Ask A Physicist
Have a physics or astronomy question? Whether you're curious about tiny, elusive neutrinos or the most massive black holes in the universe, we can help.
We are graduate students, research scientists and faculty in the Department of Physics and Astronomy at University of Delaware. We are developers of quantum computers, space weather forecasters, planet hunters and more!
Please email your question to email@example.com. Scroll down for information on who can ask questions and how to phrase your question.
- Why is it that colours of the visible spectrum (e.g. orange) can be "faked" by mixing other colours (e.g. red and yellow)?
- How does something explode into a non existent space? It would seem to me that would be theoretically impossible!
Attraction and Repulsion of Two Charged Particles
- Could you please tell me how quantum field theory describes the attraction and repulsion of two charge particles via exchanging photons?
Magnetic Force Between Stationary Electrons
- I've heard that electrons have magnetic fields while at rest. However, if an electron is at rest then putting something like "qv" into the Biot-Savart law will lead to a zero field because "qv" is equal to zero. Is there an equation that would allow me to calculate the force between two electrons at rest from their inherent magnetic fields?
- If one could fold space in order to travel vast distances relatively fast, how far could one travel, and in what time frame? What effects would the travel have on our bodies and what would a person see if they looked out the window?
- What's the percentage of habitable planets in the Galaxy? What's the current estimate of how may planets have life?
Big Bang -> Black Hole?
- Consider our universe at the moment of the Big Bang, or perhaps a very brief moment after the initiation of the Big Bang. Wouldn't the mass density of the universe at the moment of the Big Bang have been sufficient to form/maintain a black hole rather than an explosive expansion?
Blue light and sleep deprivation
- I was recently advised to switch to red lights in the evening to help with my sleep patterns. I am told that the key is to achieve light as red as possible on the spectrum. Can this be achieved by filtering a white light through a red cover or does the light emitted have to be intrinsically red itself (eg the difference between a Christmas light with a red cover and a red heat night light for reptiles)?
- Light and Photography
- Electricity and Magnetism
- Solar System
- Extrasolar planets
- Brown dwarfs
- Black holes
- Special relativity
- General relativity
- Big Bang
- History of science
- The Space Race
- K-12 Education
Who can ask questions?
- We welcome questions from K-12 students and teachers. We ask that students put their age or grade level in the email so we can answer at the appropriate level.
- Non-scientist members of the general public are also encouraged to submit questions. To help us answer at the right level, it's helpful if you add a little bit about your background -- for example, "I'm an accomplished amateur astronomer" or "I'm usually not interested in science, but I read something about climate change and I want to find out if it's true."
- College students may submit questions as long as they are not homework questions (see below). We can help with general physics concepts, but we will not compute or calculate anything for you.
- We advise journalists working on deadlines to contact individual scientists directly, rather than send questions to Ask A Physicist. The contributors to this page are volunteers, and we cannot guarantee that questions will be answered immediately.
- Professional physicists or astronomers should not use this service. We do not review manuscripts or check calculations.
How should I phrase my question?
- Make it specific enough that we can answer it in 1-2 paragraphs: "What types of nuclear reactions can produce neutrinos?" rather than "Tell me everything you know about neutrinos."
- However, if you make it too specific, you will trigger our homework question alert. Questions such as "Describe the five ways to measure the temperature of a star" or "If I throw a ball upward at 2 meters per second from a height of 1.5 meters, how high will it go?" will not be answered.
- We might not be able to help with questions that are specific to your locale, such as "What was that flash I saw in the sky at 10:00 PM last night?"