# Search PBS Space Time

## Results

### 2022-12-08: How Are Quasiparticles Different From Particles?

• 02:34: It even has an effective positive mass.

### 2021-04-21: The NEW Warp Drive Possibilities

• 02:30: His special theory of relativity just says that it takes infinite energy to accelerate anything with positive mass all the way to light speed.

### 2019-03-06: The Impossibility of Perpetual Motion Machines

• 10:06: According to some interpretations, negative mass should be attracted to positive mass, but positive mass should be repelled by negative mass.
• 10:58: We have a rare non-dynamo device from Adrien Romeo, who uses cogs with negative and positive mass teeth.

### 2019-01-30: Perpetual Motion From Negative Mass?

• 03:24: We know that the gravitational force between positive mass objects is attractive.
• 05:02: Even weirder, a positive mass should attract a negative mass while at the same time being repelled by it.
• 07:13: That should mean that a negative mass behaves the same in a gravitational field as a positive mass.
• 07:26: Positive mass causes spacetime to curve inwards – what we call positive curvature.
• 07:31: In the analogy a positive mass depresses the sheet so that the trajectory of an positive mass apple bends towards the massive object.
• 08:21: It suggests that positive masses attract everything and negative masses repel everything, including each other.
• 08:29: A positive mass attracts and is repelled by a negative mass.
• 09:06: ... positive mass apple gains positive momentum and energy as it speeds up, while the ...
• 10:03: In particular, with the idea of negative and positive masses accelerating each other to infinite energies?
• 12:59: ... say that, if they do, then positive mass always attracts while negative mass always repels, while others say that ...
• 13:18: ... it is: assuming that positive mass both attracts and is repelled by negative mass, come up with a way to ...

### 2019-01-24: The Crisis in Cosmology

• 14:11: ...than if it's actual, positive mass matter.
• 14:32: And yeah, those measures tell us that dark matter has positive mass I'd need to do the simulations, but I have a feeling...
• 16:34: ...is mathematically the same as a positive mass particle moving forward in time That notion makes sense in the math,...

### 2019-01-09: Are Dark Matter And Dark Energy The Same?

• 04:06: Forgetting that pressure stuff for a moment, positive masses and energies always have a positive gravitational effect.
• 04:40: Two positive masses always give an attractive force by definition.
• 04:51: But with one negative and one positive mass, the final force of gravity has the opposite sign - that makes it repulsive.
• 05:56: At the same time, the repulsive force between a negative and positive mass should repel the positive and attract the negative mass.
• 06:15: The author uses these ideas about the interactions of negative and positive mass particles to create an N-body simulation.
• 06:39: ... is because the positive mass in the galaxy attracts a halo of negative mass, but at the same time ...
• 07:20: That keeps the density of negative masses constant, even as the density of positive masses falls.

### 2018-01-24: The End of the Habitable Zone

• 12:03: After all, both matter and anti-matter have positive mass.

### 2015-10-28: Is The Alcubierre Warp Drive Possible?

• 05:08: In fact, it would take significantly more negative energy than there is positive mass/energy in the entire observable universe.
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