Does Gravity Require Extra Dimensions?

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It’s been 120 years since Henry Cavendish measured the gravitational constant with a pair of lead balls suspended by a wire. The fundamental nature of gravity still eludes our best minds – but those secrets may be revealed by turning back to the Cavendish experiment. That steampunk contraption may even reveal the existence of extra dimensions of space.

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Hosted by Matt O’Dowd
Written by Katie McCormick & Matt O’Dowd
Graphics by Leonardo Scholzer, Yago Ballarini, & Pedro Osinski
Directed by: Andrew Kornhaber
Camera Operator: Bahaar Gholipour
Executive Producers: Eric Brown & Andrew Kornhaber

#space #astrophysics #gravity

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Sujata Devi says:

Where is the new video MATT, its already Thursday I have been waiting for the new video the whole week. Do you even know how hard it is?

Federico Giunta says:

So, if I'm not wrong, the inverse square law is a consequence of the gauss' law. Could this law not be valid in the other compactified dimensions? And, shouldn't it apply also to electromagnetitism and light? Shouldn't we find the same discrepancies that we're looking for in the other fields?

Timmy Kenny says:

How fast is a star on the edge of our galaxy moving through space relative to the center of gravity in its galaxy? And does angular momentum slow down possible speed of light in a straight line relative to the Galaxy as a circular object? I don't think anything can go the speed of light in any "one" direction that it's not already given momentum in.. so then would some mass reaching its angular momentum speed limit be unable to escape the Galaxy due to it kind of needing to gain more speed to escape? Could it be something like that keeping galaxies together? I'm only talking about particles with some mass going near c given angular momentum due to a larger body of mass of course or if we're talking about a body you would have to account for its particles momentum given to it by gravity is well right?

Timmy Kenny says:

It would be really interesting to have maps of galaxies that filtered out particles going at different speeds. A picture of a galaxy seeing only the particles that are going at or very very near the speed of light and different maps for the particles that are scaling down in speed. I guess it would have to be a computer simulation cuz if it was a picture we would only see from our perspective but still

Brian Hale says:

Imagine a sphere of Einstein's elevators. They go nowhere in 3D space but we inside feel an acceleration effect we call gravity. What are we accelerating through, if not a fourth spatial dimension? When we leap, we create a gap between ourselves and the floor, but we fall back to the floor because it catches up with us. Why? Because an expanding universe in four dimensions is conic, so the force of jumping perpendicular to the floor in 3D angles away from the perpendicular up an accelerating cone (the gravity well) in 4D, closing the 3D gap and bringing us back to the floor.

Philip White says:

non science question..where did you get the awesomeness t-shirt?? ..want
one! 🙂

lqr824 says:

2:20 The graphic of the circles of arrows gives precisely the WRONG image, since they're 2-D circles and thus the number of arrows only falls with distance, not square of distance. Phenomenally bad illustration.

Troy Adler says:

this guy aged

Cosmic Ninja says:

Matt, they used a clip of you from a PBS Spacetime episode in a movie I just watched on Hulu called The Mandela Effect.

Jc Arias says:

I have study spacetime and the possible dimensions in the universe.
I have concluded that there are 11 dimensions we can observe in the universe.
I've been trying to organize then to explain to the people how they work and what they are!
But the most important find is what time is.
Time is what gives dimensions the imaginary view of them!
I hope soon to explain to humanity what time is, and what is not, so we can change everything in the near future, forever!


Completely likey then that we are infact not real, but the thoughts/dreams of an inevitably possible outcome, that we exist be the math says we might, even if just consciously curious ideas

Jason Heller says:

Couldnt we be in one of these compactified dimensions and we just can't "zoom" out enough to see the others.

mwm48 says:

Could dark matter be matter in a different dimension, or time? For example, might it be the echo of matter from the recent past? Maybe gravity gets weaker exponentially through time just as it does through space, with more recent events pulling greater than past events. Unless the event is more massive, then it would impact longer through time.

Astute Cingulus says:

It depends on what you mean by dimensions. Sean M. Carroll mentioned three definitions of dimensions in physics; for example the dimensional analysis between different fundamental units (renormalization is necessarily related for practical reasons).

Bhaurav buddy says:

Hi Guys, Is it possible to open a wormhole while standing here on earth, given the fact that earth is moving through space and time and a wormhole is a point in spacetime?

Will the earth just move away from the portal? or the gravity will be able to keep it going with the earth. Also how strong a planet gravity needs to be to do that?

Tyler Duncan says:

I had to pause when he said gravity may be diluted by another dimension, that’s why it’s so weak. Firstly, Why can’t it just be weak? Secondly, Is there evidence of other forces being weakened? If so doesn’t that nullify any perceived difference as a whole? In other words this theory has context if only gravity is effected by another dimension. Which I don’t believe would be the case.

Mr. Nisse says:

Absolutely, it requires extra dimensions. How can anything "accelerate" in a straight line, unless there's curvature in a direction we can't perceive?

SrmthfgRockLee says:

anticipating new episodes of PBS SPACETIme.. naruto isover, the matrix 4 isnt to come for some time… farscape, resident evil underworld..etc..stargate maried with childrenif atallcontinue. blade 4..marvel blade, ..well ok marvel bladem by abit earlier.but riddick, etc… shaman king superrobotmonkey teamhyperforce go.. mmm <3 live forthis… barely anything to watch nowdays.. but atleast i have lots of old films to watchnrewatch, keanu reevse adam sandler..famous actors, films from the 90s n 20s.

Kamilio_Kun says:

Quarantine has gone to our brains.

Fernando Tanase says:

VIDEO REQUEST: How exactly does gravity affect time

Peter Alton Mertz says:

Proud to be a SpaceTime city net-citizen, but have a time share condo over at Supercar Blondie metropolis.

Peter Alton Mertz says:

I am going to stick with the Fujiwhara Effect. The way that would work is the sum total of all forces (known and unknown) would create diffraction patterns. Obviously the area in-between two objects would have more canceling out of the forces and that amount would be very tiny when compared to the total of the other forces. Checks all the boxes and it is Occam's razor, but not really certain how one would test for that.

Soham Parmar says:

Make a vid on the new ANITA confusion

Rome NEW YORK says:

Since we're now diving more into theoretical physics on #PBSSpaceTime, we are a little curious about something that may/may not exist. Wormholes. Let say, for theory, that a part (front, end, some of the cylindrical tube…if truly cylindrical), of a wormhole, made contact with the Earth's atmosphere. What would it appear as in…daytime? Would we see a void window into space for a second or several days, or months, before moving-on? Would we notice a loud noise? Would we notice anything? Would a wormhole, theoretically, distort space around us? Could one alter the orbit/axis of a planet? Would there be catastrophe? Would we see a plethora of colors?
Just curious. Because I am still boggled as to what caused the sky to literally open-up for a few seconds, at 6:33 a.m. in August, just a smallish hole you could fit your fist in (as it appeared from Earth), see the stars, and then close-up. No we was not drunk, hungover, high, nor delusional. Not if six people saw the same darn phenomena.

J W says:

Are we going to start some sort of movement to get Matt on the Rogan podcast? How has this not happened yet



Halcyon3652 says:

If there are extra spacial dimensions that lower the effect of gravity, why does it not effect other forces like electromagnetic? I would also like to note that the Cavendish experiment, to the best of my knowledge as always been done the in presence of the earth's gravitational field. I can't help but wonder if Earth's own gravitational field might be having some other effect that is throwing off the results.

Kaerius says:

I've always thought of the curvature of spacetime caused by gravity to be in an extra dimension, but not a regular spatial one, more like an extra-spatial dimension.

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