41

Physics, Astronomy & Cosmology / Re: Return to the Centre of the Universe

« on: 12/01/2015 05:47:30 »

Can we estimate the shape and dimensions of the visible universe?  Does it have a three dimensional form?  If so, where is the centre?

Shape of the visible universe: spherical, 3 dimensional.
Radius: About 13 billion lightyears.
Center: EARTH.

We don't know how big the unseen portion of the Universe is, and don't have a good idea to its form and shape.  But, the visible portion is roughly a sphere with Earth at the center.

42

Question of the Week / Re: QotW - 10.12.12 - Is blood magnetic? And do magnetic bracelets actually work?

« on: 16/11/2014 05:41:19 »

Any "scientific" study needs a randomized control procedure, and sufficient data to tease out some results.

So, rather than putting a magnetic collar on one dog with a spinal injury, find 10 dogs with a similar injury.  Half get a magnetic collar, half get a non-magnetic collar.

Likewise with the calves.  Give the treatment to some, and no treatment to others.  You can use some historical evidence, but if your treatment protocol has changed, or perhaps other caregiving protocols. 

And, of course, you need an objective outcome, rather than a subjective interpretation.

43

General Science / Re: Would legalization of Marijuana increase general health?

« on: 02/02/2014 09:02:18 »

Personally I could care less if a person tokes on a bit of weed in the privacy of their own home.  And what they grow in their greenhouse is their business.  Nor do I really care if they had used it over the weekend, and then return to work intoxicant-free the next week.

However, I certainly don't want to be around someone operating heavy equipment while intoxicated, and we don't need more intoxicated drivers on the road.

Several US states now have legalized "medical marijuana".  However, the definition of "medical" seems somewhat lax. 

Colorado and Washington have recently legalized Marijuana.  Rather than legalizing "plantations", I would have retained restrictions on commerce, but allowed people to grow their own weed for personal use.  But, the government does spend too much effort prosecuting individuals for trivial issues.

Anyway, we'll see what happens with the states where it is now legal, and how it affects school kids and college kids.

44

Physics, Astronomy & Cosmology / Re: how big?

« on: 06/01/2014 01:26:17 »

Above I calculated that a lunar (or solar) transit of the ISS is about 2 miles (across the equator) for any spot it is viewed from the ground.

At about 4.7 miles a second, the transit would last just under 1/2 second. 

For a 2 mile diameter body, going from a partial eclipse to full, back to partial eclipse would be about 4 miles, or in total it would last for about a second.

And, on Earth, the path that the full eclipse is visible would be extremely narrow.

I'm trying to imagine the orbit that would effectively slow it down.  I'm not sure you could design a LEO orbit so that it would "hover". 

In a geostationary orbit, your satellite would appear to hover over the equator, or in a different geosynchronous orbit, it would appear to move north and south.  And the apparent velocity would be greatly reduced.  However, your satellite would need to be about 100 times as large, or about 200 miles in diameter.

45

Technology / Re: Is there a maximum temperature for a solar oven/furnace?

« on: 16/09/2013 23:09:51 »

I've seen notes about some mirrored solar furnaces rated for about 3000°C.  Perhaps the selection is because most materials melt below about 3000°C.

If one's collector was a refractory material like Tantalum hafnium carbide, perhaps one could hit up to about 4000°C before melting.  If one allowed a liquid collector, the boiling point of Tungsten Carbide is about 6000°C, but then one runs into problems with containing it and insulating it.

I suppose the question might be why one would need anything quite so hot, although undoubtedly there would be industrial uses for the ability to melt and vaporize many substances.

46

General Science / Re: TNS Posting Tips & Tricks FAQ

« on: 23/09/2012 07:34:23 »

Other Formatting Tricks and Notes

To modify or edit your existing posts click the ACTION button to the right of the message box. This is a dropdown. Select "Modify" to open the editor and alter your post. Click PREVIEW, below the message box, to see how your changes will alter your post, and click SAVE when you are happy with the edit.

47

General Science / Re: TNS Posting Tips & Tricks FAQ

« on: 23/09/2012 07:33:35 »

Searching for Information on The Naked Scientists Website

There are a couple of ways to search for information on The Naked Scientists Website (and many websites in general).

When in the Science Forum part of the website, you will find a link Search in the top bar of the page.


SearchTNS.gif (42.19 kB . 934x514 - viewed 36266 times)

Specify as much information as you can.  You can search specific sub-forums by clicking on the (+) next to "Choose a board to search in"

You can tab between fields.  Simply hitting Enter on your keyboard will start the search, or click on the Search button at the bottom right.

The other method for searching that I prefer is to use Google (or your favorite WWW search engine).

Google allows one to specify the website to search.  So, for example, one can use Google to search TNS for the word FAQ

Simply open Google.

GoogleTNS.gif (7.29 kB . 693x67 - viewed 36082 times)

For example, one can enter:
FAQ site:TheNakedScientists.com

One of the results should be this topic.  If one knows one of the authors (such as myself), one can also specify the author as part of the search.

Other options for searching for documents would be selecting Recent Topics or My Posts. 

RecentTopicsMyPosts.gif (14.65 kB . 933x150 - viewed 36049 times)

You can also click on another user's name and find recent posts by that specific user.

48

General Science / Re: TNS Posting Tips & Tricks FAQ

« on: 23/09/2012 07:33:02 »

Posting Images and Pictures

See Additonal notes on posting images here

You can easily link to images on other websites, or even to images on other parts of thenakedscientists.com (TNS) by simply putting in the name of the image surrounded by [img] [/img].  You can either type it in, or use the shortcut above the editing window.

For example, if you want to insert the Naked Scientists logo into your message, right click on the image, and click on copy image location, then paste it into your message and surround by [img] [/img]

[img] https://www.thenakedscientists.com/HTML/fileadmin/template/TheNakedScientists_files/logo/logo-Forum.gif [/img]


Keep in mind that different websites  have varying policies about hyper-linking their images.  It is generally a good idea to reference the source of the image.  Some websites encourage hyperlinking because it creates links and traffic to their websites.  Others discourage it because hyperlink traffic is considered expensive and resource intensive. 

Wikipedia images are generally public domain, and the Wikipedia policy allows hyperlinking, as long as you refer to the source.  Other images often fall under Fair Use (the definition may vary by country), but the source still needs to be referenced.

See above notes on hyperlinking to make generally condensed quotations.  You can combine the hyperlinks and images if you wish, although it may note be quite as obvious to the reader as putting a separate notation in the text.  You can also use this to hyperlink from thumbnails.

[URL=http://www.thenakedscientists.com/ ] [img] https://www.thenakedscientists.com/HTML/fileadmin/template/TheNakedScientists_files/logo/logo-Forum.gif [/img] [/URL]


Be careful that you do not hyperlink to an image on your local C: drive, or in a location that is password protected so that most users don't see it.

Adding your own images is a little more complicated, but it can be done easily enough.  You can choose a free image hosting site, but if the site is down or slow, the image becomes inaccessible.  And, they frequently purge older images, leaving broken links.  Some images are also frequently updated, so if you wish an archival copy of an image that you think might be changed, copy it to TNS (below), and reference the source.

To attach a personal image
While in the editing screen, click on "Attachments and other options".
You should see a line that says "Attach" and "Browse".  Click on the "Browse" button and select the image from your local hard drive.
Note the restrictions for uploading images to TNS:

Allowed file types: gif, jpg, pdf, png
Restrictions: 12 per post, maximum total size 192KB, maximum individual size 128KB

As a general rule, I will save images that are mainly drawings, text, and screen captures as GIFs.
I will save other photo images as JPGs or PNGs.  I usually set the size of the image to under 600x600 before attempting to upload.

You can select additional images by clicking on "more attachments".

By default the images don't get added to your message until you click "Post" or "Save".  The images are then added to your message as thumbnails at the end of the message.

You can make the images larger, and place them in an appropriate spot in your message by editing it after posting it.  Clicking on Attachments and other options.  Find your image.  Put your cursor where you wish the image to go, then click on "Insert Into Message".

Since this is a two-step process, I usually mark where I want the image to appear as I'm typing, then I can quickly scan to where I want the image and insert it.


(personal image, from my back porch winter, March 2012).

49

General Science / Re: TNS Posting Tips & Tricks FAQ

« on: 23/09/2012 07:32:12 »

Posting Hyperlinks

Generally it is easiest to type the hyperlink in by hand.  However, you can use the icon above the (full) editing box to get a start.  If you have the "Quick Reply" edit box, then click on "Preview", and you will get the more general message editing box.

There are a few basic parts.

• The link where you want to direct your hyperlink.  For example:
  http://Where_You_Want_To_Go.COM
• The text you want to display.  For example:
  Display This
• The basic syntax the program uses to display your text.
  [url=...] [/url]

So, to make it all work, you simply put in:
[url=http://Where_You_Want_To_Go.COM] Display This [/url]

Which results in the line:
Display This

It is often easiest to cut and paste the hyperlink, so you don't get it incorrect.
Ctrl-C is a shortcut to copying hilighted text.
Ctrl-V is a shortcut to pasting hilighted text.

You will sometimes see characters substituted when you paste the hyperlinks.  For example, ( is often converted to %28, and ) is often converted to %28.  Don't worry about it.  This is to make it easier for some systems to display certain formatting characters.

One thing to note, as you are doing BB code is that in general, [...] starts a code block, and [/...] ends a code block.

A hyperlink to a specific message on TNS can be a bit tricky.
The easiest way to do it is to open the post in a new window/tab.
Hit "Quote"
Hit "Preview"
Click on the link in the quote, or Right-Click on it and select "Copy Link Location".
Copy & Paste the link into your message, and it should take you to the specific desired message.

The Quote function can be used much in the same manner as the URL function.  Often to just highlight some text, I will use:
[quote] Highlight This Text [/quote]

Highlight This Text

However, if you wish to link a source into the quote, you can expand it to:
[quote=http://The_Source_of_Your_Quote.COM] Highlight This Text [/quote]

Highlight This Text

50

General Science / TNS Posting Tips & Tricks FAQ

« on: 23/09/2012 07:31:17 »

One of the easiest things to do to figure out what someone else did is to hit "Quote", then read the original message to see how they formatted their message. 

In the following few posts, I'm going to try to explain some of the more common formatting methods on the TNS website (and many similar websites).

Posting Hyperlinks
Posting Smileys (Emoticons) and special characters
Posting Images and Pictures
Searching for Information on The Naked Scientists Website
Formatting Math Equations (TeX / LaTeX)
Other Formatting Tricks and Notes

51

Physiology & Medicine / Do antibiotics accelerate wound healing?

« on: 01/10/2011 21:43:57 »

Great article about glowing bacteria, and a sign that there are many things that should not be forgotten about the past.

As far as the original question, I believe there are indications that dressing a superficial wound will accelerate its healing by holding the skin together, and retaining moisture.  You can may also receive some benefit from the use of non-medicated petroleum jellies.

Deep wounds, or wounds on the face that might cause cosmetic damage may require stitches, or physician care.