Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: PmbPhy on 24/03/2015 22:57:01

Title: What are the big questions in Physics?
Post by: PmbPhy on 24/03/2015 22:57:01
I'm going to create a list of frequently asked questions and then answer them as time marches on. My friend Edwin Taylor recommended the questions from this part of his text:                                                                                 
http://www.eftaylor.com/exploringblackholes/InsideFrontCover130112v1.pdf

There are too many to address all of them so please help me select the best ones. Thanks.

Edit: Title changed to a question.
Title: Re: Opinions sought
Post by: JohnDuffield on 25/03/2015 10:06:56
There's so many that IMHO you should start with the black hole questions.

Note though that some of the stock answers are arguably incorrect or incomplete. Hopefully yours won't be, and we can discuss the issues arising with say How fast do I fall? and Does my speed reach or exceed the speed of light?   
Title: Re: Opinions sought
Post by: David Cooper on 25/03/2015 17:26:20
Probably best to look for the questions which you think are most often answered badly and to provide good answers for them instead. There's less point in hurrying with the ones which are always answered well.
Title: Re: Opinions sought
Post by: Bill S on 26/03/2015 17:01:41
A collection of reliable answers to most, if not all, of those questions, together in a findable place would make a superb work of reference.  A major advantage of compiling such a collection of answers on a discussion forum would be that we "hitch-hikers" would have a chance to ask naive questions.  Ultimately, the answers should be understandable by people at all levels of knowledge/understanding.
Title: Re: Opinions sought
Post by: PmbPhy on 26/03/2015 17:07:07
A collection of reliable answers to most, if not all, of those questions, together in a findable place would make a superb work of reference.  A major advantage of compiling such a collection of answers on a discussion forum would be that we "hitch-hikers" would have a chance to ask naive questions.  Ultimately, the answers should be understandable by people at all levels of knowledge/understanding.
There are too many questions. Don't forget. There are many other branches of physics and that's just one topic of one branch.
Title: Re: Opinions sought
Post by: alancalverd on 26/03/2015 17:57:27
Try "why does a bicycle stay upright" as a good example of a common question with an obvious but entirely wrong answer.

Then move on to entropy: since crystals are more ordered than liquids, how can a crystal grow in a saturated solution at constant temperature?
Title: Re: Opinions sought
Post by: yor_on on 29/03/2015 10:06:52
Now, would that be due to conservation of angular momentum Alan?
http://arstechnica.com/science/2011/04/moving-bikes-stay-uprightbut-not-for-the-reasons-we-thought/
Title: Re: What are the big questions in Physics?
Post by: jeffreyH on 30/03/2015 01:50:43
When will John Duffield actually read and understand a physics textbook?
Title: Re: What are the big questions in Physics?
Post by: alancalverd on 06/04/2015 19:13:30
Now, would that be due to conservation of angular momentum Alan?
http://arstechnica.com/science/2011/04/moving-bikes-stay-uprightbut-not-for-the-reasons-we-thought/

Whilst conservation of angular momentum will keep a rolling disc upright, it's not a lot of use for a bicycle because you need to accelerate, decelerate and change direction. Where these requirements predominate over brute strength, i.e racing bikes rather than mountain bikes, the design objective is to minimise rim mass and angular momentum - yet a racing bike still stays upright in a straight line and would do so even with massless wheels.
Title: Re: What are the big questions in Physics?
Post by: PmbPhy on 06/04/2015 19:18:25
When will John Duffield actually read and understand a physics textbook?
The same day "the box" will.