Medical Emergencies on the ISS, White Dwarf VS Red Dwarf, True Color of SLS | Q&A 189

[@tidepods7257]

Bespin, gas stations on Titan would be a gold mine and is a super cool sci fi concept

[@karlhenderson1908]

Corellia. I love both the question and the answer. Tatooine (medical emergencies on the ISS was also a question I’ve pondered for a while. Thank you so much.

[@Matthew-by6vl]

My vote is Coruscant obviously...it's my question!

[@ChrisBrown-pu8sm]

I'm extremely or gigantically glad that someone cares enough to try answering our biggest questions. We must have someone willing to expose the truth hopefully at any cost. You deserve more than a thank you for your cooperation and consideration.

[@AnonymousFreakYT]

Tatooine - One note is that astronaut training includes medical training that is on par with an EMT (paramedic.) They're getting a lot more than standard Scouting "First Aid merit badge" level training.

[@echo1271]

Well, there are hardly any Doc Leafs in space. 🙈 🤭 🌿

[@universemaps]

This is my new favorite channel I'm putting myself up to date watching all your old videos.. thanks for the super interesting content!

[@chipblood]

Time Domain Astronomy sounds like an incredibly exciting field with all kinds of mysteries to unfold. I can't wait to see what the telescope uncovers after a few years...Or 20 years...Awesome video! Thank you!

[@frasercain]

Thanks! I'm glad you enjoyed it.

[@ChrisShelton024]

I vote for “Mustafar” :) I can’t wait for NGR!

[@idodekkers9165]

Hey fraser regarding the speed of light, I know it's possible to slow light in some mediums, is there a medium that slows light enough that sound (or anything else) will travel faster then it in that medium, or is the law works in any medium?

[@paulwalsh2344]

Cool question. I've heard that it takes a LONG time for a single photon created in the fusion of one hydrogen atom to a helium atom in the center of the Sun. And is that similar to the conditions that you are describing... the super dense regions of the center of stars, that those photons are slowed down significantly ?

[@idodekkers9165]

@@paulwalsh2344 actually as far as I understand, no photons from the center of the sun get out (but I am probably not understanding it correctly), what I understood is that photons in the core collide with other atoms, push the electrons to higher levels and the "falling" electron creates a new photons - but again - that's from what I understood and I may very well be wrong. I was actually referring to the fact that light is slower in other mediums like water and glass - hence the different angles in and out, and here en.wikipedia.org/wiki/Slow_light you can see they got it to real slow, and now that I read this, it seems light can be slower then sound in some mediums....

[@Raz.C]

You understand, don't you, that even 50% of c, is still 150,000,000 meters per second, right? That's 540,000,000 Km/ hour. Or 335,308,314 mph. You also understand that the speed of sound is ~ 1,000 km/ h or ~ 700 mph, right? You can see the difference between those numbers now, so I would hope your question has now been answered to your satisfaction. Ps: Having said all that, there's also some reports of light moving through BECs (Bose-Einstein Condensates, which are another state of matter. Solid, Liquid, Gas and BECs) at around 30mph!!! In THAT case, it might be possible that sound and light would have the same speed through BECs. However, it's equally possible that sound may move at 0.000001 mm/h through BECs and so the two might never achieve parity.

[@paulwalsh2344]

@@Raz.C Yeah I understand that the difference between light and sound are like six orders of magnitude difference, but I went with the spirit of the question and wondered about light through matter within say the nuclear pasta within a neutron star for instance... if calculations, which I admit I'm abysmal at, could close that gap much closer ?

[@Lou-pi5tx]

Hey Fraser, I’ve had a telescope for a year now would like to upgrade but on a strict budget. What’s your best recommendation? I’d love to be able to take pictures

[@dominic.h.3363]

I wonder if they could do an appendectomy on the ISS. It's acute enough to not leave any time for a safe return to Earth and it is a major surgery. It would also be a hell of a lot more complicated in zero-G with the way how blood is pooling. A true nightmare scenario.

[@02buddha02]

Your videos are the best!

[@msmyrk]

Tatooine: At least they don't need to worry about anaesthesia, because.... in space, no-one can hear you scream.

[@samuelec]

Corellia and Exagol, for me, were the most intriguing

[@miracleofsun]

Hey Fraser, why don't you film outside anymore? That was always 👍

[@miguelakira]

I seem to recall that he mentioned issues with light, noise, etc. that made him prefer to record inside, in a more controlled environment

[@frasercain]

It's really time consuming to set up outside and film. But with our new studio we've set it up so I'll be able to shoot outside more easily.

[@DogsaladSalad]

He's actually filming outside but Canada is so green it effectively functions as a green screen

[@Luceq]

Are you using a blue screen now?

[@blitzmotorscooters1635]

happy summer vacation bro

[@atl5305]

Hey Fraser, for our accelerating universe, how do we know that we aren’t accelerating our expansion because of the sheer force of the Big Bang? Is it possible that in universal time we’re still in the barrel of the Big Bang gun?

[@MyKharli]

I am sad that all these questions will remain unanswered as climate catastrophe is spiralling fast out of control . The biggest news the world has ever faced is that limiting temp rises to 2 deg or less is now impossible therefore the future is ultra bleak for humans and what's left of wildlife . Yet not one sentence uttered in any media ?

[@Raz.C]

Maybe we're really in a backwards universe and what's REALLY happening is that the universe is REALLY collapsing into a singularity, but our perception makes it appear to go backwards, and so we see everything expanding...

[@luthersloan7970]

Hi Fraser, thanks for your work! I've lived my whole life in Australia, recently when I was in Denmark I looked at the sky on a clear night. I swear the first thoughts in my mind were a little fear, feeling of being lost, the feeling I was on another planet. Quite the experience!

[@LordZordid]

I was sorta expecting on the walls of the Large Hadron Collider that someone had written "Kilroy was here".

[@echo1271]

The one image I've always had in my head of the LHC is the fact that it's a huge very fast underground magnet, and that it's built below Swiss farmland, and cows have cowbells around their neck... Yeah... 🙈

[@DrDeuteron]

@@echo1271 are you talking about the beam? Current is 0.58A - 0.58A = 0A. Not a good magnet. Superconducting bending magnets are 12,500A.

[@DustinCable]

Hi Fraser, the density of the sun has always baffled me. We seem to treat the photosphere of the sun as a "surface" but If I had spaceship impervious to heat/radiation and dropped below the photosphere, would I even notice? How deep do you need go before reaching anything like the density of Earth's atmosphere? Are stars like ours just large puffy clouds with linearly increasing density until you hit the core? Is the photosphere just a visual artifact? Could something orbit the sun within the photosphere? Thanks!

[@paulwalsh2344]

Love this question ! Yes, it's true that the "surface" of the Sun is actually lower density than anything we have in our planet's atmosphere.

[@Raz.C]

That's a great question. I have my opinion, which is based on my understanding of the physics involved, but I don't KNOW, so I won't bore you with an answer that might be wrong. While you're thinking about it, though, bear in mind the two opposing forces acting on atmospheric gasses; the immense gravity of the sun and the equally immense outwards, radiative pressure (your spaceship would also need to be impervious to gravity, otherwise you'd soon find yourself falling and unable to get up).

[@urdooinitrong7753]

Hey Frasier, on the Mandalor question and your answer. They are not in perfect balance. The moons orbit is increasing by about an inch a year. This has slowed down the rotation of the earth over billions of years also. Love the science stuff!

[@zapfanzapfan]

Bespin. For a barbecue on Titan you don't have to bring a propane tank, but you do have to bring an oxygen tank :-)

[@doggonemess1]

[Alderaan] At any point if you stepped off the space elevator, you would have the lateral motion of whatever altitude you reached. So at sea level, you would be moving sideways as fast as the equator. At 100 km, you would be moving only about 40 meters / sec faster, so you would fall and hit the ground as usual. If you reached high enough before stepping off, you would fall, but you could have enough sideways velocity to miss the Earth when you fell, which would put you in a highly elliptical orbit. Maybe you can grab the next elevator car on the way back around.

[@stephenkiely9244]

Hey Fraser, if the Universe is speeding up while expanding, if it reached the speed of light, would it not go back in time?

[@filonin2]

Such relativistic effects don't apply to space-time itself. It can expand or contract at any speed without dilation problems as it isn't a physical object. Physical objects with mass would go backwards in time if they could somehow go faster than light, but it would take infinite energy to do so. There would also be the issue of time stopping when you somehow reach light speed, preventing you from accelerating further since time no longer flows from your perspective.

Hi Fraser! Question: Are there stable orbits that could go inside a hollow astronomical body? Say we have an orbital ring, could satellites orbit it inside?

[@Disasterina]

Fraser! It infuriates me to watch sci-fi movies when they have a spaceship go through an asteroid field with millions of giant rocks tumbling around right next to each other. It’s prolly the most impossible thing ever in science, right? So my question is how long would it take for all those rocks to be pulverized to the size of grains of sand if was an actual real scenario? My guess is about a week. Oh, and my vote is for Bespin. Great show!

[@brick6347]

Hope you have a great summer, don't overdo the mountain bikes, and looking forward to seeing the new studio without the green screen (even though you secretly used one for years 😉)

[@Natsu84654]

W"as just thinking about the expansion. if we turn the tabel, that its not expanding but compressing. so the reason galaxys far away is getting futher away is bc we are draged faster towards the "senter" that will also increas the distance between all galaxsys in the same way. (sorry bad english:)

[@DominikJaniec]

very interesting!

[@echo1271]

I have a question, I'm just not sure how to ask it, but I'll give it a go. You mentioned the universe is probably expanding uniformly. If that is how we observe it, doesn't that put the Milky-way somewhere near the centre of the universe? If we were off centre, and the universe was expanding (for example 100mph) because we have moved due to the expansion, wouldn't the side expanding away from the centre apear to have moved further than the side on the centre? I hope you got the idea of what I was asking. Thanks. Coruscant

[@GlennKramer]

I believe I have a good question that hasn’t been asked yet: we all know that spiral galaxies rotate, with stars generally following the same direction around the galaxy’s center. But then why are the stars orbiting closely around the black hole at the center of our galaxy all seem to be coming from all over the place?

[@Raz.C]

Do you remember the Universe Song that Monty Python sing in The Meaning Of Life? If I recall correctly, they sing that the galaxy bulges to 60,000 lightyears near the core, but by us it's just 3,000 lightyears wide (thick, actually). The galaxy isn't a flat plane. The stars that are orbiting around Sag-A are orbiting in non-planar paths, however, the general motion of the majority of stars around the galaxy trends around the orbital plane. Once again, however, we have to recognise the difference between trends and individuals.

[@feelingzhakkaas]

Great video clarify all queries...thank you. My Question are... 1. WHICH STAR DOES JWST TAKES AS REFERENCE FOR FOCUSING DURING LONG OBSERVATIONS . 2. IS IT POSSIBLE TO REMOVE 6 SPIKES FROM JWST IMAGES ?

[@michaelpettersson4919]

I used to have a colleague that used instant glue to refit a tooth whenever it fell out. Thease repairs apperantly work for a couple of months before he had to do it again. I was a bit shocked when he told me why he needed to borrow my glue tube that I was working with. I can see how an medical emergency in space may go for some unorthodox solutions.

[@andreask.2675]

Shouldn't we build a second version of the Vera Rubin Telescope in the northern hemisphere? EXEGOL

[@Leggize]

Roughly speaking, JWST can see everywhere in the sky. You have to imagine the telescopes view as a disk. That disk moves through its orbit, changing its field of view to encompass any area of the sky that is required. Any given picture can only be taken at a given time.

[@dannypope1860]

Wow…the South Pole picture question was borderline regarded…

[@alaniouspalanious]

Hi fraiser, great stuff! How is it posisble for the universe to have infinite mass in a defined volume. Would that mean the overall density is the same today as right after the big bang?

[@HebaruSan]

At the heart of space shuttle reusability was a conflict of interest: Every dollar saved by the taxpayer would have been a dollar not made by the subcontractors (and part of the point of NASA is to provide demand so the US can have an aerospace industry). So those companies had incentives to fail at reusability, not advance it. With the Falcon 9, the benefits of reusability are captured by SpaceX, and there's no economic counterforce pushing back against efficiency.

[@alaniouspalanious]

Yeah but designing was bid out. If a comnpany proposed a working resuable model and it was significantly cheaper, the contract would be awarded to them

[@nickdiamond7595]

33:48 "our meat cameras" 😆

[@FiveTwoSevenTHR]

It's said that cold welding needs pressure but my understanding is that things can stick together from just contact. How much pressure does it take for cold welding to start happening?

[@hello4022]

Hi Fraser, just wondering if NASA has an earthbound twin of James webb or any of its space telescopes similar to the OPTIMISM or MAGGIE copies for perseverance and curiosity to help troubleshoot issues?

[@Daveoken]

Hey Fraiser, Do Escape Pods as we know them from films exist? where if there is an emergency you can run/hurry to an escape pod, launch and it would navigate back to earth automatically?

[@bozoerectus3207]

There's always constant speculation and discussion of 'spaghettification', and it's very interesting, but when will scientists address the issue of 'meatballization'? Could it be that black holes are in fact super-massive meatballs?

[@Raz.C]

Bah! Wake me up when we get to Parmesan Cheese-ification...

[@bozoerectus3207]

@@Raz.C Sounds interesting, I'll look into that after I'm done working on my Quantum Super String Cheese Theory.

[@Raz.C]

@@bozoerectus3207 Dude! I wanna live in THAT reality!!

[@rulingmoss5599]

Tatooine. Hey Fraser, love the show, I'd like to ask if there are any particularly exciting discoveries from TESS lately? How is it holding up?

[@publicmail2]

The foam is off white but when the suns uv hits it it turns orange, just like all spray foam does.

[@scottmedchill4210]

Have you seen a recent paper (Kevin S. Croker et al 2021) suggesting that the expanding universe could be causing black holes to be expanding as well? I was wondering if we could use this idea to explain the dark matter halos around galaxies. We already know that space expands more rapidly in the mostly empty areas between galaxies, so shouldn't any black holes in the outer rim also be expanding more rapidly?

[@hello-ji7qj]

QUESTION: Do all black holes have the same density? I know the masses are different, but is density the same?

[@frasercain]

We don't know the density of the actual black hole itself, but the math assumes that it's inifitely dense. The region within the event horizon varies in density depending on the size of the event horizon and the mass of the black hole. So, supermassive black holes are less dense within their event horizon than stellar mass black holes.

[@ComputerBladet]

Is there any plans of sending a “new Voyager” in the universe? (Why/why not) Great show

[@joewilliamsjr.1203]

Hi Fraser, Why is the outer layer of the sun hotter than the surface? This seems counterintuitive as I thought the heat would dissipate.

[@Kamel419]

29:21 - "Is it a good idea to broadcast our existence to the universe?" - IMO, the cat's out of the bag on this one. As soon as we discovered RF and began broadcasting radio and tv signals, we have been ever since broadcasting our existence to the universe whether we wanted to or not.

[@blongsiab]

It's a giant pumpkin waiting for Halloween hoping to launch once a year.

[@isaacplaysbass8568]

Question re Space Elevator; assuming that materials, cost, etc are not a factor, what would issues such as continental drift, precession etc. must be taken into consideration?

[@MdzombaBaya]

Hi Fraser, Thanks for the Q&A that is very informative. I have a question, there are these illustrations of neutron stars cannibalizing their companion stars when explaining one of the types of supernovae. I was wondering how close together do these companion stars have to be for one to steal matter from the other?

[@jamesonfjord8666]

I've had this question, for some time, but have the feeling there would be no way to investigate it - because it would be invisible to us humans, but, here it goes: What if the expansion of the universe is caused not by any energy or matter INSIDE the universe, but, similar to surface tension, when you put a drop of soap in a pan of oil and water, the whole thing expands radially, and at a greater rate. In other words, what if the universe is being sucked outwards FROM outside our visible universe? And, how would we ever know? What hypothesis' and solutions to whe whole dark energy/matter have we put to rest as unfeasible or unknowable?

[@RICK82873]

Question. virgin galactic and blue origin have completed trips to space with the idea of being able to provide a space tourist service. So just how many flights have they now made and how many people have they put into space?

[@dMarvis]

Fraser, do stars move with tendency towards its poles, opposed to in the direction of its planetary plane? Can we trust the diagrams showing us moving in a spiral through the galaxy?

[@chrisoconnell8432]

Hey Fraser, since the Vera Rubin Observatory will be so beneficial, is there an equivalent one planned for the Northern hemisphere? Seems like you'd need to cover the entire sky, not just the southern sky. Thanks.

[@Jenab7]

A while ago, I said that the _average_ star has a mass of about 0.34 solar masses. According to the luminosity function for the solar neighborhood, the _most common_ main sequence star has a mass of only 0.21 solar masses (and a visual absolute magnitude of +13).

[@DrDeuteron]

LEP was the fastest matter beam ever. The Lorentz factor was gamma = E/M = 209 GeV/m_e = 410,000. Meanwhile, LHC is around 7 TeV/M_p = 7500. At these speeds v/c = 1 - 1/(2*gamma)....so LEP was v=99.999999999997%c. Fast fast.

[@johnbennett1465]

As I understand it, we can not see the visible light of the stars in the pillars of creation. This implies that enough light years of nebula is opaque. Thus if we were inside a large nebula, we would see nearby stars, but not distant ones (in visible light). Is there something I have misunderstood about this?

[@AvyScottandFlower]

If you need a tooth pulled on the ISS, procedure indicates a fellow astronaut has to tie said molar to the Dragon, as it's departing back to Earth.

[@mralekito]

How much more difficult is it to put a spacecraft in orbit around a planet then a flyby? Would we have to send spacecraft slower if they are to be out into orbit?

[@richardaitkenhead]

Put it this way, for a flyby of pluto travel was 9 years for an orbiter it would be 40 years. It took less than 2 years for a Jupiter fly by, 6 years for juno. For the juice mission to Jupiter's moon is 7 years, voyager took 3 years for fly by. Mercury is 6 months for flyby, 6 years for orbiter. Its a lot harder

[@brettlarue1937]

Question for next Q&A. If matter can be made out of energy and matter has mass shouldn't energy have mass? Hidden dark matter?

[@dontactlikeUdonkno]

In the same way light is red-shifted, could also not time (or our perception of it) have a similar effect? Due to the relative speeds. Would this explain why the universe rate of expansion appears to be increasing? The expansion far away (in time≈distance) would 'red-shift' (metaphorically) so rate of expansion farther away (in time/distance) may appear to be happening relatively slower than than most recently; i.e. the galaxies that are closest to us.

[@Bergmaniator]

If big rip is true, would that mean that the physical preconditions for objects are also changed? Eg black holes would revert into neutron stars as the gravitational forces can no longer overcome the degeneracy thing, or theoretically vastly larger stars being able to exist due to changes in the hydrostatic equilibrium. Jupitermass object with earth surface gravity?

[@eddjordan2399]

because that's the colour of the pu foam on the external tank i believe it becomes more orange with exposure to uv (sunlight)

[@lukerobson3043]

Yeah it starts more as a orange yellow colour but uv changes it to a dark orange over time

[@rJaune]

Have there been instances of stars being made fuzzy or dimmed by nonfocusing DM lenses?

[@000fisherman]

So is the expansion of the universe accountable for the moons recession of approx, 4centimetres per year or is this something different????????????????????

[@frasercain]

No, that's totally different. The Earth's rotation is actually slowing down, and that's causing the Moon to slowly drift away to compensate.

[@galaxyclique]

I wonder about the redshift of far objects, why does the photon dont leave energy on its path thruh the Universe, and therefore be redshiftet the more distance it travels? Or is the redshift amount big enoth that we would find these paths of the Photon? also if reality is relativ, doesnt this mean that the universe can be diffrent for everybody and it depends on what the person is beliving in?

[@phoule76]

volleyball-sized? then let's call it The Big Spike, shall we?

[@mikaellindbergmuren4538]

Does The moon rotate around its own axis? I know that is has a dark side but asume that rotation would still be possible with an angle that still ceeps the dark side away from us

[@jasonlikens7087]

Hi fraser ive always wounderd if i could hold the univers in my Hand and watch the Light move from one side to another it would take Billions of years.....what if i pionted a laser pointer through the univers beeing that the univers would only be aproximatly 4 inches how long would it take.or would my size Not matter.sorry if it seems like a stupid question.

[@irontusk341]

What is the largest planet by (earth masses or diameter) that humans could feasibly walk on or live on?

[@WGSMRW]

If our universe was the size of a volleyball at the beginning, wouldn't we just need a larger sample size to see a bigger picture of the past?

[@slaphappyduplenty2436]

Can the dark energy causing the expansion of the universe be quantified in watts? I suppose it’s a standard mass times acceleration equation. If we know mass and acceleration, we’ll have the power. Also, is the acceleration accelerating, or is there an asymptote somewhere here?

[@filonin2]

Mass of what?

[@TG-rf2iu]

Yeah, but what is the universe expanding into?

[@petergerdes1094]

I thought we didn't yet know for sure the big bang was infinite (even if it's what is suggested by mass density of visible universe). We know it happened everywhere as it were but I thought it was still a possibility it was like blowing up a balloon ...but starting with the inflated balloon at a point. More mathematically it's possible that spacetime forms a compact manifold. But it's entirely possible I'm mistaken so if I am I'd love to find out why.

[@Home-Loans]

Hi Fraser. Wouldn’t it make sense for advanced civilizations to move closer to the middle of the galaxy so that they can harness the energy of the black hole and potentially slow time down for themselves in relation to the rest of the universe?

[@imbatman8472]

why would they want to be in slow motion?

[@Home-Loans]

@@imbatman8472 They wouldn’t be in slow motion. The rest of the universe would essentially be in slow motion compared to them. In essence, making them immortal

[@imbatman8472]

@@Home-Loans they would be in slow motion the closer you get to a gravity well the slower time moves.

[@stooartbabay]

Lol, I actually thought it was rust :)

[@000fisherman]

So here on earth ( i live in Australia) which way do i look to point at the big bang?????????????????

[@frasercain]

You look in every direction. The Big Bang happened everywhere.

[@jewymchoser]

Why does the James Web Space Telescope cost so much to operate? Now that it's up & running, isn't it just a matter of sending commands via a computer?

[@kentrangprofessor3963]

Why don’t the ISS have a life-pod for emergency escape???

[@frasercain]

They do have escape craft attached. Enough for all the astronauts if they need to escape.

[@monkeyking-self-proclaimed7050]

Remote doctor arm?

[@lostpony4885]

The astronauts receive an ice skate and some video tape for dental emergencies.

[@oisnowy5368]

I had a question. But I wrote it down using my special neutrino pen and now it's everywhere and nowhere and just flying through almost everything.

[@JITBWorldWide]

Tatooine. If gravity does no work how to tidal forces heat moon etc . It seems to me there is some energy transfer , but from where to where ? Does that make sense ?

[@saiprem]

Friction?

[@JITBWorldWide]

@@saiprem I know what you mean . I get the idea of how the repeated deformations of a moon (for example) could heat it up. I could do something similar with a balloon by repeatedly squashing it, but in that case I am doing work and imparting energy that I took in from somewhere else (i.e. food) and then transferred some of that to the balloon. And then that dissipated that to the atmosphere, and out of our (human balloon system). But if that is the mechanism for tidal forces and the only "force" is gravity then the heating must be result of work which implies an energy transfer. But from where does that come from and wouldn't it eventually run out as the energy dissipates from said moon . I just can't seem to square that circle.

[@theOrionsarms]

The tidal heating doesn't happen if the moon (or the smaller body that orbit the bigger) orbit in a perfect cyrcle and is tidal locked, but if the orbit is eccentric or the body isn't tidal locked a periodically deformation of its surface would happen, and the energy source is given by change in orbital mechanics and relative speed of spinning of the bodies , for example the earth moon slowly depart from earth. And because of that earth rotation speed is decreasing , probably for less than 12 hours when was formed to 24 hours of today, and still would decrease in the future, well this is a simplified explanation because also sun perturbed earth moon system but the main source of energy in that case is earth rotation.

[@JITBWorldWide]

If we were to message distant star systems with lasers , would we need to aim where that star system would be , or do they currently aim at where they are in our view.

[@chrisoconnell8432]

Depends on where the star system is. If its a nearby star, then it is orbiting the Milky Way with us and its position relative to us won't change by the time this signal reaches them. If its on the other side of the Milky Way then we would have to aim where the star is going to be, not where it is. But if its that far away it will take 100,000 years for the signal to reach them so why bother.

[@filonin2]

@@chrisoconnell8432 Any star other than the Sun will not be where you aimed since it will take years for a laser to arrive at even the closest star and stars are moving dozens of kilometers per second. Why wouldn't nearby stars be moving relative to us? Stars do not orbit in strict planes and move a lot relative to each other. Alpha Centauri has a relative motion of 21.6 km/s towards us, 11.7 km/s west and 3.1 km/s north. If you aim where it is now you'll miss. By a LOT. Total proper motion is 24.8 km/s so over 4 years that's roughly 22 AU. For a narrow-beam laser communication, there is no way you would see it 22 AU to the side. So if you were aiming at the Sun for example, the laser would be visible out near the orbit of Neptune. That's with the closest star in the galaxy, so best case scenario.

[@chrisoconnell8432]

@@filonin2 The Sun moves around the Milky Way at around 230 km/s so relative to that the stars don’t move much. That was my thinking anyway. Was also assuming the laser beam is spreading out over distance and not a theoretical laser. 22 AU is only 0.0087% of 4 light years. Admittedly I don’t know what the dispersion rate of a good laser is, but I’d be surprised if its less then that.

[@kentrangprofessor3963]

How many gravity experiments have the ISS tried out/ tested in space??? What are the results?

[@dmkmd10]

Here’s a question: what is the largest mass, potentially-habitable rocky planet where intelligent inhabitants could have a hope of getting into space?

[@jamesdubben3687]

mustafar unfast = position faster = velocity faster faster = acceleration faster faster faster = jerk faster faster faster faster = Snap faster faster faster faster faster = crackle faster faster faster faster faster faster = pop Sometime math works better than words.

[@rrawbinson]

Hi Fraser! How can astronomers predict CMEs if any telltale signs can at best travel at C? Even a probe at the sun would 'only' be able to transmit telemetry back to earth at the speed of light.

[@paulwalsh2344]

The CME isn't photons which travel at the speed of light. CME's are "burps" of molecular hydrogen and helium and a tiny bit of lithium, which travel much much slower so we can see the launch and rough direction of them and know whether or when that burp will eventually collide with the Earth's magnetosphere.

[@rrawbinson]

@@paulwalsh2344 thanks Paul! I guess the M in CME should have told me that lol

[@paulwalsh2344]

@@rrawbinson Yeah... Mass... and A LOT of it... like a big one can eject a BILLION TONS of plasma ! It's mind boggling ! But everything to do with astronomy usually is lol.

[@truvc]

Has anyone tried to “decode” or look for a signal in the dimming of Tabby’s Star and other stars like it?

[@rajedave]

This may be a silly one. But if gravity is not a force but only a geometry, why do scientists put so much effort to look for a unified theory in order to integrate it with the other three forces?

[@frasercain]

Because the other forces were able to be unified. It makes sense that there's a way to unify gravity with the other three. Why not try?

[@kylea2437]

I once read that if our atmosphere had a much higher oxygen ratio that our atmosphere would catch fire. Is that true? If not what would that % be?

[@frasercain]

The atmosphere wouldn't catch fire, but wildfires would be almost non-stop.

[@CR-iz1od]

what if our universe is orbiting a lot of very large black holes outside of the background radiation, would explain Excelleration and the lensing might be so uniform enough t wouldn't be noticed by us yet.

[@liviu-dantimar9492]

@28:30 120%C! :) @33:00 Nebulae like the zodiacal lights?

[@normanplotkin8105]

Assuming the universe is expanding If a star or galaxy from red shift appears to be x light years away but the light started it’s journey billions of years ago when it was closer wouldn’t it be logical it is even further away now?

[@tompava3923]

Mustafar

[@TexasNightRider]

Regarding broadcasting our existence makes no difference. We've already been broadcasting our existence for approximately 100 years. Due to the slow speed of light and signal degradation due to dispersion our signals will not go very far. Besides, intelligent species such as humankind are extremely rare so with the exception of other far less developed forms of life we are alone in the Milky Way Galaxy. Excellent discussion / video.

[@filonin2]

So intelligent civilizations such as our own are almost impossible to detect but you somehow know they are extremely rare and that we are alone in the Milky Way? These two ideas are contradictory. According to your own logic there could be many species at our level in our own galaxy that either haven't been broadcasting very long or very loudly or both. Nice self-refutation.

[@TexasNightRider]

@@filonin2 I believe humans are the most intelligent species currently existing in the galaxy. We may not have been the first or the last to ever exist but we are without a doubt alone. No contact of any kind will ever be established with an alien species. I have no problem with people who want to believe intelligent aliens currently exist in the Milky Way Galaxy. I want people to believe in intelligent aliens otherwise Hollywood would cease to produce great sci-fi movies. Thanks for the reply.

[@JITBWorldWide]

Exegol