SKU: 28135990914

The Substance of Spacetime: Infinity, Nothingness, and the Nature of Matter

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Description

The Substance of Spacetime: Infinity, Nothingness, and the Nature of MatterDoes Spacetime Exist? If spacetime does not exist, it certainly does so in a curiously conspicuous way, not at all like other geometric abstractions. Consider this mindbender: spacetime does not exist at all, but it doesn't exist in the void even more than it doesn't exist in the universe. Is that the description of something that does not exist? Relativity theory treats spacetime as a mathematical abstraction a four dimensional coordinate system

Does Spacetime Exist?
If spacetime does not exist, it certainly does so in a curiously conspicuous way, not at all like other geometric abstractions. Consider this mindbender: spacetime does not exist at all, but it doesn't exist in the void even more than it doesn't exist in the universe. Is that the description of something that does not exist?

Relativity theory treats spacetime as a mathematical abstraction-a four-dimensional coordinate system analogous to the three dimensions of Cartesian geometry. It does not exist, per se. It is not a "thing" in any tangible sense. It merely serves as the background needed to describe the behaviors of the "real" things that exist within it. It is no more than the stage on which the cosmic drama plays out. That's the theory.

What if spacetime exists after all? Are we not obliged to take this stuff seriously and start asking questions? What are its properties? Where did it come from? Is spacetime a simple or a composite thing? Can it be broken into simpler parts? If not, are we compelled to wonder if spacetime is actually the fundamental substance of the universe? And how does this remarkable stuff come together to form the physical world around us?

The Substance of Spacetime sets out to investigate these very mysteries and the results are truly exciting. Treating spacetime, not merely as a coordinate system, but as a real physical substance, opens a window onto reality that would otherwise be impossible to even contemplate.

If spacetime exists, everything changes.



Binding Type: Paperback
Publisher: Gadfly LLC
Published: 03/31/2016
ISBN: 9780980208849
Pages: 346
Weight: 0.97lbs
Size: 8.50h x 5.50w x 0.77d
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SKU: 28135990914

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4.0 ★★★★★
Based on 11 reviews
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Verified Purchase
Ashley T.
Cuba, US
★★★★★ 5
A favorite in our house!
Pattern Name: Ultra Ring, Size: Large, Pattern Name: Ultra Ring, Size: Large
~ Recommend if you have a dog who: is a heavy chewer/tugger, loves to chase squirrely things (it can have a wacky roll to it, which my dog thinks is so fun), gets their toys dirty or slobbery. My pup is 65 pound pitty mix - i'd definitely say this is for big dogs. Maybe medium (45+ pounds, ish?). Just my opinion, of course... but I think it's a bit thick/heavy for small pups to grab. ~ My pup LOVES this ring toy! I got this back in October - so it has been through the ringer. Atlas isn't usually a super heavy chewer, but with this toy she is. Not only does she love to play with it, she will even bring it to her bed to comfort chew (i think she likes the pressure on her back teeth... this rubbery material is SUPER sturdy but also has a little bit of "give" so I don't worry at all about her teeth). She loves to chase it / catch it on the roll. She brings it to me on the daily for play. Its good for tug, chase, or fetch. Perfect for the beach or any environment, really, as it's super easy to clean... so it comes with us everywhere. We will probably have this toy forever... there's not a single puncture mark yet. So, for me worth the cost 10x over.
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Reviewed in the United States on January 27, 2023
D
Verified Purchase
Debbie Smeltzer
Houston, US
★★★★★ 1
It’s Trash
Pattern Name: Tug Frisbee, Size: Large
Lasted maybe 1 minute… I gave it to my dog turned to throw away package, when I looked back dog had already taken a chunk off … might as well have given him the dollar bills it took to buy … they would probably last as long
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Reviewed in the United States on May 18, 2026
R
Verified Purchase
Rivertender
Whiting, US
★★★★★ 4
Arguably bulletproof
Pattern Name: Tug Pull, Size: Large
All good. The gauge is slightly large which my dog, Magnum {66 lb American Stafordshire Terrier), struggles with - slightly. Not a big problem and I am thinking that if the guuge were smaller, Magnum would be able to chew through it and ruin the toy. Comfy grip. Center piece or grip works great also because Magnum likes to grip that which allows the 2 handles to be free for human pulling. Walmart has/had a similar item, but..........one end has tiny spikes meant for the dog to grip. My dog never liked that end, however, so I always got the ucomfortable knobly end and he got the smooth human end - hah ha. Too, Magnum chewed through two of these Walmart toys., I have seen Magnum chewing on this reviewed toy, but I am seeing zero damage. Walmart's toy is cheaper, but the lifetime guarantee on this Tuff Tug toy eliminartes any price advantage. Update 6 months later - the product appears to be bulletproof.....until it wasn't. Everyone on the dog park marveled at the item's amazing durability in terms of daily severe abuse AND my dog's preoccupation with gnawing on the toy. Not only does it hold up, but there are almost no discernable chew marks. All of that said, the toy did finally show some coming apart today (mid March '24 - bought Oct '23 with lots of daily chewing and tug of war abuse). Remarkably, with a good 30% of the item's thickness chewed through - it still stands up to severe and constant tug of war strain......like nothing ever happened! We joke at the dog park that tbe toy is made of Kryptonite. Yes, it's now damaged some, but I feel it is well worth the 20.00 price for the service it has delivered...
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Reviewed in the United States on November 3, 2023
E
Verified Purchase
Eric
Houston, US
★★★★★ 3
Great chew toy, poor frisbee
Pattern Name: Tug Frisbee, Size: Large
Bought the Tug Frisbee. It's a terrific chew/tug toy (I'd give it 5 stars for this), but it's a very poor frisbee (I'd give it 1 star for this). The material is really heavy, flexible and tough which is why it's such a great chew/tug toy. But this makes a very poor flyer. And the weight is concerning enough that I wouldn't throw it at our dog. We got a great toy out of this, just not a frisbee.
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Reviewed in the United States on October 28, 2025
E
Verified Purchase
Edward Thornton
Fort Morgan, US
★★★★★ 5
Great for my beautiful blue heeler
Pattern Name: Tug Frisbee, Size: Large
If you know what a Blue Heeler cattle dog can do is pretty similar to a velociraptor. She is not damaged this in any way shape or form and, really enjoys chasing it. Just simply toss it, very sturdy, simple to clean, just the right size. I have tested a lot of toys with her, she has destroyed a lot of toys, this one's pretty much indestructible.
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Reviewed in the United States on February 28, 2026

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