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i've never claimed general relativity is wrong.
i do believe in newton's law of universal gravitation though.
On September 14 2016 06:39 oBlade wrote:Show nested quote +On September 14 2016 03:13 JimmyJRaynor wrote:On September 11 2016 11:20 LegalLord wrote:
Building a base on the moon first would be a much more sane idea. The optics aren't as great - we've already been there so it's not as "cool" a mission - but from the perspective of tackling realistic goals that could be performed quickly and yield useful results, it's a good one. its been 40+ years since a human was 500+ miles off the earth's surface. we still do not know how the circulatory system, inner ear, and lymphatic system will react when the force of gravity is very low for an extended period of time. a mission with goals such as this will be make for a great research platform to answer these questions. another big concern occurs when gravity is pulling fairly equally in 2 different directions at the same time for an extended time period. how does that impact the heart's function? the lymphatic system etc. there could be dozens of other processes in living organisms that rely on a single source of gravitational pull close to the earth's force of gravity. Do you understand that weightless people don't stay right-side up?
if really does not matter how they are standing. and "apparent weightlessness" says nothing about the gravitational forces impacting the object.
what matters is that a single source of gravity ( the earth ) accounts for 99.99+% of all the gravitational forces impacting any living thing on earth or on the space station.
now when the living thing in question has one source of gravity accounting for 85% of the forces acting on them .. and then another gravitational force in a different direction is simultaneously pulling them in another direction... how will this impact the flow of fluids in your inner ear, heart, lymphatic system.
what happens when a living thing is experiencing only 20% of the gravity their various circulatory systems are accustomed to for many, many months. will the human lymphatic system continue to operate with 100% efficiency? if not, what problems will arise due to the decreased efficacy of the lymph system circulation.
only research and actually performing real experiments under real conditions will we have the answer to these questions. and then.. whatever problems arise. how will they be solved.
its a tough problem. whoever solves it.. will be a hero.
even the differences between humans living at high altitudes and sea level are substantial and numerous. there are thousands of small differences that would kill a sea level human trying to live at high altitudes right here on earth. Research in this area did not begin until the 1960s.
https://en.wikipedia.org/wiki/High-altitude_adaptation_in_humans
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On September 14 2016 06:56 JimmyJRaynor wrote:i've never claimed general relativity is wrong. i do believe in newton's law of universal gravitation though. Show nested quote +On September 14 2016 06:39 oBlade wrote:On September 14 2016 03:13 JimmyJRaynor wrote:On September 11 2016 11:20 LegalLord wrote:
Building a base on the moon first would be a much more sane idea. The optics aren't as great - we've already been there so it's not as "cool" a mission - but from the perspective of tackling realistic goals that could be performed quickly and yield useful results, it's a good one. its been 40+ years since a human was 500+ miles off the earth's surface. we still do not know how the circulatory system, inner ear, and lymphatic system will react when the force of gravity is very low for an extended period of time. a mission with goals such as this will be make for a great research platform to answer these questions. another big concern occurs when gravity is pulling fairly equally in 2 different directions at the same time for an extended time period. how does that impact the heart's function? the lymphatic system etc. there could be dozens of other processes in living organisms that rely on a single source of gravitational pull close to the earth's force of gravity. Do you understand that weightless people don't stay right-side up? if really does not matter how they are standing. and "apparent weightlessness" says nothing about the gravitational forces impacting the object. what matters is that a single source of gravity ( the earth ) accounts for 99.99+% of all the gravitational forces impacting any living thing on earth or on the space station. now when the living thing in question has one source of gravity accounting for 85% of the forces acting on them .. and then another gravitational force in a different direction is simultaneously pulling them in another direction... how will this impact the flow of fluids in your inner ear, heart, lymphatic system. what happens when a living thing is experiencing only 20% of the gravity their various circulatory systems are accustomed to for many, many months. will the human lymphatic system continue to operate with 100% efficiency? if not, what problems will arise due to the decreased efficacy of the lymph system circulation. only research and actually performing real experiments under real conditions will we have the answer to these questions. and then.. whatever problems arise. how will they be solved. its a tough problem. whoever solves it.. will be a hero. even the differences between humans living at high altitudes and sea level are substantial and numerous. there are thousands of small differences that would kill a sea level human trying to live at high altitudes right here on earth. Research in this area did not begin until the 1960s. https://en.wikipedia.org/wiki/High-altitude_adaptation_in_humans
We have 40 years of research into exactly what happens to people in microgravity. We're not parking a space station at the Lagrange point between the Earth and moon for decades just because you don't know what a frame of reference is.
There is no evidence that the inner ear or heart can detect or rely on the curvature of spacetime. If they did, they would react to being upside-down.
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United Kingdom13775 Posts
Studying the effects of living on the Moon would be a pretty worthy endeavor though.
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PARIS — Virgin Galactic announced a contract for four launches of satellites for a planned communications constellation.
The contract, with Australian company Sky and Space Global, covers launches of multiple satellites on each of four LauncherOne missions.
Terms of the deal were not disclosed, but Virgin Galactic has previously offered LauncherOne missions for less than $10 million each.
The launches will be the first LauncherOne missions to go into low-inclination orbits, with the rocket’s carrier aircraft, a Boeing 747, taking off from an airport not disclosed in the announcement.
“Having a 747 as our flying launch site means that LauncherOne can tailor each mission to suit each customer,” Virgin Galactic CEO George Whitesides said We’ve seen an enormous level of commercial and governmental interest in launches that can reach equatorial orbits without having to pay the large performance penalty associated with transfer orbits. We’re very excited to have this agreement in place now with a great company like Sky and Space Global to deliver their satellites to orbit reliably, affordably, and flexibly.”
“We are thrilled to partner with Virgin Galactic on our exciting missions and LauncherOne’s first low inclination launches” Sky and Space Global CEO Meir Moalem said in a statement. “Just as we value purposeful innovation and customer service, Virgin Galactic shares our values and our vision for how communication can fundamentally improve lives. We have an ideal partner in Virgin Galactic’s LauncherOne and its operational flexibility and are excited to work together to change the world for good.”
Source
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On September 14 2016 07:54 oBlade wrote:
We have 40 years of research into exactly what happens to people in microgravity. We're not parking a space station at the Lagrange point between the Earth and moon for decades just because you don't know what a frame of reference is.
There is no evidence that the inner ear or heart can detect or rely on the curvature of spacetime. If they did, they would react to being upside-down.
no we don't have "40 years of research into exactly what happens to people in microgravity."
and i'm not talking about microgravity any way. i'm talking about a continuum of varied gravitational conditions that change daily as one is hurdling through space at high speeds towards another planet for months on end.
the gravitational conditions at sea level and in the space station remain the same. furthermore, there is 1 single source of gravity and its only 10% different between the space station and earth.
humans have never been at a lagrange point for an extended period of time. the only way to know how the fluid dynamics within the a human's circulatory systems change is to put the human out there and see what happens.
same applies to being at a point where gravity is very low in general.
the lymphatic systems and the cardiovascular systems will need to be rigorously tested.
there is not one expert in Cardiovascular fluid dynamics who believes the science that has been developed in the field will apply to humans flying through deep space in constantly changing gravitational conditions. not one.
On September 14 2016 07:54 oBlade wrote:
We have 40 years of research into exactly what happens to people in microgravity. We're not parking a space station at the Lagrange point between the Earth and moon for decades just because you don't know what a frame of reference is.
matter does not care what a frame of reference is. the acceleration of matter is influenced by force.
a=f/m
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United States24685 Posts
On September 14 2016 06:56 JimmyJRaynor wrote:i've never claimed general relativity is wrong. i do believe in newton's law of universal gravitation though. Show nested quote +On September 14 2016 06:39 oBlade wrote:On September 14 2016 03:13 JimmyJRaynor wrote:On September 11 2016 11:20 LegalLord wrote:
Building a base on the moon first would be a much more sane idea. The optics aren't as great - we've already been there so it's not as "cool" a mission - but from the perspective of tackling realistic goals that could be performed quickly and yield useful results, it's a good one. its been 40+ years since a human was 500+ miles off the earth's surface. we still do not know how the circulatory system, inner ear, and lymphatic system will react when the force of gravity is very low for an extended period of time. a mission with goals such as this will be make for a great research platform to answer these questions. another big concern occurs when gravity is pulling fairly equally in 2 different directions at the same time for an extended time period. how does that impact the heart's function? the lymphatic system etc. there could be dozens of other processes in living organisms that rely on a single source of gravitational pull close to the earth's force of gravity. Do you understand that weightless people don't stay right-side up? if really does not matter how they are standing. and "apparent weightlessness" says nothing about the gravitational forces impacting the object.
what matters is that a single source of gravity ( the earth ) accounts for 99.99+% of all the gravitational forces impacting any living thing on earth or on the space station.now when the living thing in question has one source of gravity accounting for 85% of the forces acting on them .. and then another gravitational force in a different direction is simultaneously pulling them in another direction... how will this impact the flow of fluids in your inner ear, heart, lymphatic system.what happens when a living thing is experiencing only 20% of the gravity their various circulatory systems are accustomed to for many, many months. will the human lymphatic system continue to operate with 100% efficiency? if not, what problems will arise due to the decreased efficacy of the lymph system circulation.
only research and actually performing real experiments under real conditions will we have the answer to these questions. and then.. whatever problems arise. how will they be solved.
its a tough problem. whoever solves it.. will be a hero.
even the differences between humans living at high altitudes and sea level are substantial and numerous. there are thousands of small differences that would kill a sea level human trying to live at high altitudes right here on earth. Research in this area did not begin until the 1960s.
https://en.wikipedia.org/wiki/High-altitude_adaptation_in_humans
I think some of the issues you raise are valid but a big part of why people are taking such serious issues with what you are saying is because of the bolded statement above. It doesn't really make sense.
You can model the effect of gravity on you (not going to get into a discussion of general relativity) by idealizing the Earth as a single point and its center of mass, or you can integrate the effect of each molecule of the Earth pulling on you in various directions (downward and at various angles, but obviously not upward). In either case, the net gravitational force you experience is the same.... a single arrow pointing towards the center of mass of the Earth. It does not matter that some of the components of that gravitational force are pulling you towards a lump of mass 100 km below Norway, and other components are pulling you in a different direction towards a lump of mass 350 km below Gary, Indiana... the physical effect on your body is a force pulling you towards the center of mass of the Earth.
If you place a person halfway between two identical objects, the person will experience no gravitational force. They will not get placed into tension.
All of the above is not as applicable when you are dealing with extremely large gravitational forces. If there is a 1 solar mass black hole 1 km to your left and another 1 km to your right, the centerline of your body feels nothing, but the sides of your body are more strongly influenced by the closer black hole, and your body is placed into tension (lethally so). Someone alluded to this earlier in the discussion.
However, for the types of space travel we are talking about, the black hole example I used is not applicable. Research into how gravity affects matter when originating from multiple bodies is not needed for the purpose of basic human health. How people are affected by zero gravity environments is also being studied very effectively in the ISS. How people would be affected by living in a 0.5 g environment might require more specialized research.
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here is the tip of the iceberg in research on cardiovascular fluid dynamics and gravity.
http://www.ncbi.nlm.nih.gov/pubmed/16101471
now keep in mind.. the lymphatic system is just as important and is a whole other subject of study.
a lot more research is required that includes actually putting real humans out there and seeing the actual impact.
On September 14 2016 08:42 micronesia wrote:
If you place a person halfway between two identical objects, the person will experience no gravitational force. They will not get placed into tension.
interesting point here...
according to fluid mechanics then the fluid of the inner ear will float anywhere randomly because no gravitation force is pulling it anywhere specific. the astronaut will experience the room as spinning. sounds rough.
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United States24685 Posts
Certainly there is room to do more research on the effect of alternative gravity environments... although reading that abstract... that post does not seem to be specifically in response to mine.
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On September 14 2016 08:52 micronesia wrote:
Certainly there is room to do more research on the effect of alternative gravity environments... although reading that abstract... that post does not seem to be specifically in response to mine.
what it addresses is the fact that research in cardiovascular fluid mechanics and gravity is ongoing and there are far more questions than answers.
if some space cowboy wants to fly off a million kms away and die of heart failure or have their immune system shut down.. be my guest. 
the people on the space station are experiencing gravitational conditions about 90% the same as earth. what happens when humans are in conditions vastly different for months.. no one knows.
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On September 14 2016 08:11 JimmyJRaynor wrote:Show nested quote +On September 14 2016 07:54 oBlade wrote:
We have 40 years of research into exactly what happens to people in microgravity. We're not parking a space station at the Lagrange point between the Earth and moon for decades just because you don't know what a frame of reference is.
There is no evidence that the inner ear or heart can detect or rely on the curvature of spacetime. If they did, they would react to being upside-down. no we don't have "40 years of research into exactly what happens to people in microgravity." and i'm not talking about microgravity any way. i'm talking about a continuum of varied gravitational conditions that change daily as one is hurdling through space at high speeds towards another planet for months on end.
There is no such word salad bullshit in real life. The human body does not care about speed. That you would write such an ill-informed sentence, reminiscent of people in the 19th century who thought the speed of a railroad would kill you, is telling of your ignorance. The solar system is hurtling through space at 230 kilometers a second. Every 12 hours your velocity changes by 2000mph as you spin around the globe first in one direction, then in the opposite. None of this means anything with respect to the health of your inner ear. Read a book.
When you send a person, or anything else. to another planet, it's in freefall the whole time. And there aren't gravitational potholes along the way.
On September 14 2016 08:11 JimmyJRaynor wrote:
the gravitational conditions at sea level and in the space station remain the same. furthermore, there is 1 single source of gravity and its only 10% different between the space station and earth.
If you were standing on top of a 500 mile building, that would come into play. Luckily the space men are in orbit.
On September 14 2016 08:48 JimmyJRaynor wrote:Show nested quote +On September 14 2016 08:42 micronesia wrote:
If you place a person halfway between two identical objects, the person will experience no gravitational force. They will not get placed into tension.
interesting point here... according to fluid mechanics then the fluid of the inner ear will float anywhere randomly because no gravitation force is pulling it anywhere specific. the astronaut will experience the room as spinning. sounds rough.
That happens to everyone who goes into zero-g.
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If I may give a physicist's viewpoint:
General Relativity is by far the best theory of gravity we have. 4 dimensional space-time curved by mass-energy solves so many problems that Newton's Universal Gravitation simply cannot (e.g. gravitational lensing). That said, it is a theory and we know (should be read as really really hope) that it is going to be replaced at some point by another theory. Quantum Gravity. So, we can't say with 100% certainty that living at a lagrange point would be identical to living in LEO. On the other hand, we can't say with 100% certainty that if I drop a ball it will fall at 9.8 m/s^2.
That's the parallel I wan't to draw here. The best theories we have suggest that if I drop the ball, it will fall at g. They also say that all unaccelerated reference frames are identical, and all of these are stable orbits which fall (ha-ha) under that category. So if you make a claim to the contrary, you're going to either need prove your idea is plausible (within or beyond general relativity) or have a way to test your claim with little marginal cost. So when you make claims about how human physiology might react in a Newtonian world, I just want to remind you that + Show Spoiler [Newton was wrong...ish] + and when we want to know how the world _actually_ is, the only tool of any use is 4 dimensional space-time.
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On September 14 2016 09:25 Mordanis wrote:If I may give a physicist's viewpoint: General Relativity is by far the best theory of gravity we have. 4 dimensional space-time curved by mass-energy solves so many problems that Newton's Universal Gravitation simply cannot (e.g. gravitational lensing). That said, it is a theory and we know (should be read as really really hope) that it is going to be replaced at some point by another theory. Quantum Gravity. So, we can't say with 100% certainty that living at a lagrange point would be identical to living in LEO. On the other hand, we can't say with 100% certainty that if I drop a ball it will fall at 9.8 m/s^2. That's the parallel I wan't to draw here. The best theories we have suggest that if I drop the ball, it will fall at g. They also say that all unaccelerated reference frames are identical, and all of these are stable orbits which fall (ha-ha) under that category. So if you make a claim to the contrary, you're going to either need prove your idea is plausible (within or beyond general relativity) or have a way to test your claim with little marginal cost. So when you make claims about how human physiology might react in a Newtonian world, I just want to remind you that + Show Spoiler [Newton was wrong...ish] + and when we want to know how the world _actually_ is, the only tool of any use is 4 dimensional space-time.
However, even in Newtonian physics the point JJR is making is pointless, because even in Newtonian physics if two opposite forces effect an object at the same spot, they just negate each other.
For some reason, JJR believes that gravity is superveryspecial and behaves in some weird way that we have absolutely no reason to believe it does, and that there is a big difference between "real" microgravity and gravity being negated by the centrifugal force on the ISS.
He has so far not given me anything that supports that claim.
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On September 14 2016 09:41 Simberto wrote:
For some reason, JJR believes that gravity is superveryspecial and behaves in some weird way that we have absolutely no reason to believe it does, and that there is a big difference between "real" microgravity and gravity being negated by the centrifugal force on the ISS.
lol, when a moon, space station, human floating on a space station etc.. orbits a planet there is 1 predominant force. the force of gravity pulling that planet towards the thing they are orbiting.
the only thing stopping the satellite from crashing into earth is its VELOCITY perpendicular to the force of gravity it is experiencing.
the force comes from 2 objects attracting each other according to
(Gm1m2)/(r^2)
there is no "centrifugal force on the space station".
the centripedal force is the only force acting upon a human in a space station... and its calculated according to the equation above.
its also the only force acting upon the space station itself.
as soon as the object lowers its velocity it will stop missing the earth and come crashing down because there is only 1 force.
so as soon as the space station falls below 7.66 km/s in velocity it'll come crashing through the atmosphere in a manner similar to the Skylab.
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for more insight about the gravitational forces impacting astronauts in and around the space station's level of orbit..
here is Michael Busch, Planetary Astronomer of the SETI Institute.
https://www.quora.com/Are-there-any-dead-astronaut-bodies-floating-around-in-space
"If an astronaut were to die in space, and their body to be floating around in low Earth orbit (e.g. at the altitude of Hubble or of the ISS or of Tiangong), the small amount of atmospheric drag that exists at that altitude would cause the corpse's orbit to degrade with a timescale of a few years. It would then burn up and disintegrate in the Earth's atmosphere."
if a dead body were floating around in space it would take years to slowly come back down to earth.
the only force acting upon the dead body is the earth's gravitational pull which is about 90% of the force of gravity to someone standing on earth. there is no "centrifugal force".
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You are describing the effects of atmospheric drag not anything relevant to the discussion at hand.
I can assure you that atmospheric drag doesnt have impact on the human circulatory system.
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To quote Jaws, they're going to need a bigger boat.
They're not doing propellant crossfeed yet and it should be easy to bring the outer cores back, even to the launch site.
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Jimmy doesn't really give good answers, and always tries to circumvent what you asked him by including an irrelevant answer to your question. See here:
On September 09 2016 23:56 JimmyJRaynor wrote:Show nested quote +On September 09 2016 21:00 ShoCkeyy wrote:
Jimmy, can you tell me any other SpaceX rocket that has blown up within the past two years? Or prior to that? Also don't come including barge rockets, because that was strictly R&D. its all about confidence and perception. one $200+ million disaster can be overcome. not two; after both challenger and columbia disasters it was ~2.5 years before another shuttle flew. the next Falcon9 launch is September 20th. stay tuned. Elon Musk is masterful when it comes to PR. "Still working on the Falcon fireball investigation. Turning out to be the most difficult and complex failure we have ever had in 14 years" sounds like Elon Musk is preparing the SpaceX fan base for some launch delays.
Instead of being able to directly answer the question, he mentions Challenger, and Columbia which both are obviously not part of SpaceX... Lol...
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I come here to read news on private space exploration, not people trying to explain why "a continuum of varied gravitational conditions that change daily as one is hurdling through space" is a sentence that should immediately condemn the writer to repeating middle school. Literally half this thread is some variation of that process.
Can we just agree not to respond to anything JJR spouts from here on in?
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EPT![[image loading]](https://upload.wikimedia.org/wikipedia/commons/1/11/A_Horseshoe_Einstein_Ring_from_Hubble.JPG)
