Ask-a-Physicist

Weight on Other Planets

If a person stepped on a home bathroom scale, and weighed 170 lbs, he would weigh a different weight on this same scale when on other planets due to the force of gravity.

If, however, a person stepped on a professional medical scale — the kind with weights attached that you slide (as opposed to a bathroom scale) and weighed 170 pounds on Earth, would the weight of the person be the same on the other planets as it is on Earth (170 lbs)? This has become a bone of contention in an otherwise ideal marriage.


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Infrared and Blackbody Radiation

Is there a particular range of frequencies at which parts of the human body (or the human body overall) normally vibrates? Because in an episode of the sci-fi TV series Fringe, they claimed that they could figure out if one character was from this universe or a parallel universe by measuring the frequency at which he was vibrating.


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Why does hot air rise?

If air is heated and its starts to go towards the space, what is the reason for this? Do you think the air molecules will get accelerated and because of this they will resist Earth’s gravitational force?


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Phases of Matter

My 9 year old wants to know if a single atom exists in a certain state of matter — or must it be associated with other atoms in order to define a state?


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Early Galaxies and the Big Bang

With the latest telescopes, we can look at some galaxy's some 13 billion light years away, correct?

And that is much older than the earth is thought to be. I also heard that we have seen what the universe looked like only a short time from its birth. So how can all this be true? If nothing can travel faster than light and the light from that moment in time would have passed the spot the earths current location long ago, how can we see that light? What am I missing? I can not fathom how we beat the light from the early universe to this spot. Something doesn't add up for me, so can someone break it down for me?


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