Science Discussion

General
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On the topic of spin gravity. The spin gravity effects show in the TV show The Expanse were quite good. Below, a cop pours some whiskey into a glass whilst on a spinning asteroid belt station ring. Demonstrating the Coriolis Effect.

From the TV show.

Since Ceres (space station ring) has been spun up to provide 0.3 g at the rim, the Coriolis effect makes things act peculiar. Spins at 0.0239 rotations per minute, about 1175 m/s at the spin equator or about x2.3 Ceres escape velocity.
Since Detective Miller was born and raised on Ceres he knows how to fill a glass with the Coriolis effect. Since he drinks too much he especially knows how to fill a glass with moss whiskey.

Source - of image and text

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Yup!

There are two causes of time dilation in General Relativity: Relative velocity, and acceleration. A rotating object experiences a centripetal acceleration in addition to its velocity of rotation, and so experiences both kinds of time dilation.

Kind of, yes, but not in the way you’re probably thinking. The warping of space-time is caused by differences in local energy density. The kind of energy we usually think of with the stretched sheet analogy of space warping is mass (mass can be considered just one form of energy, as commonly described using the equation E = mc2), but all energy does this. A rotating body has more kinetic energy than a non-rotating body with the same linear velocity, and so will produces a larger “dent” in space-time.

Mind you, this is effectively the equivalent of saying that the rotating body has more mass than the non-rotating body (just like we usually talk about bodies with higher linear velocities having more mass; it’s just a different way of thinking about the same thing. So, maybe it is in the same way you’re probably thinking, after all?).

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Dark Mercury’s ‘pencil lead crust’ revealed
Nice photo too.

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Here is a question for Kichae; Ok in the beginning everything was a small point then the Big Bang. I’m assuming were not going the speed of light away from the other side.
If so why can’t we see the other side?

Explain this in a way I can understand. (that may involve coming up with new medical procedures)

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I’ll take a stab at it, then Kichae can come in and correct everything.

We have no idea where the point of origin of the universe is. The observable universe - the extent of the universe that we can actually see due to the time the farthest light has taken to reach us - appears to expand outwards in all directions. We cannot determine from this any point from which all matter is radiating. Even if we could figure that out, the boundaries of the observable universe would prevent us from seeing it and thus anything beyond it.

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I think the simplest explanation is that over an exorbitantly large time, stars that have expanded to the other side of “the big bang” are now so far away that any light emitted hasn’t reached us yet, and that is the key point really. The light we have yet to see was emitted from stars a long time after “the big bang” event.

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I seems a bit like you’re assuming the big bang occurred at a place; that it was an explosion of tightly packed stuff into a pre-existing, empty space. That’s not what the big bang model says.

Instead, the big bang was a rappid expansion of space. Whether that is all of space, or just some local pocket of space is still an open question in GR cosmology, but either way we start with much, much less space than we have today, and, as a result, the universe was a much hotter, much more dense place. It was so hot dense, in fact, that light was only able to travel was basically zero.

Then, for some reason, the space between stuff began to grow. For people who adhere to hyperflationary theory, it grew so quickly that space expanded at many, many times the speed of light. This would have taken those light travel zones from being nanometres across to be several meters across. The distance light can travel in this new, expanded universe has grown to be 10s of centimetres, and the 10s of centimetres across region that has the location of present day Earth at its centre is our observable universe.

For those that don’t adhere to hyperinflation, this same thing happened, but more slowly, meaning the 10s of centimetres across region represents a larger chunk of the stuff at the beginning.

The universe continues to expand at such a rate that the horizon region is shoved away from us at somewhere near the speed of light. Maybe a little more, maybe a little less. Regardless, we never see much beyond those original few 10s of centimetres. Over the billions of years that have followed, the distance to that horizon has grown to some 40+ billion light years away. And remember that that’s the stuff at the distance that the universe became opaque at, so it must looks like a glowing haze (because that’s all it was at the time that light left it).

And, of course, the expansion of the universe has been accelerating for several billion years now, so the horizon actually is expanding away from us at greater than the speed of light today. So things that were once within our field of view aren’t anymore (though, to date, the stuff that we can’t see anymore is just glowing hazy gas).

So, in short, we’ve never been able to see everything, and we see a little bit less every day.

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I’m looking forward to what the up coming James Webb telescope will start to reveal to us in its first years in space. I really hope they have teams on teams on teams checking the mirror this time. From what I gather its going to be too far out to fix any problems manually.

Still, it will only see what it can, far from everything. The universe will hold onto most of its mysteries for a long long time yet.

But I am looking forward to seeing its first images. I wonder what they have planned to look at in its first post test operations, so much to chose from to point it at. Maybe they will try the same things Hubble first looked at to make a quick comparison. That’s what I would do, to show the public how much better this telescope is with side by side images (Hubble/James Webb)

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You can’t necessarily compare the Hubble and JWST. They perform entirely different function and as such were specialized to do those functions. Hubble was made to take long exposures in visible and near infrared(I think, I’m tired and too lazy to google so you can if you’re curious). This means that it can see things about as your human eye would see it, just with longer exposure times that allows more photons to hit the detector, which creates a brighter image. That ability, combined with the lack of chromatic abberation that telescopes on the ground have to deal with, is what gives hubble its ability to take such pretty pictures. Hubble is limited in it’s 5m however, and recent noise reduction techniques and larger mirror sizes(30m+) for ground telescopes is turning the tables against space based telescopes due to their cost to build and launch.

JWST on the other hand is purely in the deep Infrared spectrum of light. Afaik it can’t even take visible light photos. What makes IR special is that all* objects radiate heat in infrared. This allows us to take long exposure IR photos specializing in searching for objects. The atmosphere emits and reflects IR which makes groundbased IR telescopes impossible. I believe it’s mission is to be a IR based planet hunter that will take the first photos of exoplanets. These photos won’t be in visible light, they will just be blobs of heat. What I find incredible is JPL wants to find tiny blobs of heat next to a fusion reactor blob of heat and expect to filter that out but that’s why astronomy continues to fascinate me.

In short, any picture hubble takes will be incomparable to any pictures JWST takes simply because they are designed to function in different wavelengths. Different wavelengths of light = different types of pictures.

*If any object is <3.4 K (CMB,pretty sure that’s its temp) it will appear dark in the eyes of an IR telescope, above that and you will appear bright.

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It’s always astounded me how they can precisely detect, identify and measure things from what to normal people seem like blurry images and noisy data.

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Fourier is fascinating and magical and I suspect has a lot to do with filtering most data. Seeing dips in luminosity from a transiting planet is one thing, but detecting tiny signal next to the HUGE signal which to my intuition would seem below the noise threshold is what takes the cake.

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http://www.nature.com/news/who-ordered-that-1.19514?_utm_source=1-2-2
What are the chances they did catch the biggest thing to happen in particle physics this side of WWII? It does sound a bit too good to be true, but then again, gravitational waves? Nah…

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But it’s not confirmed were as gravity waves have been.

“If the particle exists, the implications would be enormous.”

I shy away from “if”.

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The gravity wave detection isn’t confirmed. It’s just a really strong signal from a single experiment. Two separate detectors, yes, but one experiment. It hasn’t been reproduced, neither by the original team, nor by an I dependent team.

The new particle has been detected by two I dependent teams, but the signal is weak, and the detection is indirect.

So, they’re both in the wonderful grey zone of “more research is required”.

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Thanks I’d rather be corrected then wrong.

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Gravity waves, so we’re in the early stages of the next phase in understanding gravity. Can anyone speculate on how this will eventually lead to licking the problem of creating artificial gravity plating for our future space craft. I use the term ‘gravity plating’ as we all know what is basically means.

I am a firm believer that once this problem ‘is’ ‘can’ be licked, then it will mark a massive step forward in allowing humans to venture further out into our own solar system, asteroid field and eventually the Kuiper belt (in the far future).

Gravity plating, or its real world physical discovery what ever it actually will be, along with something beyond rocket engines for deep solar system large human carrying space craft I think will be two major steps forward. Although I’m fairly sure the engine will come a long time before the ‘gravity plating’. Along with life science systems of course and radiation shielding.

Being a very frustrated futurist, I’m only hopeful to see a successful manned mission/s to Mars in my life time. And also some small Moon and maybe Asteroid outposts, if I live to 100 years or so.

Will this new proof of gravity waves, eventually lead to gravity plating. And will this need to be discovered in orbit in zero gravity. Or could something like this be created on earth. How much extra power would it require to work on earth as compared to in zero gravity (if power in the conventional term is actually required for it). For example, some inventor demonstrates it to NASA by running and jumping up onto a ‘gravity plate’ mounted on a wall. Would one be able to stand up, or maybe at least sit or kneel on this gravity plate ‘on earth’.

I realise some of this is still a little (a lot) pseudo-science at this stage of our understanding of how to create real artificial gravity in such a way it can be used to line the corridors and compartments of space fairing craft. And that also its zillions of uses for other things such as lifting large loads… and maybe one day like in ‘Interstellar’. But small steps first. Gravity plating to allow use to explore in human comfort would be a giant step forward. I’m sure by then the life systems will also be in such an advanced state to also support long duration space flight in some comfort.

Frustrated, and a futurist for sure I am. Surely now we have this proof, its not so much a dream any more. is it.

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In short, gravity waves != negative mass/energy which is what would cause repulsion.

We do have the capability of artificial gravity already, just in the form on centripetal acceleration(spinning objects). The physics and engineering behind artificial gravity of that nature is a lot easier…

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Well yes we have spin gravity and the other types, as demonstrated in the great TV show ‘The Expanse’. Spin and acceleration gravity ‘will do’ for a time but its not going to be too pleasant an experience long term as demonstrated in the TV shows imagining of the day to day coping with this form of gravity. Even more so in our real life first steps into large spin gravity sections of space craft. Maybe the first manned Mars mission, maybe sometime after. With large ‘London Eye’ sized rotating sections at 3 to 4 rotations per minute to generate 1G or thereabouts. Climbing in and out of the spinning section is going to make astronauts feel a little nauseas.

Although I’ve seen those articles reporting NASA trying to narrow down micro-spin gravity bursts in smaller set ups and for a shorter time each day where you lay down. Good for the body in it will allow easier travel in space, but still not great for sitting there and eating and drinking and sleeping in comfort.

Its gravity plating I’m really trying to get a grip of when we will know we’re on the path to that discovery. I suspect its still far off into our future, maybe next century and beyond.

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I haven’t seen the show, and while I have heard good things about it, I’m not inclined to take the experiences of a TV show to demonstrate the realities of artificial gravity. The real answer is that frankly we do not know how it may be for an astronaut. Maybe it’s tolerable, who knows. We don’t because no one has even sent a rotating hab to orbit yet.

Note: I’m not trying to disagree with you. I share many of your beliefs and the reason I went into physics/engineering is so that I can try to help(not alone) make some of the future technologies we dream of a reality. It doesn’t just happen overnight but it’s the product of hours and hours of creating failed prototypes and testing to make sure things work. I can feel the frustration through your text but things are changing. Not Anti-grav drives in a decade changing, but the slow methodical change that has been needed in the space industry. I suspect the next 20 years hold many unpredictable surprises for us in the field.