# Is it possible to bend space 'upwards'? [duplicate]

According to the theory of general relativity 'space' can be bend like a fabric.

Objects with a lot of mass bend spacetime like a well or a bowling ball on a stretched blanket.

It (images) always look like spacetime is being 'pushed' downwards thus objects swirl around the more massive object (if their velocity is fast enough to not getting pulled into the singularity).

### So I seriously ask myself, is it possible for objects / matter in the universe to push / bend spacetime 'upwards?'

Upwards in the sense that the ball in the picture (above) is bending spacetime in the other direction (vertical).

Though one problem arrises in my head already, wouldn't objects be invisible to our eyes since ,just like with the bowling ball and the blanket, it would be a layer under the actual play field <-- Instruments should be able to detect their impact right?

Info: I'm just a hobby astrophysics learner, not a physicist or a professional student in this field, so anything I've written down could be non-sense / false. Correct me if that's the case.

• I think you may have meant 'spacetime' in a few places, instead of just 'space'. – user191954 Jul 16 '18 at 13:07
• Those pictures with space (note: space!) bent down around massive objects are not really helpful in terms of thinking about spacetime curvature, I think. – tfb Jul 16 '18 at 13:16
• Not sure what to include other than that. If I type into google 'Spacetime curvature', I get exactly those kinds of images. – stringExchange Jul 16 '18 at 13:21
• You will need to bite the bullet and learn the math.:) The pictures are giving you the wrong idea that you,or anybody, can visualise 4 D space-time. – user198207 Jul 16 '18 at 13:31
• If by "bending space upward" you're referring to creating gravitational repulsion, then no, there is currently no way to do that. That said, there are a few theories that predict gravitational repulsion. For example, domain walls (essentially, boundaries between two vacuums of different energies, see e.g. arxiv.org/pdf/gr-qc/9306005.pdf) are known to create a repulsive gravitational field, but we have no evidence that they exist. We also don't know how gravity acts on antimatter, so it's possible that antimatter "falls up"; measurements are ongoing, but they're difficult. – probably_someone Jul 16 '18 at 13:37