132 reputation
9
bio website
location United Kingdom
age 74
visits member for 2 years, 6 months
seen Apr 12 '12 at 19:22

I am a cosmology layman. Have been an engineer most of my life, but I'm now technically retired. My work as an engineer, took me into safety audits, logic and logic scenarios, with regards to, the design of,the running and safety control, of industrial plant. Working with many companies such as the Admiralty, BP, etc. Logic scenarios entail, using logic to break down the individual actions/options involved in an action path, and seeing if any of these, can be replaced, to make a better action path. I've always had an interest in space, astronomy, cosmology, etc, but only in the past year, have I got deeper into that interest. I have a personal retirement project, to apply these logic principles, to look at the many actions/options, in some cosmology paths. It will probably come to nothing, but who knows. It keeps me happy.


Apr
5
comment What is solar storm?
Quote you, "search for "solar storm" on Wikipedia it redirects you to the "geomagnetic storm"" And 7 other options. Maybe we were a bit hard on Mathematics.
Apr
5
comment Has Bose-Einstein theory been considered for dark matter?
Hi John, could you please elaborate a bit. I'm sorry to ask. The two points I am talking about are "weak and (gravity) force it is interacting but only weakly so.",(are you saying it acts like gravity) and "stopping their interactions with the experimental apparatus from destroying them".(which destroys which and how) This is interesting, and not the sort of information you find when you Google "dark matter" or "dark force". I would not ask otherwise. Thank you
Apr
5
comment Earth's beginnings and early years, Re radioactive decay or not
I sometimes asked questions as I think of them. This was one of those times. I think you've answered one part of the question. I wasn't sure how you'd distinguished from the time the decay originally started, and when it started on the Earth. With regards to Argon/Krypton, could not they have been associated with Uranium elsewhere? I suspect that there is not a method of establishing the 3.9 billion years date, other than if the colliding entity, brought other Uranium with it, which could cause confusion with any Earth dating. I.E. two Uranium sources 0.7 billion years apart.
Apr
5
comment Earth's beginnings and early years, Re radioactive decay or not
@Qmechanic Thank you both for info. Very interesting, especially, physics.stackexchange.com/q/3833/2451 relating back to pre Earth's existence. Partly answers my question but not totally. Not sure what the procedure is, if it had answered my question completely. Would I need to delete my question? I was not aware of the sKeptics, site so thank you.I suspect you could have a little bit of a battle their dmckee
Apr
5
comment Change in Vapour/Liquid change point, at very low pressure
Thanks. A comprehensive answer.The only thing missing was an added comment re vapour to solid, is possible, below triple point (or something similar), which would complete the answer. It was 3 that was causing me a problem, since I miss read some data from nist.gov. Thank you again.
Apr
4
comment How do we determine the temperature of a Black Hole?
Well I agree with you there. Nearer to absolute zero than CMB. Part of the reason for asking my question, was to see what response I got. I have no doubt, if I mentioned what I thought, I would get flamed.
Apr
4
comment Why is the time taken for something to fall proprtional to acceleration due to gravity?
Didn't we all, consider ourselves pretty smart, when we were 16. Age wise, I'm a little bit ahead of you. I live in the UK, and I consider myself lucky to have been 16 when I was. In my opinion, life was a lot freer, easier, and in fact, better, then, than it is, for 16-year-olds today. I will probably be in trouble for this, though I suppose you could say, it's social history, which verges on physics.Take care.
Apr
4
comment How do we determine the temperature of a Black Hole?
I am a layman, as far as much of this is concern, and I do struggle a little bit, to take it all in. That particularly applies to the quantum side of things. I have worked with logic all my life, and that probably explains why I do not get on, with the quantum theory. Though, I have no objection to it, if it proves a point.
Apr
4
comment How do we determine the temperature of a Black Hole?
Sorry, I did take on board what you said. Ron Maimon said much the same thing and so does (Wiki) - Hawking radiation. There are so many different satellites out there now, measuring different forms of radiation etc. When I said developing, what I meant was developing a system to look directly into a black hole, at a distance, and take its temperature. Probably not feasible, since that sort of information, is not escaping.
Apr
4
comment Why is the time taken for something to fall proprtional to acceleration due to gravity?
Yes, but there are so many things that can cause a variation in g, this is why "Standard Gravity" was introduced, or should I say has always been used for near Earth tests. Even Standard Gravity assumes that the body, is falling in a vacuum. For general use near Earth's surface, the errors are low if Standard Gravity is used. As the questioner was only 16 I assumed that he would not go beyond Standard Gravity. I agree with you, that using a constant g would probably not be applicable, when drilling deep into the Earth's surface. Thanks for your comment.
Apr
4
comment How do I go from exponents to a formula?
For all near Earth tests, small g, is a constant, which is known as “standard gravity” (Google this) and its value is: g=35.30394 (km/h)/s (≈32.174 ft/s2). Because you are 16, I assumed you would be using standard gravity. I did say in my answer above, that I was surprise your teacher had left g within the square root. It could have been included in the constant C, and would then, not have caused you confusion. Once you get further away, from Earth, variations in g become greater. A big G is use for this new variable. This can also cause confusion if g and G are mixed up.
Apr
4
comment Why is the time taken for something to fall proprtional to acceleration due to gravity?
The questioner is 16, and unlikely to be involved beyond the Earth's near surface, where g is a constant known as standard gravity. I.E. g=35.30394 (km/h)/s. see my comment, above.
Apr
4
comment Why is the time taken for something to fall proprtional to acceleration due to gravity?
For all near Earth tests, small g, is a constant, which is known as “standard gravity” (Google this) and its value is: g=35.30394 (km/h)/s (≈32.174 ft/s2). Because you are 16, I assumed you would be using standard gravity. I did say in your other question, that I was surprise your teacher had left g within the square root. It could have been included in the constant C, and would then, not have caused you confusion. Once you get further away, from Earth, variations in g become greater. A big G is use for this new variable. This can also cause confusion if g and G are mixed up.
Apr
3
comment How do we determine the temperature of a Black Hole?
@RonMaimon Thank you all, for your answers. My main reason for the question, was the differences in temperature that have been given for different black holes. Generally black holes temperatures are given as very high, and then all of a sudden someone talks about a cold black hole. I think Wiki "Hawkins Radiation" explains this. I.E. Mass & CMB radiation balance. Are you aware of anyone developing a means to prove this? - NASA etc.
Apr
3
comment Change in Vapour/Liquid change point, at very low pressure
Calculater of Properties of Fluid Systems: webbook.nist.gov/chemistry/fluid
Apr
3
comment Change in Vapour/Liquid change point, at very low pressure
I should have known better since trying it out I had already had problems where it didn't select the element I had chosen. Whatever, the principle is still the same since it gives a Vapour/Liquid point, of 2.5066K for Helium. Except that, Helium does not have a triple point????. The Vapour/Liquid point of He at 1 atm. is 4.22K. So is 2.5066K the Vapour/Liquid point of He at 0.1atm. If this the case, then the V/L point has changed with pressure, which answers another point in my question. Sorry about that, but hope this makes sense. Will have to go back and get new table.
Apr
3
comment Change in Vapour/Liquid change point, at very low pressure
webbook.nist.gov has a table building feature, where you can input an element, and the pressure/temperature range you want to look at. It goes away, and comes back showing columns such as phase, pressure, density, volume,temperature, etc.I do not have the full domain address for this particular page on the site, but will try and look it out. It is a good feature, but a little cumbersome to use. It does not print the element nameon the table page. in another data area, in small print I have just noticed normal boiling point is 4.23K which is He. I did enter H as the element. See next comment.
Apr
1
comment How do the Planets and Sun get their initial rotation?
I would expect both the Earth and Mars to have different rotation rates. Both Venus and Mercury are obviously not locked to the suns rotation, otherwise they would be rotating at the same speed of the Sun, as per our Moon/Earth. As they are not locked, and in view of their small size relative to the massive variations of the Sun's surface, tidal effect would have no set pattern. It is then surprising to me, they are able to keep such a steady rotation, if it is in fact, tidal effect slowing their rotation. A personal view. Happy to be shot down, as trying to get it right in my mind.
Apr
1
comment How do the Planets and Sun get their initial rotation?
@martinb Thank you both for you reply. The related question given above, is very interesting with regards to spin, and how spin is developed. With regards to the rotation of Venus and Mercury, I thought it may well be to do with their position relative to the sun, but both planets are rotating at a far slower speed than the sun. Venus which is roughly the same size as the Earth, is rotating at 1/100th of the time it takes the Earth (and Mars) to rotate. Distance wise, proportionally, from the Sun centre, if the sun was having this effect,
Mar
31
comment Where can I find open-source weather forecast software?
There is also a lot of good info on this site, with regards to weather and other properties of the planets, etc. Example: Some good information with regard to Venus climate and the recent "Venus Express" mission, can be found at: realclimate.org/index.php/archives/2008/03/venus-unveiled Some of the comments also contain good info, but there are,a lot of them. >200. If looking for more, or different info, Try a site search for Venus. Quite a lot there. From its Domain Name, this info, is probably, not what you would expect to find here. Clive Ballard