Search found 96 matches

by Mettra
Sat May 10, 2008 3:52 am UTC
Forum: Science
Topic: Living on a (roughly) flat plain
Replies: 12
Views: 2435

Re: Living on a (roughly) flat plain

The sun moves across the sky in the day, from east to west. I'm not sure exactly what the moon does, but it seems to be more regular then our moon, while still allowing for an eclipse of the sun (the eclipse of the moon in the game I think works differently). And I haven't been able to figure out f...
by Mettra
Fri May 09, 2008 3:35 pm UTC
Forum: Science
Topic: How far will the divisibility go?
Replies: 23
Views: 3444

Re: How far will the divisibility go?

I don't think there is any serious concern in the physics community that quarks might be divisible - and even if they are, since they can't be isolated, it might not make much difference. I could be wrong. To elaborate on this point, it is thought that quarks are held together with enough force tha...
by Mettra
Thu May 08, 2008 8:58 pm UTC
Forum: Science
Topic: A giant comet is headed towards Earth (hypothetically)
Replies: 86
Views: 7274

Re: A giant comet is headed towards Earth (hypothetically)

So, basically the Earth will probably turn back to the way it was. That's kinda sad. It is sad in a way that it would perhaps be interesting to see our 'simulation' rewinded and restarted at a certain point in order to see the outcome, but it would be incredibly sad if we were knocked back to the m...
by Mettra
Thu May 08, 2008 8:48 pm UTC
Forum: Science
Topic: Living on a (roughly) flat plain
Replies: 12
Views: 2435

Re: Living on a (roughly) flat plain

You might be interested in the stuff here http://mintaka.sdsu.edu/GF/explain/atmos_refr/horizon.html . If you are on a flat 'plane' with 'negligible' atmosphere etc. etc. you can see for infinity (basically), depending on how powerful a lens you have. With an atmosphere, you have refraction and that...
by Mettra
Wed May 07, 2008 2:42 pm UTC
Forum: Serious Business
Topic: Ben Stein vs. Darwin: The Movie
Replies: 165
Views: 15887

Re: Ben Stein vs. Darwin: The Movie

I just hope that not too many scientists bother to publicly rebut this silly piece of propaganda. I'd much rather see it become a forgotten waste of money than the controversial rallying point it's meant to be. The fundamental problem with this is that people are, in general, uninformed. This is an...
by Mettra
Wed May 07, 2008 1:03 pm UTC
Forum: Science
Topic: Wheeler-deWitt Equation and the nature of time
Replies: 38
Views: 3173

Re: Wheeler-deWitt Equation and the nature of time

Correction. General relativity has solutions in which causality can be violated. However setting up the situations in which that can happen is well beyond our means. Typically they require areas of negative mass, are highly unstable, and/or require quantities of matter that we can't provide. The be...
by Mettra
Wed May 07, 2008 12:32 am UTC
Forum: Science
Topic: Wheeler-deWitt Equation and the nature of time
Replies: 38
Views: 3173

Re: Wheeler-deWitt Equation and the nature of time

Time is one of those things that simply seem to be. It bothers me that I don't know the reason behind why it is. (1) I have this same problem with gravity (Why does mass warp space-time?) I suppose the interrelatedness is not surprising given a 4 dimensional space-time universe. Still, why is there...
by Mettra
Tue May 06, 2008 1:29 am UTC
Forum: Science
Topic: Australian man claims perpetual motion machine
Replies: 58
Views: 6710

Re: Australian man claims perpetual motion machine

Uniformity is irrelevant. Gravity doesn't contribute energy to the ball because gravity is always applied to the ball in a direction perpendicular to the ball's movement. If I may, this isn't QUITE right. Gravity doesn't contribute any NET force to the ball. There is the matter of the sides of the ...
by Mettra
Wed Apr 30, 2008 2:27 pm UTC
Forum: Science
Topic: Gravity affecting energy not mass
Replies: 16
Views: 3990

Re: Gravity affecting energy not mass

Sorry to resurrect this slightly older topic, but I'd just like to stress the point once more: any increase in any kind of energy will result in an increase of gravitational attraction. Even potential energy. If you have a spring in your hands, and you pull it apart as hard as you can, you are stori...
by Mettra
Wed Apr 30, 2008 4:34 am UTC
Forum: Science
Topic: Physics Lectures (by Walter Lewin)
Replies: 18
Views: 2940

Re: Physics Lectures (by Walter Lewin)

The guy makes a fantastic review of material, but for first-timers he's a little heavy.
by Mettra
Wed Apr 30, 2008 4:09 am UTC
Forum: Science
Topic: Michio Kaku
Replies: 11
Views: 1579

Re: Michio Kaku

Horgan's argument was basically that we are at the end of the period of history characterized by scientific revolutions; there will be no new theories as world-shaking as evolution or relativity for the forseeable future, if at all. Kaku's argument was the opposite; we are on the verge of extremely...
by Mettra
Tue Apr 29, 2008 8:28 pm UTC
Forum: Science
Topic: if special relatvity is true...
Replies: 29
Views: 4388

Re: if special relatvity is true...

Alright, but let's say you're moving at a constant velocity and you see a photon bouncing between two mirrors. Logic would tell you that because the two mirrors appear to be moving that they would appear to be slower, who's correct? It would seem one is because we've tested and confirmed that time ...
by Mettra
Tue Apr 29, 2008 7:56 pm UTC
Forum: Science
Topic: The Problems with Teleportation
Replies: 55
Views: 9963

Re: The Problems with Teleportation

In any case, what if the sending booth fails to destroy the material there by the time the copy is made at the receiving booth? Is the copy of you still sitting in that booth really going to be so blasé about being destroyed now that, from your perspective, the machine malfunctioned and you're just...
by Mettra
Tue Apr 29, 2008 3:13 pm UTC
Forum: Science
Topic: "Practical" vs "Theoretical"
Replies: 9
Views: 4100

Re: "Practical" vs "Theoretical"

It seems to me there is also the matter of perspective. To one group of people, something will seem very practical, but to another different group, it might all seem very pointless and academic. This has to do with the goals of the person learning the material. One of my physics professors tells a s...
by Mettra
Tue Apr 29, 2008 2:09 am UTC
Forum: Science
Topic: "The Final Theory" Book (Now phase/group/signal velocity)
Replies: 40
Views: 5043

Re: "The Final Theory" Book

Could you explain to me what negative velocity means? Or is this a mere maths stunt? I just can't imagine how something could move with negative speed. EDIT: Explain as in: Stupid metaphors and examples. Because I can't handle numbers and formu... lae... las... more than one formula. But I'm not du...
by Mettra
Tue Apr 29, 2008 1:50 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2962
Views: 730382

Re: Common Questions

Yes, but as far as I know they still travel at the speed of light in that particular medium, don't they? Let me put it this way: Can photons have different velocities in the same medium? From what I understand, photons always travel at the speed of light, no matter the material they are in. However...

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