Ask the Van

Ask the Van is the public Q&A service of the Department of Physics at the University of Illinois (where I went to grad school). Anyone can submit a question, and physics professors and student volunteers answer as many as possible.

Questions I answered

11/11/16: Why do metals feel hot or cold to the touch?

10/29/16: Seeing reflected and emitted light

10/29/16: Forward velocity of a parachuter

10/29/16: Do planes have to correct for the coriolis effect?

9/29/16: Launching a rocket to the sun

9/16/16: How do we define communication in entanglement?

9/16/16: Why do dim objects appear brighter out of the corner of your eye?

9/16/16: Waves on a guitar string caught on camera

8/23/16: Crepuscular rays are parallel

8/15/16: The optics of sunlight

8/10/16: Volume of sugar dissolved in water

8/2/16: Why it feels like dowsing works

5/27/16: Measuring the concentration of sugar with polarized light

3/27/16: Does looking change the outcome?

3/27/16: Why do we tell people to do the experiment?

3/1/16: Why are the moon and the sun the same size in the sky?

3/1/16: Net forces and Newton

2/27/16: Is there a most effective force?

2/27/16: Why do cooked potatoes turn dark?

2/17/16: The difference between a mirror and a photograph

2/17/16: Why does total internal reflection happen?

12/14/15: Why would high RPMs be uncomfortable in artificial gravity?

11/6/15: What happens when entangled photons get redshifted?

11/6/15: Could a fighter jet tow a human?

8/18/15: Questions about relativity

8/10/15: When do you feel weightless in space?

7/29/15: Can a car accelerate to 150 mph in a city block?

7/16/15: Building an underwater rover

6/20/15: Why do electrons have spin?

6/18/15: Why is the sky blue, but the sun and moon aren't?

6/18/15: Why is a proton heavier than three quarks?

5/16/01: How do we know what will happen to the sun?

4/6/15: E = mc^2 and the energy of light

2/20/15: Slowing down (and speeding up?) a beam of light

1/26/15: Making a vacuum chamber

1/21/15: Are sunspots really black?

1/21/15: Thin and thick wires

1/9/15: How to build a telescope

12/19/14: Does a black hole accelerate light?

12/18/14: So hot you can't see it?

11/29/14: Why do we see stars as points?

11/24/14: Weight of materials on a rocket

11/23/14: Where is the light that left Earth 70 years ago?

11/3/14: Freezing a can of whipped cream

10/30/14: Seeing single photons

10/28/14: Cooling a computer in a vacuum

10/9/14: Cracks in frozen pies

10/9/14: Heating and cooling

9/25/14: Kinetic energy equal to rest mass energy

9/17/14: Two shadows from a nightlight

9/11/14: Would a matchbox full of nuclei weigh more than the Earth?

9/11/14: Can you only see reflected light?

9/8/14: Isotopes in nuclear fusion

9/3/14: How could you change your direction in space?

8/30/14: Why does matter spiral into a black hole?

8/21/14: Fact-checking Wikipedia

9/5/14: Feeling current through the human body