Old Al, he came out the blue and said, "Not only do rays move at c if what puts them out is held fast or not: they move at c even if you are held fast or not." Now that may not look like such a big deal on the face of it, but hold on. What this says is that you can move as fast or as slow as you want, and rays will go by you at c all the time. You can have a pal run past you and when you both look at a ray go by at the same time, you will both see the same ray go by at c! That is a bit wild, no? You, back in that void, you just can not say if you move or not - with the lamp or no. Not that you can't tell: it can't be said. It's moot! But for that to be true, then time also has to get in on the act. For you and your pal to see the same ray go by at the same clip, her idea of time must be off from your idea of time! I can hear you say, "No way. That can't be!" But I tell you it is. Old Al said so. He said, here, I'll show you. Get a load of this. We have Bert and Dana. Take a bus, and put Bert on the bus. The bus goes down the road. Dana, she sits here, on the side of the road. He's in the bus and she's on her ass. And now take a rock off of the moon, and let it fall at them. It hits the air and cuts in two. The two bits burn, and then land just as Bert and Dana are side by side. One hits the dirt up the road a ways, and one hits down the road a ways. Dana sees each rock at the same time, but Bert sees one rock and then sees the next rock. Now: if Bert and Dana both see Dana as the one who is "at rest", they both will say that the two bits came down at the same time. Dana will say, "I am 'at rest', and I saw them both land at the same time, so they both did, in fact, land at the same time." And Bert will say, "I move away from the rock down the road, so when I add that fact in, I can see that if I were 'at rest', I'd have seen both land at the same time. So it must be the case that they did land at the same time." Okay, but what if Bert and Dana now see Bert as the one who is "at rest"? Eh? You get to pick who is "at rest" and who isn't, no? So make Bert be "at rest". Now Bert will say, "I am 'at rest', so the one up the road beat the one down the road, on the way to the dirt, just the way I saw it." And Dana will say, "I saw them land at the same time, but I move away from the rock up the road, so when I add that fact in, I can see that the rock up the road must have beat the one down the road." So you see, when you give up on the idea of a one true "at rest", then you have to give up on the idea of a one true time as well! And even that is not the end of it. If you lose your one true way to see time, then you also lose your one true way to see size and your one true way to see mass. You can't talk of any of that, if you don't also say what it is you call "at rest". If you don't, then Bert or Dana can pick an "at rest" that isn't the same as what you used, and then what they will get for time and size and mass won't be the same. What a snag, eh? I hope you can see how that gave some of them the fits, back when old Al told us that one. But even so, that ain't the half of it. I mean, most of us know that if old Al had got hit by a bus at age ten, we'd have got this far on our own in good time. No, it was what came next that was the real slap in the face.🏁

Old Al, he came out the blue and said, "Not only do rays move at c if what puts them out is held fast or not: they move at c even if you are held fast or not." Now that may not look like such a big deal on the face of it, but hold on. What this says is that you can move as fast or as slow as you want, and rays will go by you at c all the time. You can have a pal run past you and when you both look at a ray go by at the same time, you will both see the same ray go by at c! That is a bit wild, no? You, back in that void, you just can not say if you move or not - with the lamp or no. Not that you can't tell: it can't be said. It's moot! But for that to be true, then time also has to get in on the act. For you and your pal to see the same ray go by at the same clip, her idea of time must be off from your idea of time! I can hear you say, "No way. That can't be!" But I tell you it is. Old Al said so. He said, here, I'll show you. Get a load of this. We have Bert and Dana. Take a bus, and put Bert on the bus. The bus goes down the road. Dana, she sits here, on the side of the road. He's in the bus and she's on her ass. And now take a rock off of the moon, and let it fall at them. It hits the air and cuts in two. The two bits burn, and then land just as Bert and Dana are side by side. One hits the dirt up the road a ways, and one hits down the road a ways. Dana sees each rock at the same time, but Bert sees one rock and then sees the next rock. Now: if Bert and Dana both see Dana as the one who is "at rest", they both will say that the two bits came down at the same time. Dana will say, "I am 'at rest', and I saw them both land at the same time, so they both did, in fact, land at the same time." And Bert will say, "I move away from the rock down the road, so when I add that fact in, I can see that if I were 'at rest', I'd have seen both land at the same time. So it must be the case that they did land at the same time." Okay, but what if Bert and Dana now see Bert as the one who is "at rest"? Eh? You get to pick who is "at rest" and who isn't, no? So make Bert be "at rest". Now Bert will say, "I am 'at rest', so the one up the road beat the one down the road, on the way to the dirt, just the way I saw it." And Dana will say, "I saw them land at the same time, but I move away from the rock up the road, so when I add that fact in, I can see that the rock up the road must have beat the one down the road." So you see, when you give up on the idea of a one true "at rest", then you have to give up on the idea of a one true time as well! And even that is not the end of it. If you lose your one true way to see time, then you also lose your one true way to see size and your one true way to see mass. You can't talk of any of that, if you don't also say what it is you call "at rest". If you don't, then Bert or Dana can pick an "at rest" that isn't the same as what you used, and then what they will get for time and size and mass won't be the same. What a snag, eh? I hope you can see how that gave some of them the fits, back when old Al told us that one. But even so, that ain't the half of it. I mean, most of us know that if old Al had got hit by a bus at age ten, we'd have got this far on our own in good time. No, it was what came next that was the real slap in the face.🏁