Telescope moment for me was my mom - RIP - about 30 years ago, in her 60s, realized the moon was really a spheroid - it was the shadows in the craters along the terminator line and she realized the moon wasn't a flat disc in the sky - not that she thought that, but she never really thought about it, I suppose. I remember her reaction was like a kid. It was one of the best 'grown up' moments with her I remember.
Gotta love this ginned-up narrative about "Elon Musk polluting the night sky with Starlink." Prior to Starlink, if you were observing a given astronomical object with a ground-based telescope, the odds of your image being spoiled by a satellite flying through were incredibly small... something like 10^-8. Let's conservatively assume that Starlink makes the situation three orders of magnitude worse. Now the odds of your image being spoiled are 10^-5. Still incredibly small. (Note, I'm not talking about long-exposure shots with a wide field of view, that take in many astronomical objects. Yes, you will get satellite streaks in those images. I'm talking about narrow-field-of-view images of a single object - which is the only kind of image that has value if you're studying a single object. Of course, satellites must be illuminated by the sun in order to make those streaks. Just time your shot differently, when Starlinks and other satellites are in Earth's shadow, and the streaks are gone.)
Fraser, after slingshotting through all the major RUclips science channels with real people and bypassing the constellations of bogus AI channels, I must award you the preeminent personal title as the best explainer of heavenly phenomena. Yes, above the 1m-subs placeholders because you not only know of which you speak, but clearly, summarily and passionately enlighten your audience. The award has no name but after 60+ years of watching Earthlings’ videos, I nominate you as “One of the Top Flyboys in the Know-how Department”. From where I sit, more coveted than the Fields Medal or Nobel Prize for in translation of a universal language, it means, ‘He who makes others understand.’ Thank you, Fraser.
My answer to Hadante: every dime spent on “space” is spent on the ground. It goes to engineers, programmers, fabricators, electricians, janitors, cafeteria workers, gardeners, PR flacks… A billion dollar space probe launch represents the salaries paid to thousands of workers who built and launched that probe.
Arguably a better answer than Fraser's since he just talked about basic science (and science being basic or applied is orthogonal to what its funding is - and it's not that privately-funded basic science is some kind of "technical" possibility, either). "Job creation" doesn't really justify a government programme that didn't have something else actually justified about it, though (except it often does, because so much of a professional economist's work is just crafting big-brained _sounding_ jargon that confirms what a government wants to hear).
While this is true, it's not addressing the objection that is being raised. The objection I hear is that every dollar spent on space could be spent on solving a problem here on the ground - climate change, poverty, immigration, crime, cancer, take your pick, depending on the political leanings of the objector. I think the appropriate response is that we can do more than one thing at a time. Spending this money on space provides all these basic research benefits, as well as tangible innovations that get used in every day life (the classic example being velcro). We can do space and *also* spend money on solving problems closer to home. The reason we haven't solved, or aren't making progress in, those other problems isn't because of space money; it comes down to one of two things: either the problem is intractably difficult to solve (e.g. cancer) or there isn't sufficient political will to actually solve the problem (e.g. climate change).
Your explanation and visuals of how interferometry works and how it has been accomplished was exemplary. I hope you realize how well you are serving the astronomical endeavour of science by explaining how its work so well to the general public. Kudos to you sir!
Dude I just can't pick the best question for this week because they are all good. What happened in the short break you took in doing Q & A sessions? It sure gave these people some great thoughts, which I think is brilliant. So a big thanks to them and you for bringing it all together
I vote for Alaris as top question. That a cubesat with a side length of only 3.9 inches or even just 1 inch can be launched economically is encouraging to small tech companies or small science organizations--even possibly a group of amateur scientists--indicating a real potential to adding to the body of scientific knowledge. I'd rank Dakara second as it addresses the ever intriguing nature of black holes.
I have learned by watching your show about the time dilation of material that falls into a black hole from our perspective. From our perspective, it will take till eternity for any material to pass through the event horizon.
Hi Fraser, About your request for suggestions about who to interview, how about anyone researching advanced ideas such as FTL propulsion, Electromagnetic shielding for spacecraft, artificial gravity (including the hunt for the graviton) and other frontier physics. What do you think? I’m sure it would be popular.
Jenev my fav question. So could you interview some Astro Navigator that computes slingshot courses or who invented "Slingshot" ? The people that navigated Cassini to fly through the Enceladus atmosphere and 'sniff' it would be incredible. They navigated something 800M miles away. Sounds like some pretty precise navigation.
A question that I'm curious about... What happens to all the propellant that shoots out of our rocket nozzles? Does it mostly re-enter the atmosphere? Does it fly out into solar orbit at escape velocity? Does some of it end up in Earth orbit? Similar question for the material that "burns up" in the atmosphere - will we ever get that aluminum, plastic, etc. back?
First, to your propellant question: Most propellant used today is chemical, meaning its specific impulse, and therefore exhaust velocity are below the orbital velocity or even the escape velocity of earth. Therefore any propellant used lifting of, or in orbit of earth will very, very likely to reenter and join earth again. The only exceptions might be hydrogen fuel at high orbits, or outside earth's gravity. To things that re-enter, that is it slowing down enough to get trapped by earth again. It will be a fine mist or perhaps dust that will come down in the ocean somewhere.
Topic suggestion: developments in autonomous and intelligent rovers for the further missions. For example, I'm surprised that we still don't have a rover with legs, similar to Boston Dynamics "dog" robots, that could cope with rough terrain better than wheels. Could some drone swarm approaches offer advantages? And much more.
Nice answers. I was surprised with the answers to some because I missed learning those knowledge for some reason. Also yes, Saturn is also the first planet I ever saw through a telescope and it was a magical and unbelievable experience seeing something of that shape
Hi Fraser, your description of a Black hole is about a static non-rotating Black Hole which may not in fact exist. That solution to Einsteins General Relativity equations is the Schwarzschild solution. Generally Stars rotate and since angular momentum is conserved, it is thought that Black Holes formed from the collapse of Stars are best described by the Kerr Metric which describes rotating axially symmetric black holes. Other solutions include the Reissner-Nordstrom (charged non-rotating black holes) and Kerr-Newman ( charged, rotating black hole). Take a walk down the rabit hold of a Kerr Metric black hole when time permits. I'm sure we will find the experience as presented by you to be delightful.
The big problem with Starlink now turns out to be the upper-atmosphere aluminum pollution that will obliterate the ozone layer. I don't know if making them out of magnesium or something instead would help, but we had better force them to do something.
I hope this is not another problem. I believe China have started launching their 15,000 "Thousand Sails" constellation. Humans, one step forward, two steps back.
Typical "scientist" and thinker hubris and arrogance. They look into something a bit and think they understand every consequence when they don't have a clue.
No, we need a salvage yard in orbit that processes defunct satellites into orbital infrastructure. This is the ISRU principle applied to Earth orbit. Maneuvering between orbits doesn't require the delta-V of an orbital launch, nor the thrust, thus you can use high Isp ion engines and take your time.
I live in a pretty rural tourist area (bortle 4), and it’s amazing how many people from the city complain about how it’s “too dark” and that we need more street lights.
On the space race thing. I'd agree with you. I'm not a competitive person by nature. I feel like I never know enough and am always looking for the next new thing. I'd love for our efforts to just be about continuing to find new things. I feel like SpaceX's mission encapsulates this the best to date. Their mission to focus all their efforts on making life multi-planetary help to ensure that our future can be to continue to ask more questions. It's awesome!
The speed gain of a gravitational slingshot depends on the speed of the spacecraft relative to the black hole and the speed of the black hole relative to the galaxy. Since the departure trajectory of the spacecraft relative to the black hole is the mirror image of the approach trajectory, only in a different direction, the departure speed will still be no more than double the speed of the black hole relative to the galaxy. That means that you would need hundreds of gravitational slingshots around stars or black holes to get anywhere near relativistic speed. The only advantage of using a black hole is tthat its small size allows the spacecraft to get closer which allows for a bigger change in directtion.
For that last question, I was hoping you would give like, an equation describing the amount of a boost that a spacecraft would get from a slingshot around a planet in terms of things like, the mass of the planet, how fast the planet is moving relative to the star, how close the spacecraft gets to the planet, how fast it was going to start with, etc.
In the reference frame of the planet the departure trajectory of the spacecraft is the mirror image of the approach trajectory, just in a different direction. In the planetary reference frame the spacecraft has not gained or lost any energy. Now suppose a spacecraft is launched from Earth such that when it approaches the orbit of Jupiter it is pretty muct stationary with respect to the sun. From the perspective of Jupiter its approach speed is pretty much the orbital speed of Jupiter. Now suppose that things are arranged that, relative to Jupiter the spacecraft does a complete loop so that it leaves Jupiter on a trajectory that is tthe mirror image of the approach trajectory. Suppose the orbital speed of Jupiter is v. From the Jupiter reference frame the spacecraft approach and departure speeds are both v but in the sun's reference frame the spacecraft's velocity is now the sum of Jupiter's orbital speed and its departure speed, 2v. In general the speed limit for gravitational slingshots is twice the orbital speed of the planet.
This a second trick to use close approaches to planets to gain speed called the Oberth effect. Basically, at the closest approach, you fire your engines. Since you carried the fuel in, but you’re not carrying it out, you get a boost.
How about an Interferometer with the LaGrange points 60 degrees ahead and behind earth? Laser / pulsar timing between locations to determine offset. Maybe even a third behind the moon with Webb.
Not a scientist. I have a high school education but an interest in space and a tendency to think until I've reached a logical conclusion that aligns with the information I have, which is not scientifically rigorous or educated. So what I understand about interferometers is that they are basically analog, not digital, since the light from the telescope doesn't get captured immediately like your phone camera, it's funneled into a series of fiber optic cables or just open mirrors, then recombined physically at the interferometer. The location of these machines and mirrors is so precise that breathing on one too hard would put it out of commission, and it would take days to fix. If you had telescopes at L4 and L5, and an interferometer at L2 or on Earth, you theoretically could make that work, but it would be a requirement that the orbital periods were exactly synchronized to a ridiculous degree, like nanometer precision. Not impossible I'm sure, but prohibitively difficult. Radio is digital, microwave hits that limit, infrared and above is analog. The limiting technology is atomic clocks, so maybe if we had some kind of "quantum clock" that measured, like, the vibration of an electron or a proton we would have fast enough timekeeping to digitally interferometize(?) infrared or visible light. Pulsar timing won't cut it, I have to imagine at the scale of earth's orbit that gravitational waves would completely invalidate any attempts. There's a possibility that if gravity waves are the problem we could listen to the gravity wave background and only validate results that occur during still spots but I'm sure there'd be other problems. I have to imagine we'll push that limit eventually, because scientists are actively trying to push that limit right now. It's just gonna take a while before any common sense solution will be sufficient.
@@123seven3 Nanometer stationkeeping for a baseline of 1 AU or more, mechanically? That's a tall order. Maybe "lucky imaging" could be practical. Have a laser pointing from one orbiter to the other, as a phase reference. _Try_ holding the optical paths in phase, by moving mirrors, or adaptive optics. Capture the light in _very_ short intervals, or high frame rate, if you will. Discard the "frames" with high detected phase drift from the reference laser. Keep the few frames that are _spot on._ If only there was a photo-electric phase shifter or delay, with pico-second ramp times. Or maybe I am barking up the wrong tree. I'm not a subject matter expert, either...
How about very small camera behind each starlink for asteroid / satellite detection? They do have Starlink on Pitcairn Island for descendants of the HMS Bounty Mutiny.
If all Starlink sattelites were equipped with low power telescopes and downloaded their data to a computer with the right software, the Earth would never be surprised by an asteroid again.
In your discussion about the issue of money "wasted" in space, it might have been useful to point out that money isn't just dumped into space. It pays salaries, buys goods, funds education, and lots more things here on earth. It is very much a stimulus to the economy and has a very positive effect on education and our socioeconomic systems.
The asteroid budget is one of the most important ones we have because that’s a probable extinction scenario, if we don’t have a way to change the direction of one headed straight for earth!😳
Speaking of cell phones in space, theres an app you can download that records when your cellphone camera sensor gets hit with a ray big enough to activate that pixel sensor.
Coopetition is the word coined by a Nascar driver/announcer that applies. They compete but also assist each other on and off the track. Sharing scientific results improves the outcome for everybody.
First time I ever saw Saturn in a telescope, it looked like I was looking at a picture of Saturn, as it appears in books, etc, rather than a real-time, live version of Saturn. Maybe it was the lack of background stars, or maybe it was how the telescopic version was identical to the textbook version... Whatever it was it seemed unreal, despite how real it really was.
Or 6.3 cm cube. Originally, U was a height for something slid into an electronic equipment rack (1U = 1.75", 2U = 3.5", etc). For cubesats, there isn't a rack, so they settled on just standardizing the volume. 1U is the volume of a cube that is 10 cm on a side.
@@charleslivingston2256 U = unit and in the context of cubesats it's 10cm³. While 6.3x6.3x6.3cm is arithmetically 0.25U, those dimensions are contrary to the purpose of cubesats.
So, a question about supergiant stars like Betelgeuse. As they are much, much less dense than, shall we say, "standard" sized stars, what effect does this have on its Roche limit? There has been a hypothesis that Betelgeuse may have a smaller partner, rendered invisible to us due to its proximity to the main star. Is it possible that in a supergiant star with such a low density, that another star could orbit the centre mass of the main star, but within its boundaries?
The density of Betelgeuse is far less tthan tthat of the sun. The Roche limit is not fixed and depends on the size and density of the object being disrupted. It is probable that the Roche limit of Betelgeuse for most stuff lies within the photosphere.
I think the topic I would be most interested in currently is quantum sensing. There is always a lot of talk about quantum computers, but from what little I heard about quantum sensors they are just as exiting an technology.
For the US folks.. a 2.5cm cube is a negligible amount smaller than a cubic inch which is a 2.54cm cube. ABSOLUTELY TINY for a satellite. Makes me think of those tiny tornado probes from the movie Twister 🌪️
Most of us Americans are familiar with the metric system; despite the deep-seated cultural resistance to replacing our everyday units of measurement, you won’t often find anything but metric system in use in medicine or science.
@@w3vjp568 Both Metric and Imperial are superior to the measurements the media like to use like "8 school buses long" "heavier than 3 elephants..." etc 😏
I would like to hear more interviews with Sierra Space about anything and everything they’re dreaming up. Have you watched the interview with their CEO about six months ago? It had a few interesting tidbits. I’ve noticed that in the past year more and more people are talking about orbit as an active conflict zone.
I got a Mead 80mm refractor and their computer was so bad. Had it repaired multiple times and even got the whole telescope replaced, but the new had the same flaw. They all just started moving in a fixed linear direction, quite fast when you used the go to feature.
Future Topic: Serious/realistic plans for manned missions to solar system bodies other than the moon and Mars. Moons of Mars and clouds of Venus are fine, but other destinations would be even better. thanks
Good explanation of using planets for gravity boost to speed up your spaceship. Do you think maybe thousands of years from now when maybe millions of spacecraft are using planets for speed boosts, you will start to effect the orbital velocity of those planets so much so that you will need to consider controlling how many spacecraft can do this? It is a very small reduction in speed but over time it adds up. Like the lunar tides slowing down the rotation of the earth.
Asuria. I wanna know. QUESTION (sorta): You get a free 1u Cubesat ride to LEO or lunar orbit (your choice), downlink services, and a budget of a low hundreds of thousands of dollars to build. What would FraserSat do? Bonus points for going into some detail about your component selection, the component shopping process and the approval process. SHOW US HOW.
The counter point to terrestrial based telescopes...launches are becoming cheaper and space based telescopes would be cheaper to put up without offending the devotees of mountains and cutting through the light pollution and atmosphere. No land acquisition needed. An entire fleet of telescopes can be launched where astronomers benefit by abating the fight for time at any land based observatory.
QUESTION: mental experiment: imagine a rotating tether probe with sensors/instruments along the entire length AND this probe was (mind experiment) 1 parsec long, what data could be gathered in the rotation? Now orient it to dip an end in a black hole (either rotating or a static (not rotating) dip stick (lol). Mind experiment: 1) material strength is unbreakable, 2) material is segmented to break if needed. Would it stop rotation? Time dilation implications? How would it break? What data value in the break up?
Data beyond the event horizon wouldn’t be able to escape, even if connected. Sure. But how would the time dilation work along the length of the probe? Relativity, but this probe is also one entity. I’m imagining it like a human dipping a toe in hot water. It takes milliseconds to perceive the burning hot water, so the toe is already burned before one could react. (Or other injury like severed.)
Hi Fraser! Question: You mention the use of atomic clocks with interferometers. Do more accurate clocks mean better resolution for the interferometer? Will the introduction of nuclear clocks lead to even better interferometers?
As others have pointed out there's a problem with how you describe gaining velocity from a slingshot. For starters it might be impractical to try to slingshot around a black hole because of debris but even if there were a clean one it might not be very useful. Absent changing direction, any velocity gained through the attraction of gravity going towards the black hole would be lost coming away from. You can steal momentum from a black hole that has a velocity relative to another object through a change of direction with respect to that object, but that would be very, very unlikely to get anything close to relativistic speeds.
You would get a gravitational assistant in exactly the same way you get one from planets. You're stealing a little of its orbital velocity around the center of the Milky Way.
When it comes to basic research and mass extinctions, it is scientific fact that climatic changes are involved in all the big mass extinctions (including that one of the dinosaurs)
On the cube sat topic. How feasible, practical, beneficial could it be to make a cube sat equipped with a strong enough camera that could go alone or accompanied by others to survey a planet and provide up close visuals and science with the benefit of being close to the objective?
It fails in practicality. You can't fit much of an antenna on tiny satellites, so you need a 'mothership' to send the data back. There's usually a polar orbit where that larger probe can eventually see the whole planet as it turns beneath it. This is easier and more reliable than splitting up. Separate probes are good for cases where it does something that would lose the larger ship. Things like the DART mission and entering a lava tube or any atmosphere.
The list of technological developments made possible by space exploration is immense. From satellite communications to car breaks and everything in between. Space Exploration consistently pays for itself 100 times over, or would if taxes were levied fairly anyway.
Yes absolutely, that's how the Apollo missions slowed down to land on the moon, they just went the opposite way around the moon instead of with it, it's also what the Parker solar probe is doing to slow down and fall closer to the Sun.
You can get closer to the sun this way, but you can't use the sun for a gravity assist. You can't get a gravity assist from the thing you are currently orbiting.
Taking (or giving) momentum doesn’t cause a spiral in to the sun (im sure fraser knows) it just changes the orbit a bit, its a once off. A spiral would need a constant force like atmospheric drag
Topic: Big Bang creating Helium / Lithium, Beryllium, etc. And first star creation. Lithium liquefies around 1600K, Lithium Hydride forms as a liquid around 900C. And when these molecules hit each other they stick together unless they achieve the boiling point so they would accumulate until Hydrogen starts to stick by gravity above earth size by Neptune's size.
The black hole and infinite density "problem" is just a mathematical "problem". If the infinite density is limited to an infinite small volume (hence "singularity"), it may have very well a finite mass. It all depends on how fast the density increases with decreasing volume around the singularity. Conceptually there isn't any problem at all, regardless if a singularity actually exists or not. It"s just very fundamental math.
It might be possible to look below the event horizon of a black hole under certain circumstances. The event horizon is simply the points along a sphere where the gravity of the black hole is such that not even light, or traveling at the speed of light, allows you to escape the gravity well if you get any closer. If you have two black holes orbiting one another, the line that defines the shortest distance between the two masses represents a region where the gravity of each mass is acting in opposition to the other. This means that the event horizon should shrink for each black hole, allowing a well placed probe to observe further inside each black hole than you would otherwise be able to. Or at least, that's the way it seems to me but I'm not an astrophysicist so perhaps I'm missing something.
With two supermassive black holes beginning the slow dance of merger, you could theoretically deploy a probe that had a secondary probe attached via an umbilical such that the secondary probe passes through the event horizon, and images could be delivered up the umbilical to be relayed by the primary probe.
@@JROD082384 Yes, absolutely. Supermassive in particular would be desirable because of the lack of tidal forces. When I was originally thinking about this I was actually imagining something much smaller, with two or more man made black holes of only a few million kg of mass or something that would last an hour or two before evaporating, then placing them in very specific orbits that would allow you to get arbitrarily close to exposing a naked singularity. It would be incredible to observe what happens when space time breaks down.
"Chance of cosmic ray interference increases with complexity" Also inversely proportional to logic component size. Larger lithography process means less susceptibility to cosmic ray interference. Complexity vulnerability scales linearly with complexity. Size complexity graphs different. Above a certain component size, cosmic rays simply can't immediately flip a bit, they're not individually energetic enough. Cosmic rays need to wear down large components gradually over time by demolishing the crystal structure.
Dear Fraser, sorry for "cheating" but these questions are kinda stringed together: -What are the current plans for a Huble 2.0? -Is there a scientific reason for visible light telescopes vs IR/X-ray etc? -Is there a final difference between manipulating a photo data to bring it to visual range and an actual visual range of the same object?
Question: is there any research into Solar system wide internet? As DSN hardly will be able to support major colonization - like settlements off planet or telescope on the Dark side of the Moon
Inside your space capsule or station the convective cooling of a cell phone would work just fine. Cooling only becomes a big problem if your phone is in vacuum.
Oh, sweet nostalgia 😊 Had mine for many years. Eventually left in a glass of champagne a whole night on new years, still worked in the morning. Threw it into a wall and ran over it with the bike and it still worked 😅
@@lindenhoch8396 if you deactivate the data connection and can only make and receive calls then you current smartphone will last a week on one charge too.
Funny that you used the dinosaurs ending impact as an example. I asked my son 20 years ago that same question. Dinosaurs dies cuase they never left Earth so one rock took them out. It's only a matter of time. Yes redirected rocks can save us but all the issues must looked into.
I will never say no to anything even remotely associated with dark matter. I know you have covered it a million times, but man its just fascinating that we just don't understand like 25% of the universe so casually even though we can literary use it as a tool to lens distant objects. WTH?
Re: your rant re: population numbering annoyance: one potential way to rename with backwards compatibility would be to use letters in the new naming convention (e.g. Population A, Population B, etc.). This way, there's no collision with the old convention, and over time, it can hopefully just fade or be regex'ed into oblivion.
Regarding why a telescope company might be suffering: It wouldn't surprise me if there are still manufacturing and sales ripple effects from the pandemic, like has happened to so many other industries. In 2020 and 2021 there was sudden and massive demand for hobby and recreation items, and then that petered off again when people returned to work, leaving many companies in the lurch.
Belsa. Well then. That anton petrov video in the triple lensed supernova being used to hone in on the hubble tension should blow your mind! Supernova H0pe i believe.
@@frasercain lol. I must have not been thrown that one by youtube yet. I only found your channel a couple weeks ago! So just been gobblin up what youtube throws my way. :) im sure yout7be will throw it my way soon.
Question: If fusion gave us 'unlimited' free energy would it be possible to recycle waste by heating it to a plasma in an arc furnace and then use electric fields to sort/refine every atom by mass into individual storage bins?
The Giant Magellan Telescope will be 25 meters in diameter, the Extremely Large Telescope will be 39 meters. Compared to JWST, what difference will the two Earth telescopes be? What would a 50 meter telescope be compared to all the others? Thanks, Jason
Considering the deflection of an asteroid’s orbit by even a slight amount is said to make a large difference over time in avoiding a potential impact, why is it not a more significant consideration of the long-term effects of orbital deflection of planets by using gravity assist maneuvers? Is there some mechanism of gravity on this larger scale (and like using GA maneuvers on BHs in the galaxy) that makes this negligible? Or is it simply that the amount it changes by for those scales only becomes significant millions of years or more later, so we ignore it?
You probably need to know a bit more about the radio processing in a cell phone before you attempt this question. I used to work on implementing older 2G/3G radio receiver algorithms and I suspect that the SPEED of the cellphone in orbit (relative to the base stations) would cause serious problems. For normal terrestrial speeds, and even for the twits that try to use them in flight, the doppler effects on the mobile signal are corrected for. I doubt that the algorithms are designed for 17,000 mph doppler shifts! Then there's the network issues of managing the selection of and handover between base stations. Not sure those higher layer algorithms are designed to handle an orbiting cellphone. Also, I suspect that the towers of newer systems (4G,5G) don't waste a lot of energy targetting receivers up in space, they're probably phased array directional links that don't have "up" in their coverage map (maybe they do, maybe general aviation reuires cell service to aircraft, but agina, those are moving 1-2 orders of magnitude slower than an orbiting object)
INTERVIEW IDEA I'm fascinated by globular clusters. Is there a research team dedicating their focus to studying the orbital dynamics of stars in globular clusters, as this must be an amazing place to map gravity wells and how space curvature fluctuates in such a densely packed volume of space. Also, whether there could be gravitational wave effects that one day might be perceivable.
At any size if the heat was from radioactive decay or tidal heating from orbiting something like Jupiter. You just need to avoid losing gas to space from smaller objects. If you mean heat from fusion I'm skeptical life as we know it could survive any situation where that's happening. The chemistry we depend on only works in a fairly narrow pressure range. Too low and we can't diffuse enough oxygen into our blood (or water boils in our cells). Too high and it impacts chemical reactions we depend on. Even if you had a brown dwarf with the right temp and pressure this would probably only exist within a narrow altitude band far above any surface. Anything growing there will find it incredibly difficult to stay in the survivable zone, so I don't see how primitive life could get started.
@@ericsmith6394 my thoughts derived from the fact that just by digging few kilometres down in earth crust, the temperature rises. I don't know the cause but I think it's just for pressure. This heat could reach the surface or create some kind of thermal vents without radioactive decay. I was wondering if this could be a possibile scenario
@@PitchWheel yes and it's not unlike when the Earth froze over and life survived at the hydrothermal vents. The Earth has heat leftover from its formation, radioactive decay, and a small amount from tidal heating. There's plenty of heat in there. All planets will have formation and radioactive heat. Jupiter's moons get a lot of tidal heating, but Earth's moon does not because it's tidally locked and in a circular orbit.
Question! What is the approx theoretical upper limit for the number of subscribers that Starlink can technically handle? Could Starlink handle 1B subscribers? Whatever the answer is then IMO Starlink has the strong potential to make SpaceX the richest company in the history of the planet 🇺🇳🗽🇺🇦🗽🇺🇳
hi Fraser, I have a question that torments me: If the rotation of the planet produces the movement of the Earth's core and the magnetic field that surrounds us, in addition to the trade winds, why does the expenditure of energy not cause the movement to stop?
Ok Fraser, I have a question about bendy light. If black holes curve space and gravitationally lens, could a strong enough telescope with enough granularity allow us to see back in time. Can the light from our star or galaxy be reflected back by the event horizon by being bent around the black hole?
Dakara? I don't see a community tab anywhere. Sorry. Also, when it comes to topics, I would like to know more about, I would like to know what kinds of scientific principles scientists might use to shed light on the nature of dark energy. Are there math equations that could help, since it seems to be related to universal expansion? Could we possibly find ways to detect dark matter and dark energy? Could they possibly be different facets of one unknown thing? I have so many questions and zero answers. 😶
Telescope moment for me was my mom - RIP - about 30 years ago, in her 60s, realized the moon was really a spheroid - it was the shadows in the craters along the terminator line and she realized the moon wasn't a flat disc in the sky - not that she thought that, but she never really thought about it, I suppose. I remember her reaction was like a kid. It was one of the best 'grown up' moments with her I remember.
Gotta love this ginned-up narrative about "Elon Musk polluting the night sky with Starlink." Prior to Starlink, if you were observing a given astronomical object with a ground-based telescope, the odds of your image being spoiled by a satellite flying through were incredibly small... something like 10^-8.
Let's conservatively assume that Starlink makes the situation three orders of magnitude worse. Now the odds of your image being spoiled are 10^-5. Still incredibly small.
(Note, I'm not talking about long-exposure shots with a wide field of view, that take in many astronomical objects. Yes, you will get satellite streaks in those images. I'm talking about narrow-field-of-view images of a single object - which is the only kind of image that has value if you're studying a single object. Of course, satellites must be illuminated by the sun in order to make those streaks. Just time your shot differently, when Starlinks and other satellites are in Earth's shadow, and the streaks are gone.)
Fraser, after slingshotting through all the major RUclips science channels with real people and bypassing the constellations of bogus AI channels, I must award you the preeminent personal title as the best explainer of heavenly phenomena. Yes, above the 1m-subs placeholders because you not only know of which you speak, but clearly, summarily and passionately enlighten your audience.
The award has no name but after 60+ years of watching Earthlings’ videos, I nominate you as “One of the Top Flyboys in the Know-how Department”. From where I sit, more coveted than the Fields Medal or Nobel Prize for in translation of a universal language, it means, ‘He who makes others understand.’
Thank you, Fraser.
"...of *what* you speak," not "...of which you speak."
@@Raz.CHa! Like "to boldly go" when it should be "to go boldly".... you are of course correct, but Star Trek is responsible for a lot of bad English.
My answer to Hadante: every dime spent on “space” is spent on the ground. It goes to engineers, programmers, fabricators, electricians, janitors, cafeteria workers, gardeners, PR flacks…
A billion dollar space probe launch represents the salaries paid to thousands of workers who built and launched that probe.
Got to better than the trillions spent to blow things up.
Arguably a better answer than Fraser's since he just talked about basic science (and science being basic or applied is orthogonal to what its funding is - and it's not that privately-funded basic science is some kind of "technical" possibility, either).
"Job creation" doesn't really justify a government programme that didn't have something else actually justified about it, though (except it often does, because so much of a professional economist's work is just crafting big-brained _sounding_ jargon that confirms what a government wants to hear).
While this is true, it's not addressing the objection that is being raised. The objection I hear is that every dollar spent on space could be spent on solving a problem here on the ground - climate change, poverty, immigration, crime, cancer, take your pick, depending on the political leanings of the objector.
I think the appropriate response is that we can do more than one thing at a time. Spending this money on space provides all these basic research benefits, as well as tangible innovations that get used in every day life (the classic example being velcro). We can do space and *also* spend money on solving problems closer to home. The reason we haven't solved, or aren't making progress in, those other problems isn't because of space money; it comes down to one of two things: either the problem is intractably difficult to solve (e.g. cancer) or there isn't sufficient political will to actually solve the problem (e.g. climate change).
I had nothing but good experiences ordering from Orion Telescope and the staff was super helpful and friendly.
Your explanation and visuals of how interferometry works and how it has been accomplished was exemplary. I hope you realize how well you are serving the astronomical endeavour of science by explaining how its work so well to the general public. Kudos to you sir!
We want a SPACE ORCS specialist!
Dude I just can't pick the best question for this week because they are all good. What happened in the short break you took in doing Q & A sessions? It sure gave these people some great thoughts, which I think is brilliant. So a big thanks to them and you for bringing it all together
46:00 X-ray astronomy. Always skimped on. What’s the latest in discoveries and tech? Any sensor fusion with the other big projects?
I vote for Alaris as top question. That a cubesat with a side length of only 3.9 inches or even just 1 inch can be launched economically is encouraging to small tech companies or small science organizations--even possibly a group of amateur scientists--indicating a real potential to adding to the body of scientific knowledge. I'd rank Dakara second as it addresses the ever intriguing nature of black holes.
I have learned by watching your show about the time dilation of material that falls into a black hole from our perspective. From our perspective, it will take till eternity for any material to pass through the event horizon.
Hi Fraser,
About your request for suggestions about who to interview, how about anyone researching advanced ideas such as FTL propulsion,
Electromagnetic shielding for spacecraft, artificial gravity (including the hunt for the graviton) and other frontier physics. What do you think? I’m sure it would be popular.
This is a great show. I’m really impressed!
Cartego
When I was young, my brother let me see Jupiter and the Jovian moons through his telescope. That was the beginning of my love of space.
Jenev my fav question. So could you interview some Astro Navigator that computes slingshot courses or who invented "Slingshot" ? The people that navigated Cassini to fly through the Enceladus atmosphere and 'sniff' it would be incredible. They navigated something 800M miles away. Sounds like some pretty precise navigation.
Belote: archaeologists have the same nomenclature, where the first layer is the youngest. I think it is the necessity.
Also, follow up interviews with some of the interesting people you haven’t talked to in a few years would be cool.
More about Solar/Magnetic soaring if you can, actual flying in space not just falling with style.
A question that I'm curious about... What happens to all the propellant that shoots out of our rocket nozzles? Does it mostly re-enter the atmosphere? Does it fly out into solar orbit at escape velocity? Does some of it end up in Earth orbit? Similar question for the material that "burns up" in the atmosphere - will we ever get that aluminum, plastic, etc. back?
First, to your propellant question: Most propellant used today is chemical, meaning its specific impulse, and therefore exhaust velocity are below the orbital velocity or even the escape velocity of earth. Therefore any propellant used lifting of, or in orbit of earth will very, very likely to reenter and join earth again. The only exceptions might be hydrogen fuel at high orbits, or outside earth's gravity.
To things that re-enter, that is it slowing down enough to get trapped by earth again. It will be a fine mist or perhaps dust that will come down in the ocean somewhere.
Topic suggestion: developments in autonomous and intelligent rovers for the further missions. For example, I'm surprised that we still don't have a rover with legs, similar to Boston Dynamics "dog" robots, that could cope with rough terrain better than wheels. Could some drone swarm approaches offer advantages? And much more.
20:32 In the same episode of The Astronomers as The Sidewalk Astronomer, John Dobson a group did a version of that with VHS cassettes.
Nice answers. I was surprised with the answers to some because I missed learning those knowledge for some reason. Also yes, Saturn is also the first planet I ever saw through a telescope and it was a magical and unbelievable experience seeing something of that shape
In a hundred years we may have scopes positioned to use the sun as a secondary gravitational lens for other "known" distant lenses.
Hi Fraser, your description of a Black hole is about a static non-rotating Black Hole which may not in fact exist. That solution to Einsteins General Relativity equations is the Schwarzschild solution. Generally Stars rotate and since angular momentum is conserved, it is thought that Black Holes formed from the collapse of Stars are best described by the Kerr Metric which describes rotating axially symmetric black holes. Other solutions include the Reissner-Nordstrom (charged non-rotating black holes) and Kerr-Newman ( charged, rotating black hole). Take a walk down the rabit hold of a Kerr Metric black hole when time permits. I'm sure we will find the experience as presented by you to be delightful.
The big problem with Starlink now turns out to be the upper-atmosphere aluminum pollution that will obliterate the ozone layer. I don't know if making them out of magnesium or something instead would help, but we had better force them to do something.
I hope this is not another problem. I believe China have started launching their 15,000 "Thousand Sails" constellation. Humans, one step forward, two steps back.
Typical "scientist" and thinker hubris and arrogance. They look into something a bit and think they understand every consequence when they don't have a clue.
Probably Titanium than Aluminium?
No, we need a salvage yard in orbit that processes defunct satellites into orbital infrastructure. This is the ISRU principle applied to Earth orbit. Maneuvering between orbits doesn't require the delta-V of an orbital launch, nor the thrust, thus you can use high Isp ion engines and take your time.
I live in a pretty rural tourist area (bortle 4), and it’s amazing how many people from the city complain about how it’s “too dark” and that we need more street lights.
Another awesome video. Your channel is so great 🎉
On the space race thing. I'd agree with you. I'm not a competitive person by nature. I feel like I never know enough and am always looking for the next new thing. I'd love for our efforts to just be about continuing to find new things. I feel like SpaceX's mission encapsulates this the best to date. Their mission to focus all their efforts on making life multi-planetary help to ensure that our future can be to continue to ask more questions. It's awesome!
Glad you asked; my topic - how are we still talking to the Voyager space craft. Why hasn't that knowledge all dissipated with time. Thanks!
The speed gain of a gravitational slingshot depends on the speed of the spacecraft relative to the black hole and the speed of the black hole relative to the galaxy. Since the departure trajectory of the spacecraft relative to the black hole is the mirror image of the approach trajectory, only in a different direction, the departure speed will still be no more than double the speed of the black hole relative to the galaxy. That means that you would need hundreds of gravitational slingshots around stars or black holes to get anywhere near relativistic speed. The only advantage of using a black hole is tthat its small size allows the spacecraft to get closer which allows for a bigger change in directtion.
For that last question, I was hoping you would give like, an equation describing the amount of a boost that a spacecraft would get from a slingshot around a planet in terms of things like, the mass of the planet, how fast the planet is moving relative to the star, how close the spacecraft gets to the planet, how fast it was going to start with, etc.
In the reference frame of the planet the departure trajectory of the spacecraft is the mirror image of the approach trajectory, just in a different direction. In the planetary reference frame the spacecraft has not gained or lost any energy. Now suppose a spacecraft is launched from Earth such that when it approaches the orbit of Jupiter it is pretty muct stationary with respect to the sun. From the perspective of Jupiter its approach speed is pretty much the orbital speed of Jupiter. Now suppose that things are arranged that, relative to Jupiter the spacecraft does a complete loop so that it leaves Jupiter on a trajectory that is tthe mirror image of the approach trajectory. Suppose the orbital speed of Jupiter is v. From the Jupiter reference frame the spacecraft approach and departure speeds are both v but in the sun's reference frame the spacecraft's velocity is now the sum of Jupiter's orbital speed and its departure speed, 2v. In general the speed limit for gravitational slingshots is twice the orbital speed of the planet.
This a second trick to use close approaches to planets to gain speed called the Oberth effect. Basically, at the closest approach, you fire your engines. Since you carried the fuel in, but you’re not carrying it out, you get a boost.
Thanks to you both!
How about an Interferometer with the LaGrange points 60 degrees ahead and behind earth? Laser / pulsar timing between locations to determine offset. Maybe even a third behind the moon with Webb.
Not a scientist. I have a high school education but an interest in space and a tendency to think until I've reached a logical conclusion that aligns with the information I have, which is not scientifically rigorous or educated.
So what I understand about interferometers is that they are basically analog, not digital, since the light from the telescope doesn't get captured immediately like your phone camera, it's funneled into a series of fiber optic cables or just open mirrors, then recombined physically at the interferometer. The location of these machines and mirrors is so precise that breathing on one too hard would put it out of commission, and it would take days to fix. If you had telescopes at L4 and L5, and an interferometer at L2 or on Earth, you theoretically could make that work, but it would be a requirement that the orbital periods were exactly synchronized to a ridiculous degree, like nanometer precision. Not impossible I'm sure, but prohibitively difficult.
Radio is digital, microwave hits that limit, infrared and above is analog. The limiting technology is atomic clocks, so maybe if we had some kind of "quantum clock" that measured, like, the vibration of an electron or a proton we would have fast enough timekeeping to digitally interferometize(?) infrared or visible light. Pulsar timing won't cut it, I have to imagine at the scale of earth's orbit that gravitational waves would completely invalidate any attempts. There's a possibility that if gravity waves are the problem we could listen to the gravity wave background and only validate results that occur during still spots but I'm sure there'd be other problems.
I have to imagine we'll push that limit eventually, because scientists are actively trying to push that limit right now. It's just gonna take a while before any common sense solution will be sufficient.
@@123seven3 Nanometer stationkeeping for a baseline of 1 AU or more, mechanically? That's a tall order.
Maybe "lucky imaging" could be practical. Have a laser pointing from one orbiter to the other, as a phase reference. _Try_ holding the optical paths in phase, by moving mirrors, or adaptive optics. Capture the light in _very_ short intervals, or high frame rate, if you will. Discard the "frames" with high detected phase drift from the reference laser. Keep the few frames that are _spot on._
If only there was a photo-electric phase shifter or delay, with pico-second ramp times. Or maybe I am barking up the wrong tree. I'm not a subject matter expert, either...
The Lagrange points are nott massive bodies. Any focussing effectt would be extttremely weak.
@@hermanrobak1285 The LISA gravity wave detector is aiming to do just that.
Thinking in the shower, while listening to a podcast… respect 👍👍👍
How about very small camera behind each starlink for asteroid / satellite detection? They do have Starlink on Pitcairn Island for descendants of the HMS Bounty Mutiny.
If all Starlink sattelites were equipped with low power telescopes and downloaded their data to a computer with the right software, the Earth would never be surprised by an asteroid again.
@@surferdude4487 Vera Ruben should solve that problem.
In your discussion about the issue of money "wasted" in space, it might have been useful to point out that money isn't just dumped into space. It pays salaries, buys goods, funds education, and lots more things here on earth. It is very much a stimulus to the economy and has a very positive effect on education and our socioeconomic systems.
The asteroid budget is one of the most important ones we have because that’s a probable extinction scenario, if we don’t have a way to change the direction of one headed straight for earth!😳
Speaking of cell phones in space, theres an app you can download that records when your cellphone camera sensor gets hit with a ray big enough to activate that pixel sensor.
Coopetition is the word coined by a Nascar driver/announcer that applies. They compete but also assist each other on and off the track. Sharing scientific results improves the outcome for everybody.
this is a cool video format you can just click on the question you want
First time I ever saw Saturn in a telescope, it looked like I was looking at a picture of Saturn, as it appears in books, etc, rather than a real-time, live version of Saturn.
Maybe it was the lack of background stars, or maybe it was how the telescopic version was identical to the textbook version... Whatever it was it seemed unreal, despite how real it really was.
4:10 judging by pictures I googled, it's 2.5x10x10cm.
Or 6.3 cm cube.
Originally, U was a height for something slid into an electronic equipment rack (1U = 1.75", 2U = 3.5", etc).
For cubesats, there isn't a rack, so they settled on just standardizing the volume. 1U is the volume of a cube that is 10 cm on a side.
@@charleslivingston2256 U = unit and in the context of cubesats it's 10cm³. While 6.3x6.3x6.3cm is arithmetically 0.25U, those dimensions are contrary to the purpose of cubesats.
Alright!! Looking forward to this and can’t sleep anyway. No reason really just the world on a seesaw for the next few days 😮😢😳😱🫡🤗🦾
So, a question about supergiant stars like Betelgeuse. As they are much, much less dense than, shall we say, "standard" sized stars, what effect does this have on its Roche limit? There has been a hypothesis that Betelgeuse may have a smaller partner, rendered invisible to us due to its proximity to the main star. Is it possible that in a supergiant star with such a low density, that another star could orbit the centre mass of the main star, but within its boundaries?
nice PFP, lol
@@MagnumMatt09 As is yours, good sir.
The density of Betelgeuse is far less tthan tthat of the sun. The Roche limit is not fixed and depends on the size and density of the object being disrupted. It is probable that the Roche limit of Betelgeuse for most stuff lies within the photosphere.
I think the topic I would be most interested in currently is quantum sensing. There is always a lot of talk about quantum computers, but from what little I heard about quantum sensors they are just as exiting an technology.
Inflation as a topic for a video please
For the US folks.. a 2.5cm cube is a negligible amount smaller than a cubic inch which is a 2.54cm cube. ABSOLUTELY TINY for a satellite. Makes me think of those tiny tornado probes from the movie Twister 🌪️
Most of us Americans are familiar with the metric system; despite the deep-seated cultural resistance to replacing our everyday units of measurement, you won’t often find anything but metric system in use in medicine or science.
@@w3vjp568 Both Metric and Imperial are superior to the measurements the media like to use like "8 school buses long" "heavier than 3 elephants..." etc 😏
I figured it out. In proof that the US will use anything but the metric system. 50 BMG is 12.7 mm, so it just a little smaller than 2 of those. lol.
@@Otisthelesser 12.7mm is exactly a half inch so thats a great conversion 😂 and 7.62 is between 1/4 and 1/3 of an inch
I’ve lived abroad Im a dual citizen and honestly we are onto something with the imperial system. Inches are fierce
I would like to hear more interviews with Sierra Space about anything and everything they’re dreaming up. Have you watched the interview with their CEO about six months ago? It had a few interesting tidbits. I’ve noticed that in the past year more and more people are talking about orbit as an active conflict zone.
I got a Mead 80mm refractor and their computer was so bad. Had it repaired multiple times and even got the whole telescope replaced, but the new had the same flaw. They all just started moving in a fixed linear direction, quite fast when you used the go to feature.
Future Topic: Serious/realistic plans for manned missions to solar system bodies other than the moon and Mars. Moons of Mars and clouds of Venus are fine, but other destinations would be even better. thanks
Nationalism as a "dirty fuel" for fueling exploration is a great analogy , thank you.
Interesting! The final parsec problem solved...by Aliens! Lol (ship gravitation assist by black holes)
Good explanation of using planets for gravity boost to speed up your spaceship. Do you think maybe thousands of years from now when maybe millions of spacecraft are using planets for speed boosts, you will start to effect the orbital velocity of those planets so much so that you will need to consider controlling how many spacecraft can do this? It is a very small reduction in speed but over time it adds up. Like the lunar tides slowing down the rotation of the earth.
Asuria. I wanna know.
QUESTION (sorta): You get a free 1u Cubesat ride to LEO or lunar orbit (your choice), downlink services, and a budget of a low hundreds of thousands of dollars to build. What would FraserSat do? Bonus points for going into some detail about your component selection, the component shopping process and the approval process. SHOW US HOW.
The counter point to terrestrial based telescopes...launches are becoming cheaper and space based telescopes would be cheaper to put up without offending the devotees of mountains and cutting through the light pollution and atmosphere. No land acquisition needed. An entire fleet of telescopes can be launched where astronomers benefit by abating the fight for time at any land based observatory.
Good luck with orbiting even a 30 metre optical telescope.
@@rogerphelps9939 I don't understand. Why is luck necessary?
QUESTION: mental experiment: imagine a rotating tether probe with sensors/instruments along the entire length AND this probe was (mind experiment) 1 parsec long, what data could be gathered in the rotation? Now orient it to dip an end in a black hole (either rotating or a static (not rotating) dip stick (lol). Mind experiment: 1) material strength is unbreakable, 2) material is segmented to break if needed.
Would it stop rotation? Time dilation implications? How would it break? What data value in the break up?
Data beyond the event horizon wouldn’t be able to escape, even if connected. Sure.
But how would the time dilation work along the length of the probe?
Relativity, but this probe is also one entity.
I’m imagining it like a human dipping a toe in hot water. It takes milliseconds to perceive the burning hot water, so the toe is already burned before one could react. (Or other injury like severed.)
Hi Fraser! Question: You mention the use of atomic clocks with interferometers. Do more accurate clocks mean better resolution for the interferometer? Will the introduction of nuclear clocks lead to even better interferometers?
As others have pointed out there's a problem with how you describe gaining velocity from a slingshot. For starters it might be impractical to try to slingshot around a black hole because of debris but even if there were a clean one it might not be very useful. Absent changing direction, any velocity gained through the attraction of gravity going towards the black hole would be lost coming away from. You can steal momentum from a black hole that has a velocity relative to another object through a change of direction with respect to that object, but that would be very, very unlikely to get anything close to relativistic speeds.
You would get a gravitational assistant in exactly the same way you get one from planets. You're stealing a little of its orbital velocity around the center of the Milky Way.
When it comes to basic research and mass extinctions, it is scientific fact that climatic changes are involved in all the big mass extinctions (including that one of the dinosaurs)
IIRC, some cubesats use cellphone hardware.
On the cube sat topic. How feasible, practical, beneficial could it be to make a cube sat equipped with a strong enough camera that could go alone or accompanied by others to survey a planet and provide up close visuals and science with the benefit of being close to the objective?
It fails in practicality. You can't fit much of an antenna on tiny satellites, so you need a 'mothership' to send the data back. There's usually a polar orbit where that larger probe can eventually see the whole planet as it turns beneath it. This is easier and more reliable than splitting up.
Separate probes are good for cases where it does something that would lose the larger ship. Things like the DART mission and entering a lava tube or any atmosphere.
Thank you.
The list of technological developments made possible by space exploration is immense.
From satellite communications to car breaks and everything in between.
Space Exploration consistently pays for itself 100 times over, or would if taxes were levied fairly anyway.
Fraser, perhaps a look at a few of these advances would make a good show.
Perhaps a look at a few of these advances would make a good show.
Can we reverse gravity assist off of Jupiter, fall towards the Sun, and gravity assist off of the Sun and go insanely fast?
Yes absolutely, that's how the Apollo missions slowed down to land on the moon, they just went the opposite way around the moon instead of with it, it's also what the Parker solar probe is doing to slow down and fall closer to the Sun.
You can get closer to the sun this way, but you can't use the sun for a gravity assist. You can't get a gravity assist from the thing you are currently orbiting.
@@fluffysheap Correct, the PSP used the Earth and Venus to slow and lower it's orbit to the Sun
Taking (or giving) momentum doesn’t cause a spiral in to the sun (im sure fraser knows) it just changes the orbit a bit, its a once off. A spiral would need a constant force like atmospheric drag
Love your channel, Fraser. I have a question. Is the Multiverse still just a theory or is it more than that? Thanks and keep up the good work. Jason
Still just a theory. There's no evidence it's true.
I would imagine that the closest you can get to a planet without hitting a mountain or being slowed down by the atmosphere is a limiting factor.
For me, looking at Saturn is like looking at a cartoon.
Topic: Big Bang creating Helium / Lithium, Beryllium, etc. And first star creation. Lithium liquefies around 1600K, Lithium Hydride forms as a liquid around 900C. And when these molecules hit each other they stick together unless they achieve the boiling point so they would accumulate until Hydrogen starts to stick by gravity above earth size by Neptune's size.
So my old Motorola flip brick, in terms of electronics, would last longer in space than my current smartphone.
Also worth noting Tektites, and micrometeor/space dust
Cosmic rays also cool
Let’s put disc golf course on the moon and mars. How would frisbees fly differently? Inside a crater could have baskets
Wouldn't they just fly in a straight line with the only motion being that created by the throw and gravity?
The black hole and infinite density "problem" is just a mathematical "problem". If the infinite density is limited to an infinite small volume (hence "singularity"), it may have very well a finite mass. It all depends on how fast the density increases with decreasing volume around the singularity. Conceptually there isn't any problem at all, regardless if a singularity actually exists or not. It"s just very fundamental math.
It might be possible to look below the event horizon of a black hole under certain circumstances. The event horizon is simply the points along a sphere where the gravity of the black hole is such that not even light, or traveling at the speed of light, allows you to escape the gravity well if you get any closer. If you have two black holes orbiting one another, the line that defines the shortest distance between the two masses represents a region where the gravity of each mass is acting in opposition to the other. This means that the event horizon should shrink for each black hole, allowing a well placed probe to observe further inside each black hole than you would otherwise be able to. Or at least, that's the way it seems to me but I'm not an astrophysicist so perhaps I'm missing something.
With two supermassive black holes beginning the slow dance of merger, you could theoretically deploy a probe that had a secondary probe attached via an umbilical such that the secondary probe passes through the event horizon, and images could be delivered up the umbilical to be relayed by the primary probe.
@@JROD082384 Yes, absolutely. Supermassive in particular would be desirable because of the lack of tidal forces. When I was originally thinking about this I was actually imagining something much smaller, with two or more man made black holes of only a few million kg of mass or something that would last an hour or two before evaporating, then placing them in very specific orbits that would allow you to get arbitrarily close to exposing a naked singularity. It would be incredible to observe what happens when space time breaks down.
A .25 U cube sat would be 2.5cm x 10cm x 10 cm.
A 2.5cm x 2.5cm x 10cm would be a 1/16 U.
(2.5 x 2.5 x2.5 would 1/64)
@@tehaury a U is not a measure of volume but length of a side
@@JT-ky9grit’s a standard volume. 10x10x10. A 1.5U is 15x10x10
@@tehaury you're correct
there's a cool mario story related to a bit being flipped
"Chance of cosmic ray interference increases with complexity"
Also inversely proportional to logic component size. Larger lithography process means less susceptibility to cosmic ray interference. Complexity vulnerability scales linearly with complexity. Size complexity graphs different. Above a certain component size, cosmic rays simply can't immediately flip a bit, they're not individually energetic enough. Cosmic rays need to wear down large components gradually over time by demolishing the crystal structure.
love the stargate planets
Dear Fraser, sorry for "cheating" but these questions are kinda stringed together:
-What are the current plans for a Huble 2.0?
-Is there a scientific reason for visible light telescopes vs IR/X-ray etc?
-Is there a final difference between manipulating a photo data to bring it to visual range and an actual visual range of the same object?
Question: is there any research into Solar system wide internet? As DSN hardly will be able to support major colonization - like settlements off planet or telescope on the Dark side of the Moon
*FAR side of the moon.
It gets just as much sunlight as the side you can see all the time...
Inside your space capsule or station the convective cooling of a cell phone would work just fine. Cooling only becomes a big problem if your phone is in vacuum.
Bring a Nokia 3310 and not an Iphone. There, problem solved. As a bonus, the battery will last all week.
Oh, sweet nostalgia 😊
Had mine for many years. Eventually left in a glass of champagne a whole night on new years, still worked in the morning. Threw it into a wall and ran over it with the bike and it still worked 😅
Taking pictures might be difficult when lacking a camera.
@@filonin2 Phones weren't always cameras also. Back in the 3310 days they were just phones.
@@lindenhoch8396 if you deactivate the data connection and can only make and receive calls then you current smartphone will last a week on one charge too.
Yeah but what would be the point? You couldn't take pictures or communicate
Funny that you used the dinosaurs ending impact as an example. I asked my son 20 years ago that same question. Dinosaurs dies cuase they never left Earth so one rock took them out. It's only a matter of time. Yes redirected rocks can save us but all the issues must looked into.
16:00 _"Galileo thought it_ [Saturn] _had ears"_
Ha! I didn't know that!
I will never say no to anything even remotely associated with dark matter. I know you have covered it a million times, but man its just fascinating that we just don't understand like 25% of the universe so casually even though we can literary use it as a tool to lens distant objects. WTH?
taking pictures of things at different with your interferometer principle, take a second picture months later and make the most awesome stereograph?
Re: your rant re: population numbering annoyance: one potential way to rename with backwards compatibility would be to use letters in the new naming convention (e.g. Population A, Population B, etc.). This way, there's no collision with the old convention, and over time, it can hopefully just fade or be regex'ed into oblivion.
Or just forget the population category and start using generation 1, 2, 3. Anton Petrov often uses that, and it's really clear.
Questions for Question Video.
Why are stars we see orbiting Sagittarius A* not showing any gravitational lensing?
Regarding why a telescope company might be suffering: It wouldn't surprise me if there are still manufacturing and sales ripple effects from the pandemic, like has happened to so many other industries. In 2020 and 2021 there was sudden and massive demand for hobby and recreation items, and then that petered off again when people returned to work, leaving many companies in the lurch.
Hey Fraser, when you are talking about metal polluted stars, are you talking about astronomical metal or periodic table metal?
Anything higher than helium on the periodic table is considered metal by astronomers
@@frasercain yup - that's what I was asking.. : ) if astronomical metal or actual one, thanks
Belsa. Well then. That anton petrov video in the triple lensed supernova being used to hone in on the hubble tension should blow your mind!
Supernova H0pe i believe.
I reported on that two weeks ago on Space Bites. The perfect gravitational lens.
@@frasercain lol. I must have not been thrown that one by youtube yet. I only found your channel a couple weeks ago! So just been gobblin up what youtube throws my way. :) im sure yout7be will throw it my way soon.
Question: If fusion gave us 'unlimited' free energy would it be possible to recycle waste by heating it to a plasma in an arc furnace and then use electric fields to sort/refine every atom by mass into individual storage bins?
The Giant Magellan Telescope will be 25 meters in diameter, the Extremely Large Telescope will be 39 meters. Compared to JWST, what difference will the two Earth telescopes be? What would a 50 meter telescope be compared to all the others? Thanks, Jason
Considering the deflection of an asteroid’s orbit by even a slight amount is said to make a large difference over time in avoiding a potential impact, why is it not a more significant consideration of the long-term effects of orbital deflection of planets by using gravity assist maneuvers? Is there some mechanism of gravity on this larger scale (and like using GA maneuvers on BHs in the galaxy) that makes this negligible? Or is it simply that the amount it changes by for those scales only becomes significant millions of years or more later, so we ignore it?
You probably need to know a bit more about the radio processing in a cell phone before you attempt this question.
I used to work on implementing older 2G/3G radio receiver algorithms and I suspect that the SPEED of the cellphone in orbit (relative to the base stations) would cause serious problems. For normal terrestrial speeds, and even for the twits that try to use them in flight, the doppler effects on the mobile signal are corrected for. I doubt that the algorithms are designed for 17,000 mph doppler shifts! Then there's the network issues of managing the selection of and handover between base stations. Not sure those higher layer algorithms are designed to handle an orbiting cellphone. Also, I suspect that the towers of newer systems (4G,5G) don't waste a lot of energy targetting receivers up in space, they're probably phased array directional links that don't have "up" in their coverage map (maybe they do, maybe general aviation reuires cell service to aircraft, but agina, those are moving 1-2 orders of magnitude slower than an orbiting object)
INTERVIEW IDEA
I'm fascinated by globular clusters. Is there a research team dedicating their focus to studying the orbital dynamics of stars in globular clusters, as this must be an amazing place to map gravity wells and how space curvature fluctuates in such a densely packed volume of space. Also, whether there could be gravitational wave effects that one day might be perceivable.
Thank you Fraser!
At what size would a planet be so massive to generate heat and support life without a star?
At any size if the heat was from radioactive decay or tidal heating from orbiting something like Jupiter. You just need to avoid losing gas to space from smaller objects.
If you mean heat from fusion I'm skeptical life as we know it could survive any situation where that's happening. The chemistry we depend on only works in a fairly narrow pressure range. Too low and we can't diffuse enough oxygen into our blood (or water boils in our cells). Too high and it impacts chemical reactions we depend on. Even if you had a brown dwarf with the right temp and pressure this would probably only exist within a narrow altitude band far above any surface. Anything growing there will find it incredibly difficult to stay in the survivable zone, so I don't see how primitive life could get started.
@@ericsmith6394 my thoughts derived from the fact that just by digging few kilometres down in earth crust, the temperature rises. I don't know the cause but I think it's just for pressure. This heat could reach the surface or create some kind of thermal vents without radioactive decay. I was wondering if this could be a possibile scenario
@@PitchWheel yes and it's not unlike when the Earth froze over and life survived at the hydrothermal vents. The Earth has heat leftover from its formation, radioactive decay, and a small amount from tidal heating. There's plenty of heat in there. All planets will have formation and radioactive heat. Jupiter's moons get a lot of tidal heating, but Earth's moon does not because it's tidally locked and in a circular orbit.
I live in the states in Pennsylvania specifically and satellite internet is the only option so starlink is a massive good for people in this area
Question! What is the approx theoretical upper limit for the number of subscribers that Starlink can technically handle? Could Starlink handle 1B subscribers? Whatever the answer is then IMO Starlink has the strong potential to make SpaceX the richest company in the history of the planet 🇺🇳🗽🇺🇦🗽🇺🇳
hi Fraser, I have a question that torments me: If the rotation of the planet produces the movement of the Earth's core and the magnetic field that surrounds us, in addition to the trade winds, why does the expenditure of energy not cause the movement to stop?
Ok Fraser, I have a question about bendy light. If black holes curve space and gravitationally lens, could a strong enough telescope with enough granularity allow us to see back in time. Can the light from our star or galaxy be reflected back by the event horizon by being bent around the black hole?
Dakara? I don't see a community tab anywhere. Sorry. Also, when it comes to topics, I would like to know more about, I would like to know what kinds of scientific principles scientists might use to shed light on the nature of dark energy. Are there math equations that could help, since it seems to be related to universal expansion? Could we possibly find ways to detect dark matter and dark energy? Could they possibly be different facets of one unknown thing? I have so many questions and zero answers. 😶