Neil, talking about misnomer, I can argue zero gravity is also a misnomer. Because it is equivalencies principle and relativity after all. You never in zero gravity, the gravitational force of earth is equally opposed by the acceleration of your space vehicle or body towards and around the earth, thus you feel this apparent zero gravity in the orbit. And by the way, you don't need to go to space for that, you can feel that in the same 737 if it accelerates equally but opposite to earth gravitational force. Oh, you can say floating on water is no different, the gravitational force of the earth is opposed by the water surface tension if you are those tiny insects, or buoyant force, which is nothing but water molecules rush towards all direction. You may argue, floating on water is just like standing on land, Duh, the land is equally oppose you with same force. After all it is relativity you know. My point is, you are playing with words and accusing others of ignorant. What you are doing is called, logomachy.
@@HaroldKuilmanChuck is superior as a Human as he is more intelligent than intellectual aka worthless. Tyson is sometimes too intellectual to realize he isn't being Human but combative and vindictive like mama.
Being funny requires a person to be intelligent. We take comedians to be silly at times but they are the ones outsmarting us and thinking of something mostly spontaneously, which makes us giggle!
Thank you for finally mentioning The Expanse. It's such an amazing show that actually got a lot of the science correct. Obviously some things were embellished for drama and artistic reasons, but many things were spot on. Especially their ship designs in order to generate artificial gravity when the engines are on. Half way to their destination, the ship would flip so the rockets were then slowing them down while still generating gravity. Good on Chuck for mentioning that at the end! They should definitely do an explainer about the show and all its science. First, though, Neil needs to watch all the seasons!! Beltalowda!
I'm glad they gave another shout out to The Expanse. An amazing story, and even better for science lovers. I've seen all 6 seasons in continuum 5 times now and also read all 9 books, and planning to re-read them soon.
@@tonyping3159 their enthusiasm would show through and spark interest in young minds . The teachers I had were to obvious that it was a paycheck and they didn't care about only one student at a time . The richest family or smartest student . Wouldn't waist there time to help a struggling or poor sole , nothing in it for them .
Thanks, guys, for letting me relive my college physics class (looong time ago). I love your shows, and the pure joy of learning you show, and then give to me!
Now to get the kids to listen. I had pleanty of good teachers, but a lot of the classes, I was focused on the cute girls in the seats in front of me. Or I could be distracted in my own mind, on how I am going to make it through Gym class the next period. Or trying to impress other peers on what I think at the time makes me special. School Age kids are not fully developed mentally, and while they do learn a lot, it does take more effort to teach them, because their are a lot more on their minds than that engaging Physics class.
Good question. The reason has to do with the fact that we can't nullify gravity completely in an orbiting spacecraft. There will be a tidal force if you are on the near side or the far side of the spacecraft to Earth. There will also be gravity between the occupants of the spacecraft, and from the spacecraft itself. Gravity isn't exclusively created by planets, moons, and stars, but we have experimental data to show that mountains have gravity, and that lead balls, bowling balls, and cinder blocks can be sources of gravity (as you can see in a homemade Cavendish experiment). It takes several hours to feel the effects of microgravity, so that is why it is still within rounding error, considered zero-g. We're talking micronewtons per kg, if not nanonewtons per kg, so you really need a sensitive experiment to see that it is there.
Make a explainer on why you can't just accelerate for 10 months to reach the speed of light while you just experience 1g the whole time. At what point does it go wrong.
"g" is acceleration. More specifically, "g" is acceleration due to explicit force(s). A car in a sharp turn exerts an explicit force on the occupants. A rocket after liftoff exerts an explicit force to lift astronauts into space. Gravity is everywhere -- it is called "Netwon's universal law of gravitation" for good reason. But, if other explicit forces are absent, then the resulting "free fall" (due to gravitational forces only) is perceived identically to an absence of forces. However, the gravitational force has spherical symmetry. Each mass creates spherical shells around itself wherein all other masses get accelerated toward that mass. These spherical shells are different from a rocket engine's acceleration in one small respect: these spherical shells result in "tidal forces" -- closer objects have higher acceleration and the acceleration vectors are not parallel. In fact, these tidal forces (and small orbit corrections) are what NASA calls "microgravity." "If you accelerate at 1 g for ten months" -- in whose frame of reference? It is not possible for mass to reach the speed of light. Viewed from earth, the ship would become more and more sluggish. At first, only very precise measurements would note the decreased acceleration. But above 0.9 c, the observed acceleration gets closer and closer to zero despite the occupants of the ship 'feeling' the same 1 g acceleration as from the beginning. Contrarily, if you tried to accelerate the ship so that viewers on earth observed a constant 1 g acceleration, then the occupants of the ship would experience higher and higher "upward" force. Eventually, this force would crush them and the ship.
I am a professional Elevator Mechanic. And, I feel like Neil Degrasse Tyson should know that the Elevator is the safest form of public transportation. Elevators have Safety devices all over the place. 😊If an elevator falls, it doesn't fall far before the safeties grab the rails.
Yeah, he knows that. In previous videos, mentions have been made of Otis' invention of the safety elevator in 1853 etc. However, as a scientist, whenever Neil mentions an elevator, he always means an "ideal" elevator, not a real one. To him, an ideal elevator is one that is suspended solely by a cable above a hollow elevator shaft. And as soon as the cable is cut, it starts falling straight down, unobstructed, friction-free, and unaffected by air resistance. Einstein (1879-1955) too visualized an elevator the same way. Not quite what you and I would call an ideal elevator-but this is Neil's channel, so we have to abide by his definition.
Why so much hate for the term "microgravity"? In my understanding this is supposed to indicate that gravity (or perceived gravity) is never exactly zero. Gravitational pull is slightly different over every point over Earth due to minute differences in density. This should cause small tidal effects. At the altitude of the ISS there is also still noticeable atmospheric drag. Likewise, photons from the sun and other sources constantly push against your spacecraft, causing ever so slight acceleration. I think "microgravity" captures this reality well, and it is easier to say than "forallpracticalpurposeszerogravity".
I tried the water experiment. Unfortunately I didn't have a water bottle to hand so I improvised. I urinated while jumping up and down on my neighbour's trampoline with my phone recording my "experiment". I would have uploaded the footage but I'm having problems getting my phone back from the police who my neighbour's called. Suffice to say, my experiment did not produce the expected results and some of the community hours I was given as a sentence in the subsequent trial, required me to clean up the mess.
but is it really zero G? I thought they said it's micro G, because eventually the small amount of molecules in the 'air' where you are orbiting is just enough to slow you down to degrade you back to Earth. So, aren't you slightly less than zero G after the engines stop, until you eventually hit the atmosphere and then slow down enough to feel (earth's) gravity again.? (Earth being any gravitational center)
What if gravity is condensed space time that has been displaced by the massive objects at the center of the “gravitational field”. Since the only way to experience more space in a given time is to move through it (space) and space time would be denser as you get closer to the displacing object this would determine the direction of acceleration ie movement ie the effect we call gravity. This would explain why time dilation occurs when close to massive and dense objects as well as at great speeds. In both cases the observer is experiencing a greater amount of space without an increased amount time. Perhaps it’s the “fabric” of the universe trying to return to the homogeneous state in which its laws were established (shortly after the Big Bang). In either case time, space, and motion through space are tightly connected.
The symmetry of Chuck's hairline is representative of absolute mathematical perfection. I'm so jealous. I'm younger than he is and was born with Neil deGrasse Tyson's hairline. No disrespect to Tyson because we're both going through the same never-ending struggle with barbers that can't fix naturally crooked hairlines.
Just a fun fact for the Expanse. Most of the characters you see are from the belt where they have very low gravity. They use earth’s gravity as a form of torture on these people in a scene (the weight of their body harming itself after NEVER experiencing that much gravity). This means the acceleration and the deceleration they use (the main characters who are largely from lower gravity places) is a much lower rate than what would be 1G for us. Which would also mean earth’s fleet can accelerate and decelerate with more force shortening their travel times (assuming they can afford the additional fuel).
@@tagmaster9522 Correction : Martian MARINES train in 1g. Normal Martians don't, and wouldn't be able to stand 1g for very long. Even Martians in the Martian Navy but who are not Marines (like Bobby and her unit) but who pilot and crew the MCRN ships wouldn't be able to stand 1g - and even the Marines themselves like Bobby wouldn't be able to stand it for very long either. The show didn't show this scene (obviously they couldn't because it was mostly inner dialogue) but when Bobby was brought to Earth to testify about the Ganymede incident, and when she first landed and experienced Earth's gravity for the first time, it was then that it hit her that all that training they had been doing at 1g for a possible attack on Earth was useless since they would never have been able to last in a combat situation for very long in 1g even with all the training they had. Training in 1g and LIVING, BREATHING and existing in 1g and two completely different things, as she learned from her time on Earth. Earthers don't train in 1g - the LIVE in 1g, so they don't notice it or have to adjust to it. (P.S. - one detail they did get correct on the show as a neat kind of Easter egg sort of thing was during the panel on Earth when Bobby was testifying, in the second session in the afternoon (which Chrisjen had cleverly and intentionally planned to have them split that way), all the Martians in the Martian delegation were sat on the chairs all slumped back and exhausted from having been in Earth 1g for longer than they're used to. It gave the Earther's a home-field advantage from not having to negotiate with the Martians during the negotiation session from a position of (literal) weakness and exhaustion like the Martians had to. The show shows all the Martians sitting slumped back and looking drained on their chairs and I thought that was so so great that they did that)
It's not just the Marines. It was all personnel who went off world. That way Earth wouldn't have an advantage in speed or if Mars invaded. Also, service was compulsory, so every Martian served at some point and all of them had the training. When Bobby went to Earth she was disoriented due to actual gravity in conjunction with everything else ie vertigo, (the same reason people get sea sick. Your eyes and ears are telling you different things) You can trian for weight but not for the sensory overload. The reason she was able to adjust was the homeless guy she gave the meds to. A big difference is, in training, the pull stops when the training does. On a planet, it doesn't. Chrisy said the gravity of earth isn't like training. It's an oppressive force, the weight of the world pulling you down.
Space is often described as a zero-gravity environment, but this is a bit of a misnomer. In reality, objects in space experience microgravity due to the continuous free-fall towards Earth or other celestial bodies, creating the sensation of weightlessness. This aligns with Einstein's equivalence principle, which states that local effects of gravity are indistinguishable from acceleration. How do these principles help us understand the effects of gravity on objects and experiments conducted in space?
Dont forget the space station correcting its orbit… Astronauts hit the Wall, each other or other objects, if not Holding something firm grip. They get a Warning before correction burst happens😅 So they dont get hurt in this procedure 🤷🏼♂️
3:37 is not correct. The Lagrange point it not where Earth's gravity and the Moon's gravity are equal and opposite It's where they are equal and opposite in a rotating reference frame that keeps the moon fixed, so you must include centrifugal force to make it work.
6:35 if you wait enough time, you'll know whether you're on a rocket accelerating at 1g, or on a stationary rocket on earth. at some point, you'll have accelerated to lightspeed, at which point you'll stop accelerating, and become weightless again (and reach the end of time since relative to you, the time of everything else stopped) whereas on earth, you'll continue to feel 1g
Often times when people think "zero G" they think "no gravity well." Thing is, there's no place in the known universe that has a zero gravity gradient. The closest you could get to that would be in a super-void between galaxies. If you leave the Earth/Moon gravity well, now you're in the Sun's gravity well. Leave that and you're in the Milky Way's gravity well. Leave that and you're in the local cluster's gravity well, and so-on. There is no point in space where gravity just "switches off." There are places where it's stronger and places where it's weaker, but nowhere where space-time is completely 100% flat.
I love when chuck is listening to Neil; and he repeats what he’s saying 0.00002 seconds after Neil says it. like he knew this info already and they said it at the same time!😭
I hoped would talk about true zero gravity the implications of time dilation on a point having true “zero gravity” Also. I’ve been very curious about the net gravitational forces acting on us in a cosmic scale. Arbitrarily starting with our galaxies central black hole. This might allow a calculation of “universal time zones” Also. What point in the universe truly has lowest gravity.
How much money does Spotify pay you , teacher Tyson to disseminate info there first ? I need a number to figure out the equation to quantify your character
Oh this explainer opened a huge question for me, if accelerating at 1G for a few months would take us to a significant fraction of the speed of light, what is stopping us from sending a probe to proxima centauri for example. Is it that the amount of fuel needed to give even a light craft such acceleration is simply too much?
Speed itself can't harm anyone, unless you hit something. Which is indeed not avoidable, when you consider, that even collisions with photons from the microwave background could harm you :P
A coordinate system in free fall can be made small enough that, relative to itself, the gravitational field around its origin is basically Minkowskian. That is, the 16 components of the gravity field/tensor are not functions of space-time, and objects will resist any acceleration. This is also called an Inertial System. In general, the gravity tensor field is a function of space-time; therefore, gravity has a gradient, and the force of gravity will hold objects in their predicted geodesic motion, which generally is accelerated motion, usually with only a radial component. The tangential resistance to change its geodesic is traditionally thought of as its "mass." The resistance to change its radial acceleration is traditionally thought of as its "weight."
Microgravity vs zero gravity: Tidal forces. Even the ISS is big enough to experience tiny but measurable differences in acceleration between its extremities. Therefore the ISS is not completely in zero gravity, therefore "microgravity."
Hey Neil and Chuck I just wanted to find a way to thank u guys for opening my mind agian I would love to look at stars and galaxy nebulas but I live in Wisconsin how would I go about doing it
6:45ish I thought we used G as a term express equivalency to earth gravity for the difference in inertia in relation to two objects. ie in a fighter jet, you experience at 4g your 150lb body as if your 600lb, but you aren't being pulled toward the plane's mass. the plane is just adding to your inertia in a particular direction. if the plane had a gravitational effect on you then in a negative 4g maneuver the same person would have an outsized pull of the plane toward your mass. your body is not pulling that plane toward it, the plane is increasing the difference in inertia as the heavy plane radically alters your inertial vector dragging you along.
I think when they refer to microgravity its because gravity at surface of the earth is ~9.8 but as you go above (or below) the surface the gravity keeps reducing(in different factors)....So if you're in an object that is long enough....say 100m tall, the gravity at the two ends of that object will be slightly different.....and when you go further away from the Earth, that difference can be significant....especilly in the orbital zone....for instance an object that is 100m long orbiting the earth 2000 km away from the surface will have a 1% gravity difference(from earth) between its two ends that are facting towards and away from earth
These guys are just rocking I teach physics and love this show so much … Initially I thought Chuk was just irritating and obstructing the flow … but guess what … I was wrong … he is an awesome comedian with perfect timings … and also seems to be very smart ….I can’t watch this show without Chuk now …
Thank you so much the Elon Musk ji, Neil deGrasse Tyson ji for Praising our Prime Minister Modiji😍🧡 U Earned Lifetime Respect and Support of all Hindus😍🧡🚩🕉️ We Hindus Love u so much Elon Musk ji, Neil Degrasse Tyson ji😍🧡 May Bhagwan bless you both alot, always keep u both successful like this🙏Hare Rama Hare Krishna🙏🕉️
Would microgravity be so named because everything of mass is attracted to every other thing of mass? In a free falling spaceship you would still be slightly drawn toward the closest wall or anything with mass.
In theory yes, but that’s gonna be truly negligible. Its the slight atmospheric drag that even the ISS experiences, as well as tidal, vibrational and centrifugal forces that manifest in the station.
The space station falls a small amount each orbit and needs to be periodically lifted to keep it at the property altitude. So there is a small amount of g forced since it is not going fast enough to completely cancel Earth's pull.
Yep exactly what I was thinking but surely we are wrong because NDT wouldn’t miss that . If there was near 0 particles ( 0 is impossible to create a perfect vacuum.I was also thinking the gravity pull is different on anything that is not a point so given a size difference you can’t balance it ??
9:08 Neil I believe is incorrect that someone in a balloon with a scale would weigh the same as someone on the surface, since gravity effects get weaker the further you are from the center of the planet. So if you want to weigh the least on the surface of Earth, you would go to the highest peak on the equator in order to weigh yourself. Combining the centrifugal force of the spinning planet plus the difference in gravity on the high elevation.
Yes, Neil has mentioned in several earlier explainers that you weigh more at the poles and less on the equator and on the top of mountains. Also yes, you'll weigh a little less in a balloon that's above Earth's surface (and isn't ascending or descending) than on Earth's surface. But because such balloons don't go up too high, the difference in weight will be too small to be noticeable on a typical scale.
Plus didn't think about it but air pressure at sea level and air pressure at 5,000 feet would not be the same downward force added upon the gravity force exerted upon you to define your "weight."
Can I ask: when I see a slowly spinning middle of a hollywood spacecraft, as it spins, would it not cause the rest of the craft to spin in the opposing direction? Thank you. If I had the money, I would support you, and ask the question there, but I'm a retired adjunct faculty college instructor who never got paid much, and had no retirement benefits, so im forced to beg for this answer here. Forgive me.
Oh, what an amazing explanation on acceleration unit. With every second your speed increases by the value of acceleration. It's beautiful, because it's so simple ❤❤❤
I'd love to hear more talk about the "artificial gravity" on the expanse that is created by centrifical force. It's been a while since I saw the show, I only watched the first season, but I recall like water flowing in a spiral when being poured out in those environments. Love to hear more about that.
*generated, not "created" aka "instantly manifested from nothing." Generation is a pricess, a thing if cause and effect or "causality" if you prefer putrid and gaudy terms of intellectuals.
That scene with the water pouring is because they are on Ceres and they artificially spin it to create gravity. Dr Becky explains this in one of her videos here -> ua-cam.com/video/O25-_eEdxaw/v-deo.html
I can watch Neil and Chuck videos over and over … the most rewarding experience!! I wish we can have some politicians with 10% of these guys knowledge and common sense … we’ll be great again !🖖
Wouldn't the thickness of and direction of growth of her sideburns have something to do with how they stick out of her head? Wouldn't several factors dictate how her hairs look while weightless? I'm just a gear rockin truck driver.
From your reference point, it is zero G, but from any other point of reference, you have a non-zero acceleration. If you were on the ISS, would you eventually hit the front of it if you were floating in the middle, due to the frictional deceleration cause by atmospheric drag?
When you reach that L1 point where both moon and earth have the same pulling influence upon you, how are other gravitational forces act like from the sun or Jupiter??
Indeed there are other influences of gravity. This is why spacecraft usually do loops (at Lagrange points), to average things out. At least thats why i assume they do the loops.
The Expanse is so great because they represent stuff like acceleration, gravity and deceleration so realistically. Great references to the show. Thank you guys!
According to general relativity. If you are falling towards a massive object like a planet. Relative to the planet you are accelerating, in earths case at a rate of 9.8m/s squared. However, you will not feel any acceleration because technically, from your inertial frame of reference, you aren't. When you stand still on the Earth, technically, you are accelerating upwards at 1g which feels like your weight pulling you down.
What Einstein understood back then is not that being in a rocket or a box accelerating through space is like artificial gravity. What he understood, is that it is in deed gravity. In your boxx you accelerate through space and you are "pushed" towards the opposite direction, but here on ground level, what's happenening is that it's space that accelerates through you towards the center of the Earth. Space is falling in an acceleration and the only thing that prevent you from following the move, is the soil, exactly as the one in your box, in your rocket. It's not two different phenomenons, it is the same exact thing going on. Let me reformulate, if you agree that movment is always related to space, and if it is space that moves around you, not the opposite, well, you are actually moving, it is relativity. Here on your planet's ground, you are constantly accelerating through space upward, the reason you are not noticing it, is because everything accelerate with you, just as if you were in a rocket accelerating in space. A mind blowing experience for you, next time you have the luck to see a starry sky, lie down, don't stand looking up, just lie down, and watch, what you see is not up above you anymore, it is right before you, you are facing it, you are in deed in space accelerating in your "rocket".
I gave a scenario to chatGPT I: Consider a scenario where a star is approximately 999 times more massive than the Sun, and there is an object weighing 1 kg located 99 million km away from the star. Assuming the star has the same radius as the Sun. Calculate the time it would take for the object to reach the surface of the star? and the speed at which it would be traveling? " ChatGPT: The speed of the object near the surface of the star would be approximately 721,899,162 m/s. I: But that is about 2.4 times the speed of light :) I wish Neil deGrasse explain it.
Hi @StarTalk! OK so this confuses me, that planetary gravity is indistinguishable from acceleration. I mean, I get that in some sense gravity===acceleration. I think I could design a spaceship that WOULD let me figure out whether I was accelerating through space, or sitting on a planet of finite size. If I have a really large space ship, let's say 4K miles wide, with a completely flat floor. The engines are installed such that the floor is normal to the direction of acceleration. As I accelerate, I'll find the acceleration vector is always straight "down" - and the acceleration vectors are all parallel. But if I land this space ship on Earth, the 4K miles is wide enough that the acceleration vectors will, measurably, not be parallel, because "down" will be towards the center of the mass to which it's attracted. I don't think this is very disputable. So how narrow a spaceship would I need, to be able to detect this lack of parallelism? EDIT TO ADD: OK I found the answer. The Equivalence Principle usually includes "locally" (Acceleration in a flat space-time is locally indistinguishable from gravity). So everyone more educated than me already knows this. I found this discussed in a Sabine Hossenfelder video (link below). And another way to do it is to have a tall spaceship - gravity-induced weight will be lower at the top of the spaceship than at the bottom, but acceleration-induced weight will be the same. ua-cam.com/video/vng2-R64rAY/v-deo.html
5:00 isnt that called G-Force, rather then Gravity? When you sayd, when you egnite the engine on a Spaceship. I mean Gravity comef from an Object with just big mas, and G-Force is what YOUR BODY does to the ship. EDIT: 13:20 looks like i just had to wait so Neil confirms me lol.....
The ISS is not in pure freefall. It is interacting with Earth's atmosphere. That results in a very tiny deceleration, right? (I guess one could include light from the Sun and solar winds.) I don't know what NASA means by micro gravity, but would that tiny effect from the atmosphere result in a micro gravity? Also, you cannot accelerate to the speed of light (which of course you know), yet you gave a finite period of time. Also, did that calculation account for relativistic mass? If it sounds like I am being picky, I am following your lead, for example, when you complained about Cronkite or NASA calling it microgravity.
There is a reason why NASA uses the term "microgravity" as opposed to "zero-g", which usage becomes clear once you understand the context within which it is most appropriately used: research. Imagine, for example, a Get Away Special payload containing science experiments attached to the side wall or adapter beam in the shuttle's cargo bay. Certainly, one would like to have those experiments performed in an idealistic, pristine, zero-g environment. But in reality is that achievable? As it turns out, no. Even without the shuttle's OMS firing, there are plenty of events within the shuttle (and some without) which can cause vibrations and accelerations, i.e. forces, throughout the shuttle's frame (e.g., the activities of the astronauts and the shuttle's internal systems, drag). And any experiment attached to the shuttle's frame (i.e., not floating around in the interior) will feel these forces. Typically, the amplitude of these forces tend to be on the order of 10^(-6) g's, hence NASA's very specific use of the term micro-g. For example, the paper linked to below by Darin Gates of Bristol Aerospace mentions the in situ accelerometer data of their G-521 payload as measuring peak forces of about 140 micro-g. And although I don't have the data off-hand, this seems consistent with what we measured on the payloads I was involved with. Although the term micro-g is, perhaps, sometimes used casually and cavalierly to talk about the space environment generally, its fundamental, primary, and important usage is with regards to the characterization of the environment within which a scientist can expect their research to be carried out when performed aboard an orbital space platform such as the shuttle or ISS. ntrs.nasa.gov/api/citations/19940014697/downloads/19940014697.pdf
Dear Dr. Neil deGrasse Tyson, I LOVEEE to hear and talk about science and space, appreciate everything that YOU and your hosts do! Wondering about misleading microgravity, just maybe NASA thinks about microgravity as the condition the body is in - "0" G, but when the body acts on it self with its own gravity? Like a water drop, every time its in "0" G forms a sphere, because of its own mass and gravity acting on its self (e.g. microgravity) ;) am I right?
Water droplets become round in "0" G not due to own microgravity but due to water molecules attracting each other through electric charges within the molecules. That is how most substances on human size scales stay together. Gravity is much too weak of a force to attract small masses compared to electromagnetic forces. Gravity is about 20 orders of magnitude weaker than electromagnetic forces. Gravity only becomes significant when there are huge masses involved.
See if you can get the equivalence principle experiment to work at home. What happens?
Mama Earth says, " *come back FU..KER* "..😂😂!!
fell. towards earth
Neil, talking about misnomer, I can argue zero gravity is also a misnomer. Because it is equivalencies principle and relativity after all.
You never in zero gravity, the gravitational force of earth is equally opposed by the acceleration of your space vehicle or body towards and around the earth, thus you feel this apparent zero gravity in the orbit. And by the way, you don't need to go to space for that, you can feel that in the same 737 if it accelerates equally but opposite to earth gravitational force. Oh, you can say floating on water is no different, the gravitational force of the earth is opposed by the water surface tension if you are those tiny insects, or buoyant force, which is nothing but water molecules rush towards all direction.
You may argue, floating on water is just like standing on land, Duh, the land is equally oppose you with same force. After all it is relativity you know.
My point is, you are playing with words and accusing others of ignorant. What you are doing is called, logomachy.
Who you talkin' bout. Haha
Please make a video explaining why free fall is the only state that's inertial, and therefore that standing on the earth is a state of acceleration.
Neil and Chuck for 2024
If only that was possible. We’re stuck with octogenarian white dudes
Just Neil please 😅 🙏
Nah I want Chuck and Neil
@@HaroldKuilmanChuck is superior as a Human as he is more intelligent than intellectual aka worthless.
Tyson is sometimes too intellectual to realize he isn't being Human but combative and vindictive like mama.
They both work together well their pleasing the nerds and average Joe, I still find myself not worthy of being in their presence 😁
I love Chuck for his comedy and the fact that he is WAY smarter then he lets on.
Chuck is definitely intelligent 👌, he's curious too 😊
True. He's the class clown that the teacher wouldn't mind having.
my thoughts exactly
Being funny requires a person to be intelligent. We take comedians to be silly at times but they are the ones outsmarting us and thinking of something mostly spontaneously, which makes us giggle!
@@Capt.Alron.DAbsolutely!!
I love how science just makes these two happy. Chuck is especially brilliant but then most comedians actually are.
What kind of a liquid would you put in a big gulp cup that wouldn't make a mess..?
Thank you for finally mentioning The Expanse. It's such an amazing show that actually got a lot of the science correct. Obviously some things were embellished for drama and artistic reasons, but many things were spot on. Especially their ship designs in order to generate artificial gravity when the engines are on. Half way to their destination, the ship would flip so the rockets were then slowing them down while still generating gravity. Good on Chuck for mentioning that at the end!
They should definitely do an explainer about the show and all its science. First, though, Neil needs to watch all the seasons!!
Beltalowda!
Remember that guy Epstein dying from the acceleration of his own invention? The Expanse did a lot of things right. Damn I miss that series.
@@diegofernandez4789 The longest funerals ever ! :)
Beltalowda❤
@@michaelharris680❤ milowda inyolawda
What kind of a liquid would you put in a big gulp cup that wouldn't make a mess..?
You guys always manage to put a smile on my face even when times are tough. And I learn something too. Thanks for that.👍
That's everything we strive for, thanks for your feedback :)
A put some pudding in my belly 😋
@@StarTalk What kind of a liquid would you put in a big gulp cup that wouldn't make a mess..?
I'm glad they gave another shout out to The Expanse. An amazing story, and even better for science lovers. I've seen all 6 seasons in continuum 5 times now and also read all 9 books, and planning to re-read them soon.
when i get the funds i plan to get them i loved the show and want way more lol
I wish I could have gotten teachers like them back in school . The passion and fun , I might have even liked being there and learning .
Right!!!! I would have loved science class if Neil was our teacher or professor
if you need a good teacher to love science, than you really only like science.
You're asking scientists to be your teachers, ain't nobody got time for that😂
For sure. They would have the struggling students excited to learn and pass their tests.
@@tonyping3159 their enthusiasm would show through and spark interest in young minds . The teachers I had were to obvious that it was a paycheck and they didn't care about only one student at a time . The richest family or smartest student . Wouldn't waist there time to help a struggling or poor sole , nothing in it for them .
Thanks, guys, for letting me relive my college physics class (looong time ago). I love your shows, and the pure joy of learning you show, and then give to me!
Niel looks like he gets angry when he is teaching lol
Never lose your interest in physics!
We should make StarTalk mandatory in all schools, teaching curriculum, and in the education system! 💛✨
Shhhh.... you'll upset the Christians.
50% ?
@@wrestlenewsnetwork5564 do we have any Lions?
Now to get the kids to listen. I had pleanty of good teachers, but a lot of the classes, I was focused on the cute girls in the seats in front of me. Or I could be distracted in my own mind, on how I am going to make it through Gym class the next period. Or trying to impress other peers on what I think at the time makes me special. School Age kids are not fully developed mentally, and while they do learn a lot, it does take more effort to teach them, because their are a lot more on their minds than that engaging Physics class.
@@gazzam3172 Well we dnt want another "crusade". RELEASE THE LIONS!!!!
Why do they call it Microgravity if it's Zero G?
Good question. The reason has to do with the fact that we can't nullify gravity completely in an orbiting spacecraft. There will be a tidal force if you are on the near side or the far side of the spacecraft to Earth. There will also be gravity between the occupants of the spacecraft, and from the spacecraft itself. Gravity isn't exclusively created by planets, moons, and stars, but we have experimental data to show that mountains have gravity, and that lead balls, bowling balls, and cinder blocks can be sources of gravity (as you can see in a homemade Cavendish experiment).
It takes several hours to feel the effects of microgravity, so that is why it is still within rounding error, considered zero-g. We're talking micronewtons per kg, if not nanonewtons per kg, so you really need a sensitive experiment to see that it is there.
Chuck is the class clown that ACTUALLY learned and was attentive rather than just pretending to be funny all the time
Chuck will soon be Dr.Chuck
Make a explainer on why you can't just accelerate for 10 months to reach the speed of light while you just experience 1g the whole time. At what point does it go wrong.
great question! wondered the same!
"g" is acceleration. More specifically, "g" is acceleration due to explicit force(s). A car in a sharp turn exerts an explicit force on the occupants. A rocket after liftoff exerts an explicit force to lift astronauts into space. Gravity is everywhere -- it is called "Netwon's universal law of gravitation" for good reason. But, if other explicit forces are absent, then the resulting "free fall" (due to gravitational forces only) is perceived identically to an absence of forces.
However, the gravitational force has spherical symmetry. Each mass creates spherical shells around itself wherein all other masses get accelerated toward that mass. These spherical shells are different from a rocket engine's acceleration in one small respect: these spherical shells result in "tidal forces" -- closer objects have higher acceleration and the acceleration vectors are not parallel. In fact, these tidal forces (and small orbit corrections) are what NASA calls "microgravity."
"If you accelerate at 1 g for ten months" -- in whose frame of reference? It is not possible for mass to reach the speed of light. Viewed from earth, the ship would become more and more sluggish. At first, only very precise measurements would note the decreased acceleration. But above 0.9 c, the observed acceleration gets closer and closer to zero despite the occupants of the ship 'feeling' the same 1 g acceleration as from the beginning. Contrarily, if you tried to accelerate the ship so that viewers on earth observed a constant 1 g acceleration, then the occupants of the ship would experience higher and higher "upward" force. Eventually, this force would crush them and the ship.
I am a professional Elevator Mechanic. And, I feel like Neil Degrasse Tyson should know that the Elevator is the safest form of public transportation. Elevators have Safety devices all over the place. 😊If an elevator falls, it doesn't fall far before the safeties grab the rails.
Yeah, he knows that. In previous videos, mentions have been made of Otis' invention of the safety elevator in 1853 etc. However, as a scientist, whenever Neil mentions an elevator, he always means an "ideal" elevator, not a real one. To him, an ideal elevator is one that is suspended solely by a cable above a hollow elevator shaft. And as soon as the cable is cut, it starts falling straight down, unobstructed, friction-free, and unaffected by air resistance. Einstein (1879-1955) too visualized an elevator the same way. Not quite what you and I would call an ideal elevator-but this is Neil's channel, so we have to abide by his definition.
Thanks for uploading this video guys❤
Maybe we could get in the habit of saying “free fall” instead of “zero g”, then everyone’s happy, right?
Why so much hate for the term "microgravity"? In my understanding this is supposed to indicate that gravity (or perceived gravity) is never exactly zero.
Gravitational pull is slightly different over every point over Earth due to minute differences in density. This should cause small tidal effects. At the altitude of the ISS there is also still noticeable atmospheric drag. Likewise, photons from the sun and other sources constantly push against your spacecraft, causing ever so slight acceleration.
I think "microgravity" captures this reality well, and it is easier to say than "forallpracticalpurposeszerogravity".
I tried the water experiment. Unfortunately I didn't have a water bottle to hand so I improvised. I urinated while jumping up and down on my neighbour's trampoline with my phone recording my "experiment". I would have uploaded the footage but I'm having problems getting my phone back from the police who my neighbour's called. Suffice to say, my experiment did not produce the expected results and some of the community hours I was given as a sentence in the subsequent trial, required me to clean up the mess.
but is it really zero G? I thought they said it's micro G, because eventually the small amount of molecules in the 'air' where you are orbiting is just enough to slow you down to degrade you back to Earth. So, aren't you slightly less than zero G after the engines stop, until you eventually hit the atmosphere and then slow down enough to feel (earth's) gravity again.? (Earth being any gravitational center)
This video and your Achieving Orbit video are literally mind-blowing! Love this channel! Thanks Neil and Chuck!
I’m crying 😅😅😅😅😅😅😅😅😅😅 but I’ve also been educated!!!! Bravo 👏🏾 gentlemen!!!!! It’s a win 🏆
What if gravity is condensed space time that has been displaced by the massive objects at the center of the “gravitational field”. Since the only way to experience more space in a given time is to move through it (space) and space time would be denser as you get closer to the displacing object this would determine the direction of acceleration ie movement ie the effect we call gravity. This would explain why time dilation occurs when close to massive and dense objects as well as at great speeds. In both cases the observer is experiencing a greater amount of space without an increased amount time. Perhaps it’s the “fabric” of the universe trying to return to the homogeneous state in which its laws were established (shortly after the Big Bang). In either case time, space, and motion through space are tightly connected.
who come here after recommendation by PRASHANT DHAWAN sir
The symmetry of Chuck's hairline is representative of absolute mathematical perfection. I'm so jealous. I'm younger than he is and was born with Neil deGrasse Tyson's hairline. No disrespect to Tyson because we're both going through the same never-ending struggle with barbers that can't fix naturally crooked hairlines.
Just a fun fact for the Expanse.
Most of the characters you see are from the belt where they have very low gravity. They use earth’s gravity as a form of torture on these people in a scene (the weight of their body harming itself after NEVER experiencing that much gravity).
This means the acceleration and the deceleration they use (the main characters who are largely from lower gravity places) is a much lower rate than what would be 1G for us.
Which would also mean earth’s fleet can accelerate and decelerate with more force shortening their travel times (assuming they can afford the additional fuel).
The Martians train in 1G so they could do it as well.
Spot on and it's also shown in physical strength differences between troops loved the expanse for getting so many things right
@@tagmaster9522
Correction :
Martian MARINES train in 1g.
Normal Martians don't, and wouldn't be able to stand 1g for very long.
Even Martians in the Martian Navy but who are not Marines (like Bobby and her unit) but who pilot and crew the MCRN ships wouldn't be able to stand 1g - and even the Marines themselves like Bobby wouldn't be able to stand it for very long either.
The show didn't show this scene (obviously they couldn't because it was mostly inner dialogue) but when Bobby was brought to Earth to testify about the Ganymede incident, and when she first landed and experienced Earth's gravity for the first time, it was then that it hit her that all that training they had been doing at 1g for a possible attack on Earth was useless since they would never have been able to last in a combat situation for very long in 1g even with all the training they had.
Training in 1g and LIVING, BREATHING and existing in 1g and two completely different things, as she learned from her time on Earth.
Earthers don't train in 1g - the LIVE in 1g, so they don't notice it or have to adjust to it.
(P.S. - one detail they did get correct on the show as a neat kind of Easter egg sort of thing was during the panel on Earth when Bobby was testifying, in the second session in the afternoon (which Chrisjen had cleverly and intentionally planned to have them split that way), all the Martians in the Martian delegation were sat on the chairs all slumped back and exhausted from having been in Earth 1g for longer than they're used to.
It gave the Earther's a home-field advantage from not having to negotiate with the Martians during the negotiation session from a position of (literal) weakness and exhaustion like the Martians had to.
The show shows all the Martians sitting slumped back and looking drained on their chairs and I thought that was so so great that they did that)
@@Cbricklyne damn I never realized that to be the case. I thought they sat like that on 2nd session was because they had a huge lunch lol.
It's not just the Marines. It was all personnel who went off world. That way Earth wouldn't have an advantage in speed or if Mars invaded. Also, service was compulsory, so every Martian served at some point and all of them had the training. When Bobby went to Earth she was disoriented due to actual gravity in conjunction with everything else ie vertigo, (the same reason people get sea sick. Your eyes and ears are telling you different things) You can trian for weight but not for the sensory overload. The reason she was able to adjust was the homeless guy she gave the meds to. A big difference is, in training, the pull stops when the training does. On a planet, it doesn't. Chrisy said the gravity of earth isn't like training. It's an oppressive force, the weight of the world pulling you down.
Finally, you guys addressed The Expanse as "for real physics" TV show.
Space is often described as a zero-gravity environment, but this is a bit of a misnomer. In reality, objects in space experience microgravity due to the continuous free-fall towards Earth or other celestial bodies, creating the sensation of weightlessness. This aligns with Einstein's equivalence principle, which states that local effects of gravity are indistinguishable from acceleration. How do these principles help us understand the effects of gravity on objects and experiments conducted in space?
15:30 I did the math. It will take 353 days 19 hours and 53 mins to attain light speed accelerating at 1g
Would you know how to calculate the amount of fuel per kg needed to maintain that acceleration?
Dont forget the space station correcting its orbit… Astronauts hit the Wall, each other or other objects, if not Holding something firm grip. They get a Warning before correction burst happens😅 So they dont get hurt in this procedure 🤷🏼♂️
GREAT ! SEIZE THE DAY,,,, HOW WAS YOUR EXPERIENCE WITH MODI..
2 LEGENDS LAUGH😂 .... "THE SPACE CHRONICLES"❤❤
3:37 is not correct. The Lagrange point it not where Earth's gravity and the Moon's gravity are equal and opposite It's where they are equal and opposite in a rotating reference frame that keeps the moon fixed, so you must include centrifugal force to make it work.
6:35 if you wait enough time, you'll know whether you're on a rocket accelerating at 1g, or on a stationary rocket on earth.
at some point, you'll have accelerated to lightspeed, at which point you'll stop accelerating, and become weightless again (and reach the end of time since relative to you, the time of everything else stopped) whereas on earth, you'll continue to feel 1g
Often times when people think "zero G" they think "no gravity well." Thing is, there's no place in the known universe that has a zero gravity gradient. The closest you could get to that would be in a super-void between galaxies. If you leave the Earth/Moon gravity well, now you're in the Sun's gravity well. Leave that and you're in the Milky Way's gravity well. Leave that and you're in the local cluster's gravity well, and so-on. There is no point in space where gravity just "switches off." There are places where it's stronger and places where it's weaker, but nowhere where space-time is completely 100% flat.
True, unless that person is "shut out" in some direction fast so speed would be greater than any nearby gravitational pull.
@@milosstojanovic4623 I wasn't referring to acceleration, just the ambient curvature of space-time itself. Gravity produced by mass, not acceleration.
I love that The Expanse is recognized. It's the best space novellas I've ever seen and read.
Neil, you ignored relativistic effects in your 10 month 1 G acceleration. Not very accurate past a few % of C.
I love when chuck is listening to Neil; and he repeats what he’s saying 0.00002 seconds after Neil says it. like he knew this info already and they said it at the same time!😭
I hoped would talk about true zero gravity the implications of time dilation on a point having true “zero gravity”
Also. I’ve been very curious about the net gravitational forces acting on us in a cosmic scale.
Arbitrarily starting with our galaxies central black hole.
This might allow a calculation of
“universal time zones”
Also. What point in the universe truly has lowest gravity.
How much money does Spotify pay you , teacher Tyson to disseminate info there first ? I need a number to figure out the equation to quantify your character
Oh this explainer opened a huge question for me, if accelerating at 1G for a few months would take us to a significant fraction of the speed of light, what is stopping us from sending a probe to proxima centauri for example. Is it that the amount of fuel needed to give even a light craft such acceleration is simply too much?
15:31 But humans can't survive light speed travel, correct? Or am I wrong?
Speed itself can't harm anyone, unless you hit something.
Which is indeed not avoidable, when you consider, that even collisions with photons from the microwave background could harm you :P
@@yourguard4 So in other words, "no. Humans can't survive light speed travel"
A coordinate system in free fall can be made small enough that, relative to itself, the gravitational field around its origin is basically Minkowskian. That is, the 16 components of the gravity field/tensor are not functions of space-time, and objects will resist any acceleration. This is also called an Inertial System.
In general, the gravity tensor field is a function of space-time; therefore, gravity has a gradient, and the force of gravity will hold objects in their predicted geodesic motion, which generally is accelerated motion, usually with only a radial component. The tangential resistance to change its geodesic is traditionally thought of as its "mass." The resistance to change its radial acceleration is traditionally thought of as its "weight."
Microgravity vs zero gravity: Tidal forces. Even the ISS is big enough to experience tiny but measurable differences in acceleration between its extremities. Therefore the ISS is not completely in zero gravity, therefore "microgravity."
Does that mean if I’m taking a wiz it will stop in free fall? Enquiring minds want to know.
Chuck impressed me pulling up the Lagrange point 😂😂
I think they call it micro gravity because of the atmospheric drag, tidal forces, etc. decelerating the space station.
who is here after PM Modi and prashant sir video
Hey Neil and Chuck I just wanted to find a way to thank u guys for opening my mind agian I would love to look at stars and galaxy nebulas but I live in Wisconsin how would I go about doing it
Neil gets so amped up talking about physics. I enjoy that.
I learned about lagrange points as a little kid watching mobile suit gundam.
I can't stop the video until I hear Neil say, "keep looking up". ❤😊
I tried that. Kept walking into lampposts. 😂😂😂
PM Modi and Neil Tyson, 2 of my favoruite people met today.
6:45ish I thought we used G as a term express equivalency to earth gravity for the difference in inertia in relation to two objects. ie in a fighter jet, you experience at 4g your 150lb body as if your 600lb, but you aren't being pulled toward the plane's mass. the plane is just adding to your inertia in a particular direction. if the plane had a gravitational effect on you then in a negative 4g maneuver the same person would have an outsized pull of the plane toward your mass. your body is not pulling that plane toward it, the plane is increasing the difference in inertia as the heavy plane radically alters your inertial vector dragging you along.
I'm listening to this while I'm in the car and the tire screeching sound at 4 minutes was misleading.
I think when they refer to microgravity its because gravity at surface of the earth is ~9.8 but as you go above (or below) the surface the gravity keeps reducing(in different factors)....So if you're in an object that is long enough....say 100m tall, the gravity at the two ends of that object will be slightly different.....and when you go further away from the Earth, that difference can be significant....especilly in the orbital zone....for instance an object that is 100m long orbiting the earth 2000 km away from the surface will have a 1% gravity difference(from earth) between its two ends that are facting towards and away from earth
search "SRTM torque rotation"
I love Mr. Tyson's enthusiasm, it makes learning fun. Teachers, take note.
Big hope that _The Expanse_ gets more seasons and finish the book.
It's the most realistic space series ever.
These guys are just rocking
I teach physics and love this show so much …
Initially I thought Chuk was just irritating and obstructing the flow … but guess what … I was wrong … he is an awesome comedian with perfect timings … and also seems to be very smart ….I can’t watch this show without Chuk now …
Thank you so much the Elon Musk ji, Neil deGrasse Tyson ji for Praising our Prime Minister Modiji😍🧡
U Earned Lifetime Respect and Support of all Hindus😍🧡🚩🕉️
We Hindus Love u so much Elon Musk ji, Neil Degrasse Tyson ji😍🧡
May Bhagwan bless you both alot, always keep u both successful like this🙏Hare Rama Hare Krishna🙏🕉️
They did hat experiment on the steven colbert show.
Would microgravity be so named because everything of mass is attracted to every other thing of mass? In a free falling spaceship you would still be slightly drawn toward the closest wall or anything with mass.
In theory yes, but that’s gonna be truly negligible. Its the slight atmospheric drag that even the ISS experiences, as well as tidal, vibrational and centrifugal forces that manifest in the station.
The space station falls a small amount each orbit and needs to be periodically lifted to keep it at the property altitude. So there is a small amount of g forced since it is not going fast enough to completely cancel Earth's pull.
Yep exactly what I was thinking but surely we are wrong because NDT wouldn’t miss that . If there was near 0 particles ( 0 is impossible to create a perfect vacuum.I was also thinking the gravity pull is different on anything that is not a point so given a size difference you can’t balance it ??
9:08 Neil I believe is incorrect that someone in a balloon with a scale would weigh the same as someone on the surface, since gravity effects get weaker the further you are from the center of the planet.
So if you want to weigh the least on the surface of Earth, you would go to the highest peak on the equator in order to weigh yourself. Combining the centrifugal force of the spinning planet plus the difference in gravity on the high elevation.
Yes, Neil has mentioned in several earlier explainers that you weigh more at the poles and less on the equator and on the top of mountains.
Also yes, you'll weigh a little less in a balloon that's above Earth's surface (and isn't ascending or descending) than on Earth's surface. But because such balloons don't go up too high, the difference in weight will be too small to be noticeable on a typical scale.
Plus didn't think about it but air pressure at sea level and air pressure at 5,000 feet would not be the same downward force added upon the gravity force exerted upon you to define your "weight."
Can I ask: when I see a slowly spinning middle of a hollywood spacecraft, as it spins, would it not cause the rest of the craft to spin in the opposing direction?
Thank you. If I had the money, I would support you, and ask the question there, but I'm a retired adjunct faculty college instructor who never got paid much, and had no retirement benefits, so im forced to beg for this answer here. Forgive me.
I think "micro gravity" refers to gravitational pull of different masses on ISS.
That and the atmospheric drag, since the atmosphere doesn't diminish completely to zero at the altitude of ISS.
There is an actual free fall elevator for experimental research of zero G in Germany. Fall takes about one or two seconds.
Up to 10 seconds (falling "up and down").
Oh, what an amazing explanation on acceleration unit. With every second your speed increases by the value of acceleration. It's beautiful, because it's so simple ❤❤❤
16:50 A good rule of thumb, Lord Nice, is, "Add about ten meters per second, for every second it's (you're) falling".
I'd love to hear more talk about the "artificial gravity" on the expanse that is created by centrifical force. It's been a while since I saw the show, I only watched the first season, but I recall like water flowing in a spiral when being poured out in those environments. Love to hear more about that.
*generated, not "created" aka "instantly manifested from nothing."
Generation is a pricess, a thing if cause and effect or "causality" if you prefer putrid and gaudy terms of intellectuals.
That scene with the water pouring is because they are on Ceres and they artificially spin it to create gravity. Dr Becky explains this in one of her videos here -> ua-cam.com/video/O25-_eEdxaw/v-deo.html
@@linyenchin6773 god created centrifical force! /S
@@edwardallenthree There is no evidence for the existence of any god.
@@fredbohm4728 bless you, the slash ess means sarcasm.
I can watch Neil and Chuck videos over and over … the most rewarding experience!! I wish we can have some politicians with 10% of these guys knowledge and common sense … we’ll be great again !🖖
Fantastic! Feed my brain!! ❤ Thanks, Neil and Chuck!
Chuck at 16:46 Eureka Eureka!! 😂
spinny spin spin or throwing somthing mean no 0-g
Wouldn't the thickness of and direction of growth of her sideburns have something to do with how they stick out of her head? Wouldn't several factors dictate how her hairs look while weightless? I'm just a gear rockin truck driver.
'Peripheral uniform gravity'
UA-cam wont allow video links fascists
Clearly Neil has recently diversified his investment portfolio to include stock in 7-11. 😂
You guys always put a smile on my face 😂
From your reference point, it is zero G, but from any other point of reference, you have a non-zero acceleration. If you were on the ISS, would you eventually hit the front of it if you were floating in the middle, due to the frictional deceleration cause by atmospheric drag?
When you reach that L1 point where both moon and earth have the same pulling influence upon you, how are other gravitational forces act like from the sun or Jupiter??
Indeed there are other influences of gravity. This is why spacecraft usually do loops (at Lagrange points), to average things out. At least thats why i assume they do the loops.
The Expanse is so great because they represent stuff like acceleration, gravity and deceleration so realistically. Great references to the show. Thank you guys!
If gravity warps/distorts spacetime and acceleration is exactly the same, can it also be said to be a distortion in spacetime?
I was thinking the same 🙊
“When you turn on your rocket…”- Neil D Tyson, 2023
"Prashant Dhawan sir " ko sunkar kon kon aaya h?
Lot a love 🤩 from India
I clicked the Like button as soon as Chuck mentioned the Lagrange point 😂✨
I love Startalk 🖤
Neil and Chuck, you're doing amazing work. I love you guys.
Neil's the real 0G 😎
Plz make videos on gravity for our better understanding. My request to you sir.
Neil "So..." deGrasse Tyson 😁
According to general relativity. If you are falling towards a massive object like a planet. Relative to the planet you are accelerating, in earths case at a rate of 9.8m/s squared. However, you will not feel any acceleration because technically, from your inertial frame of reference, you aren't. When you stand still on the Earth, technically, you are accelerating upwards at 1g which feels like your weight pulling you down.
What Einstein understood back then is not that being in a rocket or a box accelerating through space is like artificial gravity.
What he understood, is that it is in deed gravity.
In your boxx you accelerate through space and you are "pushed" towards the opposite direction, but here on ground level, what's happenening is that it's space that accelerates through you towards the center of the Earth.
Space is falling in an acceleration and the only thing that prevent you from following the move, is the soil, exactly as the one in your box, in your rocket.
It's not two different phenomenons, it is the same exact thing going on.
Let me reformulate, if you agree that movment is always related to space, and if it is space that moves around you, not the opposite, well, you are actually moving, it is relativity.
Here on your planet's ground, you are constantly accelerating through space upward, the reason you are not noticing it, is because everything accelerate with you, just as if you were in a rocket accelerating in space.
A mind blowing experience for you, next time you have the luck to see a starry sky, lie down, don't stand looking up, just lie down, and watch, what you see is not up above you anymore, it is right before you, you are facing it, you are in deed in space accelerating in your "rocket".
I gave a scenario to chatGPT
I: Consider a scenario where a star is approximately 999 times more massive than the Sun, and there is an object weighing 1 kg located 99 million km away from the star.
Assuming the star has the same radius as the Sun.
Calculate the time it would take for the object to reach the surface of the star?
and the speed at which it would be traveling? "
ChatGPT: The speed of the object near the surface of the star would be approximately 721,899,162 m/s.
I: But that is about 2.4 times the speed of light :)
I wish Neil deGrasse explain it.
Hi @StarTalk!
OK so this confuses me, that planetary gravity is indistinguishable from acceleration. I mean, I get that in some sense gravity===acceleration. I think I could design a spaceship that WOULD let me figure out whether I was accelerating through space, or sitting on a planet of finite size.
If I have a really large space ship, let's say 4K miles wide, with a completely flat floor. The engines are installed such that the floor is normal to the direction of acceleration. As I accelerate, I'll find the acceleration vector is always straight "down" - and the acceleration vectors are all parallel.
But if I land this space ship on Earth, the 4K miles is wide enough that the acceleration vectors will, measurably, not be parallel, because "down" will be towards the center of the mass to which it's attracted. I don't think this is very disputable. So how narrow a spaceship would I need, to be able to detect this lack of parallelism?
EDIT TO ADD: OK I found the answer. The Equivalence Principle usually includes "locally" (Acceleration in a flat space-time is locally indistinguishable from gravity).
So everyone more educated than me already knows this. I found this discussed in a Sabine Hossenfelder video (link below). And another way to do it is to have a tall spaceship - gravity-induced weight will be lower at the top of the spaceship than at the bottom, but acceleration-induced weight will be the same.
ua-cam.com/video/vng2-R64rAY/v-deo.html
5:00 isnt that called G-Force, rather then Gravity? When you sayd, when you egnite the engine on a Spaceship. I mean Gravity comef from an Object with just big mas, and G-Force is what YOUR BODY does to the ship.
EDIT: 13:20 looks like i just had to wait so Neil confirms me lol.....
The ISS is not in pure freefall. It is interacting with Earth's atmosphere. That results in a very tiny deceleration, right? (I guess one could include light from the Sun and solar winds.) I don't know what NASA means by micro gravity, but would that tiny effect from the atmosphere result in a micro gravity?
Also, you cannot accelerate to the speed of light (which of course you know), yet you gave a finite period of time. Also, did that calculation account for relativistic mass?
If it sounds like I am being picky, I am following your lead, for example, when you complained about Cronkite or NASA calling it microgravity.
12:35 Does anyone know where is the original video for this experiment?
ua-cam.com/video/kDmb-AVTM6k/v-deo.html
There is a reason why NASA uses the term "microgravity" as opposed to "zero-g", which usage becomes clear once you understand the context within which it is most appropriately used: research.
Imagine, for example, a Get Away Special payload containing science experiments attached to the side wall or adapter beam in the shuttle's cargo bay. Certainly, one would like to have those experiments performed in an idealistic, pristine, zero-g environment. But in reality is that achievable? As it turns out, no.
Even without the shuttle's OMS firing, there are plenty of events within the shuttle (and some without) which can cause vibrations and accelerations, i.e. forces, throughout the shuttle's frame (e.g., the activities of the astronauts and the shuttle's internal systems, drag). And any experiment attached to the shuttle's frame (i.e., not floating around in the interior) will feel these forces.
Typically, the amplitude of these forces tend to be on the order of 10^(-6) g's, hence NASA's very specific use of the term micro-g. For example, the paper linked to below by Darin Gates of Bristol Aerospace mentions the in situ accelerometer data of their G-521 payload as measuring peak forces of about 140 micro-g. And although I don't have the data off-hand, this seems consistent with what we measured on the payloads I was involved with.
Although the term micro-g is, perhaps, sometimes used casually and cavalierly to talk about the space environment generally, its fundamental, primary, and important usage is with regards to the characterization of the environment within which a scientist can expect their research to be carried out when performed aboard an orbital space platform such as the shuttle or ISS.
ntrs.nasa.gov/api/citations/19940014697/downloads/19940014697.pdf
Dear Dr. Neil deGrasse Tyson, I LOVEEE to hear and talk about science and space, appreciate everything that YOU and your hosts do!
Wondering about misleading microgravity, just maybe NASA thinks about microgravity as the condition the body is in - "0" G, but when the body acts on it self with its own gravity? Like a water drop, every time its in "0" G forms a sphere, because of its own mass and gravity acting on its self (e.g. microgravity) ;) am I right?
Water droplets become round in "0" G not due to own microgravity but due to water molecules attracting each other through electric charges within the molecules. That is how most substances on human size scales stay together. Gravity is much too weak of a force to attract small masses compared to electromagnetic forces. Gravity is about 20 orders of magnitude weaker than electromagnetic forces. Gravity only becomes significant when there are huge masses involved.