William George Unruh

Physics

John Crowe From Dublin, asks,

If I knew the centre of the universe and began to travel toward it, would I begin to decrease in velocity due to the increasing expansion of the...


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Physics

Monty From saskatchewan, asks,

What exactly is gravity? Is it a wave or a ray? What exactly is the attraction that makes gravity...


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Physics

Dom Elbon From Nottingham, England, asks,

Is gravity lumpy? If you were standing in a valley, then on a mountain, would your weight be less then become more, as you walked up from the valley...


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Physics

Hammad From Phoenix, asks,

If one were to drop an item on the surface of the sun, assuming the object could free fall to the center of the sun, how long would it take, taking...


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Physics

Shane C. asks,

Could you explain the idea that gravity could be thought of a depression or well, much like when a heavy object is placed on a blanket which is held...


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Physics

Sahm Atman From Berkeley, CA, asks,

I understand why magnetism is a relativistic effect, "caused" by Lorenz contraction effectively increasing charge density. I have also read that in...


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Physics

Karl-Alexander Berg Brisebois From Dunham, asks,

Conservation of momentum can explain the exchange of a virtual photon between two electrons and the repulsive force that results. But it cannot...


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Physics

Michal Jaworski From Calgary, asks,

A black hole is a central point the size of a pinhead where a huge amount of mass is concentrated. If, by the two equations F=(GMm)/r^2 and...


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Physics

Sahm Atman From Berkeley, asks,

Supposedly in classical electromagnetism an accelerating charge radiates. If so, why? If so, then does an observer in the accelerating frame "see"...


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Physics

Sylvain Koenig from the University of Lausanne (Switzerland) asks,

Why would one person when he returns from travel at the speed of light have aged differently than someone else who stayed...


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Physics

BALKRISHAN ARORA From Pune, India, asks,

1. I would like to know when was Hubble's constant discovered / invented? 2. How many times it was changed? 3. The names of the scientists who...


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Physics

David Graveline asks,

What are the most recent theories about what existed before our big bang? Have there been one or even several ones before this one...


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Physics

Karl-Alexander berg brisebois From Dunham, asks,

Heisenberg's uncertainty principle tells you that the mass of a particle multiplied by the imprecision of its position mutiplied by the imprecision...


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Physics

Jen Collard From Brockville, asks,

Light cannot escape from a black hole, because of the black hole's mass. If this is true, then light must be affected by mass. Would it not then be...


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Physics

Marin From Split, Croatia, asks,

What happens when electrons pass through a magnetic field at a velocity near...


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Physics

Christian From Peterborough, asks,

In the constellation of Pegasus there is an object called "Einstein's Cross". I understand that it's a sort of cosmic mirage with the idea of...


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Physics

Christian From Peterborough, asks,

I have a question about black holes. If light/matter are drawn towards a black hole are they not accelerated to speeds faster than light from...


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Physics

Matthew From Darwin, Australia, asks,

Why is quantum physics used to try and explain the future predicting behaviour of light as is shown in
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Physics

Brent Harrington From Bolton, asks,

I am trying to find out how much light curves at the Earth's surface due to gravity. Ideally, how much does light drop over a given...


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Physics

Peter Schwarz From Toronto, asks,

I understand that even in a finite volume, there are an infinite number of points. Why does the Planck area not apply...


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Physics

Scott Mayers From Saskatoon, asks,

Assuming the speed of light, c, what would be the distance of a photon traveling in empty space be in one second? I know this is c,...


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