл бұрын

Miguel Akira , Shkadov engine You move your star, and your planetary system goes along with it.

@frasercain 6 жыл бұрын

Here's a video we did about that: kzfaq.info/get/bejne/j6ydnZBhxtqslJ8.html

@vitamincisgoodforme 5 жыл бұрын

If you could make your way to the edge of the expanding universe, probably meaning that you'd have to be travelling at faster than the speed of light, and you looked back with some high tech equipment, theoretically should you be able to "see" everything that has ever happened? Or like you said, can some "photon info" get lost through things like black holes?

@zapfanzapfan 6 жыл бұрын

If we had 1,5 g then getting to orbit would be about as difficult as launching something towards Mars, if we had 2 g then getting to orbit would be about as difficult as launching something towards Pluto. I wonder how higher gravity would affect the atmosphere?

@massimookissed1023 6 жыл бұрын

zapfanzapfan , we would have more atmosphere, and it would be deeper and more dense. There would probably be more hydrogen in it too, as it would be harder for H₂ molecules to escape Earth's grasp.

@R.Instro 6 жыл бұрын

I bet our respiration system would have to get an upgrade for 2G to be comfortable, too... or develop dolphin skin & start living in water full-time to compensate.

@zapfanzapfan 6 жыл бұрын

Lower gravity would make the atmosphere thicker (stretch further out from the surface), like on Titan, higher gravity would do the opposite I guess. But at some point when the gravity is enough to hold on to helium and hydrogen it will likely get thicker again, question is where that transition happens.

@MrGeocidal 6 жыл бұрын

Venus has a denser atmosphere than Earth yet Venus has slightly less gravity than Earth.

@mikhailb5645 6 жыл бұрын

Hi, Fraser! How would the Moon work as a launch pad? Lower gravity on one hand and current launch costs from the Earth surface on the other. Do we get better efficiency for gravitational slingshot over Jupiter while launching from the Moon compared to launch from the Earth? Thanks!

@frasercain 6 жыл бұрын

The Moon would be a great launch pad for exploring the Solar System. Did you ever see this episode of our QA? kzfaq.info/get/bejne/h9iKdpugr77Rg6s.html

@fursurething8659 6 жыл бұрын

Thanks for the info. Guess we will just have to wait for one of those beautiful sun shades that nasa is working on 🌞

@frasercain 6 жыл бұрын

Yeah, those will help. ;-)

@georgechadwick4243 6 жыл бұрын

Quick question: on any future colony on mars would it reach the stage where many animals are transported their to provide food for example

@frasercain 6 жыл бұрын

I'm not sure we'll ever see cows on Mars, for example, we're probably going to be seeing cultured meat that's grown.

@depizixuri58 4 жыл бұрын

What if the universe is "round", and a photon traveling in "straight line" returns to his origin from the opposite side? maybe we could not see "ourselves", but we would be able to observe out galaxy from outside. There is any simulation of how would the universe look? What would be different on the observation of galaxies, from the view point of testing the hypotheses with astronomy?

@magzire 6 жыл бұрын

What kind of technology could move a planet

@damage6316 6 жыл бұрын

Hi Fraser, How far away could we detect a civilization of comparable size and technological advancement to humanity?

@frasercain 6 жыл бұрын

Right now we can't see very far, but once we get more powerful telescopes, we could detect pollution. If they want to communicate, though, we could detect a targeted radio transmission.

@fraxyv21 6 жыл бұрын

Q&A: Comments on the recently observed visible-matter-only galaxy?

@frasercain 6 жыл бұрын

We talked about it last night in the Weekly Space Hangout: kzfaq.info/get/bejne/Y5hpgtae0p20gX0.html

@Random-gy2bg 6 жыл бұрын

Fraiser, do magnets work in space? Do the poles attract/repel each other the way they do on Earth?

@frasercain 6 жыл бұрын

Sure, if you took a bar magnet to space, it would work the same way it does on Earth.

@Random-gy2bg 6 жыл бұрын

Fraser Cain What if I were in a space ship and passed close by Jupiter or another large planet with a large magnetic field, would that planet effect the way it works?

@massimookissed1023 6 жыл бұрын

Mason Creed , your bar magnet would behave like a compass, orienting itself to be attracted to the nearest of the planet's poles.

@marcusfpavani 6 жыл бұрын

Hey Fraser! About the water used for radiation shielding: would we be able to use the same water for consumption later? Or would that water be contamined?

@frasercain 6 жыл бұрын

No, it'll actually turn into heavy water over time. You don't want to drink that.

@marcusfpavani 6 жыл бұрын

I see! But does the heavy water keep working as radiation shielding? Or does it have to be renewed every certain amount of time?

@konradbiay4011 6 жыл бұрын

Hi Fraser, I've got a question for you. Would it be possible to explain the very fast rotating galaxies by a huge number of supermassive black holes or even by something that is more massive than the most massive known black holes and would cause different effects?

@ericthatcher 6 жыл бұрын

Hi Fraser, Great video’s. Is there evidence that Europa has oxygen in the water under the ice? I watched a video about life that lives on thermal vents on earth. they we’re talking about that kind of life is very sensitive to oxygen levels in the water. Since Europa doesn’t have tidal action how likely is to be life on any of the frozen moons in the solar system?

@frasercain 6 жыл бұрын

I can't imagine how you'd get oxygenation like we have here on Earth. But there are lifeforms that do okay without oxygen.

@johnwolf7073 6 жыл бұрын

2:07 that was so funny ! xD we love u fraser ! :)

@frasercain 6 жыл бұрын

Thanks!

@brobrah4595 6 жыл бұрын

Was wondering about the water shielding. Does water or can water get radiation saturated and need to be changed? Or would it just be to simply fill up the "domes" or whatever and forget about it?

@CarFreeSegnitz 6 жыл бұрын

Judging from how highly radioactive nuclear waste is treated, sunk into a pool of water, the water shield could probably just stay there.

@plexibreath 6 жыл бұрын

Great question, I look forward to seeing someone answer this.

@frasercain 6 жыл бұрын

Water is used to block radiation for nuclear reactors and it does get more radioactive over time.

@massimookissed1023 6 жыл бұрын

Bro Brah , EM radiation stopped by water would just cause some heating (like a microwave oven) and maybe some flourescence too. Those effects would be temporary. Cosmic rays are actually particles, and if stopped would become suspended in the water, ~ gives it that space flavour.

@bman7653 6 жыл бұрын

Fraser, if water is to be used as a radiation shield, does that water remain potable? Or does it become somewhat radiated, enough to be unusable?

@massimookissed1023 6 жыл бұрын

Bryan Dunlop , if it absorbs enough neutrons the Hydrogen atoms become Deuterium and then Tritium, which IS radioactive...

@frasercain 6 жыл бұрын

It becomes heavy water over time, which you wouldn't want to drink.

@joannacheneler9990 6 жыл бұрын

Fraser i have a question around the heat death of the universe. If our own sun is the third generation of stars could there be a forth generation that extends the heat death another few billion years?

@frasercain 6 жыл бұрын

There will still be stars forming far into the future, but eventually every stray piece of hydrogen will get used up in the formation of a star.

@danielduarte6086 6 жыл бұрын

thanks for the great videos! its a pleasure to support your channel on Patreon, recommend all to do it! What is the fastest growing business for space? I mean not Spacex directly, but its suppliers/partners? What education should i get to increase my chances to be part of space work?

@DrNappers 6 жыл бұрын

Using water as radiation shielding has been mentioned in several videos. What effect (if any) does this radiation have on the water? E.g., assuming the water was drinkable to start with, does it remain drinkable after absorbing the radiation or is it only then useful for other things?

@frasercain 6 жыл бұрын

No, it becomes radioactive. Here's a conversation about it on Quora: www.quora.com/Does-water-become-radioactive-after-being-used-as-coolant-in-nuclear-power-plant

@massimookissed1023 6 жыл бұрын

Fraser Cain , some of that is from slightly dissolving the fissile fuel, so it would be toxic as well as radioactive. :( But heavy water from neutron absorption is also bad. Prof Poliakov did a *Periodic Video* for Brady Haran about how it's bad, m'kay. I dunno what Cody was thinking...

@frasercain 6 жыл бұрын

Found the video, thanks! kzfaq.info/get/bejne/nN97ac6Bzp7PZ2w.html

@LordKingPotato 6 жыл бұрын

Hi Frasier, what's your favourite Galaxy from the photographs that have been taken so far?

@ericsorensen4691 6 жыл бұрын

Hey Fraser, I was just thinking about supernovae, like ya do, and I was wondering: is it true that stars don't create *any* heavier-than-iron elements unless they go supernova? Or is it possible that there is a relatively small amount created during a large star's normal lifecycle? I can imagine that maybe here and there a few iron or nickel ions get a little extra kick from some nearby fusion reaction, enough to make them fuse. Is that possible?

@frasercain 6 жыл бұрын

Right, you can only get elements heavier than iron in a supernova, and now it looks like you can with colliding neutron stars.

@matadorprime6555 6 жыл бұрын

With all the stars in a galaxy, and all the galaxies in the universe producing so much heat, why is space so cold?

@frasercain 6 жыл бұрын

The vast distances involved make the total amount of radiation falling on any one spot so low.

@IlicSorrentino 6 жыл бұрын

Great as always. Question: if you use water to shield from radiation... can you use that water for drinking?

@vrstovsek 6 жыл бұрын

Hey Fraser love the show! Question: What is the purpose of all the smoke on rockets (and underneath them) some time before the launch to space. Is it for cooling? Also, why is the fire exhaust on a rocket getting wider after some time when the rocket is climbing? I hope you know what I meant. I'm not an english speaker... Greetings from Croatia! Thanks

@frasercain 6 жыл бұрын

Thanks! That's actually water vapor from the huge pools underneath rockets. These pools dampen the sound and heat from the rockets so they don't tear apart their launch towers.

@dyshexiia 6 жыл бұрын

Hey fraser a kinda weird question i was thinking what would happen if you compress earth down to its Schwarzschild radius but it were to spin so fast that its just out of this zone... and what would happen if it just slowed down JUST slightly to the point where it collapse would there be some sort of epic boom or would it just collapse and become a normal black hole? (Kinda of a weird question but hey xD)

@frasercain 6 жыл бұрын

If you compressed the Earth down to become a black hole, essentially, and then spun it up, you wouldn't be able to reveal it again. The maximum speed you could spin it would be less than the speed of light, and it would take an infinite amount of energy to spin it faster and faster.

@maxnewellmz8025656 6 жыл бұрын

When Betegeuse explodes will it leave behind a nebula similar to M1?

@frasercain 6 жыл бұрын

Yeah, a supernova remnant.

@vovacat1797 6 жыл бұрын

Hey, Fraiser! What if we find a way to create antimatter with greater than 50% efficiency? Aren't we gaining profit from annihilating it then, just because regular matter also annihilates, and we didn't create that, it was just sitting there all along before being turned into energy. Is that possible?

@charleswickizer8471 6 жыл бұрын

Do we know where the first solar eclipse occurred on our planet and or where the last one will occur?

@NorthernChev 6 жыл бұрын

Consider this... Since SpaceX contracts with NASA to take humans to the ISS I understand the government requiring the Dragon Capsule to be human certified. But nobody owns Mars and SpaceX is a private corporation... To land on Mars you wouldn't think they would need any government' "certification" where there is no governing body. Do you think SpaceX should be required to meet the US government's certifications for the Dragon Capsule (or any other part of the rocket) to take humans to a place like Mars that has no government? My focus here is on the "required" part of it. What do you think?

@frasercain 6 жыл бұрын

No, if they're launching to Mars, I don't think they'd require any certification beyond FAA guidelines for protecting the Earth. What happens to them on that journey is up to them.

@ajdaniels 6 жыл бұрын

Hey Fraser! I just read that Mars' core has been shut off and thus Mars lost its atmosphere. Doesn't that make any terraforming attempt futile?

@frasercain 6 жыл бұрын

Yes, but there are some ways you could deal with that. Did you see this video? kzfaq.info/get/bejne/Y8d_etRz2ZmWon0.html&list=PLbJ42wpShvml6Eg22WjWAR-6QUufHFh2v

@dbaker059 6 жыл бұрын

Since a black hole is just space falling in on itself faster than light what if two non rotating black hole event horizons came into contact with each other would there not be a "neutral" spot momentarily that might allow something to escape?

@p-mtc3900 6 жыл бұрын

If time passes faster when gravity is lower, then if we would have developed on Mars, would our brains work faster, would we be more developed species? Then any species in low gravity planet will have chance to become developed faster then we...I'm not sure if I got this correct.

@frasercain 6 жыл бұрын

The amount of time dilation in that situation is a fraction of a fraction. Like a few extra seconds over millions of years.

@marshmallowmonster7731 6 жыл бұрын

Hi Fraser, I wonder: Does centrifugal force, made by Earth's (or other planet's, asteroid's etc.) rotation, counters or affects gravity in some way?

@tehrsbash 5 жыл бұрын

Hey Fraser, I was wondering, Soon after the big bang when the entire universe was only the size of a proton would it still be considered 'infinitely large'? Also what was the 'edge' of this proton sized universe like?

@petercrisp4543 6 жыл бұрын

Hi Fraser. Why would you need to cool a telescope if space is cold anyway? Obviously there's a reason as I have a feeling the people who build them have most likely had that idea but I'm struggling.

@frasercain 6 жыл бұрын

Because you're trying to observe cold objects, like brown dwarfs and newly forming solar systems. You can't see them if your telescope is too hot.

@R.Instro 6 жыл бұрын

Using a warm telescope to see objects in the infrared is like trying to see visible light objects with a scope made out of a tube lined with light bulbs. =D Just as you radiate body heat in the form of IR light, so too does the telescope, emitting more & more IR as it gets warmer. For a telescope trying to detect IR, _emitting_ IR gets to be a severe limitation, so we try to keep them as cold as physically possible.

@EASYTIGER10 6 жыл бұрын

9:30 Wouldn't it make more sense to rotate the entire space station along its longitudinal axis and have the donuts permanently fixed to get the "gravity fix"? 'The people would just rotate in the central axis with the space station. If anything needs to "not rotate" (eg communication equipment or solar panels), then have THEM rotate independent of the rest of the module. They don't after all need an airtight link to the rest of the station.

@massimookissed1023 6 жыл бұрын

EASYTIGER10 , the simulated G force you'd feel is based on *rotation rate X radius,* and since you don't wanna spin too fast else you'll puke, you wanna get AWAY from the axis. You'd want a central hub for docking & comms dishes etc.

@R.Instro 6 жыл бұрын

Cylinders & wheels both work (probably), but while cylinders do need to spin faster to get the same apparent gravity as a wheel of the same mass, I like the O'Neil idea especially for large habitats because it preserves a micro-gravity environment for the length of the tube, which makes for a pretty convenient storage/transport system in-station, which can be accessed by elevators from w/in, & docking ports on the ends from w/out.