h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Very interesting...but can someone tell me what happens for a sphere? What is the fourth spatial dimension look like when applied to a sphere?

I hope one of these boffs can help you with that one, lensman. Have you tried the external sites, too - they are very good and have good graphics.

Thanks for your interest Trillian's Child,

Being a new member may I ask you a question?

Am I right in saying that by posting my question on the tesseract forum that is where it is seen and that is where my question will be answered?

Or, can I send the question directly to an expert -are they the 'guru's'? If so, how do I know which guru to ask?

OOOPs - that's three questions! Sorry!

Hope you can help me get started,

Cheers,

L.

No problem. Glad to help. It may well be that the author of the Tesseracts entry has not activated the edited version of his entry so that he automatically receives any comments made here. This is not automatic. When I discovered that, I went round to all the entries listed on my page and clicked the link "Click here to be notified....." That's how I saw your question.

So the best place to go is to look at the entry again, and click on the Researchers name of the person who wrote it, which will take you to his personal space. Look at the most recent conversations there, and see if this person is still around - i.e. if he has posted to any forums in the last few weeks. Place your question again with a catchy "subject" line such as "Your Tesseracts Entry" directly on his personal space as well. If you are still not sure, or do not hear anything, try the same with the other researchers mentioned in this entry.

Whoops ! I've just seen that three researchers are quoted. Flaming Moose was the actual author, I only included one or two tidbits from the others. One big complaint that authors and researchers and subeds have around here is that the order for the list of researchers is arbitrary (probably numerical in order of U-number) and there is no way of seeing who put most work into an entry. However, Henry really knows a lot about them and Bagpuss (not listed, but definitely still online) is a maths student, as far as I remember.

HTH

I've thought about this a little. It again comes back to two-dimensional objects. You get a sphere by rotating a circle around a three-dimensional axis. So you get a hypersphere by rotating a sphere around a four dimensional axis. How you would diagram this, I have no earthly idea, but hey, tesseracts don't exist on earth, do they?

I don't have a clue what a four-dimensional sphere would look like if the fourth dimension is space, but if the fourth dimension is time I can tell you: You would have a sphere that starts off as nothing, then expands up to its maximum radius, then contracts back down to nothing again. If you were to graph the radius of this sphere as a funtion of time you would get a cosine wave.

r(t)=(rmax)cost