All Big Issues
The Instigator
Pro (for)
Tied
0 Points
The Contender
Con (against)
Tied
0 Points

# Gravity can be defined as pressure resulting from space displacement

Do you like this debate?NoYes+2

Post Voting Period
The voting period for this debate has ended.
after 0 votes the winner is...
It's a Tie!
 Voting Style: Open Point System: 7 Point Started: 7/20/2015 Category: Science Updated: 2 years ago Status: Post Voting Period Viewed: 1,510 times Debate No: 77909
Debate Rounds (4)

22 comments have been posted on this debate. Showing 1 through 10 records.
Posted by tejretics 1 year ago
Your explanation of GR is awesome, FT.

Just as a question/note, you say, "In Euclidean geometry, that's easy: you draw a straight line going up. That line represents a movement through time but not through space. The result is there's no gravity on that object; it's sitting completely still. But remember, this assumes a Euclidean geometry. The geometry of space-time is not Euclidean."

I agree that a straight line going up is the Euclidean explanation. The reason the geometry of space-time isn't necessarily Euclidean is the presence of gravity, etc. In Euclidean geometry, the straight line going up is the shortest way to connect the two points because they're on a flat surface. Gravity means the universe isn't necessarily spatially flat. But recent research in cosmology has shown that the universe is spatially flat, because gravity is "cancelled out" by scalar energy and vice versa [http://map.gsfc.nasa.gov...], which means shouldn't the geometry of space-time be Euclidean at large scales?
Posted by captmurk 2 years ago
Thanks for the response. Such an interesting topic. Last question I have, that I've thought about quite a bit in the last couple months. GR explains (please excuse any scientific verbiage inaccuracies) how objects of mass will curve, bend (whatever the right word is) space; and, therefore, GR explains beautifully how other objects are influenced by that geometric curvature (orbits, acceleration, etc.). But one thing GR doesn't explain (to the best of my limited knowledge) is WHY mass affects and bends the geometry of space. I figured perhaps the mere existence of matter creates a displacement of that geometry (or whatever it is), which results in a fundamental changing of it. I don't specifically understand the way it warps and bends like you do, but perhaps it is displacement that causes it? Feel free to respond if you'd like. Thanks again.
Posted by FourTrouble 2 years ago
Also, notice how much more elegant GR is now that you understand it as simply the geometry of space-time. The beauty of gravity is that it just happens. It's not a force. It's just a result of measuring distances between two points in space-time
Posted by FourTrouble 2 years ago
If you look up GR on youtube, you're gonna find tons of videos representing space is a fabric -- those videos are wrong. Every single one of them.
Posted by FourTrouble 2 years ago
In popular media, there's this pliable "fabric" idea that has completely ruined a proper understanding of general relativity. There's no "substance" to space. People have been looking for the "substance" of vacuum (of empty space), and they call that the "ether," but nobody has found that yet, and most physicists don't think an "ether" exists (there's tons of reasoning why but I can't tell you what it is personally).

The idea of the "substance" of space simply doesn't make sense; space is a "dimension." You ask "what exactly is that geometry made of," but that's something I cannot answer in anything but mathematical terms, language like manifolds, metric spaces, and so on. What is a geometry? It's a good question, and all I can tell you is that it's not a "substance"; the best I can say is that it's a dimension, it's what allows you to measure distances, and so on. You're saying "mass can bend the geometry of space," which is partially correct. The idea is that mass affects the distance between two objects. You could look at that as a curvature of space-time, or alternatively, of a curvature in the shortest path between those two objects (as I did in the example I gave you during the debate). Either way, the key idea is that gravity is an emergent phenomenon related to measuring distances between two points in space-time. Space-time itself is simply our dimensions.

I think the "fabric" idea comes from trying to represent space-time (four dimensions) in a Euclidean space, but honestly, it's just wrong. There's no truth to it whatsoever. Space is a dimension; it's what gives us a measurement of distance. It's not a substance. I dunno if that helps but hopefully it does.
Posted by captmurk 2 years ago
FourTrouble, I enjoyed your thorough explanation of GR and space. I also liked your coordinate system example. Some good knowledge shared in that round. I do, however, recall space being referred to as a pliable "fabric" many times, in many different ways, on topics covering astrophysics. Is there some truth to that, despite it not being a fundamental component of GR? If you are just done with me and this topic, I totally understand. I'm just speaking from a more conversational perspective right now, and your knowledge of GR would be insightful regarding the "substantive" qualities of space that I've heard of elsewhere in theoretical physics. Just to reiterate my question to you: if mass can bend the geometry of space, which in turn effects mass passing trough that bent geometry, what exactly is that geometry made of? Thanks again for the debate.
Posted by captmurk 2 years ago
Thank you for accepting. Looking forward to it.
Posted by FourTrouble 2 years ago
I've wanted to do a science debate for a while, so hopefully this will be fun.
Posted by Discipulus_Didicit 2 years ago
@Berend

He is likely talking about Tejretics, whose profile age is 15. Like commondebator said though you can claim
any age you want so its not really relevant.

Who knows if this is the case with tej? As a matter of fact, who cares?

My answer to the second question is 'lots of people do but not me'
Posted by Berend 2 years ago
Who's this "15"year old that is one of the best debater on religion?
No votes have been placed for this debate.