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Not common sense compatible


RichP714

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Some of my favorite things contradict 'common' knowledge.  e.g. if you remember from school that the angle of incidence equals the angle of reflection,  then you might think otherwise..........

 

 

 

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58 minutes ago, Nahash5150 said:

So now the question is...

 

Did we actually land on the moon or was it staged?  :D

 

 

Yes.

 

As atmosphere gets thinner, a rocket engine's thrust plume spreads wider and vertical force is diminished.  Some SSTO (single stage to orbit) vehicles get around this, and the aerospike engine can continuously vary it's plume shape.

 

Back then the Rockets had to be staged. one nozzle shape for higher atmospheric pressures, another for vacuum and a couple for in between

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2 hours ago, Nahash5150 said:

So now the question is...

 

Did we actually land on the moon or was it staged?  :D

 

The best argument  I've heard against such an assertion is that, had America staged a moon landing the Russians would have been the most motivated and well equipped to debunk such a hoax, since they wanted to get there first.

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There's a lot of heated back and forth about it, that is for sure. But then again, we're arguing whether the earth is round or flat.

 

However it does appear that space is flat, and the expansion is accelerating, so no big crunch.

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Anecdote: 

 

Hollywood seems to miss the science behind this..., recall Superman's landing on the farm..., that scene showed an acute angle of incidence, (not to mention a 45 degree left-turn upon reentry??) then a very long impact crater.  (They did get a flash, at impact, though.)  The impact crater comes into the picture at about 1:00 on this video, then a better view again at 3:00 in.  Sad to note that they could have got it right, and educated..., but, no.  The NASA, Ames, Lose Alamos seminal research pre-dated this movie.

 

 

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On 1/30/2019 at 7:07 AM, AndrewJohn said:

Anecdote: 

 

Hollywood seems to miss the science behind this..., recall Superman's landing on the farm..., 

 

Right on!  That's a perfect example.  It's more likely that any given individual will attempt to incorporate an unfamiliar phenomenon into their experience by trying to fit that phenomenon into their existing framework,  rather than do the work of comprehending the principles behind the phenomenon (which would expand their existing framework).  The square peg approach, and it often is incomplete.

 

In your example above the Astronomer and the Animator are both gifted; the Astronomer realizes an esoteric aspect of what is being modeled that the Animator is probably ignorant of.

 

If you think of the transaction as a conservation of momentum at very high velocity, it becomes more clear that the conversion of the falling mass into kinetic energy will have a spherical wavefront, except at extreme grazing angles

 

That's always a danger when trying to understand something with incomplete information

Edited by RichP714
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57 minutes ago, RichP714 said:

That's always a danger when trying to understand something with incomplete information

 

Thus the whole reason for science, when applied properly.

 

It was interesting to see Pluto's surface with minimal craters. Supposedly, there's still quite a bit of geological activity there, including cyclic ice formations.

 

I always thought that other moons in the SS that have much more interesting craters than the Moon, like Mimas (Saturn). The 'Death Star'...

 

Image result for huge craters on moons

 

It doesn't appear there was any orbit on that one!

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18 minutes ago, RichP714 said:

 That's a different kind of flat than the flat earthers are talking about

 

Truly! It only means that space-time cannot hide itself based on location (at least on a large scale). However, if the earth was flat, by comparison, then we should be able to see every city from where we stand, given enough elevation and magnification.

 

Admittedly, the 'universe is flat' may only be an indication that it is much larger than we think.

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21 hours ago, Nahash5150 said:

if the earth was flat

 

My question for the flat earthers is why do we have time zones? 

 

21 hours ago, Nahash5150 said:

the 'universe is flat'

 

I don't understand this. If it all started with a big bang and little to no resistance, wouldn't the universe expand spherically unless the big bang was a shaped charge :D

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1 hour ago, Sk1Bum said:

I don't understand this. If it all started with a big bang and little to no resistance, wouldn't the universe expand spherically unless the big bang was a shaped charge :D

 

Two different notions of 'flat' are at play here; for the flat earthers it's the physical shape of an object (spherical or planar) within a given 'space' (usually they are talking about Euclidian space (the typical X,Y and Z, in a cartesian grid, that we are familar with)

 

for cosmologists, it's the 'shape' of the space itself, and by 'shape' they are not talking about appearance, they are talking about if that space behaves as if it is open, closed or flat

Curvature

Shape of the Universe

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@Sk1Bum I remember studying physics when I was in grade school and the notion of the curvature of space was always elusive. My tutors, like Isaac Asimov, tried to explain it but it didn't make much sense because we can't visualize it in 3+1 dimensions. However, we can abstract it in 3 dimensions like the surface of sphere. For instance, we know that the earth is a sphere because if we are at sea, land masses appear and disappear out of view. This indicated that our location relative to another object is subject to a curvature that causes it to become invisible because we can't see though the water or earth. With Space, it is the same idea. However, space appears flat because we can see objects, and energy, all the way back before there were stars. In fact, we can still see the first light, often called the 'Cosmic Background Radiation'. Essentially, if space was curved, we'd expect a horizon beyond which we cannot see. We'd see only signatures, or maybe reflections of objects, but not the objects themselves. The 'flatness' of space reveals that our relative locations, on a grand scale, experiences little distortion across billions of light years of distance and time, even all the way back before galaxies and stars existed.

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Thanks Greg, that helps. I took a 100 level astronomy three years ago, and we discussed cosmic background radiation. We didn't discuss extra dimensions because the class didn't require algebra as a prerequisite. We didn't discuss the flatness of space.

 

That was the single most enjoyable class that I've taken.  Maybe that was because it was the only class I took that semester where I wasn't 20+ years older than the instructor. :D 

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6 hours ago, Nahash5150 said:

For instance, we know that the earth is a sphere because if we are at sea, land masses appear and disappear out of view. This indicated that our location relative to another object is subject to a curvature that causes it to become invisible because we can't see though the water or earth. With Space, it is the same idea. However, space appears flat because we can see objects, and energy, all the way back before there were stars. In fact, we can still see the first light, often called the 'Cosmic Background Radiation'. Essentially, if space was curved, we'd expect a horizon beyond which we cannot see. We'd see only signatures, or maybe reflections of objects, but not the objects themselves. The 'flatness' of space reveals that our relative locations, on a grand scale, experiences little distortion across billions of light years of distance and time, even all the way back before galaxies and stars existed.

 

dynamic horizons typically indicate curvature, yes, but the universe (commonly agreed upon as being 'flat') has a limit to it's observable contents; which is a type of horizon.  Some of the universe is now far enough distant from us that its light will never reach us, even though it's said to be flat.  Local and global geometry at play.  e.g. when mass interacts with space it distorts it (gravitational lensing) so space can be locally curved, yet globally flat.

 

Those lumps in the CBR?  distortion!

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1 hour ago, RichP714 said:

 

dynamic horizons typically indicate curvature, yes, but the universe (commonly agreed upon as being 'flat') has a limit to it's observable contents; which is a type of horizon.  Some of the universe is now far enough distant from us that its light will never reach us, even though it's said to be flat.  Local and global geometry at play.  e.g. when mass interacts with space it distorts it (gravitational lensing) so space can be locally curved, yet globally flat.

 

Those lumps in the CBR?  distortion!

 

Yes, but the local distortions are tragically small compared to the whole, not unlike hills and valleys on the surface of the earth, although far smaller a ratio by comparison. It's flat as far as we know, because if it is curved, then the universe would be much larger than we can see, and I don't think anyone has discounted that. For all practical purposes, the observable universe is flat, and that's 13.8 billion light years in every direction.

 

Distortion everywhere indeed. The universe has a tube transfer function. :--D

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20 hours ago, Nahash5150 said:

For all practical purposes, the observable universe is flat, and that's 13.8 billion light years in every direction......

 

Well, I'm not counting, but those that do say it's about 46 billion light years.  (remember when you were a kid, and there was evidence for stars within the universe being older than the universe itself? funny in hindsight). I might be missing something, but I don't see the connection to whether the existence of a horizon is evidence of flat space

 

 

20 hours ago, Nahash5150 said:

It's flat as far as we know, because if it is curved, then the universe would be much larger than we can see, and I don't think anyone has discounted that. 

 

I'm confused again; the Universe is, as far as is known, larger than we can 'see'; by that logic, 'larger than we can see' implies a horizon, and a horizon (in intrinsic space) implies curvature.  The statement quoted reads as "It's flat because it's curved."  It's likely best to think in terms if extrinsic space, rather than attempt to force a characteristic of intrinsic space upon it.

 

 

20 hours ago, Nahash5150 said:

Yes, but the local distortions are tragically small compared to the whole, not unlike hills and valleys on the surface of the earth, although far smaller a ratio by comparison.

 

Not necessarily; e.g. if you stand at the event horizon of a black hole, light waves curve such that you can see the back of your own head.  That's not a small perturbation of space.  From a distance, you (according to some research) can see the portion of the accretion disc that is behind the black hole.  Gravitational lensing let's us see things that aren't even there; and both are not small phenomenon.

 

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On 2/9/2019 at 6:11 PM, Nahash5150 said:

 

Yes, but the local distortions are tragically small compared to the whole, not unlike hills and valleys on the surface of the earth, although far smaller a ratio by comparison. It's flat as far as we know, because if it is curved, then the universe would be much larger than we can see, and I don't think anyone has discounted that. For all practical purposes, the observable universe is flat, and that's 13.8 billion light years in every direction.

 

Distortion everywhere indeed. The universe has a tube transfer function. :--D

 

This may more clearly demonstrate that trying to square peg Euclidian attributes into the round hole of space-time doesn't work.  

 

 

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@RichP714  I personally never claimed the universe was flat, nor did I claim it was curved - I merely communicated what the prevailing theory is and how physicists themselves explain it.

 

On 2/10/2019 at 4:02 PM, RichP714 said:

Well, I'm not counting, but those that do say it's about 46 billion light years.  (remember when you were a kid, and there was evidence for stars within the universe being older than the universe itself? funny in hindsight). I might be missing something, but I don't see the connection to whether the existence of a horizon is evidence of flat space

 

I used the age scale, you are using the euclidean distance scale.

 

On 2/10/2019 at 4:02 PM, RichP714 said:

I'm confused again; the Universe is, as far as is known, larger than we can 'see'; by that logic, 'larger than we can see' implies a horizon, and a horizon (in intrinsic space) implies curvature.  The statement quoted reads as "It's flat because it's curved."  It's likely best to think in terms if extrinsic space, rather than attempt to force a characteristic of intrinsic space upon it.

 

Again it's not my logic here...the point is if it is curved it is huganomious! For practical purposes, it is believed to be flat. If it is not flat, then it is much, much bigger than we expect.

 

On 2/10/2019 at 4:02 PM, RichP714 said:

Not necessarily; e.g. if you stand at the event horizon of a black hole, light waves curve such that you can see the back of your own head.  That's not a small perturbation of space.  From a distance, you (according to some research) can see the portion of the accretion disc that is behind the black hole.  Gravitational lensing let's us see things that aren't even there; and both are not small phenomenon.

 

By scalar comparison, a black hole is infinitesimal compared to space-time. There's no meaningful ratio between the two, in fact. That is not to say the phenomenon of space-time can't be explored more dramatically by observing and thinking about black holes, only that by order of actual scale, their disturbances are not expected to influence the curvature of space-time, no more than Mount Everest defines the shape of the Earth, even though one could fall to their death from its summit.

 

About the video...

 

Yeah, I read Machio Kaku's 4th Dimension too, and Flatland. It's rather pointless to get that deep here...

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2 hours ago, Nahash5150 said:

@RichP714  I personally never claimed the universe was flat, nor did I claim it was curved - I merely communicated what the prevailing theory is and how physicists themselves explain it.

 

 

Your first post re universal shape said

Quote

However it does appear that space is flat, and the expansion is accelerating, so no big crunch

 

This conflates two contradicting ideas, and began my attempt to get your contributions to this topic back on track.  Remember that, in ALL of this, I see my self more as a line judge, trying to keep a topic on course, rather than an all knowing being.  As such, I was trying to illustrate where your comprehension of flatness, expansion and the idea of a non-Euclidian space deviates from what those that study these effects are actually saying.  Your statement above is more in line with the 'steady state' theorists than what has followed since, and I was attempting to re-direct away from those outdated ideas.

 

 

2 hours ago, Nahash5150 said:

I used the age scale, you are using the euclidean distance scale.

 

 

I am not in any way referring to Euclidian geometry, scales or distances; yes, you are using an age and conflating it with an idea of curvature, arriving at an erroneous conclusion (when you started talking about horizons).

 

 

 

2 hours ago, Nahash5150 said:

Again it's not my logic here...the point is if it is curved it is huganomious! For practical purposes, it is believed to be flat. If it is not flat, then it is much, much bigger than we expect.

 

 

The flatness of a Non-Euclidian space has nothing to do with its size.  It's possible for a theory of  universal geometry to be so completely curved that it is not much larger than the earth;  IN such a universe, a 'flat' earth would appear spherical, so NO,  curved space does not imply huganomious-ness.  I wasn't indicting your logic, rather I was trying to correct your interpretation of other's frameworks

 

2 hours ago, Nahash5150 said:

By scalar comparison, a black hole is infinitesimal compared to space-time. There's no meaningful ratio between the two, in fact. That is not to say the phenomenon of space-time can't be explored more dramatically by observing and thinking about black holes, only that by order of actual scale, their disturbances are not expected to influence the curvature of space-time, no more than Mount Everest defines the shape of the Earth, even though one could fall to their death from its summit.

 

 

Researches talk about 'Super Massive' black holes all the time.  They know what they mean (that the observable size of a black hole has no real definition, as it exists as a point like rupture in the fabric of space-time).  Thus, there is no scalar comparison between a non-defined point in space-time and the observable universe.

 

You were talking about horizons and topology when you brought the idea that a hill's existence doesn't negated the idea of a much more curved horizon, and that comparing scales of curvature was somehow applicable.  I mentioned how this is incorrect, and you brought it up again in your riposte.

 

2 hours ago, Nahash5150 said:

Yeah, I read Machio Kaku's 4th Dimension too, and Flatland. It's rather pointless to get that deep here...

 

 

Well, I wasn't talking about either of those concepts, but I agree; I've thrown out ideas for this science 'club' for about a month, and there's no traction here.

 

Did you get any meaningful data regarding sound rooms?  I hope it was worthwhile in that sense at least.

 

an observation:  I mentioned to you when we were setting up this club that crippling the 'recently posted' code by eliminating sound room additions kinda sucked.  I still feel this way.  Yes, there are other ways to promote a sound room (e.g. via a 'digest' post as I've done every Sunday), but you don't get a feeling at ALL for engagement.  The room itself has overall view and reply stats, but they are comprehensive, including ALL dates of a topic.  For instance, a topic may have very intense interest at first, but then nothing.  Another topic may have the same overall number of engagements, but over the course of several weeks.  There's currently no way to determine engagement frequency, other than writing down how many reads for each topic for each day and then subtracting from yesterday's data.  The 'recently posted' list would allow this if it wasn't crippled.

 

Remember that, in ALL of this, I see my self more as a line judge, trying to keep a topic on course, rather than an all knowing being. 

 

 

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